•BERKELEY
LIBRARY
JNIVERSITY OF
CALJPORMIA
LANDSCAPE
ARCHITECT'',;*
The Gift of Beatrix Farrand
to the General Library
University of California, Berkeley
REEF POINT GARDENS
LIBRARY
PUBLICATIONS OF THE ARNOLD ARBORETUM, No. 9
A
MONOGRAPH OF AZALEAS
RHODODENDRON SUBGENUS
ANTHODENDRON
BY
ERNEST HENRY WILSON
AND
ALFRED REHDER
ISSUED APRIL 15, 1921
PRINTED FROM THE INCOME OF THE WILLIAM L. BRADLEY FUND
THE UNIVERSITY PRESS
CAMBRIDGE
1921
A MONOGRAPH OF AZALEAS
.
.
PUBLICATIONS OF THE ARNOLD ARBORETUM, No. 9
A
MONOGRAPH OF AZALEAS
RHODODENDRON SUBGENUS
ANTHODENDRON
BY
ERNEST HENRY WILSON
AND
ALFRED REHDER
ISSUED APEIL15, 1921
PRINTED FROM THE INCOME OF THE WILLIAM L. BRADLEY FUND
BY
THE UNIVERSITY PRESS
CAMBRIDGE
1921
LANDSCAPE
ARCHITECTURE
Add'l
Farrand Gift
LANDSCAPE
ARCH.
LIBRARY
PREFACE
THE value of Azaleas as garden plants in the eastern United
States, where few of the Rhododendrons with persistent leaves
can be successfully cultivated, has led to the critical studies of
these plants which appear on the following pages.
Mr. Wilson's long journeys in eastern Asia has made it pos-
sible for him to study all the species of the Japanese Empire
and China as wild plants, and to become familiar with the
Azaleas growing in Japanese gardens. For many years the
Arboretum has been engaged in a field study of the American
species, and has been able to place at Mr. Render's disposal
the large amount of material which is preserved in this her-
barium, and which has been supplemented by that contained in
other American collections.
The Azaleas of northern Japan and Korea, and of the
northern United States, are already growing in the Arboretum,
but the gardens of the southern states and of California have
still much to gain by the introduction of the species of the
southern states and those of southern Japan, China, and
Formosa, and this publication will not have accomplished its
purpose if it fails to induce the more general cultivation of
these plants in the United States and Europe.
The art of the hybridizer has produced many interesting and
beautiful Azaleas. Imperfect records have made the study of
many of these hybrids difficult and uncertain, and this difficulty
is increased by the fact that many of them are no longer culti-
vated unless, having escaped the change of fashion in plants,
they are still growing in English gardens, planted about the
middle of the last century, and I venture to suggest to my
associates in the English Rhododendron Society that the study
of Azaleas in European gardens might add much to the knowl-
edge of the origin and value of many of these plants.
C. S. SARGENT, Director.
ARNOLD ARBORETUM
MARCH, 1921.
609
TABLE OF CONTENTS
PAGE
PREFACE . > * v
THE AZALEAS OP THE OLD WORLD. By Ernest Henry Wilson . 1
THE AZALEAS OF NORTH AMERICA. By Alfred Rehder .... 107
DOUBTFUL NAMES • 197
OAQ
ILLUSTRATIONS
ADDITIONS 206
INDEX. 207
THE AZALEAS OF THE OLD WORLD
BY
ERNEST HENRY WILSON
THE AZALEAS OF THE OLD WORLD
INTRODUCTION
BOTANISTS may hold different views on the classification of
the subdivisions of the large genus Rhododendron, but garden-
ers and lovers of plants in general have no difficulty in recog-
nizing Azaleas as distinct from other groups of the genus. It
is hi the popular rather than in the strictly technical sense that
the title of " Azaleas of the Old World " is applied here. These
plants with few exceptions are sun-loving; and their wide popu-
larity among the peoples of the Orient, of America, of Europe
and Australia is due largely to the brilliancy of their flowers,
their floriferousness and the ease with which many of them can
be cultivated. In the Orient they have been favorite garden
flowers from very early times and in the Occident for more than
a century some have been familiar and valued greenhouse plants,
and in recent years it has been found that several are more
hardy than they were generally supposed to be. In the Arnold
Arboretum such hardy kinds as R. obtusum var. Kaempferi and
R. japonicum are among the most satisfactory and most beau-
tiful of Asiatic plants. Farther south and in California the old
Azalea amoena and A. ledifolia and the newer "Hinodegiri" are
much grown in gardens. Others are less known, but I believe that
in the near future both in increased variety and in quantity
Azaleas will have a much more important place in gardens. In
certain groups the hybridists in Europe have wrought wonder-
ful results, and the field is still full of promise. In Japan, in the
city of Kurume, selection and raising from seed has been in
progress among a single group for a century, and these plants are
now beginning to find their way into the Occident. With these
facts in view the need for a critical survey of the species and
forms seems necessary. Through confusion with other species
and for lack of accurate names many good plants have become
lost from our gardens, and others for the same reason have not
been introduced. During my travels in China I greatly admired
l
2 THE AZALEAS OF THE OLD WORLD
the red-flowered Azalea of the country so abundant on the hills
from the coast to the extreme west, from near sea-level to 1300 m.
altitude. So common is it that in May much of the country-
side is a blaze of red. For years I unhesitatingly accepted this
plant as the Azalea indica of Linnaeus, considering the differ-
ence in the number of stamens an unimportant triviality. In
1912-13, when working up the Rhododendron material for Sar-
gent's Plantae Wilsonianae in conjunction with my colleague,
Alfred Rehder, I became conscious that all was not so simple
as I had assumed. The question as to what Azalea indica really
was began to arouse my interest. On the occasion of the Arnold
Arboretum Expedition to Japan in 1914 I devoted much time
to the problem, and in Yaku-shima in February collected an
Azalea which later I discovered to be the true Azalea indica of
Linnaeus. I questioned many botanists in Japan, but none at
that time had any definite views on the subject. Nevertheless,
by deduction and comparative study I arrived at the conclusion
that the group of Azaleas cultivated in Japan under the name
" Satsuki" all belonged to Linnaeus' species and that the ma-
terial collected in Yaku-shima was its wild parent. On my re-
turn to the Arnold Arboretum early in 1915 I critically com-
pared the material I had collected with Linnaeus' description
and with the old figures on which his species was based, and the
proof of this theory was absolute.
Japan is so rich in Azaleas, both wild on the mountains and
cultivated in gardens, parks and temple grounds, that at the
end of 1914 I felt that beyond establishing the identity of
Azalea indica I had acquired no more than a moderate working
knowledge of the group. My interest, however, was keener than
ever. Being favored with another opportunity to visit the
Orient I determined to devote as much time as possible to the
study of these Azaleas. During 1917 and 1918 I visited many
places famous in Japan for Azaleas and gathered specimens and
information from all sides. On my visits to Korea, Liukiu and
Formosa I collected much new material. The result is that on
my various visits to the Chinese and Japanese Empires I have
seen growing wild, with few exceptions, every species known
from those regions and almost every known variety and garden
form. In Japan in 1914 and again in 1917-18 I received in-
estimable assistance from Mr. H. Suzuki, President of the
INTRODUCTION 3
Yokohama Nursery Company and one of the foremost horticul-
turists in Japan. Together we visited Mt. Kirishima and the
famous Azalea district of Kurume in Kyushu, also those near
Osaka and Tokyo. He introduced me to all the leading special-
ists, gave of his own store of knowledge freely, and without
his help it would have been quite impossible to have delved so
deeply into the cultivated Azaleas of Japan. It is with keen
pleasure that I acknowledge my indebtedness to this genial and
scholarly gentleman. I know not how many hundreds of speci-
mens of my own collecting have been available for this work,
and in addition, through the courtesy of the Director of Kew
and the Keeper of the Gray Herbarium of Harvard University,
I have had on loan all their material, so rich in old types of these
Azaleas. In Tokyo, through the courtesy of Professor J. Matsu-
mura, I have examined the material preserved in the Herbarium
of the Imperial Botanic Garden. Dr. Merrill has kindly loaned
me the material preserved in the Herbarium of the Bureau of
Science, Manila. To Dr. T. Nakai I am indebted for much
useful information relative to certain critical Azaleas to which
S. Komatsu has recently given names with brief descriptive
notes in Japanese.
The study of long-cultivated garden plants is exceedingly
complex, and to fathom some of the problems is almost beyond
human skill. This statement is as trite as it is true, and I freely
confess that I have found the problems presented by many of
these Azaleas more intricate than those of the Japanese Cherries.
Notwithstanding my unusual opportunities in the field and in
the gardens of the Orient and the abundant herbarium material
at my command I should have been ill equipped for the task
but for the collection of living plants cultivated for nearly three-
quarters of a century on the Sargent estate in Brookline, Mass.
This collection has been zealously maintained and is rich in old
garden types introduced through Fortune and others, some of
which have apparently been lost in Europe. Professor Sargent's
knowledge of these Azaleas is profound, and it is under his sym-
pathetic guidance and help that this little treatise has developed
from chaos to order, and to him most largely is due what merit
it contains.
HISTORY
THE cultivation of plants and the development of gardens is ever a
sign of a nation's advance toward culture and refinement. How early
this art began in the Orient we do not know, though history tells us
that plants like the Yulan and Moutan Paeony were highly esteemed
garden flowers among the Chinese during the Tang Dynasty (618-
907 A. D.)- It is much to be regretted that we are so ignorant of the
early history of China. It is known that during the Han Dynasty
(B. C. 206-A. D. 25) the Chinese had intercourse with India and Zan-
zibar. If proof were needed of their visiting these countries at an early
period it is supplied by the presence in south China and Formosa of
such typical African plants as Cactus-like Tree Euphorbias. Such
species as E. triangularis Desf., E. neriifolia L. and E. tirucalli L. are
common hedge-plants and are naturalised in certain places like Hong-
kong, Kowloon and elsewhere in China, and near Takao in Formosa,
as they also are in parts of India. In point of fact E. tirucalli was
named by Linnaeus from material which came from India. Did we
know more about the early travels of the Chinese it is possible that
we should find that they were acquainted with America long before
its discovery by Columbus. In south China, Formosa and the Liukiu
Islands A gave fourcroydes Lem. is naturalised, but this may have been
introduced by the Portuguese, and so too may have been Maize and
Tobacco. Much more difficult is it to account for Opuntia Dillenii
Haw. naturalised and abundant not only on the Yunnan plateaux but
in the valley of the Tung River in a remote part of extreme western
China. It is significant also that Boym in his Flora Sinensis published
in 1656 figures such characteristic American plants as the Pineapple
(Ananas saliva Schult. f.), the Sweetsop or Custard Apple (Anona
squamosa L.) and the Guava (Psidium guajava L.), which were evi-
dently common plants in China when he was there (1642-53). In
what era the love for flowers began to manifest itself in Japan is un-
certain, but Buddhism in its Chinese form was introduced from Korea
about 552 A. D. and from then until the 8th century Korean and
Chinese monks and nuns visited Japan for purposes of proselytism.
From the 8th century onward it became more usual for the Japanese
4
HISTORY 5
monks to go to China in order to study the doctrines of the best ac-
credited teachers at the fountain-head. These monks introduced into
Japan a number of favorite trees and shrubs like the Ginkgo, Yulan,
Moutan Paeony, Chinese Quince, the Tea-plant, Buddha's Tree
(Tilia Miqueliana) , Sophora japonica, Prunus tomentosa, P. japonica,
Paulownia tomentosa, such fruit trees as the Peach, Apricot, Persimmon,
Pear, Apple, Plum, Cherry, Loquat, the Orange and its relatives and, in
all probability, the Chrysanthemum also. Though they probably did
not originate the love for gardens these monks must have greatly stimu-
lated it. The mutual love of flowers among the peoples of the Orient
induced and fostered the introduction of plants from one country to
another in the Far East even as it did in the Levant and, in later days,
as it has in the Occident. And so we find the history of garden plants
intimately associated with the social life of the peoples. We know
nothing of early intercourse between the Japanese and Chinese prior
to the introduction of Buddhism to Japan. We do know that Chinese
monks introduced their favorite flowers to Korea, that Chinese and
Korean monks carried them to Japan, and it is safe to assume that
these same monks and their Japanese disciples carried to Korea and
to China plants of Japan which appealed to their aesthetic sense. In
fact the presence in temple-grounds and other sacred places in China
of the Cryptomeria, which is endemic in Japan, and of many varieties
of Japanese Camellias and Azaleas in Chinese gardens, is positive proof
that Japanese plants were long ago introduced into China.
The illustrious Venetian, Marco Polo, who lived many years in
China during the latter part of the 12th century and to whom we owe
the first authentic account of that mighty empire, notices from his
own observation many of the vegetable productions of China used
for economic purposes. After his memorable travels China was for a
long time closed to European access and had been altogether forgotten
in Europe when in 1516 the Portuguese first arrived in China. The
Portuguese claim the honor of having first introduced the Sweet-
Orange from China to Portugal some time between 1545 and 1548.
About the end of 1542 the Portuguese adventurer, Mendez Pinto,
discovered Japan, first touching at the island now known as Tanaga-
shima south of Kagoshima in Kyushu. The Portuguese made their
way north as far as Oita in northeast Kyushu where Mendez Pinto
in 1543 received a friendly reception from the local Daimyo. The
arquebus Pinto carried astounded the Japanese, who had never before
seen any explosive weapon. In 1549 St. Francis Xavier reached Japan
6 THE AZALEAS OF THE OLD WORLD
and introduced Christianity; he visited Oita, and going north to Hondo
established a mission at Yamaguchi, a few miles north of Shimonoseki.
This newly introduced religion soon claimed thousands of adherents,
much to the alarm of the Japanese Daimyos and military men backed
by Buddhist priests, and a period of persecution commenced. The
native Christians migrated to Nagasaki, which soon became one of the
chief marts of Portuguese trade.
In 1596 the Dutch first visited Java and other islands of the East
Indies and in 1602 the Dutch East India Company was established.
The war which then ensued between the Dutch, Spaniard and Portu-
guese for possession of the spice islands lasted until 1610 when the
Dutch remained master of these seas. The seat of the Dutch govern-
ment was first established on the island of Amboyna, but in 1619 it
was transferred to the newly founded city of Batavia in Java. In 1600
a Dutch ship visited Japan, and nine years later the Dutch East India
Company sent several vessels to Firando (Hirado), northwest of Naga-
saki, where they were well received by the Japanese. In 1611 a formal
edict in favor of their trade was obtained. A Dutch factory and also
an English factory were established at Hirado the same year.
In 1624 Christianity was proscribed in Japan and the land was
closed to foreigners. The Portuguese, English and Spaniards, who also
had a factory, were expelled and only the Dutch and the Chinese were
permitted to carry on trade, and that under galling restrictions. The
Dutch factory was removed in 1639 to Deshima, then an islet at the
head of Nagasaki harbor but now absorbed into the foreshore. And
so Japan secluded herself for over two centuries from contact with the
outer world until the advent of the American Expedition in 1853-54
under command of Commodore Perry. All this may seem to have
little to do with plants and with Azaleas in particular and yet they
are inextricably bound up with the subject. It is to the merchant
adventurer that we owe all our first plant introductions from Japan
and our early knowledge of the flora. From 1690-92 Engelbert
Kaempfer, in the service of the Dutch East India Company, lived in
Japan, and in his Amoenitates Exoticae, published in 1712, he gives an
admirable account of Japanese plants. He gives good figures of many
of these under the vernacular names and among them an Azalea now
known as R. obtusum var. Kaempferi Wils. In all Kaempfer mentions
twenty-one Azaleas, and it is interesting to note that many of the
vernacular names he gives are in common use to-day. C. P. Thunberg
in 1775 visited Japan in the capacity of physician to the Dutch Com-
HISTORY 7
pany and in 1784 published his Flora Japonica, the first post-Linnaean
work on the flora of the Orient. Thunberg mentions the Azaleas under
their vernacular names and relegates them all to Azalea indica. Ac-
cording to Juel (PL Thunb. 391 (1918)) they represent R. obtusum
Planch., R. japonicum Suring. and R. mucronatum G. Don.
Lastly in this connection mention must be made of Philipp von Sie-
bold, who joined the service of the Dutch East India Company and
lived at Deshima from 1823 to 1829. To him we owe the magnificent
Flora Japonica; also he introduced about 1830 such ornamental plants
as Lilium elegans and L. speciosum from Japanese gardens, and, twenty
years later, several others including Mains floribunda, M. Sieboldii
and certain flowering Cherries.
About 1677 the English East India Company established a factory
at Amoy and in 1684, after a conflict with the Portuguese, one at
Canton. Through this company many Chinese plants were introduced
to India during the 18th century and early in the 19th century to
England; they include several Azaleas. However, in China the Jesuit
priests were the first to inform us about the flora of the land. In 1790
Joannis de Loureiro, a Portuguese, published his Flora Cochinchinensis
and mentions one species of Azalea (A. punctata), but this remains an
obscure plant and may not belong to the genus.
During the last quarter of the 17th century Jakob Breyne, a
merchant of Danzig and a distinguished botanist, visited Holland and
saw growing there several famous garden plants of the Orient which
he duly records in his Prodromus Plantarum. On page 24, pt. I, pub-
lished in 1680, we read " Chamaerhododendron exoticum amplissimus
floribus liliaceis. Frutex spectabilis elegans. In horto Beveringiano."
This is the plant on which Linnaeus (Spec. 1753) bases his Azalea
indica. Breyne does not say from what country this shrub had been
brought, but P. Hermann, in his Academici Horti lugduno-batavi
catalogue, p. 152 (1687), describes the same plant under the name of
"Cistus Indicus Ledi alpini foliis, floribus amplis," figures it on page
153, and reports that it was introduced from Jaccatra, which is Ba-
tavia, in Java. No species of Azalea grows in India, and it has been
generally supposed that this Azalea had been brought to Batavia by
the Chinese, but I am of the opinion that it was taken there from Japan
by Dutch traders. In the gardens of Nagasaki and elsewhere, then
as now, it was a common garden plant and, moreover, it is indigenous
in the warm southern parts of Japan. That at the early date men-
tioned plants from Japan were growing in gardens in Holland is certain,
8 THE AZALEAS OF THE OLD WORLD
and the Tea-plant was introduced from Japan about 1689. Breyne
(Prodromus, I. 4) states that he saw in the garden of Hieronymus van
Beverningk in 1678 a fine specimen of the Camphor-tree which had
been introduced from Japan. Again, in his Prodromus, II. 66 (1689)
Breyne tells of six varieties of Chrysanthemum from Japan which he
saw growing in Holland gardens. All these early introductions seem
to have been lost. I have carefully looked through many old books
of the 18th century and I find no references to any species of Azaleas
being in European gardens, and they appear to have been unknown in
Europe at the close of the 18th century. The one oriental species was
known to Linnaeus through the books. In Batavia, however, several
were grown, as we know from the writings of Burmann and Blume.
In Aiton's Hortus Kewensis (1810) Azalea indica is stated to be in
cultivation in Kew, having been introduced from China in 1808 by the
Court of Directors of the East India Company in the ship "Cuffnels"
Captain Wellbank. This plant was Rhododendron Simsii Planch., and
here began a confusion between Linnaeus' species and the Chinese
Azalea which still survives. Through the activities of officers of the
East India Company at the close of the 18th and the beginning of the
19th centuries English gardens were enriched by many Chinese plants.
No officer was more active in this work than John Reeves, who as
Chief Inspector of Tea in the Company's establishment at Canton
resided in Macao and Canton from 1812 to 1831. He was either the
immediate or indirect source from which our gardens derived Camel-
lias, Moutan Paeonies, Chrysanthemums, Roses, Wistaria sinensis
and many Chinese Azaleas including R. Farrerae Tate, a pretty Hong-
kong species, and also R. phoeniceum G. Don, destined to be of so
much value as a stock on which to graft " Indian Azaleas," so called.
In 1818 or 1819 Samuel Brooks, a nurseryman at Ball's Pond, New-
ington Green, sent out to China Joseph Poole, a gardener, and through
him secured among other plants Azalea indica alba (R. mucronatum
G. Don) and Azalea indica purpurea plena (R. mucronatum f.
plenum Wils.). In 1823 Azalea sinensis (R. molle G. Don) was
received from China by Loddiges of Hackney and by William Wells,
nurseryman, of Redleaf. In 1832 Joseph Knight, nurseryman, of
Chelsea, London, secured Azalea indica variegata (R. indicum f.
variegatum DC.) and A. indica lateritia (R. indicum Sweet) brought
home from China by Mr. M'Killigan. In 1821 Rhododendron Farrerae
was reintroduced and in 1832 R. indicum var. ignescens Sweet, both
through Captain Farrer of the East Indiaman "Orwell," who gave
HISTORY 9
them to Tate, a nurseryman, of Sloane Square, London. In the Botan-
ical Register, t. 56 (1842), is figured a double red-flowered Azalea said
to be of Chinese origin and in the possession of William Wells, Esq.,
of Redleaf . These various Azaleas by hybridization and selection soon
became the parents of a number of good plants which are figured in
the periodicals of the time. Especially valuable was the Azalea indica
variegata which in the hands of Knight, and of Ivery, another English
nurseryman, yielded several very ornamental varieties.
In 1843 Robert Fortune was sent to China by the Horticultural
Society of London, and his travels and explorations there, which ended
in 1861, inaugurated a new era in the history of plant introduction
from that country. He sent from Chinese gardens at Shanghai and
elsewhere to England many Azaleas, including such new ones as Aza-
lea obtusa (R. obtusum Planch.), Azalea ramentacea (R. obtuswn
f. album Rehder), Azalea crispiflora (R. indicum var. crispiflorum
Schneid.), Azalea amoena (R. obtusum f. amoenum Wils.), Azalea
narcissiflora (R. mucronatum f. narcissiflorum Wils.), Azalea vit-
tata (R. Simsii var. vittata Wils.) and Azalea Bealii (R. Simsii
var. vittata f. Bealii Wils.). There is no need to emphasize the value
of these new Azaleas. His vittata with lilac flowers and Bealii with
red-striped flowers gave an impetus to the raising of new forms and
may be said to have initiated an industry which has resulted in the so-
called race of " Indian Azaleas." The true R. indicum, whose progeny
are not amenable to forcing, dropped out and the forms of R. Simsii,
R. mucronatum and R. obtusum — seminal, branch sports and hybrids —
took its place, and to these we owe the familiar greenhouse Azaleas
of to-day. There is no necessity for pursuing the subject further except
to point out that all the Azaleas from the Orient up to 1860 were
cultivated plants introduced from gardens and that the wild parent
and habitat of none except R. Farrerae and R. molle were known.
The opening of Japan, which followed the signing of treaties first
with America in 1854 and then with other powers, soon led to the
introduction of a great number of valuable garden plants to America
and Europe. Strange to say the Azaleas for which Japan is famous
seem to have been passed over for a number of years, probably on the
assumption that they were the same as those already introduced to
our gardens from China. From 1859-64 C. Maximowicz, the famous
Russian botanist, travelled in Japan, and to him we owe our first com-
prehensive account of the wild flora of that country. Maximowicz
and his Japanese collector, Tschonoski, were among the first to collect
10 THE AZALEAS OF THE OLD WORLD
seeds of Azaleas and by this means introduced into Petrograd R.
reticulatum G. Don and R. linearifolium var. macrosepalum Mak.
Maximowicz also introduced plants of R. linearifolium S. & 7., its
variety macrosepalum and R. scabrum G. Don. In 1861 a Hollander,
J. B. Groenwegen, claims to have received direct from Japan seeds of
R. japonicum Suring., one of the most valuable of all hardy Azaleas.
Crossed with the Chinese R. molle G. Don this has given rise to the
lovely but short-lived Kosterianum hybrids; all these, again mixed
with the so-called Ghent hybrids (R. luteum X American species), have
produced the race of Azaleas named X R. mixtum Wils.
Under each species and variety the story of its introduction is re-
corded, so in this historical chapter I need not repeat it. Curiously
enough the most common and one of the most conspicuously beau-
tiful Azaleas of Japan, with flame-red flowers and figured by Kaempfer,
was ignored until 1892, when Professor Sargent sent seeds to the
Arnold Arboretum where it has proved not only perfectly hardy but
one of the most valuable exotic plants. This and R. japonicum, raised
by Professor Sargent from seeds sent from the Jardin des Plantes in
1876, were the first oriental Azaleas to be raised from seeds in America.
Turning to Korea there is little to say, for prior to the beginning of
this century the Occident had received no living plants or seeds direct
from that country. A common Azalea of Korea, the lovely R. Schlip-
penbachii Maxim., found its way to Japan, and from there was sent to
England by James H. Veitch in 1893. The first seeds of an Azalea
sent from Korea was in 1905 when Mr. J. G. Jack sent to the Arnold
Arboretum seeds of R. yedoense var. poukhanense Nakai, a hardy species
of compact habit with rose-purple, fragrant flowers.
From the Liukiu Islands no Azaleas, either plants or seeds, have been
sent direct to the Occident, but the large-flowered R. scabrum G. Don,
better known as R. sublanceolatum Miq., endemic there, was long ago
brought to Japan, and in Kyushu in particular it is a common garden
plant. This Azalea was apparently in cultivation in England when
G. Don wrote his General System in 1834, but seems to have been lost
soon afterward. Maximowicz in 1864 sent it to Petrograd, but it ap-
pears to have been unknown in England when reintroduced by Mr.
Notcutt in 1911. The only Formosan Azalea introduced into Europe
prior to my visit in 1918 was R. Oldhamii Maxim, which was raised by
Messers Veitch from seeds sent in 1878 by Charles Maries. The
Philippine Island species has not yet been introduced.
DISTRIBUTION
OF the thirty-four species of Azaleas enumerated here thirty-three
are widely scattered over the countries of the Orient having their
northern limit in central Hokkaido, their southern on Luzon in the
Philippines; from east to west they are found from the shores of the
Pacific Ocean in Japan to the extreme west of China proper. They
belong to four well-marked sections of the genus Rhododendron, two
of which (Tsutsutsi and Sciadorhodion) are peculiar to the Orient;
two (Rhodora and Pentanthera) are represented also in America.
The thirty-fourth species is R. luteum Sweet which belongs to the last-
named section. It grows in the Caucasus, the Pontus region of the
Black Sea and in Lithuania, Poland, and southwestern Russia, and is
the only species of the groups here discussed known to grow west of
China proper.
Geographically the east Asiatic species are found over 45 degrees
of longitude and 30 degrees of latitude and altitudinally from sea-level
to about 3300 m. They are social plants and where climate and soil
conditions are favorable, as in most parts of Japan, of Korea and of
China from about the latitude of Shanghai south, these Azaleas are
perhaps the most common shrubs. The Chinese R. Simsii and R. Ma-
riesii grow also in Formosa, and a variety of the first-named is endemic
on the Kawanabe Islands off the northwest coast of the Liukiu Archi-
pelago. The Japanese R. serpyllifolium is said to grow on Okinawa,
the main island of the Liukius. At least three (R. Schlipperibachii,
R. Tschonoskii and R. Weyrichii) of the four Korean species grow also
in Japan. One (R. phoeniceum) is unknown in a wild state and is of
doubtful standing. The others are endemic in the different countries
of the Orient.
It is remarkable that in western China only the section Tsutsutsi
with three species is represented, and on the Himalayas no member of
the four sections is known to grow, yet in these two regions the sub-
genus Eurhododendron has its headquarters and is represented by
hundreds of species. In Malaysia, too, where the subgenus Vireya is
so richly represented, no species of our subgenus is known. The great
concentration of species is in Japan. Formosa, considering its small
11
12 THE AZALEAS OF THE OLD WORLD
size, is also rich in Azaleas. In China these Azaleas are poorly repre-
sented by eight species of which only three are really common and
widespread. This is singular in view of the remarkable richness of
the Chinese flora in general. In Korea four species grow, but at most
only one (R. yedoense var. poukhanense) is endemic and specimens of
an Azalea much like this have been collected in Bitchu province,
western Japan. In Japan Azaleas reach their northern limits in
central Hokkaido, where R. Tschonoskii, R. Albrechtii, R. obtusum
var. Kaempferi and R. reticulatum are found. The marked absence
of limestone in Japan is favorable to the family Ericaceae which is
richly represented there, and on the volcanic mountains Azaleas are
astonishingly abundant. The small-flowered R. obtusum, the wild
type of which is the form japonicum, is local, being confined to Kiri-
shima and to a few other mountains in Kyushu, but the large-flowered
variety Kaempferi grows in plenty from the extreme south, northward
to central Hokkaido. The same is true of the magenta-flowered R. reti-
culatum. Billions of plants of these two species are scattered on the
grass and shrub-clad slopes, in thickets, in thin woods and on the
margins of forests. In May from Kyushu to central Hondo travelling
by train or along the roads one is never out of sight of the blossoms of
these Azaleas; in June the same is true for the north until their limit
of distribution is reached. Many districts are famous for their Azaleas,
and of these I may mention the slopes of Mt. Fuji, the Hakone moun-
tains and the Nikko region. In Yamato province, and also round
Fuji and Nikko R. japonicum with its clusters of large flame-colored
flowers grows in millions. Indeed it is to her Azaleas that Japan owes
much for the color which decks her countryside. And what joy it is to
ramble through this flower-clad land in spring and early summer. In
autumn the leaves of such species as R. japonicum, R. Tschonoskii,
R. reticulatum, R. quinquefolium, R. pentaphyllum and R. linearifolium
change to rich shades of yellow, orange, crimson and vinous purple.
These autumn tints, like the wealth of brilliantly colored flowers in
spring and early summer, arrest attention on every side, and small
wonder that the Japanese have taken Azaleas into their gardens, parks
and temple grounds and cultivated them from time immemorial. The
only truly woodland species are R. quinquefolium and R. pentaphyllum,
but so adaptable to different conditions are R. reticulatum and R. 06-
tusum var. Kaempferi that they too may be considered woodland
plants. In dark ravines, by the sides of torrents and in the forests of
the Nikko region R. quinquefolium is plentiful, lighting up the dark and
DISTRIBUTION 13
solemn depths with its snow-white, almost bell-shaped flowers. Crown-
ing a knoll among mixed trees round the Hashimoto Tea House at
Chuzenji and high up on the steep, wooded slope behind the Lakeside
Hotel near the same place R. pentaphyllum is common, and I shall
never forget the day in June, 1914, when I first beheld these bushes
covered with masses of bright rose-pink blossoms. These two may
be classed as small trees and among the Azaleas of eastern Asia are
only approached in size by the pink-flowered R. Schlippenbachii.
R. Tschonoskii has the smallest flowers of any species of Azalea and,
indeed, in this respect is only approached by the Chinese R. Seniavinii.
But in size of plant the real dwarf species is R. serpyllifolium, which is
common in the Idzu province, and is also known from Mt. Unzen
near Nagasaki, and from Okinawa in the Liukiu Archipelago. Yet
individual plants of R. obtusum f . japonicum at alpine limits of vege-
tation are equally dwarf.
By the sides of rock-strewn torrents high up on mountains on
Yaku-shima Island R. indicum, the first-known of all Asiatic Azaleas,
forms dense thickets more than a metre high, but in the gardens of
Japan it is a dwarf and hugs the ground closely. The lovely R. mu-
cronatum with its pure white, fragrant flowers has not been found wild
though its pale purple-flowered variety ripense is common by the sides
of certain rivers in the island of Shikoku. The pink to rose-colored
R. linearifolium var. macrosepalum with sticky leaves and flower-buds
and an extraordinarily variable and glandular calyx is abundant in
thin Pine-woods and among scrub round Futagawa, Yoshino and
near Osaka. Very remarkable is the distribution of the red-flowered
R. Weyrichii, which is known only from parts of Shikoku in the east,
from the Goto Islands in the Japan Sea, and from the island of Quel-
paert off the south of Korea. The small-leafed R. tosaense is confined
to parts of the island of Shikoku, and R. Schlippenbachii, which is
really a Korean species, grows sparingly on Chokai-san and one or two
other mountains in northern Hondo. The slender-branched R. Al-
brechtii grows in thickets and on the margins of forests from the Nikko
region northward to central Hokkaido, but is nowhere really common.
On the foot-hills of Adzuma-yama the remarkable R. nipponicum, with
its campanulate white corolla, shreddy, cinnamon-brown bark and
fragile fruit, is common in open grass and scrub-clad country, but is
not known elsewhere. On Mt. Kirishima in Kyushu R. obtusum
f . japonicum grows under alpine conditions, but the most truly alpine
species of east Asiatic Azaleas is R. Tschonoskii, widespread in Japan
14 THE AZALEAS OF THE OLD WORLD
on high mountains from Shikoku and central Hondo north to central
Hokkaido, and in Korea found on the summit of the Chiri-san. All in
all the most widely spread, most variable, most spectacularly beautiful
and most useful of the red-flowered Japanese Azaleas is R. obtusum
and its variety Kaempferi.
In Korea, from Chiri-san in the extreme south of the peninsula to
fifty miles north of Gensan, grows R. Schlippenbachii. It is partial to
rocky places and thickets and often in thin woods it is the dominant
undergrowth. On the famous Diamond Mountains in northeastern
Korea it is particularly plentiful in mixed, rather open woods and on
cliffs; in early summer its myriads of blossoms literally form sheets of
pure pink for miles and miles. On exposed cliffs the habit is stiff and
sturdy, but in the shade of trees the branches are slender. On Chiri-
san it is usually a tree-like bush, four metres tall, and it is on this
mountain range that this Azalea reaches its maximum size. On bare,
grass-clad and shrub-clad slopes and inline-woods from the latitude of
Seoul southward to the island of Quelpaert R. yedoense var. pouk-
hanense abounds. In full exposure it ofte» forms low mats several
yards wide, but among shrubs it is occasionally 1.5 m. tall. This and
R. Weyrichii are the only species that grow on Quelpaert, and the
last-named is unknown on the mainland of Korea.
In China the red-flowered R. Simsii is wild from the coast to the
extreme west, the valley of the Yangtsze River being the northern limit
of its range. In many places it is extraordinarily abundant, and in
May whole hillsides are red with its flowers. This species is wild in
the extreme south of Formosa, and a well-marked variety (eriocarpum)
is endemic on the Kawanabe Islands off northern Liukiu. This is the
only Chinese species known to grow wild outside of China proper, but
phylogenetically it and R. obtusum may be considered of common
origin, and to these China and Japan owe the wealth of brilliant red
color, so dominant a feature in their spring landscapes. The lovely
yellow-flowered R. moUe, better known under Sweet's name of R. si-
nense, is found on open hillsides from the coast near Ningpo to Ichang
in central China. It is a social plant though local in distribution.
R. Mariesii grows in thickets and thin woods from Fokien to western
Hupeh and also in Formosa, but its near relative R. Farrerae is confined
to Hongkong and a few places in the neighboring province of Kwan-
tung. On open mountains in western Yunnan the small-flowered
R. microphyton is abundant; this is the most alpine of the Chinese
species and, with the little known R. atrovirens, is the most western of
DISTRIBUTION 15
the section Tsutsutsi. The other two Chinese species are R. Seniavinii
and R. Mariae, and these are apparently rare and confined to the east-
central and south-central provinces.
In Liukiu the gaudy-flowered R. scabrum is endemic, but was long
ago taken to the gardens of southern Japan where it is a common plant
to-day. This species has the largest flowers of all Azaleas, and in a
wild state and in gardens where it flowers freely is strikingly conspic-
uous. Unfortunately in the Occident its tendency is to flower sparingly.
I strongly suspect that R. phoeniceum, unknown as a wild plant though
introduced from Canton about 1824, and the popular stock for grafting
the " Indian Azaleas" of western gardens, is specifically not really
distinct from R. scabrum.
Although eight species grow wild in Formosa, Azaleas cannot be
called a prominent feature of the vegetation. The red-flowered R. Old-
hamii is widespread, and in districts in the north like Mt. Daiton and
round Lake Candidius in the centre of the island it is fairly abundant.
On grass-clad mountain slopes east of Ari-san the pretty, pink-flowered
R. rubropilosum is plentiful. The others, so far as my personal knowl-
edge goes, are local if not actually rare plants. Lastly, on Luzon in the
Philippine Islands grows R. subsessik, the most southern representative
of the group.
The distribution and the number of the species in the four groups
are shown in the following table : —
Teutsutsi Sciadorhodion Rhodora Pentanthera
Japan 8 4 3 1
Korea 2 2
Liukiu 3 - - -
Formosa 7 1 - -
China 5 2 1
Philippines 1 - - -
Pontus region, Caucasus, *)
Lithuania, Poland and >• ' - - 1
southwestern Russia )
CLASSIFICATION
MANY of our favorite garden plants of oriental origin came to us
from the gardens of China and Japan and in some instances their wild
prototypes have not yet been discovered. Often when the wild plant
has been discovered it has been found to differ greatly from that
already in cultivation, and in consequence has to be designated as a
variety or form of the described garden type. Phylogeny and taxon-
omy are often opposed, which is regrettable but unalterable. Stu-
dents of the floras of the Orient, particularly those of China and
Japan, cannot too strongly bear in mind the fact that a great many
of the earliest described species are based on cultivated plants. Let
me illustrate this by reference to Japan. The Japanese, like the Chinese
and Koreans, are lovers of the odd and curious in flowers and trees for
which they have an innate love. Nearly every house, from the poorest
hovel' to the castle of the feudal lord or his descendants, boasts a few
flowers or a garden of some sort. The Japanese love their mountains,
many of which are sacred and on most of them shrines have been
raised. Pilgrimages to these mountains and shrines are a passion with
the people and as mementoes of their visits it is a common practice,
and has been for centuries, to bring back some strange or curious
plant for their gardens. The result is that Japanese gardens are full
of odd and curious plants — dwarf plants, weeping plants, fastigiate
plants, plants with variegated and curiously incised foliage, plants with
abnormal flowers. This love of flowers has been fostered by Buddhist
priests, and this has led to mutual exchange of plants among the
peoples of China, Korea, Japan and Liukiu. Now if it be properly
realised that it was from such gardens — really museums of oddities —
that our early plants were taken and names applied to them the diffi-
culty of identifying them with their wild parents will be better under-
stood and appreciated.
Until after 1860 all the Azaleas introduced from the Orient were
from gardens, chiefly those of Batavia, Canton and Shanghai. As the
plants flowered they were given specific and varietal names, but no
attempt to discover their origin was made. Some were placed under
the genus Azalea and others under that of Rhododendron. Salisbury
16
CLASSIFICATION 17
(Prodr. 286 (1796)) was the first to point out that Azalea and Rhodo-
dendron could not be maintained as distinct genera. In 1834 G. Don
(Gen. Syst. III. 843) placed all the known species under Rhododendron.
Indiscriminate naming, however continued, and in 1854 Planchon, in
Flore des Serres, IX. (1854), and in Revue Horticole (1854), reviewed the
varieties from the Orient, placed all under Rhododendron and multi-
plied considerably the specific names. In 1870 Maximowicz (Mem.
Acad. Sci. St. Petersburg, se*r. 7, XVI. No. 9 (Rhodod. As. Or.))
monographed the Rhododendrons of eastern Asia, and his work has
remained the basis of all subsequent studies. Maximowicz dealt
with the subject in a thorough and masterly manner. I differ from
him widely in the conception and limits of certain sections and species,
and in the systematic position of some varieties and forms, but I am
none the less sensible of the great value of his pioneer work.
Many will regret the change of names involved but none more so
than myself. These changes are as unfortunate as they are unavoid-
able. I adhere strictly to the rule of priority as laid down in the
Vienna rules, and while this may sometimes be deemed a nuisance its
fairness cannot be questioned. Moreover, if we are ever to enjoy fixed
order in plant nomenclature it can only be brought about through
strict adherence to accepted and established rules.
It is a pity that Planchon's name Azalea cannot be used for the sub-
genus. It is based on the genus Azalea of Linnaeus, the type of which
is Azalea procumbens L., now known as Loiseleuria procumbens Desv.
The six species enumerated under Azalea by Linnaeus (Spec. 150
(1753)) belong to two subgenera and one distinct genus, namely,
Loiseleuria. With Planchon's name eliminated the oldest valid name
for the subgenus is Anthodendron Endlicher.1
Of the four sections of the subgenus with which we are concerned
three were established by G. Don (Gen. Hist. III. (1834)) and one
(Sciadorhodion) is proposed here. The section Tsutsutsi G. Don was
based on the plant figured by Kaempfer (Amoen. Exot. (1712)), which
is R. obtusum var. Kaempferi and is an excellent type of this homo-
geneous group. G. Don included R. reticulatum and R. Farrerae, but
these have deciduous leaves, no appressed, flattened, bristle-like
hairs and lack other features characteristic of Tsutsutsi proper. For
this reason I refer them to a new section, Sciadorhodion. G. Don also
includes R. molle which belongs to his section Pentanthera. Planchon
1 For full details see page 115.
18 THE AZALEAS OF THE OLD WOKLD
in Flore des Serres, IX. (1854), emends Don's name to Tsutsia, includes
under it R. molle and R. Farrerae, and adds R. Championae Hook. In
the last-named species the flowers develop from clustered, axillary
buds, and it belongs to the section Choniastrum Franchet. Maximo-
wicz emends the section; calls it Tsutsia, but keeps under it R. Cham-
pionae. He also emends Planchon's subgenus Azalea and employs it
as a section to include R. Farrerae, R. molle and others; he also places
in it R. macrosepalum, which obviously belongs to the section Tsutsutsi.
Of the new section Sciadorhodion, R. Schlippenbachii may be taken
as the type, and under it we place R. reticulatum and R. Farrerae, referred
by G. Don to his section Tsutsutsi, also R. Weyrichii which Maximo-
wicz includes in his section Azalea. Together these form a very homo-
morphic group. The type of G. Don's section Pentanthera is the
Eurasian R. luteum Sweet, but as most of the species are American
I leave the discussion of it and also of the section Rhodora G. Don,
the type of which is American though a majority of the species are
Japanese, to my colleague Alfred Rehder.
KEY TO THE ASIATIC SECTIONS OF THE SUBGENUS
ANTHODENDRON ENDL.
Flowers and leaves from the same bud.
Shoots with flattened, appressed, bristle-like hairs; leaves persistent or some-
times deciduous, usually dimorphic, scattered on the branches, elliptic to
lanceolate or oblanceolate . . . I. Tsutsutsi.
Shoots glabrous or villose, without bristle-like hairs; leaves deciduous, not di-
morphic, in whorls at the end of the branchlets, scattered only on vigorous
shoots, usually rhombic to obovate, rarely ovate . . .II. Sdadorhodion.
Flowers from the terminal bud, leaves from lateral buds below.
Corolla rotate-campanulate; stamens 8 to 10 III. Rhodora.
Corolla funnel-form; stamens 5 IV. Pentanthera.
KEY TO THE ASIATIC SPECIES
SECT. I. TSUTSUTSI G. DON
Bud-scales not viscid; shoots densely clothed with flattened, appressed hairs.
Corolla funnel-form-campanulate.
Stamens 5 (5 to 8 in R. tosaense).
Style villose at base R. breviperulatum, p. 28.
Style glabrous at base.
Leaves linear-lanceolate to lanceolate or oblanceolate.
Leaves crenate-dentate; flowers red to rose-red, more than 2.5 cm.
across R- indicwn, p. 22.
Leaves entire; flowers lilac-purple, less than 2 cm. across
R. tosaense, p. 52.
Leaves oval or obovate to lanceolate.
Leaves more than 1 cm. long, the midrib beneath covered with hairs
and usually with scattered hairs on the whole under surface
R. obtusum, p. 29.
Leaves 1 cm. to 1 cm. or less long, glabrous beneath, except a few
brown hairs on the midrib R. serpyllifolium, p. 53.
Stamens 7 to 10.
Style villose at base.
Leaves narrow-lanceolate to oblanceolate, crenate-dentate; stamens 10
. R. Kanehirai, p. 28.
Leaves oval to obovate or lanceolate, entire; stamens 7 to 10.
Flowers lilac to magenta; leaves generally elliptic-oblong, acute
R. subsessile, p. 51.
Flowers pink.
Leaves conspicuously dimorphic, obovate to obovate-oblong,
abruptly mucronate, 2 to 4.5 cm. long . R. lasiostylum, p. 50.
Leaves not conspicuously dimorphic, often widest below the middle,
elliptic-ovate to ovate-oblong or elliptic to elliptic-oblong,
acute R. rubropilosum, p. 52.
19
20 THE AZALEAS OF THE OLD WORLD
Style glabrous.
Flowers more than 2.5 cm. across; leaves elliptic to elliptic-oblong or
oblong-obovate, from 2 to 5 cm. long R. Simsii, p. 45.
Flowers less than 2.5 cm. across.
Leaves lanceolate, acuminate R. atrovirens, p. 50.
Leaves oval to oblanceolate, 1 cm. or less long . R. Nakaharai, p. 54.
Corolla with short, rarely long, cylindric tube and spreading lobes; stamens 5,
rarely 4.
Style villose at base; flowers white to rose-color . . . R. Seniavinii, p. 57.
Style glabrous.
Leaves persistent; flowers 5-partite.
Corolla rose-purple, leaves not conspicuously dimorphic, oval to
lanceolate R. microphytum, p. 57.
Corolla lilac-colored, with a long tube; leaves conspicuously dimorphic,
lanceolate or elliptic to oblong-obovate . . . . R. Mariae, p. 58.
Leaves deciduous; flowers white, 4 to 5 partite; leaves narrow-lanceolate
to ovate-lanceolate or oblong-obovate, often prominently 3-nerved
R. Tschonoskii, p. 55.
Bud-scales viscid on inner surface; corolla wide funnel-form; calyx-lobes green,
ample; style glabrous.
Shoots densely clothed with flattened, appressed hairs; leaves conspicuously
dimorphic; stamens 10.
Leaves persistent, calyx-lobes glandular-ciliate.
Corolla scarlet to rose-red; calyx-lobes oval to lanceolate; leaves sub-
crenulate, coriaceous R. scabrum, p. 59.
Corolla rose-purple to magenta; calyx-lobes lanceolate; leaves entire,
subcoriaceous R. phoeniceum, p. 61.
Leaves deciduous or semipersistent, obscurely crenate-serrate, veins im-
pressed above; corolla rose to rose-purple, fragrant, often double; calyx-
lobes lanceolate, not glandular R. yedoense, p. 64.
Shoots with few appressed, flattened hairs and many spreading, pilose often
glandular hairs.
Stamens 8 to 10; leaves persistent or semipersistent, not conspicuously
dimorphic.
Corolla red, not viscid; stamens 10; ovary glandular; leaves not viscid
beneath R. Oldhamii, p. 66.
Corolla white or pale-purple, viscid outside; stamens 8 to 10; ovary gland-
less; leaves viscid beneath R. mucronatum, p. 68.
Stamens 5; leaves deciduous or semipersistent, lanceolate to oblanceolate-
ovate or linear-lanceolate; corolla pink to pale rosy purple, viscid without,
funnel-form or divided into linear segments; ovary glandular
R. linearifolium, p. 74.
SECT. II. SCIADORHODION REHD. & WILS.
Leaves broadest below the middle; stamens nearly equal.
Leaves ovate; corolla pale lilac-purple; stamens 8 to 10; fruit conic-ovoid on
a curved pedicel R. Farrerce, p. 79.
Leaves ovate to ovate-lanceolate; corolla rose-color; stamens 10; fruit short-
cylindric, erect R. Mariesii, p. 80.
Leaves broadest about or above the middle.
Leaves rhombic; fruit cylindric.
Stamens subequal; corolla red, rotate-funnel-form; style villose
R. Weyrichii, p. 82.
KEY TO THE ASIATIC SECTIONS OF THE SUBGENUS 21
Stamens unequal, sometimes declinate; corolla rotate-campanulate.
Corolla rose-purple to magenta; style glabrous, villose or lepidote or both;
leaves with long scattered hairs when young, glabrescent at maturity;
fruit cylindric, furrowed R. reticulatum, p. 83.
Corolla white; style glabrous; leaves densely ciliate, short-villose, at least
on midrib at maturity; fruit cylindric, terete R. quinquefolium, p. 87.
Leaves broadly obovate; corolla pink; style glandular; fruit oblong-ovoid,
verruculose R. Schlippenbachii, p. 88.
SECT. III. RHODORA G. DON
Corolla rotate-campanulate.
Leaves obovate to oblong-oblanceolate, pubescent below; flowers 3 to 6, ma-
genta; fruit conic-ovoid, bristly glandular R. Albrechtii, p. 91.
Leaves elliptic to narrow-elliptic, glabrescent; petiole bearded; flowers 1 or 2,
bright rose-pink; fruit spindle-shape, glabrous, verrucose
R. pentaphyllum, p. 92.
Corolla campanulate, white; leaves obovate to panduriform, subsessile with scat-
tered, bristly hairs; fruit oblong-ovoid, verruculose, with thin valves, wavy
at the margin when open R. nipponicum, p. 93.
SECT. IV. PENTANTHERA G. DON
Corolla wide-funnel-form, non-glandular.
Stamens as long as the yellow corolla; leaves softly pubescent, often canescent;
winter-buds velutinous R. molle, p. 95.
Stamens shorter than the orange- or flame-red, rarely yellow corolla; leaves
glabrous except on the veins beneath; winter-buds glabrous
R. japonicum, p. 99.
Corolla tubular with spreading lobes, glandular R. luteum, p. 103.
ENUMERATION OF THE SPECIES
SECT. I. TSUTSUTSI G. DON
Rhododendron section Tsutsutsi G. Don, Gen. Syst. III. 845 (1834),
excluding Nos. 30, 31, 36, 39.
Azalea Linnaeus, Spec. 150 (1753), as to species No. 1.
Tsutsutsi Adanson, Fam. PL II. 164 (1763).
Loiseleria Reichenbach, Fl. Germ. Exc. I. 416 (1830).
Beverinckia Salisbury ined. ex DeCandolle, Prodr. VII. pt. 2, 726 (1839).
Rhododendron section Toutousi Duchartre in Orbigny, Diet. Univ. Hist. Nat.
XI. 120 (1849).
Rhododendron subgenus Tsutsia Planchon in Fl. des Serr. IX. 75 (1854); in
Rev. Hort. 1854, 45.
Rhododendron section Tsutsugi Miquel, Fl. Ind. Bat. II. 1059 (1857).
Rhododendron section Tsusia Maximowicz in Mem. Acad. Sci. St. Peters-
burg, se>. 7, XVI. No. 9, 32 (Rhodod. As. Or.) (1870), excluding No. 17.
Azalea subgenus Tsutsutsi K. Koch, Dendr. II. pt. 1, 171 (1872), excluding
species No. 6.
Shrubs with dense twiggy branches; shoots densely or sparsely clothed with
appressed, flattened, red-brown or rufous hairs, occasionally also with spreading
soft hairs. Flowers from terminal bud, with leafy shoots from axils of lower
scales of same bud. Leaves evergreen or half evergreen, rarely deciduous, more
or less villose, rarely glandular. Corolla funnel-form, campanulate-funnel-form,
rarely cylindric, with short spreading lobes; stamens 5 to 10, equal or unequal in
length, never declinate, puberulous, or pubescent; ovary strigose, sometimes glan-
dular. Fruit conic or conic-ovoid, glabrescent or strigose- villose, 5-celled; seeds
wingless.
This section is confined to eastern Asia, where it is represented by 22 species.
Rhododendron indicum Sweet, Brit. Flaw. Gard. ser. 2, II. sub. t.
128 (1833). — G. Don, Gen. Syst. III. 845 (1834), excluding varieties. —
De Candolle, Prodr. VII. pt. 2, 726 (1839), in part. — Siebold & Zucca-
rini in Abh. Akad. Munch. IV. pt. III. 131 (Fl. Jap. Fam. Nat. 7) (1846),
in part. — Miquel, FL Ind. Bat. II. 1059 (1857). — Maximowicz in
Mem. Acad. Sci. St. Petersburg, se*r. 7, XVI. No. 9, 37 (Rhodod. As. Or.)
(1870), in part. — Franchet & Savatier, Enum. PL Jap. I. 291 (1875),
in part. — Schneider, III. Handb. Laubholzk. II. 506, figs. 331 1-m,
332 a-d (1911).— Render in Bailey, Stand. Cycl. Hort. V. 2944 (1916).—
Komatsu in Tokyo Bot. Mag. XXXII. [18] (1918).
Azalea indica Linnaeus, Spec. 150 (1753). — Burmann, Fl. Ind. 42 (1768). —
Willdenow, Spec. I. pt. 2, 831 (1798). — Persoon, Syn. 212 (1805). — Aiton,
22
ENUMERATION OF THE SPECIES 23
Hort. Kew. ed. 2, 1. 318 (1810), as to description and synonyms. — Roemer
& Schultes, Syst. Veg. IV. 374 (1819), excluding 0. — Blume, Cat. Gewass.
Buitenz. 44 (1823); Bijdr. Fl. Ned. Ind. 852 (1825). — Sprengel, Syst. Veg.
I. 628 (1825).
Azalea indica var. b. spatulata Blume, Bijdr. Fl. Ned. Ind. 852 (1825).
Azalea indica var. d. angustifolia Blume Bijdr. FL Ned. Ind. 852 (1825.)
Azalea indica var. e. floribunda Blume, Bijdr. Fl. Ned. Ind. 852 (1825).
Azalea macrantha Bunge in Mem. Soc. £tr. Sci. St. Petersbourg, II. 115
(Enum. PI. Chin. EOT. 41) (1833).
Azalea indica lateritia Lindley in Bot. Reg. XX. t. 1700 (1834).
Rhododendron macranthum G. Don, Gen. Syst. III. 846 (1834).— Sweet, Brit.
Flow. Gard. ser. 2, III. t. 261 (1834).
Rhododendron decumbens D. Don apud G. Don, Gen. Syst. III. 846 (1834).
Azalea Danielsiana Paxton, Mag. Bot. I. 129, t. (1834).
Rhododendron indicum S. ? lateritium DeCandolle, Prodr. VII. pt. 2, 726 (1839).
Azalea ? macrantha De Candolle, Prodr. VII. pt. 2, 718 (1839).
Azalea decumbens De Candolle, Prodr. VII. pt. 2, 718 (1839).
Rhododendron Breynii Planchon in Fl. des Serr. IX. 77 (1854).
Rhododendron Danielsianum Planchon in FL des Serr. IX. 79 (1854).
Rhododendron lateritium Planchon in FL des Serr. IX. 80 (1854).
Rhododendron Sieboldii 0. serrulatum Miquel in Ann. Mus. Ludg.-Bat. I.
33 (1863).
Azalea Breynii Andr<§ in Belg. Hort. XV. 183 (1865).
Azalea lateritia Hort. ex Andre" in Belg. Hort. XV. 185 (1865).
Rhododendron indicum j. macranthum Maximowicz in Mem. Acad. Sci. St.
Petersbourg, se*r. 7, XVI. No. 9, 39 (Rhodod. As. Or.) (1870).— Franchet &
Savatier, Enum. PL Jap. II, 292 (1875). — Makino in Tokyo Bot. Mag.
XXIV. 77 (1910). — Matsumura, Ind. PL Jap. II. pt. 2, 461 (1912).
Rhododendron indicum y. macranthum a. macranthum genuinum Maximowicz
in Mem. Acad. Sci. St. Petersbourg, se"r. 7, XVI. No. 9, 39 (Rhodod. As.
Or.) (1870). — Makino in Tokyo Bot. Mag. XXIV. 77 (1910).
Rhododendron indicum y. macranthum b. lateritium Maximowicz in Mem. Acad.
Sci. St. Petersbourg, se>. 7, XVI. No. 9, 39 (Rhodod. As. Or.) (1870).—
Makino in Tokyo Bot. Mag. XXIV. 77 (1910).
Rhododendron lateritium var. brachytrichum Nakai in Tokyo Bot. Mag. XXIX
[261] (1915).
Rhododendron hangnoense Nakai in Tokyo Bot. Mag. XXIX. [261] (1915).
Rhododendron indicum f . lateritium Rehder in Mitt. Deutsch. Dendr. Ges. XXIV.
225 (1916); in Bailey, Stand. CycL Hort. V. 2944 (1916).
Rhododendron indicum var. brachytrichum Komatsu in Tokyo Bot. Mag.
XXXI. [18] (1918).
Japan: Kyushu, prov. Osumi, Yaku-shima, side of torrents, alt.
300-800 m. February 19, 1914, E. H. Wilson (No. 6003); same place,
without collector's name (Herb. Bur. Sci. Manila) ; prov. Hizen, Naga-
saki, 1873, Capt. Blomfield (Herb. Kew) ; same locality, ex Herb. Lugd.-
Bat. 1863, as R. Sieboldii var. minor, in part (Herb. Kew and Herb.
Gray); same locality, cultivated, 1863, C. Maximowicz (Herb. Kew,
co-type of R. indicum y. macranthum b. lateritum Maximowicz) . Hondo,
prov. Shinano, 1864, Tschonoski (Herb. Kew); prov. Sagaim, Hakone,
cultivated, June 21, 1914, E. H. Wilson (No. 6888); near Uraga, 1862,
24 THE AZALEAS OF THE OLD WORLD
C. Maximowicz (Herb. Kew and Herb. Gray, co-type of R. indicum
y. macranthum subvar. a. genuinum Maximowicz) ; prov. Suruga, foot of
Mt. Fuji, cultivated, June 13, 1914, E. H. Wilson (No. 6932); prov.
Musashi, Yokohama, cultivated, 1862, C. Maximowicz (Herb. Kew and
Herb. Gray); Tokvo. cultivated. July 2, 1882, K. Miyabe', same locality
(Herb. Bot. Gard. Tokyo, type of R. lateritium var. brachytrichum
Nakai); prov. Shimotsuke, Nikko., alt. 600-1000 m. cultivated and
sub-spontaneous, June 20 flowers, October 20 fruit, 1914, E. H. Wilson
(Nos. 6816, 6818, 7709).
Cultivated: Java ex Herb. Ludg.-Bat. 1863, as R. indicum Sweet
(Herb. Kew); Hongkong Bot. Gard. May 12, 14, 31, 1919, W. J.
Tutcher.
The only place where I have seen this species truly wild is Yaku-shima, an island
some ninety miles south of Kagoshima and interesting as being the southern limit
of the range of a great many Japanese plants. On that island R. indicum Sweet is a
common fluviatile shrub growing from a half to two meters high and forming dense
masses in open country on the banks of rock-strewn streams. Elsewhere in Japan
I found it cultivated only, although in old burial and temple grounds it is often
more or less naturalized. Makino says it grows spontaneously in the provinces of
Kii and Yamato in Hondo and not so very far from the old capital of Kyoto. In
an old burial ground at Nikko the plants were prostrate or nearly so and with
their scattered, large red flowers strongly suggested the Rock Cistus, and one saw
how very applicable was the name the ancients gave this plant. The plants though
often decumbent are naturally upright and very densely branched; the branches
are slender but rigid and are clothed with flattened, appressed, strigose, chestnut-
brown hairs which in the second and third years lose their color and disappear.
The leaves are sub-coriaceous and crowded, short-petioled, narrow-lanceolate,
lanceolate to oblanceolate, mucronulate, dark green, rather shining above, pallid
or sub-glaucous beneath, ciliolate, usually remotely crenate-dentate, with scat-
tered, closely appressed, red-brown setose hairs on both surfaces; in the autumn
the leaves change to crimson and vinous purple. The flowers are terminal, solitary
or in pairs; the corolla is broad-funnel shape, opening at the same time or im-
mediately before annual growth commences, bright red to scarlet, sometimes rose-
red; there are 5 stamens shorter than the style but equalling or exceeding the
corolla in length.
In Japanese gardens this Azalea is a prime favorite and I was told that some-
thing like two hundred named forms are recognized. It is planted on or among
rocks, singly or in groups, and is used as a garden edging. It bears trimming well, and
its naturally low, dense habit makes it particularly useful in the gardens of Japan.
Its native name is "Satsuki-tsutsuji," that is Fifth-month Azalea, from the fact
that it blossoms in June, which is the fifth month of the year reckoning by the old
Chinese calendar.
The first mention of this plant in a European book is in Breyne's Prodromus, I.
23 (1680), which I have not seen, but in the edition of 1739 it is mentioned in pt.
1. 16 as " Chamaerhododendron exoticum, amplissimis floribus liliaceis." Breyne
was a merchant of Danzig and a distinguished botanist who visited Holland dur-
ing the last quarter of the 17th century and in his Prodomus described the re-
markable plants he saw there. His "Chamaerhododendron " was growing in the
garden of a Mr. Beveringk, but no mention is made of its country of origin.
ENUMERATION OF THE SPECIES 25
Hermann in his Academici Horti lugduno-batavi catalogus 152. fig. (1687), de-
scribes and figures it under the name of "Cistus Indicus, Ledi Alpini foliis &
floribus amplis." He cites Breyne and says the plant came from Jaccatra (that
is Batavia, Java). Hermann's figure though crude is easily recognized as repre-
senting the plant we are discussing and can in fact be identified with no other
species. Doubtless it was taken by Dutch trading ships from Nagasaki to Batavia
and from there to Holland. Ray in his Historic, Plantarum II. 1895 (1688) men-
tions it, citing Hermann and Breyne. On this plant of Breyne, Hermann and Ray,
Linnaeus (Spec. 150 (1753)) bases his Azalea indica so there can be no mistake as
to its identity even though Linnaeus gives the habitat as the East Indies, and
cites " Tsutsusi Kaempfer Amoen. 845, t. 846," which is Rhododendron obtusum
var. Kaempferi Wils. The plant of Breyne and Linnaeus is Kaempfer's " Token,
vulgo Satsuki, Cytisus Liliifer autumnalis Tsutsusi congener," of which he men-
tions (Amoen. Exot. fasc. V. 849 (1712)) five kinds, including single and double-
flowered red and white forms.
Linnaeus' species was introduced into England in 1833 by Mr. M'Killigan to
Knight's Nurse^in Chelsea under the name of Azalea indica lateritia and flowered
there for the first time in May 1834. About the same time forms differing slightly
in color were brought from China to England by officers commanding the East India
Company's trading ships and named Azalea Danielsiana, R. macranthum and R.
decumbens. According to Hovey (Mag. Hort. V. 25 (1839)) Azalea lateritia and
A. Danielsiana were introduced from England into Boston, Mass., in 1838. Up to
about 1845 color forms, many of seedling origin, of R. indicum were more numerous
in our gardens than those of R. Simsii and these with forms of R. phoeniceum
and R. mucronatum (Azalea ledifolia) collectively constitute the Azalea indica of
the period. It is recorded that on March 13, 1837, ten varieties of Azaka in-
dica were exhibited at Ghent by Mr. Charles Deloose and awarded a gold medal.
After 1850 the true Rhododendron indicum and its forms rapidly dropped from
cultivation and the name was appropriated for the varieties of the Chinese R.
Simsii Planch. Aiton in 1810 and Sims in 1812 were first to unite the Japanese
and Chinese plants; Sweet in 1832 made the Chinese plant a variety of R. indicum.
The rest of the story is told by the synonomy, but that the confusion is complete is
proved by the fact that to-day Linnaeus' plant is absolutely unknown to gardens
under the name he gave it. In fact it has become more or less lost to cultivation,
although its double-flowered form, bakaminaeflorum, is well known and appre-
ciated. R. indicum is really a very pretty species and well adapted for rockeries
in mild, moist countries, and is about as hardy as R. obtusum f. amoenum Wils.
I sent seeds and plants of it from Japan to the Arnold Arboretum in 1914. The
Azalea "3. T. Lovett " of American gardens, claimed to be of hybrid origin
is nothing but the true R. indicum. Up to about 1850 several varieties of this
Azalea were cultivated under the name of "Indian Azaleas" and in all proba-
bility hybrids between it and R. Simsii Planch, were obtained. Such old varieties
as "The Bride "with white flowers, and Van Houtte's Azaka indica punctulata,
A. punctulata variegata, A. punctulata omnicolor (Fl. des Serr. XVI. 17, tt. 1618-
1623 [1865]) are, I think, hybrids between the two species. In the evolution of
the large-flowered " Indian Azalea" of commerce of to-day I doubt if R. indicum
has had any part. The fact that it cannot be forced by strong heat to blossom out
of season is against it, since this is a marked feature of the " Indian Azaleas" of
greenhouses to-day. When grafted on the vigorous R. phoeniceum the size of the
flowers is increased.
A form with white flowers is : —
Rhododendron indicum f. hakatashiro Millais, Rhodod. 193 (1917).
26 THE AZALEAS OF THE OLD WORLD
Rhododendron indicum f. Hakatajiro Komatsu in Tokyo Bot. Mag. XXXII.
[45] (1918).
This is often seen in old Japanese gardens and has been introduced into England.
A form with salmon-red flowers whitish at the base is: —
Rhododendron indicum f. tanimanoyuki Millais, Rhodod. 193 (1917). —
Komatsu in Tokyo Bot. Mag. XXII. [45] (1918).
The best known to-day of all the forms of R. indicum is: —
Rhododendron indicum var. balsaminaeflorum Nicholson in Kew
Hand-list, pt. 2, 53 (1896); ed. 2, 499 (1902). — Bean, Trees and Shrubs
Brit. Isl II. 362 (1914). — Millais, Rhodod. 193 (1917).
Azalea Rollissoni T. Moore in Florist and Pomol. 1878, 35 fig. — Garden
XVIII. 254, t. 249(1880).
Azalea rosaeflora R. Dean in Fl. Mag. XIX. t. 418 (1880).
Azalea balsaminaeflora Carriere in Rev. Hort. 1882, 432 t. — Nicholson, Diet.
Gard. I. 149, fig. 196 (1887).
Azalea indica var. rosifiora Render in Bailey, Cycl. Am. Hort. I. 122, fig. 176
(1900).
Rhododendron indicum var. rosiflorum Render in Bailey, Stand. Cycl. Hort.
V. 2944 (1916); in Mitt. Deutsch. Dendr. Ges. XXIV. 226 (1916).
Rhododendron indicum Rollisoni Millais, Rhodod. 193 (1917).
This interesting little plant is common in the gardens of Japan, and it is there, as
in the West, of very slow growth. It is uncertain whether it was first introduced
into England or France. In the Garden, XVIII. p. 254 (1880), it is said to have
been " introduced about three years ago by Messrs. Rollisson." Carriere says it
was introduced into France from Japan by M. Vie*sener in 1877. On Long Island,
New York, it is harcly in sheltered, shady places. Bean says " it has lived out-
of-doors for many years at Kew but prefers a milder climate," Millais states that it
is "a great favorite for rock gardens, where it does not always flourish." The
Japanese name for the Azalea is " Romany o-satsuki."
Similar but rather less double is: —
Rhododendron indicum f. kinnozai Millais, Rhodod. 1913 (1917).
An old form is: —
Rhododendron indicum f. variegatum De Candolle, Prodr. VII. pt. 2,
726 (1839).
Azalea, indica var. a. variegata Blume, Bijdr. FL Ned. Ind. 852 (1825). —
Lindley in Bot. Reg. XX. t. 1716 (1834). — Hovey, Mag. Hort. V. 25
(1839).
Rhododendron indicum f. Matsushima Millais, Rhodod. 193 (1917).
This has white and red striped and spotted flowers and blooms irregularly the
year round. In the nursery district round Osaka it is known as " Shiki-takane-
satsuki." In Blume's time it was cultivated in Java, and according to Lindley it was
introduced into England by Mr. M'Killigan in 1833, to Knight's nursery in Chelsea,
London. From this Azalea Knight raised several seedling forms which received
names. Such plants as Azalea indica exquisita Lemaire (in Fl. des Serr. III. t.
239 (1847), syn. R. indicum equisitum Lemaire) and Azalea indica Iveryana albo-
ENUMERATION OF THE SPECIES 27
cincta Van Houtte (in Fl des Serr. XI. 211, 1. 1180 (1856)), are probably seedlings
from Azalea indica variegata. So too are Azaleas " Gledstanesii," " Iveryana,"
"Charles Encke " and " Reine Louise." In fact this var. variegatum was the
parent of most of the best "Indian Azaleas" cultivated up to about 1850. Ac-
cording to Hovey the var. variegatum was introduced into Boston, Mass., in 1838,
and for many years was a familiar and much admired plant at exhibitions. It is
still cultivated in the Holm Lea collection, so also are the above mentioned named
forms. These Azaleas were famous in their day and have been grown in this coun-
try for more than seventy years. "Gledstanesii" was raised by Metesers Rollis-
son of Tooting and exhibited for the first time in London on May 15, 1841. It
was imported into this country by Hovey & Co., Boston, Mass., who exhibited it
before the Massachusetts Horticultural Society on May 2, 1846. In England the
var. variegatum appears to have been lost to cultivation until quite recently, when
it was reintroduced under the name used by Millais.
A curious and abnormal form is: —
Rhododendron indicum f . polypetalum Wilson, n. comb.
Rhododendron indicum 7. macranthum c. polypetalum Maximowicz in Mem.
Acad. Sci. St. Petersburg, se>. 7, XVI. No. 9, 40 (Rhodod. As. Or.) (1870).
Cultivated: Hongkong Bot. Gard. May 20, 1919, W. J. Tutcher.
I have seen the Herb. Kew co-type of this curious plant with its petaloid, deeply
laciniate calyx and no corolla. In Japan its vernacular name is " Kin-no-zai." I
have not seen this plant nor the following, which has a proper calyx and a deeply
laciniate corolla.
Rhododendron indicum f . laciniatum Wilson, n. comb.
Rhododendron indicum y. macranthum subvar. b. lateritium f. laciniatum
Makino in Tokyo Bot. Mag. XXVII. 110 (1910).
Makino gives " Shide-satsuki " as the Japanese name of this curious form.
Komatsu enumerates several other forms, but the only other it is necessary to
mention here is the very distinct: —
Rhododendron indicum var. crispiflorum Schneider, III. Handb.
Laubholzk. II. 506 (1911). — Render in Bailey, Stand. Cycl Hart. V.
2944 (1916).
Azalea crispiflora Hooker in Bot. Mag. LXXIX. t. 4726 (1853). — Lemaire,
Jard. Fl. IV. t. 430 (1854). — Hovey, Mag. Hort. XXIII. 70 (1857); XXIV.
141 (1858).
Azalea indica crispiflora Van Houtte in Fl. des Serr. IX. t. ad p. 79 (1854).
Rhododendron crispiflorum Planchon in FL des Serr. IX. 83 (1854); in Rev.
Hort. 1854, 67.
This interesting variety has thicker leaves than the type and the wavy margins
of its corolla give it a distinct appearance. The Azalea indica var. grandiflora
Blume, of which there is a specimen in Herb. Kew collected by Thomas Lobb, is
similar, but the margin of the corolla is not wavy. R. indicum var. crispiflorum,
was introduced into England from China by Robert Fortune to the nursery of
Messers Standish & Noble in 1850 or 1851. It was imported from England .to
Boston, Mass., in 1855 by C. M. Hovey; soon afterwards a plant was acquired by
Ignatius Sargent, Esq., father of Professor C. S. Sargent, and descendants of the
38 THE AZALEAS OF THE OLD WORLD
original plant are in the Holm Lea collection to this day. In England it appears
to have been lost to cultivation until plants were sent to Kew and elsewhere from
Holm Lea by Professor Sargent.
Rhododendron Kanehirai Wilson, n. sp.
Frutex ramosissimus, 1-2.5 m. altus; rami graciles, ramulosi, juveniles pilis
compressis castaneis adpressis vestiti. Folia petiolata, dimorpha; vernalia sparsa,
lineari-lanceolata vel oblongo-lanceolata, 2-5 cm. longa, 0.5-1.5 cm. lata, acuta,
glanduloso-mucronulata, basi attenuata, obscure crenato-serrata, supra atrovi-
ridia, subtus pallida, utrinque pilis lucide brunneis strigosis adpressis vestita,
venis supra impressis; folia aestivalia in apice ramulorum aggregata, lineari-
oblanceolata vel anguste obovata, 1.5-3 cm. longa, 0.2-0.6 cm. lata, apice acuta
vel rotundata, ceterum ut vernalia; petioli 1-5 mm. longi, dense pilis compressis
castaneis adpressis vestiti. Flores terminales, bini vel raro solitarii, carminei vel
ecarlatini; pedicelli robusti, erecti, 5-8 mm. longi, dense pilis castaneis strigosis
vestiti; calyx plerumque bene evolutus; lobi virides, erecti, rotundati vel ovales,
1-5 mm. longi, 1-2 mm. lati, pilis adpressis lucide castaneis ciliati; corolla anguste
infundibuliformis, 2.5-4 cm. longa et 2-2.5 cm. lata, glabra; stamina 10, ineaqualia,
corolla breviora, filamentis gracilibus infra medium papillose pubescentibus, an-
theris 1-1.5 mm. longis; ovarium dense pilis cinereis vel castaneis strigosis ob-
tectum; stylus gracilis, 3-4 cm. longus, ad basin pilis paucis compressis strigosis
instructus, stigmate parvo capitato. Fructus non visus.
Formosa: prov. Taihoku, Urai, in a garden at the police station,
April 1, 1918, E. H. Wilson (No. 10,276).
This new species is closely related to R. indicum Sweet, which is distinguished
chiefly by its smaller leaves, rather larger, usually solitary flowers, its 5 stamens
with anthers from 2 to 3 mm. long and by its stouter and glabrous style. The
chief morphological difference is the number of stamens, and it may eventually
prove that this new species is a decandrous variety of the old Linnean plant. I
saw it in the garden mentioned above and was told that the plants had been brought
from the higher slopes of the surrounding mountains. It is distinct from anything
else I have seen and apparently has nothing to do with any of the species described
by Hayata. The flowers vary in color from carmine-red to scarlet.
Rhododendron breviperulatum Hayata, Icon. PI. Formos. III. 129
(1913). — Kanehira, Formos. Trees, 318, fig. 16 (1917). — Komatsu in
Tokyo Bot. Mag. XXXII. [14] (1918).
Formosa : prov. Nanto, Horisha, planted in Hotel garden, December
6, 1918, E. H. Wilson (No. 11,206).
This red-flowered Azalea is well characterized by its 5 stamens and its pilose
style; also by its leaves, which are oblong to oblanceolate or more rarely oblong-
ovate, with no conspicuous difference between those of the spring and summer.
The calyx-lobes are membranous, reddish, from 3 to 4 mm. long, ciliate and pilose
without, glabrous within. The corolla is from 2.5 to 3 cm. long and broad; the
Stamens are nearly as long as the corolla and have rather large purple anthers.
The young shoots and leaves are clothed with red-brown to gray appressed hairs.
The plants my specimens came from were from 1 to 1.5 cm. tall and had rather
slender branches. I was told that they had been brought from the neighboring
mountains.
ENUMERATION OF THE SPECIES 29
I cannot be absolutely sure of the correct identification of this plant. It agrees
very well with Hayata's description, though the calyx and corolla are larger than
he describes them, and the apiculate base of the anthers is by no means very
apparent.
Rhododendron obtusum Planchon in Fl. des Serr. IX. 80 (1854); in
Rev. Hort. 1854, 64. — Schneider, III Handb. Laubholzk. II. 506, fig.
332e (1911). — Render in Bailey, Stand. Cycl. Hort. V. 2944 (1916). —
Jour. Jap. Bot. I. [173] fig. (1917). — Komatsu in Tokyo Bot. Mag.
XXXII. [39] 1918. — Miyazawa in Tokyo Bot. Mag. XXXII. [318]
(1918).
Azalea indica Thunberg, FL Jap. 84 (1784), in part, not Linnaeus. — Juel,
PI. Thunb. 391 (1918).
Azalea obtusa Lindley in Jour. Hort. Soc. Lond. I. 152 (1846); in Bot. Reg.
XXXII. t. 37 (1846).
Rhododendron Thunbergii Planchon in FL des Serr. IX. 78 (1854).
Rhododendron Sieboldii minor Miquel in Ann. Mus. Ludg.-Bat. I. 33 (1863);
II. 164 (1865-66); Prol. FL Jap. 96 (1866-67).
Azalea Thunbergii Andre" in Belg. Hort. XV. 184 (1865).
Rhododendron indicum 5. obtusum Maximowicz in Mem. Acad. Sci. St. Peters-
bourg, ser. 7, XVI. No. 9, 40 (Rhodod. As. Or.) (1870). — Franchet & Sava-
tier, Enum. PL Jap. I. 292 (1875). — Matsumura, Ind. PL Jap. II. pt. 2,
461 (1912). — Bean, Trees and Shrubs Brit. Isles, II. 362 (1914). — Millais,
Rhodod. 193 (1917).
Azalea indica var. obtusa Render in Bailey, Cycl. Am. Hort. I. 122 (1900).
Rhododendron indicum Kirishima Millais, Rhodod. 193 (1917).
Rhododendron obtusum f . a. Honkirishima Komatsu in Tokyo Bot. Mag. XXXII.
[39] (1918).
Japan: Kyushu, prov. Osumi, Kirishima-jinza in a garden, said to
have come from Nishi-Kirishima, May 5, 1918, E. H. Wilson (No. 10,328) ;
prov. Hizen, Nagasaki, G. H. Langsdorff (Herb. Kew); same locality,
cultivated, 1863, C. Maximowicz (Herb. Kew, Herb. Gray); probably
same locality, von Siebold (Herb. Kew, Herb. Gray) ; Hondo, prov. KU,
May 3, 1886, H. Mayr-, prov. Musashi, Tokyo, cultivated, May 11,
1883 (Herb. Kew); same locality, May 12, 1904, K. Sakurai; cultivated,
Imperial Botanic Garden, Tokyo, March 29, 1914, E. H. Wilson (No.
6338) ; Yokohama, cultivated, Yokohama Nursery Company's grounds,
April 30, 1918, E. H. Wilson] Tokyo, Hilgendorf, ex Mus. Bot. Berol.
(Herb. Bur. Sci. Manila); prov. Rikuzen, Sendai, cultivated, May 26,
1888, U. Faurie (No. 2296, Herb. Kew); prov. Ugo, Akita, cultivated,
May 20, 1888, U. Faurie (No. 2132, Herb. Kew); Japan, without
locality, L. Savatier (Herb. Kew) ; without locality or collector's name,
ex Herb. Lugd.-Bat. (Herb. Kew, Herb. Gray as R. Sieboldii var. minor
Miquel).
30 THE AZALEAS OF THE OLD WOULD
It is always unfortunate when a selected or garden form has to do duty as the
type of a species. Such is the case here and the result is that the phylogenetic
order is inverted. Under the name of " Kirishima-tsutsuji " this plant has for cen-
turies been grown in Japanese gardens. By this name it is mentioned by Kaempfer
(Amoen. Exot. fasc. V. 849 [1712]), and his description is perfectly accurate. It is
a densely branched, twiggy plant, seldom more than a metre high and usually less,
and has small, scarlet, slightly scented flowers. Like all its relatives it is exceed-
ingly floriferous, and in April and early May, as Kaempfer says, the whole plant
appears blood red. In the autumn the leaves are lustrous and assume fine crimson
tints. The typical form has rather pointed corolla-lobes, as shown in Lindley's
figure, and this is the one so abundantly grown around Tokyo and Yokohama. At
Kurume in Kyushu this typical form is called " Hiryu." In the nursery district
round Osaka a form with rounded corolla-lobes is grown and sold as the Kirishima
Azalea, and it is this form that is grown in many western gardens as the real R. ob-
tusum Planch. At Kurume what appears to be this form is called " Hino-tsukasa."
A hose-in-hose form of the type is grown around Tokyo as "Yayegiri" and at
Kurume as " Yayehiryu." In addition a number of other slight forms are grown,
some of which are mentioned by Komatsu.
Like a number of other Japanese Azaleas this plant was first sent to western
gardens from China. Robert Fortune found it in the Pou-shan Azalea gardens
near Shanghai, and sent it to the Horticultural Society of London in 1844. For-
tune saw in the same Chinese garden the hose-in-hose (semi-double) form.
Fortune's introduction was named and figured by Lindley. The figure shows the
obovate, rounded, obtuse, mucronate summer leaves of the previous year and two
newly developed elliptic-lanceolate, acute spring leaves. Too little attention has
been paid to the fact that the red-flowered species of this section of Rhododendron
all have dimorphic leaves. Those which are formed immediately after the flowers
open are from lanceolate to ovate or elliptic in shape, acute, light green in color
and membraneous in texture. The "spring leaves" are followed by "summer
leaves," which are smaller, more or less obovate in shape, obtuse or rounded at the
apex, dark green and fairly coriaceous. These spring leaves are normally de-
ciduous and the summer leaves persistent, but climate exercises a strong in-
fluence,— the colder it is the more deciduous the leaves, and vice versa. In the
early summer when the larger spring leaves predominate, the plant presents a very
different appearance to what it does in late autumn or early spring when the small
obovate summer leaves only are present. The overlooking or inappreciation of
this simple fact has resulted in much confusion in the classification of the species
and forms.
Now as to the origin of R. obtusum. Its name " Kirishima Azalea " would appear
to suggest its original habitat. Working on this clue I visited Mt. Kirishima and
am convinced that the so-called " Kirishima Azalea " is simply a color form of the
Azalea so extraordinarily abundant on this mountain and hereunder referred to as
f . japonicum. Long ago some pilgrim to this sacred mountain took back a plant
or plants as a souvenir, planted it in his garden and from it (or them) has sprung
all the plants of this particular Azalea in gardens to-day. The Japanese have
always been fond of making pilgrimages to their sacred shrines and mountains,
and their houses and gardens are often museums filled with souvenirs of such
visits. The Azalea known as amoena is unquestionably of like origin, and so
too is " Hinodegiri," a more recent comer but an established favorite in our gardens.
Further, the race of Azaleas known as " Kurume Azaleas," with which we are
only just now becoming acquainted, is a garden product derived by long cultiva-
tion from the same common stock — the vari-colored Azalea of Mt. Kirishima,
f . japonicum Wils.
ENUMERATION OF THE SPECIES 31
A form with white flowers is: —
Rhododendron obtusum f . album Schneider, III. Handb. Laubholzk.
II. 506 (1911). — Render in Bailey, Stand. Cyd. Hort. V. 2944 (1916).
Azalea ramentacea Lindley in Jour. Hort. Soc. Lond. IV. 291, fig. (1849).
Rhododendron ramentaceum Planchon in Fl. des Serr. IX. 81 (1854); in Rev.
Hort. 1854, 65.
Azalea obtusa alba Mottet, Diet. Hort. Jard. I. 302 (1892-93).
Rhododendron (Azalea} Indicum obtusum album, Garden and Forest, IX. 394,
fig. 52 (1896). — Bean, Trees and Shrubs Brit. Isl. II. 362 (1914).—
Millais, Rhodod. 193 (1917).
Azalea indica var. obtusa f . alba Render in Bailey, Cyd. Am. Hort. I. 122
(1900).
Azalea amoena alba Moller's Deutsch. Gartn. Zeit. XVIII. 476, fig. (1903).
Cultivated : Hort. Holm Lea, Brookline, Mass.; Hort. Berckmans,
Augusta, Georgia, March 18, 1909, April 6, 1914, C. S. Sargent.
This is another of Fortune's introductions from China to the garden of the
Horticultural Society of London. It was received in May, 1846, from Hongkong,
and certainly from a garden (although this is not expressly stated) and doubt-
less of Japanese origin. It has the dense, twiggy habit characteristic of its class,
pure white flowers with a normal calyx and rather large leaves. In every essen-
tial respect it agrees with f. japonicum Wils., of which it is nothing but a selected,
cultivated form, as are A. obtusa, A. amoena, "Hinodegiri" and the "Kurume
Azaleas." Among the latter are several white-flowered forms with relatively large
leaves. Under f . japonicum the origin of this "obtusum" group of Azaleas is dis-
cussed, but I may add here that variants of f . japonicum having white flowers have
been found wild on Nishi-Kirishima. Such a plant is growing in a garden at the
foot of the mountain and from it I gathered specimens. I have been unable to
find out just when this plant was introduced into America but in all probability it
was very soon after its appearance in England. For more than sixty years it has
been cultivated in the Holm Lea collection and from there was sent by Professor
Sargent to England, where it appears that it had become lost, and to the Berck-
mans and to other gardens.
A form with a small corolla and long exserted stamens is: —
Rhododendron obtusum f. macrostemon Wilson, n. comb.
Rhododendron macrostemon Maximowicz in Mem. Acad. Sci. St. Petersbourg,
ser. 7, XVI. No. 9, 41, t. 3, figs. 15-20 (Rhodod. As. Or.) (1870).— Franchet
& Savatier, Enum. PL Jap. I. 292 (1875). — Okubo in Tokyo Bot. Mag.
IX. 40 (1895). — Schneider, III. Handb. Laubholzk. II. 507, fig. 332 h-k
(1911). — Millais, Rhodod. 205 (1917).
Rhododendron indicum var. macrostemon Okubo & Makino in Tokyo Bot.
Mag. XVI. 178 (1902). — Matsumura, Ind. PL Jap. II. pt. 2, 461 (1912).
Rhododendron Kaempferi var. macrostemon Makino in Jour. Jap. Bot. I. 18
(1917). — Komatsu in Tokyo Bot. Mag. XXXII. [43] (1918).
Japan : Hondo, prov. Musashi, Tokyo, cultivated, 1862, C. Maxi-
mowicz (Herb. Kew, co-type).
This garden plant is characterised by its small flowers, minute calyx, and long
exserted stamens, which are three times as long as the corolla. It is, however,
32 THE AZALEAS OF THE OLD WORLD
more a condition of than a distinct form. In all the forms of R. obtusum, including
the large flowered var. Kaempferi, the stamens are variable in length, and are in-
constant in this from year to year. In the wild f . japonicum and the cultivated
" Kurume Azaleas " the stamens are conspicuously variable in length. The same is
true of the/, multicolor. Besides the co-type cited above there is another Japanese
specimen in the Kew Herbarium from Maximowicz, collected by Tschonoski in
Shinano province, central Hondo, in 1864, and labelled, apparently in Maximo-
wicz's handwriting, " Rhod. indicum a. Kaempferi forma subalpina." This differs
only in having larger flowers than those of his R. macrostemon.
A well-known form with magenta-colored flowers is : —
Rhododendron obtusum f. amoenum Wilson, n. comb.
Azalea amoena Lindley in Paxton, Flow. Gard. III. 81, t. 89 (1852). — Hooker
in Bot. Mag. LXXIX. t. 4728 (1853). — Rev. Hort. 1854, 241, t. — Van
Houtte in Fl. des Serr. IX. 75, t. 885 (1854). — Hovey, Mag. Hort. XXII.
9 (1856); XXIII. 70 (1857); XXIV. 141 (1858).
Rhododendron amoenum Planchon in Fl. des Serr. IX. 80 (1854); in Rev. Hort.
1854, 64. — Bean, Trees and Shrubs Brit. Isl. II. 341 (1914).
Rhododendron Buergeri Miquel in Ann. Mus. Lugd.-Bat. I. 34 (1863); in II.
164 (1865-66); Prol. Fl Jap. 96 (1866-67).
Rhododendron indicum c. amoenum d. genuinum Maximowicz in Mem. Acad.
Sd. St. Petersburg, s6r. 7, XVI. No. 9, 41 (Rhodod. As. Or.) (1870).—
Franchet and Savatier, Enum. PL Jap. I. 292 (1875). — Matsumura, Ind.
PI. Jap. II. pt. 2, 461 (1912). — Millais, Rhodod. 193 (1917).
Rhododendron indicum e. amoenum b. normale Maximowicz in Mem. Acad. Sci.
St. Petersburg, se'r. 7, XVI. No. 9, 41 (Rhodod. As. Or.) (1870).
Rhododendron indicum c. amoenum c. Buergeri Maximowicz in Mem. Acad.
Sci. St. Petersburg, se>. 7, XVI. No. 9, 41 (Rhodod. As. Or.) (1870).
Azalea amoena Caldwelli Caldwell apud Van Geert, Icon. Azal. Ind. 45, 1. 17
(1882).
Azalea indica var. amoena Render in Bailey, Cycl. Am. Hort. I. 122 (1900).
Rhododendron Kaempferi var. amoenum Render in Sargent, Trees and Shrubs,
II. 30 (1907). — Schneider, III. Handb. Laubholzk. II. 505, fig. 332, f-g
(1911).
Rhododendron obtusum var. amoenum Render in Bailey, Stand. Cycl. Hort.
V. 2944 (1916). — Komatsu in Tokyo Bot. Mag. XXXII. 41 (1918).
Azalea amoena Hatsu-giri Millais, Rhodod. 113 (1917).
Japan: Kyushu, prov. Hizen, cultivated, Nagasaki, 1863, C.
Maximowicz (Herb. Kew, Herb. Gray). Hokkaido, prov. Oshima,
Hakodate, cultivated, 1861, C. Maximowicz (Herb. Kew as f. normale
Maxim.). Without locality, probably Nagasaki, ex Herb. Lugd.-
Bat. (Herb. Kew as R. Buergeri Miquel).
Cultivated: Hort. Standish (Herb. Kew, type of Bot. Mag. t.
4728). Arnold Arboretum, May 29, 1884, May 24, 1902 (Nos. 862-1,
862-2).
This Azalea, with its small, rich magenta-colored flowers, its small leaves and
dense, twiggy habit, is too well known to need further description. It was first
sent to England in 1850 or 1851 from Shanghai by Robert Fortune and was soon
recognized as the most hardy of its class. It is generally assumed to be of Chinese
ENUMERATION OF THE SPECIES 33
origin, but there is no evidence to support this view. On the contrary, I do not think
there can be any doubt whatever that it is a Japanese plant and merely a color
form of the Azalea so abundant on Nishi-Kirishima, Kyushu, hereunder de-
scribed as f . japonicum. Moreover it is simply one of a race of charming Azaleas
which for more than one hundred years have been grown and developed in the
city of Kurume in the southern island of Kyushu, Japan, and is now becoming
known as " Kurume Azaleas." The typical form of amoenum has hose-in-hose flowers
and is known at Kurume under the name of " Kochonomai"; it is considered the
hardiest of all. The single-flowered form, the f . normale of Maximowicz, is known
and more especially around Tokyo, as " Hatsu-giri." The peculiarity of the calyx
becoming petaloid and forming a hose-in-hose flower is common to the whole race
of " Kurume Azaleas " and is found in every one of the white and colored forms,
and by selection and vegetative propagation it becomes fixed.
The typical amoenum with hose-in-hose flowers was introduced into America
by C. M. Hovey, Boston, Mass., in 1855 and soon established itself as a favorite
exhibition plant. There are numerous named forms of this Azalea, and in 1879
Pynaert (Rev. Hort. Belg. V. 277), figures Azalea amoena "Mrs. Carmichael " and
mentions five others that were in commerce. In recent years, at least, amoenum
has been used in hybridizing with forms of R. Simsii and the result is a beautiful
race of small-flowered, hose-in-hose Azaleas of which the well-known " Hexe "
("Firefly" of American gardens) is a familiar example. Near Boston amoenum
is not entirely hardy but on Long Island and southward it is perfectly so.
The wild form of the species is: —
Rhododendron obtusum f. japonicum Wilson, n. comb.
Rhododendron indicum «. amoenum a. japonicum Maximowicz in Mem. Acad.
Sci. St. Petersburg, se>. 7, XVI. No. 9, 41 (Rhodod. As. Or.) (1870).
Rhododendron Kaempferi var. japonicum Render in Sargent, Trees and Shrubs,
II. 30 (1907). — Schneider, III. Handb. Laubholzk. II. 505 (1911).
Rhododendron indicum var. japonicum Makino in Tokyo Bot. Mag. XXII. 56
(1908).
Rhododendron kiusianum Makino in Tokyo Bot. Mag. XXVII. 174 (1914);
in Jour. Jap. Bot. I [173J fig. (1917). — Komatsu in Icon. PL Koisikav. II.
95, t. 132 (1915); in Tokyo Bot. Mag. XXXII [18] (1918).
Rhododendron amoenum var. japonicum Bean, Trees and Shrubs Brit. Isl.
II. 341 (1914). — Millais, Rhodod. 113 (1917). -^
Rhododendron obtusum Miyazawa in Tokyo Bot. Mag. XXII. [318] (1918),
not Planchon.
. , ^ ^^ ^
Japan: Kyushu, prov. Hizen, Wunzen (Mt. Onsen) near Naga-^-^- Vv ^.
saki, 1863, C. Maximowicz (Herb. Kew, Herb. Gray); prov. Osumi,
Kirishima-jinza, in a garden, October 1, 1918, E. H. Wilson (No.
10,957); Nishi-Kirishima, alt. 600-1600 m., May 5, 1918, E. H. +
Wilson (Nos. 10,329, 10,333); same locality, alt. 1300 m., March 10, ****^^ f^T
1914, E. H. Wilson (No. 6255); same locality, November 1, 1918,^****" + J*W
E. H. Wilson (Nos. 11,248, 11,250, 11,255 seeds only); same locality,
June 1, 1916, S. Kawagoe; same locality, May 18, 1917, Z. Tashiro; same
mountain, Makizono, May 4, 1918, B. Miyazawa; Kirishima-jinza,
cultivated, plant said to have come from Mt. Kirishima, May 5, 1918,
34 THE AZALEAS OF THE OLD WORLD
E. H. Wilson (Nos. 10,327, flowers white). Hondo, prov. Settsu,
cultivated round Osaka, May, 1918, E. H. Wilson (form " Hinode-
giri") ; prov. Musashi, cultivated, Hatagaya, Hort. Oishi, May, 1914,
E. H. Wilson (80 named forms of " Kurume Azaleas ")•
Cultivated: Hort. J. S. Ames, 1920 (10 forms of "Kurume
Azaleas"); Hort. Kew, May 17, 1909; Hort. Holm Lea, March, 1920
(50 forms "Kurume Azaleas").
This is the phylogenetic type of the race of small flowered Azaleas so plentiful
in Japan and of which amoena, obtusa, and "Hinodegiri" are perhaps the best
known in western gardens. It is especially abundant on the wind-swept slopes
of Nishi-Kirishima, an active volcano in south Kyushu. It is found above the
tree-level, growing among lava and in volcanic ashes with coarse grasses and mis-
cellaneous low shrubs. At its lowest altitudinal range the leaves are persistent,
but higher up they are deciduous. The plants are seldom a metre tall, more usually
less than half of this, and quite commonly they are prostrate or hug boulders
closely. The habit is normally dense and twiggy, but when sheltered a few strong
shoots develop and the plant becomes relatively tall and sparsely branched. The
leaves vary greatly in size according to altitude and exposure and are smallest on
the plants which annually shed their foliage. On an average plant the spring
leaves are oval to elliptic-ovate, from 1 to 2 cm. long and from 0.5 to 1 cm. wide,
but they may be smaller or larger. The upper surface is bright green and the
under usually pallid. The summer leaves are darker, more coriaceous and from
oblanceolate to obovate in shape, with the mucronate apex rounded or acute.
Normally the leaves are tufted at the ends of the twigs, but on free-growing shoots
they are scattered; both shoots and leaves are clad with appressed, pale gray to
yellowish, straight hairs. The flowers vary a little in size, in degree of fragrance,
and greatly in color; the most common shades are rosy mauve to magenta, but
salmon and salmon-red are plentiful; pink, scarlet and crimson are rather rare.
Plants bearing white flowers are occasionally found. It is very floriferous; each
twig terminates in a flower-bud, often in a cluster of from three to five, and from
each one to three flowers develop in the spring. • The bud-scales are dry, nowhere
glandular, and are ciliated with pale gray hairs. The calyx is usually well developed
with green, oval to nearly orbicular, ciliate lobes; sometimes it is quite small. The
corolla lobes may be rounded or pointed and the stamens may be shorter or longer
than the corolla; the anthers vary in color from pale yellow-brown to deep magenta,
this being correlated with the color of the flowers. The capsule is variable in size
and the calyx-lobes are persistent.
From the above facts is it apparent that this plant is responsive to varying
ecological conditions and that its extreme forms present a very different appear-
ance. This is indeed true, nevertheless this form is well marked and, except that
there is no definite demarkation between it and the variety Kaempferi, presents no
difficulty unless an attempt be made to subdivide it. This I find impossible to do,
and fortunately it is not necessary, since all the color forms have received names in
gardens and may be classed under the general title of " Kurume Azaleas," from
a town in Kyushu where much attention has been paid to their cultivation and
development.
The type of this form came from Mt. Onsen, a volcano not far from Nagasaki,
but I do not know whether it is plentiful there. It also grows on other Kyushu
mountains. On Kirishima it is abundant and when in flower forms sheets of color on
the bare or grass-clad, bleak slopes and is strikingly attractive. Mt. Kirishima, of
ENUMERATION OF THE SPECIES 35
which there are two principal peaks, Nishi and Higashi, is a sacred mountain cele-
brated in Japanese mythology. It was on Nishi-Kirishima that the god Ninigi,
grandson of the sun-goddess Amaterasu, alighted when he came down from heaven
to pave the way for the conquest of Japan. A bronze sword, fixed in the ground,
hilt upward, crowns the peak and is considered to be a relic of this divinity. To a
place so sacred pilgrimages have been made by the Japanese from time immemo-
rial. With their profound love for flowers some of the pilgrims would certainly
take back as a souvenir living plants of this charming Azalea. Naturally it was
named for the mountain, and in the course of time was distributed widely in the
gardens of Japan. It is easily understood that a plant bearing flowers of an un-
usual color would be that selected as a souvenir by the average pilgrim. It is such
forms that reached gardens first, and so we find the red obtusa the magenta amoena,
the white alba to be the earliest known. In the autumn of 1918 I collected a quan-
tity of seeds on Nishi-Kirishima for the Arnold Arboretum. These have been widely
distributed, and it will be interesting to watch the range of variation in the habit
foliage and flowers of resultant plants. I fear, however, that they will not prove
so hardy as the var. Kaempferi, but that they will find a welcome in gardens I am
quite sure.
On visiting Nishi-Kirishima, where between 650 and 1500 m. altitude this form
japonicum grows in great abundance, and after seeing the wide range of color among
the flowers, I am absolutely convinced that this Azalea is the wild parent of the
race known as " Kurume Azaleas." The plant ( R. obtusum Planch.) which, following
International Rules, has to do duty as type of this species, also belongs to this race,
and of it too there is a hose-in-hose form known as " Yayehiryu " in Kurume.
Another of these Azaleas which in recent years has become widely known is the
brilliant red-flowered " Hinodegiri." Curiously this form so abundant in Tokyo and
Osaka gardens is to-day not grown at Kurume. But good as the forms named
above are, they are surpassed by many hardly known in western gardens, and
in fact scarcely known in Japan outside of Kurume and a narrow circle of
enthusiasts. Millais in his Rhododendrons makes the first reference to the race
in a European publication. I first became acquainted with "Kurume Azaleas" in
1914, when at the invitation of Mr. H. Suzuki of the Yokohama Nursery Company
and a foremost Japanese horticulturist, I accompanied him on a visit to the nursery
district at Hatagaya, a few miles north of Tokyo. There, in the garden of Mr.
Oishi, I saw thousands of tiny plants bearing white and colored flowers of nearly
every hue. I secured a set of fragments and dried them for our herbarium, and
later, in 1916, at my suggestion Mr. John S. Ames, North Easton, Mass., pur-
chased a selection of living plants from Mr. Oishi's collection. These arrived in
the spring of 1917 and were the first " Kurume Azaleas " introduced into eastern North
America. In May, 1917, I saw in the Yokohama Nursery a few large plants of
" Kurume Azaleas," trained into umbrella-shape, in full flower and this decided me to
visit the place of their origin. This became possible in the spring of 1918 and I was
fortunate to have as a companion my friend Mr. H. Suzuki. Kurume is some 800
miles south by west from Tokyo and is quite an important city, but the fame of its
Azaleas is likely to make it better known in the near future. The Azaleas are
grown in a number of gardens and nurseries, but the oldest and best collection is
that of Mr. Kijiro Akashi. This fine old gardener has for more than forty years
devoted himself to the development of this race of Azaleas and has raised from
seeds and perpetuated by cuttings nearly all the forms in cultivation. Mr. Akashi
gave me the history of the race, and it seems that it originated about one hundred
years ago with a gentleman named Motozo Sakamoto, who lived at Kurume. The
parents came from sacred Mt. Kirishima, but whether brought from there by
Sakamoto himself or given to him by some pilgrim is uncertain. At any rate,
36 THE AZALEAS OF THE OLD WORLD
Sakamoto cultivated several kinds and raised and selected seedlings, including one
he named "Azuma-kagami," from which it is claimed all the pink-flowered forms
have descended. After the death of Mr. Sakamoto his collection passed into the
possession of Akashi with the result above stated. The original plant of " Azuma-
kagami " is still healthy, and I tried but without success to induce Mr. Akashi to
part with it. Japanese experts recognize by name more than 250 kinds of Kurume
Azaleas, but the differences are often infinitesimal. I made a selection of fifty kinds
in duplicate which the following year (1919) safely reached the Arnold Arboretum.
The two leading experts, Messers Akashi and Kuwano, at my suggestion selected
the following six as the pick of them all: — " Takasago " (pale pink, hose-in-hose),
" AzumaKagami" (deep pink, hose-in-hose), "Kirin" (deep rose shading to silvery
rose, hose-in-hose), "Kumo No Uye" (pure salmon), "Kurai No Himo" (car-
mine, hose-in-hose), "Kureno Yuki" (white, hose-in-hose). My companion and
I concurred, but had the number been twenty the task would have been much
easier.
To my mind the " Kurume Azaleas " are the loveliest of all Azaleas. The colors are
so pure and exquisite and of every hue and shade from white, pink and salmon to
scarlet, crimson and the richest magenta. Many of them are delicately fragrant.
The hose-in-hose forms have none of the ugly features of double flowers, but on the
contrary they are singularly attractive and the flowers last longer. The stamens,
always five, are straight, exserted or included and the anthers vary in color from
pale yellow-brown to blackish crimson; the color of the corolla and that of the
anthers being correlated. The plants are often trained as low standards with a
compact umbrella-shaped crown; less commonly they are dense and globose, or
open and irregular in form. They are extremely floriferous, and in season the blos-
soms often completely hide the leaves. The leaves are of course dimorphic, but
apart from this they vary considerably in size, in their shades of green, in their
autumn-coloring and in their degree of persistence. In a great measure these
variations are correlated with the color of the flowers, and experts in Japan can with
ease distinguish each variety by its foliage and general appearance. It is strange
that a race so rich in forms and of such decorative value should have remained un-
known to us until now. Yet the explanation is simple. Interior Kyushu is little
known to the western world, and even to those Japanese whose home is on the
other islands. The feudal system of government which until comparatively recently
obtained in Japan created and preserved this aloofness. Further, Kurume is
remote from the horticultural centres of Osaka and Yokohama, from whence we
have drawn the bulk of our garden plants and where a business is made of growing
for export. Nagasaki is much nearer, but in the days of Thunberg and Siebold,
Veitch, Maximowicz and Fortune intercommunication was difficult, and for for-
eigners impossible. And so it has resulted that the product of Sakamoto's hobby
richly developed by Akashi has remained hidden from the outside world until
now. During the last decade the fame of the Kurume Azaleas has reached Osaka,
Tokyo and other places, and growers have obtained stocks and are propagating
them apace. Unfortunately every grower and enthusiast names the plants accord-
ing to his fancy and the result in a few years will be chaos. And this is helped
by the fact that every slight sport or variant is kept and named and no attempt
at selection made. I do not see how it is possible to improve upon the strain
grown in Kurume unless yellow could be injected. What is needed is rigorous selec-
tion and the reduction of the named forms to fifty or less. In the past seedling
selection and preservation of sports by vegetative propagation have been the sole
means employed in the evolution of the race of "Kurume Azaleas," but now attempts
at hybridising them with the large flowered " Indian " and " ledifolia " types
are in progress. This may result in a new race, but whether it will be as lovely and
ENUMERATION OF THE SPECIES
37
fascinating as the present one is doubtful. In the matter of their origin Mr. Akashi
was careful to inform me that for purposes of policy he had not before set forth the
facts so clearly and that more or less distorted versions had appeared in print in
Japan. To test the story for ourselves Mr. Suzuki and I on leaving Kurume visited
and ascended Nishi-Kirishima and were convinced.
In the garden of Mr. Akashi I selected and obtained a double set of the under-
mentioned fifty varieties of these Azaleas which I consider the best, and these
safely reached the Arnold Arboretum on April 24, 1919. The names are those
of the originator, Akashi, and therefore authentic. The plants will be propa-
gated and distributed under these names and, owing to the reprehensible habit of
changing names by Japanese nurserymen, will probably remain the only set with
standard names in existence.
No. 1. SEIKAI flowers white, hose-in-hose
2. KURENO YUKI flowers white, hose-in-hose
3. SHIN SEIKAI flowers creamy white, hose-in-hose
4. YOROZUYO flowers white
5. NANI WAGATA flowers white, suffused with salmon-pink
6. TANCHO flowers flesh-color, hose-in-hose
7. HACHIKA TSUGI flowers white, suffused with lavender
8. IROHAYAMA . flowers white, margined with pale lavender
9. Hoo flowers white, tinged with pink
10. STJIYOHI flowers flesh-color
11. TAKASAGO flowers pale pink, the color of apple-blossoms
12. KASUMI GASEKI flowers pale pink
13. BIJINSUI flowers pale pink
14. ASAGASUMI flowers rose-pink, hose-in-hose
15. KIMIGAYO flowers pink
16. AZUMA KAGAMI flowers deep pink, hose-in-hose
17. OSARAKU flowers white, suffused and margined with
lavender
18. OTOME flowers blush pink
19. AYA KAMMURI flowers rose-color
20. SHINTOKI No HAGASANE . flowers rose, shading to pink, hose-in-hose
21. SAOTOME flowers rose-color
22. KIRIN flowers deep rose, shading to silvery rose
23. TAMAFUYO flowers white, striped peach-color
24. KIRITSUBO flowers rosy mauve
25. OMOINE flowers pale lavender
26. OINO MEZAME flowers deep rose-color
27. KATSURA No HANA . . . flowers rose-color
28. SHIN UTENA flowers pale salmon
29. KUMO No UYE flowers pure salmon
30. BENIFUDE flowers salmon
31. SUGA No ITO flowers pure pink
32. KASANE KAGARIBI .... flowers dull salmon-red
33. TSTJTA MOMIJI flowers bright red
34. SUETSUMU flowers crimson
35. FUDESUTE YAM A flowers light red
36. IMA SHOJO flowers bright red, hose-in-hose
37. RASHO MON flowers scarlet
38. WAKA KAYEDE flowers red
39. YAYEHIRYU flowers bright scarlet, hose-in-hose
38 THE AZALEAS OF THE OLD WORLD
40. KURAI No HIMO flowers carmine, hose-in-hose
41. AGEMAKI flowers carmine
^42. HINODEGIRI flowers bright crimson
43. AIOI flowers color of almond-blossoms, hose-in-
hose
44. SAKURA TSUKASA. . . . , flowers rosy mauve
45. TAMA No UTENA flowers pale salmon
46. GOSHO ZAKURA flowers white, striped peach-color
47. UKAMUSE flowers vermilion, hose-in-hose
48. HINODE No TAKA .... flowers crimson
49. OSARAKU SEEDLING . . . flowers white, suffused and margined with
lavender
50. HANA ASOBI flowers red
Rhododendron obtusum var. Kaempferi Wilson, n. comb.
Azalea indica Thunberg, Fl. Jap. 84 (1784), in part, not Linnaeus.
Rhododendron Kaempferi Planchon in Fl. des Serr. IX. 77 (1854); in Rev.
Hort. 1854. — Rehder in Sargent, Trees and Shrubs, II. 29, t. 113 (1907),
flowers here represented with more than 5 stamens; in Bailey, Stand. Cycl.
Hort. V. 2944, fig. 3393 (1916). — Schneider, III. Handb. Laubholzk. II.
505, fig. 331 g-k (1911). — Bean, Trees and Shrubs Brit. Isl. II. 363
(1914). — Millais, Rhodod. 197, fig. (1917). — Komatsu in Tokyo Bot. Mag.
XXXII. [16] (1918).
Rhododendron Sieboldii Miquel in Ann. Mus. Lugd.-Bat. I. 33 (1863), exclud-
ing varieties; in II. 164 (1865-66); Prol. Fl. Jap. 96 (1866-67).
Azalea Kaempferi Andre" in Belg. Hort. XV. 184 (1865).
Rhododendron indicum a. Kaempferi Maximowicz in Mem. Acad. Sci. St.
Petersburg, s6r. 7, XVI. No. 9, 38 (Rhodod. As. Or.) (1870). — Franchet
& Savatier, Enum. PI. Jap. I. 291 (1875). — Matsumura, PL Nikko, 71
(1894); Ind. PL Jap. II. pt. 2, 460 (1912). — Shirasawa, Icon. Ess. For.
Jap. II. t. 61, figs. 1-10 (1908).
Azalea Indica var. Kaempferi Rehder in Bailey, Cycl. Am. Hort. 1. 122 (1900) ;
in Holler's Deutsch. Gartn.-Zeit. XVII. 417, figs. (1902).
Rhododendron scabrum var. Kaempferi Nakai in Tokyo Bot. Mag. XXXIII.
208 (1919).
Rhododendron scabrum var. Kaempferi f. 2. latifolium Nakai in Tokyo Bot.
Mag. XXXIII. 209 (1919).
Rhododendron scabrum var. Kaempferi f. 3. tubiflorum Nakai in Tokyo Bot.
Mag. XXXIII. 209 (1919). Komatsu in Icon. Koisikav. IV. 7, t. 216 (1918).
Rhododendron scabrum var. Kaempferi f . 4. angustifolium Nakai in Tokyo Bot.
Mag. XXXIII. 209 (1919). Komatsu in Icon. Koisikav. IV. 31, t. 228 (1918).
Japan: Kyushu, prov. Osumi, Yaku-shima February 25, 1914,
E. H. Wilson (No. 6082); Mt. Kirishima, western slopes, alt. 1000-
1500 m., March 8, 1914, E. H. Wilson (No. 6228) ; lower slopes of Nishi-
Kirishima, alt. 600 m., May 5, 1918, E. H. Wilson (No. 10,334);
foothills round base of Nishi-Kirishima, sea-level to alt. 500 m., May
4, 1917, E. H. Wilson (Nos. 10,326, 10,330, 10,334); same general
locality, April 29, 1917, Z. Tashiro; prov. Satsuma, Kagoshima,
March 15, 1917, E. H. Wilson; same locality, May 6, 1918, E. H.
ENUMERATION OF THE SPECIES 39
Wilson (No. 10,343); Togo, March 14, 1914, E. H. Wilson (No. 6278);
prov. Hizen, Nagasaki, 1862, R. Oldham (Nos. 505, 507, 508, 607,
Herb. Kew, Herb. Gray); same locality, A. C. Maingay (Nos. 872,
882, Herb. Kew); prov. Buzen, Kokura, April 20, 1903, U. Faurie.
Shikoku, prov. Tosa, Osaki, June 5, 1889, K. Watanabe (Herb. Gray).
Hondo, prov. Yamaguchi, near Onoda, June 17, 1918, E. H. Wilson
(Nos. 10,379, 10,380, 10,381); between Habu and Asa, May 7, 1918,
E. H. Wilson (No. 10,368A); round Ajisa, May 17, 1917, E. H. Wil-
son (No. 8424); prov. Yamato, Yoshino, April 22, 1914, E. H. Wilson
(No. 6575); prov. Shinano, above Narai, alt. 1100 m., September 3,
1905, /. G. Jack; without precise locality, 1864, Tschonoski (Herb.
Kew); Togakushi-yama, July 9, 1884 (Herb. Kew); prov. Idzu,
Oshima, March 30, 1917, July, 1918, E. H. Wilson (No. 8200); prov.
Sagami, Hakone, May 12, 1918, E. H. Wilson (No. 10,365); Miya-
noshita, August 24, 1892, C. S. Sargent; Kamakura, May 2, 1914,
E. H. Wilson (No. 6610); prov. Musashi, Yokosuka, May, 1875,
H. N. Moseley (Herb. Kew); Yokohama, 1862, C. Maximowcz
(Herb. Kew); Mt. Takao, H. Takeda (No. 89, Herb. Kew); Mt.
Mitake, May 19, 1907, K. Sakurai; prov. Shimotsuke, between Nikko
and Lake Chuzenji, September 3, 1892, C. S. Sargent; in a garden at
Umagaeshi, near Nikko, alt. 1000 m., June 4, 1914, E. H. Wilson
(No. 6807); shores of Lake Chuzenji, November 3, 1892, C. S. Sar-
gent; Nikko region, alt. 100-1500 m., May 16, 1914, E. H. Wilson
(No. 6679); prov. Ugo, Akita, May 17, 1888, U. Faurie (No. 2128
Herb. Kew); Lake Towada, June 25, 1894, U. Faurie (No. 13,272);
prov. Mutsu, Shichi-nobe, June 15, 1886, U. Faurie (No. 661); prov.
unknown, Mt. Nagi, Mimasaka, May 8, 1903, S. Arimoto (Herb.
Gray); without locality, 1866-74, L. Savatier (Herb. Kew, Herb.
Bur. Sci. Manila). Hokkaido, prov. Oshima, Hakodate, C. Wright
(Herb. Kew, Herb. Gray); same locality, July, 1859, C. Wilford (No.
1017, Herb. Kew); same locality, 1861, M. Albrecht (Herb. Kew,
Herb. Gray); same locality, July 29, 1888, T. Tokubuchi; prov. Iburi,
Nobori-betsu, June 15, 1893, U. Faurie (No. 10,020, Herb. Kew);
Chitose, June 12, 1889, T. Tokubuchi; prov. Hidaka, T. Tokubuchi;
Samani-sando, June 19, 1884, K. Miyabe (Herb. Gray); prov. Ishi-
kari, Sapporo, July 29, 1888, May 8, 1895, T. Tokubuchi; same locality,
October, 1891, K. Miyabe; same locality, May 24, 1903, S. Arimoto
(Herb. Gray) ; ex Agricultural College, Sapporo, June 7, 1885.
Cultivated: Arnold Arboretum (Nos. 3690, 3690-1, 3690-3,
3690-5, 3697).
40 THE AZALEAS OF THE OLD WORLD
This is the Mountain or Hill Azalea (Yama-tsutsuji) of Japan, where it is abund-
ant from Yaku-shima in the extreme south to central Hokkaido in the north. Its
altitudinal range is from sea-level to about 1600 m., though north of the Nikko
region it is much less. In May and June by the wayside and on the hills and
mountain-slopes it is most conspicuous with its wealth of brilliant red flowers. It
grows among grasses and in thickets, also on the edge of forests and among the
undergrowth in thin woods, but it is a sun-loving plant and is seen to best advantage
in open thickets on mountain-slopes. The height is from 1 to 3 m., but averages
from 1 to 1.5 m., and according to situation it may be densely or laxly branched and
form either a broad or a narrow, twiggy bush. In the warmer parts of Japan all
the summer leaves and often some of the large spring leaves are persistent, but in
the colder parts they are both deciduous. The spring leaves vary in shape from
lanceolate or lanceolate-ovate to elliptic, and in size from 1.5 to 6 cm. in length
and from 0.8 to 3 cm. in width, and they may be either acute or obtuse; the summer
leaves are elliptic to obovate in shape, as is usual in the group to which this plant
belongs. The pubescence on the shoot, leaf, calyx, ovary and fruit varies in color
from pale gray to rufous. Typically the color of the flowers is red, usually bright
red, but it varies considerably and, excluding the forms to be mentioned later,
may be any shade from flesh-color to bright red. In size the flowers vary some-
what but average from 2.5 to 4 cm. across. The corolla-lobes are rounded or
pointed. The calyx is normally well-developed and the lobes are green, ciliate and
usually rounded, and from suborbicular to elliptic or ovate in shape, and from 2 to
8 mm. long; usually they are from 2 to 4 mm. long and occasionally they are scarcely
noticeable. The stamens may be included or exserted and this considerably affects
the appearance of the flowers; the anthers vary in color from pale yellow-brown to
blackish purple. The fruit is woody, erect, ovoid and from 0.6 to 1.5 cm. high, and
when open the valves are recurved for about one-third their length.
In its typical form this variety, with its relatively large clustered flowers each
with five stamens, cannot be confused with anything else, but there are interme-
diate forms which inextricably link it with R. obtusum. The extremes look widely
different, yet on analysis size alone remains, and in this there is every gradation
both among the leaves and flowers. The degree of persistence of the leaves, which
is dependent upon winter temperature and exposure, strongly affects the appearance
of the plants. The leaves, flowers, genital organs and fruit vary in size, and the
flowers, anthers and pubescence vary in color. Round the base of Nishi-Kirishima
the typical red-flowered var. Kaempferi is plentiful; on the middle and upper slopes
of the mountain the typical f . japonicum abounds. In my ascent of this moun-
tain and after exhausting every means I could think of I failed completely to dis-
cover where one variety ended and the other began. The transition was both
gradual and complete. At my request my colleague, Alfred Rehder, has critically
examined the mass of material in our possession and is in complete agreement as
to the specific identity here set forth. I confess that I should much prefer to keep
Kaempfer's Azalea as a species distinct from R. obtusum, but the facts as I inter-
pret them will not permit of this. Whether var. Kaempferi or the f . japonicum
is best entitled to be considered the phylogenetic type of the species is difficult to
determine, but the first named is much more widely distributed, and north of
Hamamatsu, in prov. Totomi, central Hondo, is the only representative of the
species.
Kaempfer's Azalea was first introduced to the Occident by Professor Sargent,
who sent seeds of it from the Nikko region and elsewhere in Japan to the Arnold
Arboretum in the autumn of 1892, where plants flowered in May, 1897. It has
proved both hardy and amenable to cultivation here, and in late May and early
June of each year flowers abundantly, producing most vivid and spectacular floral
ENUMERATION OF THE SPECIES 41
displays. The flowers last longer and are seen to best advantage when growing in
the partial shade of conifers and other evergreen plants. In full sun the flowers bleach
and fade more quickly. In the Arnold Arboretum the leaves are quite deciduous.
This Azalea is the only kind with red flowers hardy in this Arboretum and is one
of the most valuable exotic flowering plants ever brought into cultivation in eastern
North America.
A form with white flowers is : —
Rhododendron obtusum var. Eaempf eri f . albiflorum Wilson, n. name.
Rhododendron Kaempferi f. album Nakai in Tokyo Bot. Mag. XXIX. [261]
(1915).
Unknown to me and described in Japanese only. Presumably normal except
for its white flowers but possibly the same as the f . monstrosum Wilson.
A form with vari-colored flowers is : —
Rhododendron obtusum var. Kaempferi f. multicolor Wilson, n. f.
Japan : Hondo, prov. Yamaguchi, round Ajisu, May 17, 1917,
E. H. Wilson (No. 8420 type, 8421, 8422, 8423, 8419, 8418, 9417,
8416); same locality, September 28, 1918, E. H. Wilson (No. 10,959
seeds only); between Habu and Asa, May 7, 1918, E. H. Wilson
(No. 10,368); prov. Mikawa, round Futagawa, May 9, 1918, E. H.
Wilson (No. 10,347).
This form differs from Kaempfer's Azalea in its vari-colored flowers which
range from pale pink, salmon or mauve to purple and magenta. Some of the shades
are exquisite and scarcely two companion bushes have flowers of identical color.
In size the flowers vary slightly, and those of No. 10,368 are from 1.5 to 2.5 cm.
across and no larger than those of some plants of the f . japonicum. In fact this
new form is the link connecting the var. Kaempferi with the wild f . japonicum.
In certain localities this multi-colored form is abundant, as in those cited, and
also round Tajimi, near the city of Nagoya, in province Owari. Curiously, where
this form is plentiful the typical red-flowered Kaempferi is entirely absent or nearly
so. The soil around Ajisu is rotten granite, round Tajimi and Futagawa gravel
and brick clay; on the same formation and in the same general neighborhood
Kaempfer's Azalea grows in great plenty. On Nishi-Kirishima, where the many-
colored f . japonicum and the typical var. Kaempferi both grow, the soil is vol-
canic ashes and detritus. It is plain, therefore, that soil has nothing to do with the
variation in the color of the flowers, neither has altitude nor exposure. The cause
would appear to be innate and not due to external conditions.
I collected much seed of this new form from the neighborhood of Ajisu, and this
has been distributed in England and in this country by the Arnold Arboretum, and
many plants have been raised. If it should prove hardy this form may prove the
forerunner of a new race of welcome colors among hardy Azaleas.
A form with double flowers is: —
Rhododendron obtusum var. Kaempferi f . plenum Wilson, n. comb.
Rhododendron Kaempferi var. plenum Nakai in Tokyo Bot. Mag. XXIX.
[261] (1915).
42 THE AZALEAS OF THE OLD WORLD
Japan: Kyushu, prov. Chikugo, Koradai, near Kurume, April,
1918, K. Akashi; without locality, May, 1918, B. Miyazawa.
In this plant the calyx is normal but the stamens and pistil are petaloid. Aka-
shi's specimen has rather small flowers salmon-red in color and is from a sponta-
neous plant. Miyazawa's is in size and color typical Kaempferi with double flowers.
He told me this was also from a wild plant.
A form with petaloid calyx forming hose-in-hose flowers and which
also has been found wild is: —
Rhododendron obtusum var. Kaempferi f. Komatsui Wilson,
n. comb.
Rhododendron Kaempferi var. Komatsui Nakai in Tokyo Bot. Mag. XXIX.
[261] (1915).
A form with monstrous flowers may be designated: —
Rhododendron obtusum var. Kaempferi f. monstrosum Wilson,
n. f.
Korea: prov. Keiki, cultivated, said to have come from Japan,
Agricultural Experimental Station, Suigen, May 24, 1917, E. H.
Wilson (No. 8482).
In this curious plant the corolla is white and has a petaloid calyx, the pistil is
abnormal and in most flowers is changed to a staminode, the stigma being changed
to a swollen, abortive anther which is often conspicuously aristate. The flowers
though hose-in-hose are as large as those of ordinary Kaempferi. Possibly this is
the same as Nakai's f . album.
A form with abortive or nearly abortive corolla is: —
Rhododendron obtusum var. Kaempferi f. cryptopetalum Wilson,
n. comb.
Rhododendron ledifolium S. cryptopetalum Maximowicz in Mem. Acad. Sci.
St. Petersburg, ser. 7, XVI. No. 9, 36 (Rhodod. As. Or.) (1870). — Matsu-
mura, Ind. PL Jap. II. pt. 2, 462 (1912).
Rhododendron Kaempferi f . f . Kinshibe Komatsu in Tokyo Bot. Mag. XXXII.
[43] (1918).
Japan: Hondo, prov. Kawachi, Yamomoto, cultivated, May 8,
1918, E. H. Wilson; prov. Musashi, Hatagaya, cultivated, April 29,
1914, E. H. Wilson (No. 6593).
This is a monstrous form long cultivated in Japanese gardens under the name
of " Kinshibe- tsutsuji." The corolla may be entirely suppressed or represented by
from 1 to 5 deeply laciniate, strap-shaped lobes. The stamens vary from 5 to 10
(usually 7 to 10) ; the filaments are variable in length, often curled, bright crimson
in color, and may be either normal in shape or slightly flattened and petaloid; the
anthers are yellow. It has no garden value, being simply a curiosity. As to its
specific identity there can be no question, and I am at a loss to understand why
Maximowicz referred it to R. ledifolium (R. mucronatum G. Don).
ENUMERATION OF THE SPECIES 43
A form with purple flowers and from 5 to 10 stamens is: —
Rhododendron obtusum var. Kaempferi f. mikawanum Wilson,
n. comb.
Rhododendron indicum var. mikawanum Makino in Tokyo Bot. Mag. XXIII.
251 (1909).
Rhododendron Kaempferi var. mikawanum Makino in Jour. Jap. Bot. I. 18
(1917). — Komatsu in Tokyo Bot. Mag. XXXII. [371 (1918).
Rhododendron purpureum Komatsu in Tokyo Bot. Mag. XXXII. [161 (1918).
Rhododendron poukhanense Komatsu I. c. [12] (1918), as to the Japanese plant,
not LeVeille".
Rhododendron poukhanense f. obtusifolium Komatsu I. c. [37] (1918).
Rhododendron poukhanense f. acutifolium Komatsu I. c. [38] (1918).
Rhododendron scabrum Nakai in Tokyo Bot. Mag. XXXIII. 207 (1919), not
G. Don.
Rhododendron scabrum var. Kaempferi, f. 1. purpureum Nakai I. c. 208.
Japan : Hondo, prov. Suruga, near Ashitake-yama, lower slopes of
Mt. Fuji, June 20, 1918, H . Suzuki; prov. Musashi, Ome, near Tokyo,
May 31, 1918, E. H. Wilson.
This is a form of the common Mountain Azalea of Japan having purple flowers
and from 5 to 10 stamens. It is found here and there mixed with the type and is
occasionally cultivated, being known as the " Murasaki Yama-tsutsuji " (Purple
Hill Azalea). It is in cultivation in the Arnold Arboretum from plants I brought
from Japan in the spring of 1919. The increase in the number of stamens is in-
teresting, and is another instance of the extraordinary range of variation which
obtains in R. obtusum. In Tokyo I saw specimens from Hangno which Komatsu
refers to R. poukhanense, but it is not that species and I could find no character by
which to separate them from Makino' s variety. The material was collected on the
Chichibu Mountains in the western part of Musashi province. It has flowers in
pairs, red-purple in color, with dark purple anthers; the leaves are rather long,
lanceolate and glabrescent, and the pedicels and calyx are clothed with gray pubes-
cence. Komatsu's R. purpureum is based on a specimen collected in Yumato prov-
ince. It has the foliage of typical var. Kaempferi, pale rose-purple colored flowers
each with from 7 to 10 stamens; the calyx-lobes are lanceolate, acuminate and erose.
Nakai in the Tokyo Bot. Mag. (XXXIII. 207 [1919]) identified this plant with
R. scabrum G. Don. I do not understand how he arrived at this conclusion unless
he was guided solely by the color of the flowers. This f. mikawanum never has
flowers 3 inches in diameter, which is the size given by G. Don, neither are the
leaves coriaceous. It seems to me that the plant described by G. Don as R. scabrum
is that which Miquel later described as R. sublanceolatum; from the description I
do not see how it can have anything to do with R. obtusum var. Kaempferi or any
of its forms.
A hybrid race with richly colored flowers of small to medium
size is : —
X Rhododendron Sanderi Wilson, n. hyb.
Rhododendron Simsii " Garnet " x R. obtusum Planchon.
This is an interesting and valuable race that has been raised and developed at
Holm Lea, Brookline, the home of Professor C. S. Sargent. About thirty-five years
44 THE AZALEAS OF THE OLD WORLD
ago the gardener, Charles Sander, collected seeds from the Holm Lea collection of
"Indian Azaleas' ' and from them raised many plants. Among these when they flowered
were two of dwarf, compact habit which produced relatively small flowers (3 cm.
diam.) carmine-red or crimson-lake in color. In the Holm Lea collection was the
well-known "Indian Azalea Decora" of European origin and introduced into the
garden of Marshall P. Wilder, Dorchester, Mass., about 1847. It is highly probable
that this was the parent of the two Azaleas above mentioned. The best of these
two Sander named " Garnet." This he crossed with an unknown Azalea having
small red flowers obtained from M. Atkinson, gardener for Mr. John L. Gard-
ner, Brookline, Mass., which to-day Sander thinks was R. dbtusum Planch. After
a close study of the race I think this conclusion is correct. The best of the hybrids
from the above parents were crossed with R. dbtusum f . album Schneid. and gave
rise to forms with rose-pink flowers. In more recent years the well-known " Hino-
degiri " has been used with excellent results. The outcome of some three decades
of hybridising, selecting and recrossing is a race of beautiful Azaleas of compact
twiggy habit with flowers from 2.5 to 4.5 cm. in diameter in varying shades of
rose-pink, salmon, red, scarlet and fiery crimson. Among the scarlet and crimsons
are deeper and richer shades than I have seen among any of the Azaleas of China
and Japan. The influence of R. Simsii forms is seen in the number of stamens,
which varies from 5 to 10 and is inconstant on the same individual; also in the
size of the flowers and in the ease with which the plants may be forced into blossom
during the winter and early spring months. Some of the forms have flowers no
larger than those of R. obtusum, though in the majority the flowers exceed in size
those of that plant. The race is singularly attractive and highly ornamental, and
it needs no expert knowledge to predict for X R. Sanderi a great future. Among
the best forms are " Suzuki," scarlet maroon, " Hebe," white with rose-red stripe,
" Hermione," deep salmon-red, " Ruby " crimson maroon, " Uncas," dark scarlet,
"Helena," rose-pink, "Hilda Hedlund," deep pink, "Holm Lea," crimson-
maroon, " Vulcan," salmon-red, " Natalie," salmon, " Muriel," rose-red, " Alice
Sargent," bright salmon-red, " Rose Queen," deep rose, " Havemeyer," rose-red,
" Brookline," carmine, " Venus," cerise, " Jupiter," fiery-red, " Mars," intense
scarlet, "Vivid," scarlet. To this group must be referred the highly appre-
ciated and well-known Azalea "Hexe"1 or "Firefly" of American gardens, which
is a hybrid between R. obtusum f. amoenum and R. Simsii "Due de Nassau."
This favorite Azalea with rich red, hose-in-hose flowers was raised by Otto
Forster, Lebenhof, near Scheibbs, Lower Austria, about 1885, and was first exten-
sively cultivated round Dresden. At first it was not particularly esteemed and was
used as a stock on which to graft the ordinary "Indian Azaleas" of commerce;
later it became one of the most popular varieties, and before the Great War was
imported in hundreds of thousands into this country for decorative purposes. It
roots freely from cuttings and flowers profusely when quite small. One of its
parents, Azalea " Due de Nassau," is an old variety, having been exhibited in
London in June, 1862, by Charles Turner of Slough. There are several other
hose-in-hose Azaleas of much the same parentage as " Hexe." One of these,
" Vuylestekeana," has been crossed at Holm Lea with " Flambeau," a French vari-
ety, with crimson-maroon flowers of medium size. The result is a race with relati-
vely large (4 to 6 cm. diam.), hose-in-hose flowers varying in color from intense
scarlet to crimson-maroon, and perhaps the most highly colored of all Azaleas.
1 Azalea indica (Hexe) Ad. Vanden Heede in Rev. Hort. Belg. XXXI. 49, t.
(1905).
Azalea Hexe Hort. ex W. Watson, Rhodod. and Azaleas, 67 (1911).
Rhododendron indicum Hexe Millais, Rhodod. 193 (1917).
ENUMERATION OF THE SPECIES 45
Rhododendron Simsii Planchon in FL des Serr. IX. 78 (1854) ; in
Rev. Hort. 1854, 47. — Schneider, III. Handb. Laubholzk. II. 506,
figs. 331 1-m, 332 a-d (1911). — Render in Bailey, Stand. Cycl. Hort.
V. 2944 (1916).
Azalea indica Alton, Hort. Kew, ed. 2, 318 (1810), as to the plant, not
Linnaeus. — Sims in Bot. Mag. XXXVI. t. 1480 (1812). — Bentham, Fl.
Hongk. 201 (1861), as to the Hongkong plant.
Azalea indica a. punicea Sweet, Hort. Brit. 264 (1827).
Rhododendron indicum var. ignescens Sweet, Brit. Flow. Gard. ser. 2, II. t. 128
(1832). — Render & Wilson in Sargent, PL Wilson. II. 547 (1913).
Rhododendron indicum a. puniceum Sweet in Brit. Flow. Gard. ser. 2, II. sub.
t. 128 (1832).
Azalea indica ignescens Hovey, Mag. Hort. III. 72 (1837).
Rhododendron Calleryi Planchon in FL des Serr. IX. 81 (1854); in Rev. Hort.
1854, 66.
Rhododendron indicum /3. Simsii Maxim owicz in Mem. Acad. Sci. St. Peters-
bourg, ser. 7, XVI. No. 9, 38 (Rhodod. As. Or.) (1870). — Franchet in
Nouv. Arch. Mus. Paris, ser. 2, VI. 77 (1883); PL David I. 97 (1884); in
Bull. Soc. Bot. France, XXXIII. 235 (1886).
Rhododendron indicum Hemsley in Jour. Linn. Soc. XXVI. 25 (1889), as to
the Chinese plant, not Sweet. — Diels in Bot. Jahrb. XXIX. 514 (1900) ;
in Notes Bot. Gard. Edinburgh, VII. 392 (PL Chin. Forrest.) (1913). — Pam-
panini in Nuov. Giorn. Bot. Ital. n. ser. XVIII. 131 (1911). — W. Watson,
Rhodod. & Azaleas, 79 (1911), in part. — Dunn & Tutcher in Kew Bull.
Misc. Inform, add. ser. X. 155 (FL Kwangtung and Hongk.) (1914). —
Millais, Rhodod. 189 (1917), in part.
Azales indica var. Simsii Rehder in Bailey, Cycl. Am. Hort. I. 122 (1900).
Rhododendron indicum var. Matsumura in Tokyo Bot. Mag. XIV. 69 (1900).
Rhododendron indicum var. Tamurai Makino in Tokyo Bot. Mag. XVIII.
102, fig. (1904).
Rhododendron indicum 7. macranthum subvar. genuinum forma Tamurai Ma-
kino in Tokyo Bot. Mag. XXIV. 77 (1910).
Rhododendron indicum var. formosanum Hayata, Icon. PL Formos. III. 134
(1913). — Kanehira, Formos. Trees, 321, fig. 9 (1917).
China: Hongkong, Happy Valley, November 5, 1903, C. S. Sar-
gent; without locality, /. G. Champion (Nos. 122, 123, Herb. Kew,
Herb. Gray) ; without locality, C. Wright (No. 195, Herb. Gray, Herb.
Kew); April 28, 1914, Mary Strong Clemens (No. 4261, Herb. Bur.
Sci. Manila). Kwantung, Canton, March 10, 1835, S. W. Williams
(Herb. Gray); same locality, October 27-30, 1916, March 20, 1917,
C. 0. Levine (No. 438, 599, Herb. Bur. Sci. Manila); Shiuchow,
April, 1919, To Rang P'eng (No. 2761, Herb. Bur. Sci. Manila).
Chekiang, Pootoo Island, E. Faber; Ningpo, Ning-kan-jou, April 15,
1877, W. Hancock (No. 32, Herb. Kew); Mokan-shan, alt. 500 m.
August 3, 1915, F. N. Meyer (No. 1607); without locality, 1845,
R. Fortune (Nos. 72, 152, 153, Herb. Kew, Herb. Gray); hills near
Taihu Lake, April, 1881, W. R. Carles. Kiangsu, near Shanghai,
46 THE AZALEAS OF THE OLD WORLD
1915, D. Macgregor. Kiangsi, Killing, alt. 1600 m., July 28, 1907,
E. H. Wilson (No. 1682); same locality, 1873, G. Shearer (Herb.
Kew). Hunan, Yoku-shan, alt. 70-300 m., February 21, 1918, Dr.
Handel-Mazzetti (No. 480). Hupeh, north and south of Ichang, alt.
30-1300 m., May and November, 1907, E. H. Wilson (No. 3474};
same locality, A. Henry (Nos. 782, 1160, Herb. Kew, Herb. Gray);
Changyang Hsien, thickets, alt. 1300 m., May and November, 1907,
E. H. Wilson (No. 3472) : Changlo Hsien, cliffs, alt. 600-1300 m.,
May, 1907, E. H. Wilson (No. 3472a); Patung Hsien, A. Henry
(No. 1416, Herb. Kew); Nanto and mountains to northward, A.
Henry (No. 3194, Herb. Kew); Hsing-shan Hsien, alt. 1000-1800 m.,
May 14, December, 1907, E.JI. Wilson (No. 56JT): " Kao-hien-scian,"
alt. 800 m., May, 1907, C. Silvestri. Szech'uan, Chungking, 1885,
F. S. A. Bourne (Herb. Kew); Kiating Fu, alt. 300-800 m., May,
1908, E. H. Wilson (No. 3475); Mt. Omei, May, 1904, E. H. Wilson
(Veitch Exped. No. 5143); without locality, A. von Rosthorn (No.
2148); Yunnan or Kueichou, 1911, A. Hosie (Herb. Kew). Yunnan,
Menztsze, alt. 1500-2000 m., A. Henry (Nos. 99QQb. 99QJT, 9900e,
Herb. Kew, Herb. Bur. Sci. Manila); same locality, alt. 1600-2300 m.,
April, 1893, W. Hancock (No. 155, Herb. Kew); Mile, A. Henry
(No. 9900d); " Momyen," June 3, 1868, D. J. Anderson (Herb. Kew);
near Tali Fu, Tsang-chan, alt. 2500 m., J. M. Delavay (No. 1122,
Herb. Kew); Tali Fu, alt. 2200-2600 m., cultivated, G. Forrest (No.
4173); " Ho-yeh-shui," north end of Lichiang Valley, alt. 2900 m.,
cultivated by Mossoo natives, May, 1906, G. Forrest (No. _228fc Herb.
Kew); without locality, G. Forrest (Nos. T832. 11.824) : i91(T R. P.
Maire (Nos. 3713, 3775, Herb. Bur. Sci. Manila).*" ~£»U,
Formosa: prov. Koshun, South Cape, Schmuser ex A. Henry
(No. 588 in part, Herb. Kew).
Cultivated: " Jardin du Luxembourg, Orangerie, 14 avril, 1822,
27 avril, 1823 " ex Herb. J. Gay (Herb. Kew).
This species grows in all the temperate parts of China and in south Formosa,
and a variety (eriocarpum Wils.) on the Kawanabe Islands off Liukiu Oshima, but it
has not been found in Japan or Korea. It is particularly abundant in the area of
the Yangtsze Valley from near Ningpo to Mt. Omei in the far west. Hancock,
on a specimen, states that " the Ningpo hills are absolutely crimson in places with
this shrub "; the same is true of the Lushan hills round Kiukiang and of the region
north and south of Ichang. It delights in rocky places, preferably cliffs, thin dry
woods and thickets, blossoms profusely, and its wealth of red flowers makes it one
of the most conspicuous of all shrubs. The habit is twiggy and much-branched
with a maximum height of three metres, but averaging about half this height.
The leaves are variable in size and with the shoots are clothed with appressed,
ENUMERATION OF THE SPECIES 47
strigose, gray to shining brown hairs. At low altitudes the leaves are compara-
tively large, from lanceolate to ovate-elliptic, and are all persistent; at its upper
altitudinal limit the leaves are much reduced in size, and nearly all fall off in the
late autumn. The leaves immediately below the winterbuds are small, relatively
thick, obovate to oblanceolate and more persistent than the other form of leaves.
The flowers are clustered, from two to six together, at the end of the shoots and
all I have seen are fairly uniform in color. The corolla is broad-funnel shape,
varying in color from rose-red through bright to dark red. The calyx varies from
an inconspicuous rim to a length of 5 mm.; the stamens are normally ten, rarely
eight, never fewer, as long or nearly as long as the corolla but shorter than the
style. In central China it is generally known as the " Yin-shan-hung." Millais
says that Forrest states under Nos. 4173, 4173a, from plants cultivated by Chinese
in the Tali Valley, that the color of the flowers is " rose to white." In China I
have never seen wild an albino of this species; Forrest's No. 4173 in Herb. Kew is
described as having rose-colored flowers. The Formosan specimen cited from
A. Henry in Herb. Kew represents Hayata's var. formosanum, the type of which
I have seen in Tokyo. It is indistinguishable from typical R. Simsii so abundant
in China, but in Formosa known only from the extreme southern end of the island.
For nearly a century and a quarter this plant has usurped the name indicum,
and in books is almost hopelessly confused with the true R. indicum Sweet, with R.
obtusum Planchon and its varieties, and with R. scabrum G. Don (R.sublanceolatum
Miquel). The first mention of the Chinese plant I can find is in Macartney's
Embassy to China, II. 524 (1797), where Azalea indica is recorded as collected
in the provinces of Kiangsi and Canton (Kwangtung) in 1793. In all probability
it is the Chinese species that was introduced into Kew " by the Hon. Court of
Directors of the East India Company " in the ship " Cuffnels," Captain Wellbank
(Aiton, HorL Kew, ed. 2. 318 [1810]), though Aiton's description is of the true
R. indicum Sweet. Sims was the first to figure the Chinese species (Bot. Mag,
t. 1480 [1812]) under the erroneous name of Azalea indica, and states that it was a
rare plant in England and that the only one that had flowered was in the collection
of James Vere, Esq. In the Kew Herbarium there are two specimens from the
Jardin du Luxembourg collected in 1822 and 1823. These are the oldest cultivated
specimens I have seen. Sweet in 1832 gave it a varietal name, and says that the
plant was imported in the East India Company's ship " Orwell " from China by
Mr. Tate. This Mr. Tate was a nurseryman in Sloane Square, London, and the
master of the ship " Orwell " was Captain Farrer, who brought a number of
Chinese plants including other Azaleas to England and handed them over to
Tate. In Braam's Icones plantarum, issued in 1818, there is a figure (t. 27) of a
red-flowered Azalea. The drawing is very crude and, while it probably is meant
for R. Simsii, it might represent any Azalea with red flowers.
The Chinese Azalea appears to have remained rare in the Occident for several
decades. In 1837, under the name of Azalea indica ignescens, it was cultivated in
America by Marshall P. Wilder, Dorchester, Mass. Fortune, from 1843 to 1856,
introduced into England from Chinese gardens many Azaleas of different kinds,
and these gave great impetus to the cultivation of these ornamental plants. The
so-called " Indian Azaleas " of western gardens have been originated almost en-
tirely from R. Simsii since>about 1850, chiefly in Belgium, but some in France
and others in Germany.
There is a very considerable literature on "Indian Azaleas" and at least one
illustrated book (Iconographie Azalees de L'Inde by Auguste van Geert, published
in 1882). Planchon (in Fl. des Serr. IX. 77 [1854]) gives a brief history of them,
and enumerates varieties in the collections of M. Margottin, M. Delessert, and
M. Michel. Some of them were forms of the true R. indicum, others of R. phoe-
48 THE AZALEAS OF THE OLD WORLD
niceum, and a few of R. Simsii; several are recorded as presumed hybrids between
R. phoeniceum and R. ledifolium (R. mucronatum G. Don) and between R. phoeni-
ceum and R. Danielsianum (R. indicum Sweet) but such hybrids are unknown
to-day and probably never existed. In La Belgique Horticole for 1865 (XV.
pp. 174-192), there is an excellent article by M. Edouard Andre with a list of vari-
eties and the names of the originators. In the various volumes of Flore des
Serres are many colored figures and notes chiefly by Louis van Houtte. In fact in
all garden periodicals from about 1850 on, there are many references and figures of
these plants. However, scientific exactness is wanting and much of their early
beginnings is obscure. As far as I can discover the introduction into England of
the striped-flowered Azalea vittata by Fortune in 1850 or 1851 led to the raising of
seedlings. Further impetus was given by the advent the same years of A. vittata
Bealii with red and white striped flowers. Many of the best varieties are branch
sports perpetuated by grafting. From the crossing of red and white flowered varie-
ties many variegated forms have originated. One of the most successful breeders
of " Indian Azaleas " of commerce was Mr. Joseph Vervaene of Ghent, whose work is
fittingly commemorated by the lovely Azaleas " Vervaeniana," and " Vervaeniana
alba." Other names immutably connected with the raising and perfecting of the
"Indian Azaleas" of commerce are Messers Knight & Perry, Ivery and Rollisson
in England; L. Eeckhaute, Haerens, Van Houtte, Van Geert, A. Verschaffelt,
J. de Kneep and Van der Cruyssen in Belgium; Lesebe, Truffaut, H. de May and
Mabire in France; Messers Schulz, E. Liebig, Seidel and Rose in Germany.
The varieties are legion, and each year adds materially to the number. All the
modern ones have been raised in Belgium or Germany, where they are cultivated
by the millions and exported to almost all parts of the world. Prior to 1914 more
than two and a half million plants were annually exported from Belgium alone.
In Germany a Eurhododendron (Cunningham's White) is much used as a stock
for these " Indian Azaleas," but not in Belgium, where R. phoeniceum and its f . con-
cinnum are chiefly so employed. According to J. Breck (hi The Horticulturist, I.
512 [1847]), Marshall P. Wilder imported from Germany by way of England and
cultivated in his garden in Dorchester, Mass., in 1847, Azalea "Optima" with dark
scarlet flowers, Azalea "Prince Albert" with scarlet flowers, and Azalea "Alba
Insignis" with large white flowers. The first two were undoubtedly derivatives of
R. Simsii and representatives of the " Indian Azaleas " of to-day, and the first intro-
duced into America so far as I can discover. The third was probably a form of
R. mucronatum. Hovey (Mag. Hart. XIV. 284 [1848]) records that on May 13, 1848,
Marshall P. Wilder exhibited before the Massachusetts Horticultural Society
Azalea " Decora," another Indian Azalea. A plant of this was acquired by Ignatius
Sargent, and its descendants are still in the Holm Lea collection.
Among the typical large-flowered forms of " Indian Azaleas " of to-day I can de-
tect no influence of any species other than R. Simsii, though without question R.
phoeniceum and its forms have been used. Those with smaller flowers, especially
the hose-in-hose kinds like " Hexe " and " Vuylstekeana," are without doubt
hybrids between forms of R. Simsii and R. obtusum f . amoenum. It is probable
also that typical R. obtusum has been employed. R. mucronatum and numerous
named forms of it are loosely designated Azalea indica, but in the evolution of the
"Indian Azalea" of present-day gardens neither this species nor the true A. indica
of Linnaeus have had any part.
Rhododendron Simsii var. vittatum Wilson, n. comb.
Azalea vittata Fortune, Tea Districts of China, 330 (1852).
Azalea indica vittata Van Houtte in Fl. des Serr. IX. t. 886 (1854). — Millais,
Rhodod. 259 (1917).
ENUMERATION OF THE SPECIES 49
Azalea indica vittata punctata Van Houtte in Fl. des Serr. IX. t. 888 (1854).
Rhododendron vittatum Planchon in FL des Serr. IX. 82 (1854); in Rev. Hort.
1854, 66. — Maximowicz in Mem. Acad. Sci. St. Petersbourg, ser. 7, XVI.
No. 9, 49 (Rhodod. As. Or.) (1870). — Millais, Rhodod. 259 (1917).
Rhododendron vittatum var. b. punctata Planchon, in Fl. des Serr. IX. 82 (1854) ;
in Rev. Hort. 1854, 66.
Azalea vittato-punctata Lemaire in III. Hort. I. t. 20 (1854).
Cultivated: Hort. Holm Lea, May 20, 1918, A. Rehder; Hort.
Berckmans, Augusta, Georgia, March 30, 1908, C. S. Sargent.
This variety has larger calyx-lobes than is usual in the species, but I have wild
specimens of the type with an equally large calyx. The most prominent distin-
guishing feature is the color of the flowers. This is white, striped with lilac-purple,
often irregularly so; sometimes the flowers are pure white or pure lilac-purple on
the same branch, occasionally they are dotted or blotched with color. Planchon
says it has been in possession of M. Paillet since 1844, and then adds that it was
one of Fortune's introductions to England. Now Fortune did not land in China
until July, 1843, so it would seem that there was something wrong with Planchon's
date or that it was introduced before Fortune's first visit. In all probability the
date is wrong. According to Fortune's account in his Tea Districts of China it
was in April, 1850, that he visited the Pou-shan gardens near Shanghai and saw
this Azalea in flower. However, he had been to these gardens on his first visit to
China (1843-45), but if he sent this variety of Azalea to England on that occasion
there is no available record of the fact. In all probability M. Paillet's plant was
R. indicum var. variegatum. Fortune's plant did not reach England before 1850
or 1851 so far as I can discover, and its acquisition according to the books led to
the raising of many seedlings. According to Hovey (Mag. Hort. XXI. 301 [1855])
an Azalea vittata rosea was exhibited for the first time in Philadelphia on April
17, 1855, by Mr. Buist. It has long been grown in the Berckmans Nurseries,
Augusta, Georgia, and in the collection at Holm Lea. The type appears to have
been lost to English gardens until recently, when Professor Sargent sent it to Kew
and elsewhere.
A form in which the flowers are striped with red is : —
Rhododendron Simsii var. vittatum f . Bealii Wilson, n. comb.
Azalea Bealii Fortune, Tea Districts of China, 330 (1852). — Lemaire in III.
Hort. I. t. 8 (1854).
Rhododendron vittatum var. g. Bealii Hort. apud Planchon in Fl. des Serr. IX.
82 (1854); in Rev. Hort. 1854, 66.
Azalea vittata Bealii Morren in Belg. Hort. XVI. 1, t. (1866).
This is another of Fortune's introductions to Messers Standish & Noble of
Sunningdale Nurseries from Pou-shan gardens, Shanghai, in 1850 or 1851, and is
characterised by its white flowers striped with red. This plant also has been a
useful parent in the evolution of the present-day race of "Indian Azaleas," as
shown by the variety " Fiirstin Baro Trysky," for example. It was imported into
America by C. M. Hovey, Boston, Mass., in 1855.
A variety with white to rose-colored flowers and geographically
widely removed from the type is : —
Rhododendron Simsii var. eriocarpum Wilson, n. comb.
Rhododendron indicum var. eriocarpum Hayata, Icon. PL Formos. III. 134
(1913).
50 THE AZALEAS OF THE OLD WORLD
Japan : Kawanabe Islands, Suwanose-shima, May, 1917, H. Ushiwo
(No. lc); Takara-shima, May 4, 1917, H. Ushiwo (No. ld, le); Taira-
shima, May, 1917, H. Ushiwo (No. lf).
These specimens were collected for me by Forestry-officer Ushiwo by courtesy
of Dr. Naito, chief of the Kagoshima forestry bureau, and are excellent, though
unfortunately unaccompanied by field notes. The flowers of the Takara-shima
specimens are white, those of that from Taira-shima pink or rose-colored. The
color of the flowers and of the pubescence more readily distinguish this variety
from the type than does the shape of the leaves pointed out by Hayata. I am sorry
that I did not see this interesting plant in a wild state and am inclined to the view
that ultimately it may prove to be a distinct species. The Kawanabe Islands are
a number of small rocky eminences which jut out of the sea south of Yaku-shima
toward the Liukiu Islands and have a flora like that of Liukiu (see Jour. Arnold
Arb. I. 183-186 [1920]).
Rhododendron atrovirens Franchet in Bull Soc. Bot. France,
XXXIII. 235 (1886). — Hemsley in Jour. Linn. Soc. XXVI. 19
(1889). — Millais, Rhodod. 124 (1917).
The species from western Yunnan is unknown to me, except from Franchet's
description. It would appear to be intermediate between R. Simsii Planch, and
R. microphyton Franch. It is said to be a large bush or small tree with lanceolate,
long-acuminate leaves narrowed to the base and glaucescent on the underside. The
flowers are described as red, clustered 3 or 4 together, and each 2.5 cm. or less in
diameter. It was discovered by Pere Delavay at " Tchen-fang-ehan " near Ta-
kouan in May, 1882, but apparently has not yet been introduced to cultivation.
Rhododendron lasiostylum Hayata, Icon. PL Formos. III. 135
(1913). — Kanehira, Formos. Trees, 321 (1917). — Komatsu in Tokyo
Bot. Mag. XXXII [14] (1918).
Formosa: prov. Nanto, between Shushu and Horisha, March 12,
1918, E. H. Wilson (No. 10,020).
This is a pretty pink-flowered Azalea of which I have seen only one plant. It
was growing on top of a rock by the trolley line at about 400 m. altitude, and was
about 1 m. high and less broad. The branches are slender and twiggy and when
young clothed with the usual appressed, flattened chestnut-brown hairs. The
young leaves, petioles, pedicels, calyx and ovary are all densely clothed with chest-
nut-brown pubescence changing to gray. The leaves are dimorphic; the spring
leaves are lanceolate to ovate-lanceolate and from 2 to 4.5 cm. long and 1 to 1.5 cm.
wide, acute and deciduous; the summer leaves are oblong-obovate to oblanceo-
late from 2 to 4.5. cm. long and 1 to 2 cm. wide, rounded and mucronate at apex
and cuneate at base; both surfaces are clothed with appressed gray to rufous-
brown hairs. The flowers are terminal, three or four together at the end of the
branchlet. The corolla is funnel-shape, pink, about 2 cm. long with spreading
lobes and about 2.5. cm. across, the tube being rather less than 1 cm. long. The
calyx is variable in size being either nearly obsolete or with distinct, rounded lobes
each a millimetre or more long. The stamens are of unequal length, the longest
equalling the corolla-lobes and overtopped by the style. It is with considerable
hesitation that I identify my specimens with this species. There are many dis-
crepancies but of trivial character the more important being the difference in
ENUMERATION OF THE SPECIES 51
size of the calyx-lobes and of the leaves. I have seen the type specimens in Tokyo
but the material is so poor that I could arrive at no definite conclusion in the
absence of my own material for comparison.
Rhododendron subsessile Rendle in Jour. Bot. XXXIV. 357 (1896).—
Merrill in Govt. Lab. Publ. (Philipp.) XXIX. 40 (1905). — Millais
Rhodod. 249 (1917).
Philippine Islands: Luzon, Prov. Benquet, Baguio, March
1907, 1913, A. D. E. Elmer (Nos. 8595, 14,298); same locality, May-
June, 1916, J. K. Santos (No. 38); same province, Mt. St. Tomas,
February 18, 1916, E. C. Leano (Forestry Bureau No. 25,125); same
locality, March, 1904, A. D. E. Elmer (No. 5799); same locality,
July 1, November 29, 1904 R. S. Williams (Nos. 1223, 2001); same
locality, May 10, 1904, P. T. Barnes (No. 922); same locality, April,
1908, H. N. Whitford (Forestry Bureau No. 11,090); Mt. Tonglon
alt. 2200 m., November 12, 1905, May, 1911, E. D. Merrill (Nos.
4815, 736); same place, August, 1906, H. M. Curran (No. 5032);
same place, December, 1906, E. A. Mearns; same place, December,
1908, M. L. Merritt (No. 14,148); Bucao, alt. 2300 m. January 4,
1909, R. J. Alvarez (No. 18,362); Mt. Pulog, January 3 & 8, 1909,
T. C. Zschokke and M. L. Merritt (Nos. 18,035, 18,172); Pauai, July,
1907, E. A. Mearns (No. 4275); same place, alt. 2100 m., June, 1909,
R. C. McGregor (No. 8420); same place, April 17, 1918, J. K. Santos
(No. 31,994); District of Lepanto, January 26, 1909, F. W. Darling
(No. 16,573); same district, Mt. Data, November 4, 1905, E. D.
Merrill (No. 4606); prov. Abra, February 8, 1909, M. -Ramos (Nos.
7249, 7105); subprov. Bontoc, alt. 1350 m. April 7, 1910, Pere M.
Vanoverber (Nos. 351, 364) — all these numbers in Herb. Bureau
Science Manila.
This Philippine species in its pubescence and foliage somewhat resembles, as
Dr. Rendle points out, the Japanese R. mucronatum G. Don, but it is non-glan-
dular, the flowers are not more than one-third the sivze and have a minute calyx
and a more tubular corolla. Its nearest relative is probably the Formosan R. ru-
bropilosum Hayata. It is evidently a twiggy plant and the young branches are
clothed with the usual flattened, appressed bristles. The oval to lanceolate per-
sistent leaves are from 1.5 to 3.5 cm. long and from 0.7 to 1.2 cm. wide, acute
and mucronate, with slightly recurved margins, the midrib impressed above, promi-
nent below. On adult leaves the upper surface is clothed with appressed white
hairs but when young both surfaces are densely covered with rufous-gray, silky
hairs. The flowers are in terminal two to several flowered clusters. The
corolla is campanulate-funnel-form, with the tube less than 1 cm. long and short
spreading lobes, and is said to be from lilac to violet-purple in color; the stamens
vary from 6 to 10, are slightly exserted and are overtopped by the graceful,
curved style which is villose at the base. The pedicels, calyx and ovary are densely
clad with ferrugineous villose and more or less flattened, straight hairs. The
52 THE AZALEAS OF THE OLD WOULD
fruit is conic-ovoid and is densely clothed with rufous, appressed and villose
pubescence.
It is widely distributed and very common on the highlands of northern
Luzon. It is evidently a very pretty species and ought to be introduced into gar-
dens. The flowers vary considerably in color and No. 364 from Bontoc is said to
have white flowers. No. 351, also from Bontoc, has very slender branches and
small, elliptic, acute leaves and is very different in appearance from the other speci-
mens. I can find no morphological differences, and it appears to be simply a con-
dition; probably the plant from which the specimen was taken was growing in the
crevice of a boulder or of a cliff.
Rhododendron rubropilosum Hayata in Jour. Coll. Sci. Tokyo,
XXX. art. 1, 173 (Mat. Fl Formos.) (1911). — Kanehira, Formos.
Trees, 326, fig. 11 (1917). — Komatsu in Tokyo Bot. Mag. XXXII.
[16] (1918).
Rhododendron caryophyllum Hayata, Icon. PL Formos. III. 130, t. 23 (1913). —
Kanehira, Formos. Trees, 318, fig. 17 (1917).
Formosa: prov. Kagi, east of Ari-san, alt. 2500-3300 m. February
2 and 4, October 26, 1919, (Nos. 9728, 9779, 10,939); same locality,
June, 1914, U. Faurie (Herb. Bur. Sci. Manila).
On the grass-clad mountain-slopes east of Ari-san this species is common
between altitudes of 2300 and 3300 m. but I did not see it elsewhere. It is a narrow
shrub from 1 to 3 m. tall, with twiggy, rigid, ascending branches, which when
young are densely covered with appressed, flattened, gray to red-brown hairs.
The leaves are persistent, scattered on the free-growing shoots and crowded at
the tip of the branchlets; in shape they vary from oblong-lanceolate to elliptic-
lanceolate and are from 1 to 4 cm. long and from 0.5 to 1.7 cm. wide, acute, tipped
with a glandular mucro and narrowed at base; the upper surface is dark green,
with scattered, appressed, pale gray hairs and the underside is pale green and
clothed with flattened, appressed, gray to brown strigose hairs, which are especially
prominent on the midrib. The petiole is densely clad with appressed, flattened
hairs similar to those on the branches. The bud-scales of the flowers are pubescent
but not glandular. The flowers are of medium size, pink spotted with rose, short-
stalked and borne several together at the end of the branchlet; the corolla is fun-
nel-shape, with spreading lobes, and from 1.5 to 2.5 cm. across. Hayata gives the
number of stamens as 10 but on my specimens I find 7 or 8 only; they are
of unequal length but shorter than the corolla. The pistil overtops the stamens
and has a relatively stout, slightly curved style, villose at the base, and the ovary
is densely clothed with pale gray soft hairs. The fruit is ovoid-conic, from 0.5
to 0.8 cm. long and densely clothed with shaggy, gray-brown hairs. The type
specimen of R. caryophyllum which I have seen, has smaller leaves and flowers
than is usual in the species which is due to the fact that the specimens came from
a wind-swept slope near the altitudinal limits of the species. My No. 9779 is simi-
lar. In late October I found many plants in full bloom and apparently it is pre-
cocious in its habit of flowering. I collected seeds, and plants of this species are
now growing in the Arnold Arboretum and in several gardens in England. They
will not be hardy except in favored localities like Cornwall and California.
Rhododendron tosaense Makino in Tokyo Bot. Mag. VI. 53 (1892);
in XVIII. 101 (1904). — Schneider, III. Handb. Laubholzk. II, 506
ENUMERATION OF THE SPECIES 53
(1911). — Matsumura, Ind. PL Jap. II. pt. 2, 465 (1912). — Ko-
matsu in Icon. PL Koisikav. II. 91, t. 130 (1915); in Tokyo Bot. Mag.
XXXII. [17] (1918).
Japan: Shikoku, prov. Tosa, round Kochi, sea-level to 1000 m.
altitude, November 20, 1914, E. H. Wilson (No. 7801).
A twiggy, eglandular shrub growing from 0.3 to 2.5 m. but usually from 1 to
1.5 m. tall, with slender branches clothed with appressed, straight gray to gray-
brown hairs. The leaves are scattered on the shoots and free-growing branches
and crowded at the end of the branchlets. They are more or less deciduous and
change in the autumn to purplish crimson; those formed in the spring are oblance-
olate or lanceolate from 1.2 to 3.5 cm. long and from 0.5 to 1 cm. broad and are
acute and clothed with appressed, straight, gray hairs; the summer leaves are
linear to oblanceolate from 0.5 to 1 cm. long and from 1 to 5 mm. wide. The
flowers are produced in clusters of from 2 to 6, but occasionally are solitary. The
corolla is lilac-purple, about 3 cm. across. The pedicels are short and the calyx
is very small and clothed with long, straight white hairs. The stamens vary in
number from 5 to 8, are of unequal length, included and overtopped by the style
which is exserted. The fruit is ovoid, about 9 mm. long, clothed with appressed,
straight hairs and subtended by the persistent calyx-lobes.
The species is abundant on the lower mountain-slopes of Tosa province, Shi-
koku, from sea-level to altitudes of 1000 m. On exposed slopes it is dwarf and
dense in habit, but in thickets it is tall and loosely branched. The summer
leaves are minute and with the slender twiggy branchlets easily distinguish this
species from others. I have seen a few flowers, but the color is not attractive
though doubtless in spring when covered with blossoms, the plant would have a
charm of its own. I saw plenty of it in November, 1914, and collected seeds for
the Arnold Arboretum. These were distributed but the plants raised here have
not proved hardy.
Rhododendron serpyllifolium Miquel in Ann. Mus. Lugd.-Bat. II.
165 (1865-66); Prol Fl. Jap. 97 (1866-67). — Maximowicz in Mem.
Acad. Sci. St. Petersburg, se> 7, XVI. 42, t. 4, figs. 18-25 (Rhodod.
As. Or.) (1870). Franchet & Savatier, Enum. PL Jap. I. 292 (1875).—
Hooker f. in Bot. Mag. CXXII. t. 7503 (1896). — Boissier in Bull.
Herb. Boiss. V. 919 (1897). — Matsumura in Bot. Mag. Tokyo XIV.
69 (1900); Ind. PL Jap. II. pt. 2, 464 (1912). — Schneider, III. Handb.
Laubholzk. II. 507, fig. 333 a-d (1911). — Bean, Trees & Shrubs
Brit. Isl. II. 378 (1914). — Millais, Rhodod. 240 (1917). — Komatsu in
Tokyo Bot. Mag. XXXII. [15] (1918).
Azalea? serpyllifolia A. Gray in Perry, Jap. Exped. II. 315 (1857); in Mem.
Am. Acad. n. ser. VI. 399 (1858-59). — Masters inGard. Chron. n. ser. XVII.
429 (1882).
Japan: Kyushu, prov. Osumi, Mt. Takakuma, March, 1912, K.
Toyohira; prov. Hizen, Mt. Unzen, April 14, 1914, K. Sakurai; Naga-
saki, cultivated, 1863, C. Maximowicz (Herb. Kew). Hondo, prov.
Settsu, near Kobe, April, 1875, H. N. Moseley (Herb. Kew); prov.
54 THE AZALEAS OF THE OLD WORLD
Idzu, May 19, 1853, C. Wright (Herb. Gray) ; same place, cultivated,
April, 1854, Messers Williams & Morrow (Herb. Gray, type); Mt.
Amagi, April 27, 1913, K. Sakurai; prov. Sagami, Hakone, April and
May, 1875, H. N. Moseley (Herb. Kew).
Cultivated: Arnold Arboretum, flowered in greenhouse, March
14, 1907; Royal Gardens, Kew, April 14, 1896 (Herb. Kew, type of
Bot. Mag. t. 7503).
During my travels in Japan I did not see this pretty little species in a wild
state. On the volcanic mountains of the Hakone region and on those of Idzu
province, especially Amagi-san, it is said to be common. This seems to be the
northern limit of its range. Matsumura gives two or three other localities in
Hondo but I have seen no specimens except one from near Kobe which probably
came from a cultivated plant. In the south island of Kyushu it grows on the
volcanic Mt. Unzen near Nagasaki, and on Mt. Takakuma in the southern prov-
ince of Osumi. Matsumura records it from Okinawa Island in Liukiu but I have
seen no material from there. In Japan it appears to be confined to purely volcanic
soils. It is also frequently cultivated there, especially in the gardens of the
peasantry.
According to Messers Williams and Morrow its Japanese name signifies
" Rice Azalea" and has reference to the leaves which are minute and smaller
than those of any other Japanese species. It was introduced into cultivation
in England by Messers Veitch, presumably through their collector Charles
Maries, and flowered for the first time in England in 1882. Later it was
introduced to America but is still very rare. In the Arnold Arboretum it has
not proved hardy. The figure in the Botanical Magazine gives a very good idea
of this species.
Differing from the type in color of the corolla only is : —
Rhododendron serpyllifolium var. albiflorum Makino in Tokyo Bot.
Mag. XXII. 57 (1908). — Schneider, III. Handb. Laubholzk. II. 507
(1911). — Komatsu in Tokyo Bot. Mag. XXXII. [15] (1918).
Of this I have seen only Makino's type which he says is from the mountains
of western Japan. Makino names it in the vernacular the " Shirobana-unzen-
tsutsuji."
Rhododendron Nakaharai Hayata in Jour. Coll. Sd. Tokyo XXV.
art. 19, 153 (Fl Mont. Formos.) (1908).— Millais, Rhodod.2W (1917).—
Kanehira, Formos. Trees, 325, fig. 15 (1917). — Komatsu in Tokyo
Bot. Mag. XXXII. [14] (1918).
Rhododendron serpyllifolium Hayata in Tokyo Bot. Mag. XX. 72 (1906), not
Miquel.
Formosa: prov. Taihoku, Mt. Shichisei ex Hayata.
I did not see this plant growing wild but in Tokyo examined the type specimen
and consider it to be a good species. As the author points out it is nearest to R.
serpyllifolium Miq. from which it is at once distinguished by its larger flowers,
each with 10 stamens.
ENUMERATION OF THE SPECIES 55
Rhododendron Tschonoskii Maximowicz in Mem. Acad. Sri. St.
Petersburg, se>. 7, XVI. 42, t. 3, figs. 8b-14 (Rhodod. As. Or.)
(1870); in Bull. Acad. Sri. St. Petersburg, ser. 3, XV. 230 (1871).—
Franchet & Savatier, Enum. PL Jap. I. 295 (1875). — Boissier
in Bull Herb. Boiss. V. 919 (1897). — Matsumura, PL Nikko, 71
(1894); Ind. PL Jap. II. pt. 2, 465 (1912). —Schneider, III. Handb.
Laubholzk. II. 507, fig. 332 l-o (1911). — Bean, Trees and Shrubs
Brit. Isl. II. 383 (1914). — Millais, Rhodod. 256 (1917). — Nakai in
Tokyo Bot. Mag. XXXI. 244 (1917); Fl. Syl. Kor. VIII. 46, t. 17
(1919). — Komatsu in Tokyo Bot. Mag. XXXII. [15] (1918).
Azalea Tschonoskii O. Kuntze Rev. Gen. II. 387 (1891).
Rhododendron trinerve Franchet apud Boissier in Bull. Herb. Boiss. V. 92
(1897).
Rhododendron Tschonoskii a. typicum Makino in Tokyo Bot. Mag. XVIII. 66
(1904).
Rhododendron Tschonoskii a. typicum a. pentamerum Makino 1. c. — Matsu-
mura, Ind. PL Jap. II. pt. 2, 465 (1912).
Rhododendron Tschonoskii a. typicum b. tetramerum Makino I. c. — Matsu-
mura I. c.
Rhododendron Tschonoskii /3. trinerve Makino in Tokyo Bot. Mag. XVIII. 66
(1904). — Schneider, III. Handb. Laubholzk. II. 507 (1911).
Rhododendron Tschonoskii /3. trinerve a. pentamerum Makino 1. c. — Matsu-
mura I. c.
Rhododendron Tschonoskii ft. trinerve b. tetramerum Makino 1. c. — Matsumura
I.e.
Rhododendron Tschonoskii var. tetramerum Komatsu in Tokyo Bot. Mag.
XXXII. [15] (1918).
Japan: Shikoku, prov. Tosa, Nakatsu-san, June 20, 1889, K.
Watanabe (Herb. Gray) . Hondo, prov. Ettchu, Mt. Tateyama, July 23,
1884, (Herb. Kew) ; prov. Shinano, Tsubakura-dake, alt. 1300-1600 m.,
not common, September 15, 1914, E. H. Wilson (No. 7455) ; Hatta-
san, July 13, 1894, U. Faurie (No. 13,356); Mt. Asama, July, 1904, U.
Faurie (No. 5831); prov. Shimotsuke, Nikko region, Lake Yumoto,
June 22, October 18, 1914, E. H. Wilson (No. 7657); same locality,
November 6, 1892, C. S. Sargent; Lake Chuzenji, August 12, 1905,
J. G. Jack; Mt. Nyoho, August 3, 1909, K. Sakurai; prov. Uzen,
Adzuma-san, alt. 800-2000 m. July 20, 1914, E. H. Wilson (Nos.
7233, 7234, 7235); mountains round Yamagata, July 12, 1889, U.
Faurie (No. 4444) ; prov. Rikuchu, slopes of Hayachine-san, alt. 1300-
2000 m. September 28, 1914, E. H. Wilson (No. 7583); Mt. Iwate
July 16, 1903, S. Arimoto (Herb. Gray); high mountains, 1865,
Tschonoskii ex Maximowicz (Herb. Kew, Herb. Gray, co-type) ; prov.
Mutsu, Nambu, Shichinoki, June 23, 1889, U. Faurie (Herb. Kew) ;
56 THE AZALEAS OF THE OLD WOELD
Lake Towada, June 25, 1894, U. Faurie (No. 13,279, Herb. Kew);
Hakkoda-san, alt. 1600 m. July 5, 1914, E. H. Wilson (No. 7122);
same locality, U. Faurie (No. 875, Herb. Kew). Hokkaido, prov.
Oshima, Esashi, August 4, 1890, K. Miyabe & Y. Tokubuchi (Herb.
Gray); prov. Ishikari, near Sapporo, September 17, 1892, C. S. Sar-
gent; Masuzan, July 30, 1897, U. Faurie (No. 636).
Korea : prov. South Keisho, Chiri-san, peak Ten-no-bo, alt. 1845 m.
November 16, 1917, E. H. Wilson (No. 9595); same place, July 30,
1913, T. Nakai.
Cultivated : Arnold Arboretum (No. 3691); Royal Gardens, Kew,
July 1, 1910; Gardens, Tokyo, May 31, 1882, K. Miyabe.
This is an alpine or subalpine species that grows on most of the high mountains
in Hondo from Shinano northward; in Hokkaido it grows sparingly as far north
as the mountains round Sapporo. From Shikoku I have seen but one specimen
and it is not reported from Kyushu. Out of Japan this species has been found only
on the Chiri-san range in south Korea. This is an interesting discovery for the
plant does not grow on Quelpaert Island where so many Japanese species are
common, neither has it been found elsewhere in Korea. In the Nikko region R.
Tschonoskii is quite common, especially round Lake Yumoto, where it grows
on shady rocks. On Adzuma-san it is abundant in places fully exposed to the sun
and this locality is about the centre of its distribution. On the wind-swept upper-
slopes of Hayachine-san it is common but north of this mountain I found it to
be rare.
The plant forms a broad, densely branched twiggy shrub from 0.3 to 2.5 m.
high but is usually from 0.5 to 1.5 m. being taller in the forest shade than on
exposed rocks. It prefers rocky ground, but seems to be equally happy in the
moist woods of Nikko and on the exposed cliffs and slopes of Adzuma and Haya-
chine mountains. Sometimes it forms a broad low mat but is more usually an
upright shrub. It is always very twiggy and the young shoots are densely cov-
ered with closely appressed, flattened rufous hairs. The short stalked leaves are
deciduous, crowded at the end of the branches, and vary in shape from narrow-
lanceolate to ovate-lanceolate or broad-oblanceolate, they are acute and mucronu-
late and may have one or three prominent nerves; the undersurface is pale and
both surfaces have long, appressed, soft, red-brown hairs which are especially
noticeable on the young leaves. The flowers are small, with a white corolla, and
are four or five partite; they have exserted stamens, and are borne in terminal
clusters of from 4 to 6 flowers in each. Except that the leaves vary in size and
may have either one or three prominent nerves, and that the flowers are tetram-
erous or pentamerous the species is very constant. From one and the same bush
on Adzuma-san I gathered specimens which exhibited the whole range of varia-
tion on which Makino founded his numerous forms. With its small white flowers
R. Tschonoskii is very distinct from all other Japanese species but as a garden
plant it has little to recommend it though in autumn the leaves change to rich
shades of orange-red and crimson.
It was discovered in 1865 by Maximowicz's Japanese collector Tschonoski on
the mountains of Rikuchu province, northern Hondo, and is figured and described
by Maximowicz. It was introduced into England by Charles Maries who sent
seeds to Messers Veitch in 1878; to this country it was introduced by Professor
Sargent who sent seeds from the Nikko region to the Arnold Arboretum in 1892.
ENUMERATION OF THE SPECIES 57
In 1917 I sent seeds to the same institution from Chiri-san in Korea. The
Japanese name for this Azalea is " Shirobana-no Kome-tsutsuji."
Rhododendron microphyton Franchet in Bull. Soc. Bot. France
XXXIII. 235 (1886). — Hemsley in Jour. Linn. Soc. XXVI. 28
(1889). — Diels in Notes Bot. Gard. Edinburgh, VII. 309, 392
(PL Chin. Forrest.) (1913). — Hutchinson in Millais, Rhodod. 210
(1917).
China: prov. Yunnan, Talang, alt. 1600m. A. Henry (No. 11,596);
Szemao, alt. 1600 m. A. Henry (No. 12,983); " Che-lin-se, Pe-yen-
tsin," May 3, 1916, Simeon Ten (Nos. 86, 86a); " Mt. Lai-chan-po,
Pe-yen-tsin," May 2, 1916, Simeon Ten (No. 83), " Ni-kou, Pe-yen-tsin,"
July 5, 1917, Simeon Ten (No. 417); Yunnan Fu, alt. 2000 m. April,
1916, 0. Schoch (No. 350 g); Tali mountain range, Lat. 25° 40' N. alt.
2600-3300 m. May to July, 1906, G. Forrest (No. 4172^ .
I have no knowledge of this plant in a wild state but according to notes on the
specimens cited above it is an erect, much-branched shrub growing from 0.3 to
2 m. tall. The branchlets are short and twiggy and closely beset with flattened,
appressed red-brown bristles. The leaves are persistent, oval to lanceolate in
shape, from 0.5 to 3.5 cm. long and from 0.5 to 1.5 broad, acute, obtuse or rounded
at the apex which is mucronulate; the upper surface is dark green, the lower pallid
and both have scattered hairs on the midrib; the underside and the petioles
are clad with red-brown bristles. The flowers are borne several together at the
end of the branchlets and in some specimens are so numerous that the stem
appears to be clothed with flowers; on others the flower-clusters are sparse. The
corolla is rose-colored with crimson markings, with a slender, cylindrical tube
from 5 to 8 mm. long and spreading lobes, and varies from 1 to 2 cm. in diameter.
The five stamens are exserted and shorter than the style. The calyx is minute or
with distinct lanceolate lobes from 1 to 4 mm. long, and like the pedicels and ovary
is clothed with straight, shining chestnut-brown hairs. The red-brown pubescence
is prominent on this plant. Its small leaves and small flowers resemble those of
certain species of the section Lepipherum, rather than those of a species of Tsutsutsi.
Where it grows plentifully on open mountain-slopes it must be conspicuous when
in bloom, and it would be a desirable addition to gardens even as a pot plant
where it would not be hardy. From the altitude given by Forrest (2600-3300 m.)
it would appear that this species is not only the most western but the most alpine
of the Chinese species of the section. As Franchet points out it is the Chinese
analogue of the Japanese R. Tschonoskii Maxim, and like that species exhibits
considerable variation in size of leaves and flowers. At first I thought Simeon
Ten's No. 417 with minute leaves and small flowers was a distinct variety but
after careful comparison and dissection I am satisfied that the distinct appearance
is the result of exposed ecological conditions.
Rhododendron Seniavinii Maximowicz in Mem. Acad. Sci. St.
Petersburg, se>. 7, XVI. No. 9, 33, t. 3, fig. 21-24 (Rhodod. As.
Or.) (1870). — Hemsley in Jour. Linn. Soc. XXVI. 30 (1889).—
Bretschneider, Hist. European Bot. Disc. Chin. 620 (1898). — Millais,
Rhodod. 240 (1917).
58 THE AZALEAS OF THE OLD WORLD
China: prov. Hunan, Yiin-shan, near town of Wukang, alt. 1350-
1400 m. June 9, 1918, Dr. Handel-Mazzetti (No. 738).
This rare and very distinct species is unknown to me in a living state. Dr.
Handel-Mazzetti says it is a shrub some 2 m. tall, and that it grows on the margins
of forests of broad-leafed trees and has white flowers with the tube of the corolla
suffused with rose-color and the upper-lobe spotted with purple. The gray and
rufous-gray appressed hairs which clothe the shoots, both surfaces of the young
leaves, the under-side of adult leaves, pedicels, calyx and ovary well characterise
the plant. It is evidently a much-branched twiggy shrub, and the shoots are clad
for a season with the usual flattened, appressed bristles of the group. The leaves
are persistent or semi-persistent, crowded at the end of the branches, dark green,
glabrescent above with impressed reticulate veins. In shape the leaves vary from
oval to lanceolate, being from 1.5 to 6.5 cm. long and from 1 to 2.5 cm. wide, acute
or obtuse and mucronate at apex. The flowers are small, clustered from 3 to 10
together at the end of the shoots; the corolla is about 1.5 cm. across, with a nearly
cylindric tube hairy on the outside, and spreading lobes. The calyx is small and
hidden beneath the gray or rufous straight hairs. The five stamens are exserted,
and are overtopped by the style, which has a capitate, lobed stigma. In Maximo-
wicz's figure the petioles vary from 0.5 to 1 cm. in length whereas on the specimen
cited none exceed 0.5 cm. but this is the only difference I can find and were more
material available this would probably disappear.
The discoverer of this species is unknown but from what Bretschneider says it
seems probable that the original specimen came from the borders of western Fokien,
a region still very little known to us. Dr. Handel-Mazzetti's discovery in south-
western Hunan is an interesting extension of the range of the species, which has
for so long remained obscure. It is not in cultivation.
Rhododendron Mariae Hance in Jour. Bot. XX. 230 (1882). —
Hemsley in Jour. Linn. Soc. XXIX. 27 (1889). — Dunn & Tutcher
in Kew Bull. Misc. Inform, add. ser. X. 155 (Fl. Hongk. and Kwang-
tung) (1912). — Hutchinson in Millais, Rhodod. 207 (1917).
China: prov. Kwangtung, Ting-woo Mt., May 26, 1918, C. 0.
Levine, Canton Christian College Herb. No. 2015 (Herb. Bur. Sci.
Manila); Loh-fau-shan, alt. 1000 m. August 10, 1917, C. 0. Levine
(No. 1563, Herb. Bur. Sci. Manila); same place, August 13, 1917,
E. D. Merrill (No. 11,103, Herb. Bur. Sci. Manila); Tiu-kaen-shan,
March, 1918, To-Kang-P'eng, Canton Christian College Herb. No.
2370 (Herb. Bur. Sci. Manila).
Known to me only from Hance's description with which the above-cited speci-
mens agree exactly. It is evidently a twiggy shrub and the branchlets are clothed
with appressed, reddish gray bristles which, changing to gray persist more or less
during a couple of seasons. The leaves are dimorphic, clustered at the end of the
branches, persistent and for a plant of its group very coriaceous; they are shining
dark green and nearly glabrous above, with impressed, reticulate veins, pale below,
with raised veins and scattered appressed rufous bristles. The spring leaves are
elliptic-lanceolate from 3 to 9 cm. long and from 2 to 3 cm. wide, acute and mucronu-
late; the summer leaves are elliptic to obovate from 1 to 3 cm. long and from 0.8
to 1.5 cm. wide, obtuse or rounded at the mucronulate apex. The petioles are
ENUMERATION OF THE SPECIES 59
etrigosely pubescent. The flowers are small, crowded in terminal clusters, and
fragrant. The corolla is lilac-colored, with a slender tube about 1 cm. long, and
small spreading lobes; the 5 exserted stamens are overtopped by the slender style
with its capitate stigma. The pedicels are straight from 1 to 1.5 cm. long and with
the annular calyx and the ovary are densely clothed with shining, rufous-brown
strigose hairs.
This species is known only from one or two localities near Canton in south
China and is evidently closely related to R. Seniavinii Maxim. So far as I know
it has never been introduced into cultivation, although discovered by the Reverend
B. C. Henry as long ago as April, 1882.
Rhododendron scabrum G. Don, Gen. Syst. III. 846 (1834).—
Maximowicz in Mem. Acad. Sci. St. Petersbourg, ser. 7, XVI. No. 9,
49 (Rhodod. As. Or.) (1870).
Rhododendron sublanceolatum Miquel in Ann. Mus. Lugd.-Bat. II. 163 (1865—
66); Prol Fl. Jap. 95 (1866-67). — Maximowicz in Mem. Acad. Sci. St.
Petersbourg, ser. 7, XVI. No. 9, 35 (Rhodod. As. Or.) (1870). — Franchet
& Savatier, Enum. PL Jap. I. 290 (1875). — Hemsley in Jour. Linn. Soc.
XXVI. 31 (1889).— Gard. Chron. XLIX. 342, fig. 157 (1911). — Jour.
Hort. Soc. Lond. XXXVII. p. cxxxi. fig. 115 (1911). — Schneider, III
Handb. Laubholzk. II. 504 (1911). — Craib in Bot. Mag. CXXXIX. t. 8478
(1913). — Bean, Trees and Shrubs Brit. Isl. II. 381 (1914). — Millais, Rhodod.
249 (1917). — Komatsu in Tokyo Bot. Mag. XXXII. [12] (1918).
Rhododendron indicuni Hooker and Arnott, Bot. Voy. Beechey 266 (1841), not
Sweet. — Matsumura in Tokyo Bot. Mag. XIV. 69 (1900).
Rhododendron Jodogawa Hort. apud Hasskarl in Cat. Hort. Bog. alt. 162
(1844).
Rhododendron indicum /3. sinensis Miquel in Ann. Mus. Lugd.-Bat. I. 33
(1863-64).
Rhododendron ledifolium /3. purpureum Maximowicx in Mem. Acad. St. Peters-
bourg, se>. 7, XVI. No. 9, 36 (Rhodod. As. Or.) (1870), in part.
Azalea sublanceolata O. Kuntze, Rev. Gen. II. 387 (1891).
Rhododendron indicum var. sublanceolatum Makino in Tokyo Bot. Mag. XVIII.
100 (1904). — Matsumura, Ind. PL Jap. II. pt. 2, 461 (1912).
Rhododendron sublateritium Komatsu in Tokyo Bot. Mag. XXXII. [12]
(1918).
Rhododendron liukiuense Komatsu in Tokyo Bot. Mag. XXXII. [12] (1918).
Liukiu: Okinawa Island, near Katena, sea-level to 100 m. March
8, 1917, E. H. Wilson (No. 8046); without locality, C. Wright (No.
172, Herb. Gray, Herb. Kew): Takuno-shima, hillsides, April 1,
1853, C. Wright (Herb. Gray).
Japan: Kyushu, prov. Satsuma, Kagoshima, cultivated, May 6,
1918, E. H. Wilson (No. 10,344, 10,345); Kajiki, cultivated, May,
1917, Z. Tashiro; prov. Hizen, Nagasaki, 1862, R. Oldham (No. 504,
Herb. Gray, Herb. Kew); same locality, G. H. Langsdorff (Herb.
Kew); same locality, 1863, C. Maximowicz (Herb. Kew); same lo-
cality, cultivated, April 25, 1903, U. Faurie (No. 7873); prov. Chi-
kugo, Kurume, cultivated, May 3, 1918, E. H. Wilson. Hondo, prov.
60 THE AZALEAS OF THE OLD WORLD
Musashi, Yokohama, cultivated, December 22, 1914, E. H. Wilson
(No. 7873); same locality, May 15, 1918, E. H. Wilson.
Cultivated: Hort. Holm Lea, Brookline, Mass., April 15, 1915;
Hort. Kew, 1912, type of Bot. Mag. t. 8478.
This is a laxly branched shrub from 1 to 2 m. high and has relatively stout
branches which are clothed in their first year with appressed, flattened, strigose, gray-
brown hairs which gradually disappear. The leaves are shining, coriaceous, nearly
glabrous except on the veins at maturity, persistent; those formed in the spring
are lanceolate to elliptic-lanceolate, from 4 to 10 cm. long and from 2 to 3.5 cm.
broad, acute or obtuse and mucronate at the apex, the base broadly cuneate, the
margin slightly recurved ciliate and sub-crenulate, the principal veins impressed
above and prominently raised on the under surface; the summer leaves are ob-
lanceolate, smaller and more coriaceous than the spring leaves and subacute or
rounded at the apex, which is mucronulate; when young the leaves have appressed,
straight gray-brown hairs more especially on the nerves and an occasional sessile
gland on the under-side; at maturity they are very sparsely pubescent except on
primary and secondary nerves; the petiole is stout, flattened, somewhat appressed
to the shoot, and is clothed with pubescence similar to that on the shoots and leaf
veins. The winter-buds are ovoid, acute, clothed with rufous, appressed straight
hairs; the inner bud-scales cinnamon-brown, ciliate, viscid on inner surface and re-
main on the base of the pedicels of the expanded flowers. The flowers are borne in
terminal clusters from 2 to 6 in each. The calyx is green, ample, the lobes usually
oval and rounded, about 6 mm. long and 5 mm. broad, sometimes one and occasion-
ally all the calyx-lobes lance-shape and 1.2 cm. or more long, acuminate, ciliate and
glandular, and covered with appressed, straight, gray hairs. The corolla is rose-red
to vivid scarlet, broad-funnel-shape about 6 cm. wide, lobed nearly to the middle;
stamens 10, included, overtopped by style. The fruit is erect, ovoid, from 1 to
1.2 cm. long, sparsely hairy, and is subtended by persistent calyx-lobes.
This species is endemic in the Liukiu Islands, where it is confined to the middle,
or Okinawa, group of islands and to Takuno-shima, the most southern of the north-
ern, or Oshima, group. It grows among shrubs, coarse grasses and Pinus luchuensis
Mayr, and when in bloom is very conspicuous. It is a common plant in gardens
round Kagoshima in south Japan, having been long ago introduced from Liukiu.
From Kagoshima it has been taken to Nagasaki and north as far as Tokyo, but it
is only in the warmer parts of south Japan that it can be described as a common
garden plant. The leaves, flowers and fruit are larger than those of other species
of the group; the leaves are also more persistent and more coriaceous. The flowers
are normally of an intense scarlet but they vary to rose-red. The calyx-lobes are
often very unequal in size on the same flower or flower-cluster and they vary too
in degree of pubescence. In habit it is more vigorous but less compact than that
of other species of the group. Specimens in Herb. Kew and Herb. Gray labelled
R. Sieboldii var. ellipticum ex Herb. Lugd.-Bat., 1863, would appear to belong here
though the flowers are abnormally small for the species. The leaves, bud-scales,
calyx and number of stamens agree and it may be that the specimens are from a
plant flowering out of season or under abnormal conditions.
Maximowicz, Miquel and Makino refer to it as the " Chinese Azalea " but there
does not appear to be any authority for the statement since the plant itself is un-
known in China. To-day in Japan generally it is known as the Liukiu (Riukiu)
Azalea, but round Kurume in Kyushu it is called "Hiwoge-yodogawa." Maximo*
wicz does not appear to have properly known this species and has confused Wright's
Tokuno-shima specimen and others with his R. ledifolium /3. purpureum yet he
ENUMERATION OF THE SPECIES 61
states that it was introduced into Petrograd in 1864. In England this Liukiu species
does not appear to have been properly known before 1911, when Mr. R. C. Notcutt
of Woodbridge exhibited it at the Royal Horticultural Society's Temple Show in
London. In 1915 I brought plants from Japan to the Arnold Arboretum. Of all
the red-flowered species of eastern Asia except the Formosan R. Oldhamii Maxim,
it is the least hardy. In Massachusetts it is a greenhouse plant and blossoms
sparsely. Miquel did not know the color of the flowers of his R. sublanceolatum
citing it as alba? which it certainly is not for no white form is known even to-day.
The color of the flowers varies from intense scarlet to rich magenta. Don gives
deep rose-color for the type and the scarlet-flowered form, which is the usual form
found growing wild, may be distinguished as f . coccineum Wilson, n. name. It is
unfortunate that we have to adopt Don's name for this species yet it is undoubtedly
the oldest since his description fits this plant and no other. He says that the leaves
are " ovate " a term not often applicable to the leaves of any Azalea, they are, how-
ever, broader in this species than in any other. Don cites as a synonym R. maxi-
mum Thunb., which is R. Mettemichii S. & Z., but no word of his description has
reference to this Eurhododendron. This Liukiu species has been cultivated round
Nagasaki and other towns in southern Kyushu I know not how long, but Don is
wrong in saying that it is native of Japan, though the mistake is natural when the
period he wrote in is considered. Komatsu bases his two species on slight differ-
ences in the shape of the leaves, in the color of the corolla and on the length of the
corolla-tube. Such trivial differences are unimportant in such variable plants as
the Azaleas of the Tsutsutsi section.
Rhododendron phoeniceum G. Don, Gen. Syst. III. 846 (1834).
Azalea indica var. y. Sims in Bot. Mag. LIII. t. 2667 (1826).
Azalea punicea Sweet apud Poiteau in Annal. de From. I. 102, 104 (1829),
not Rhododendron indicum a. puniceum Sweet.
Rhododendron indicum y. phoeniceum Sweet, Brit. Flow. Gard. ser. 2, II. sub. t.
128 (1832).
Rhododendron indicum var. speciosum D. Don in Sweet, Brit. Flow. Gard. ser. 2,
III. t. 284 (1835), excluding synonomy.
Azalea indica phoenicea Hovey, Am. Gard. Mag. I. 224 (1835). v
Azalea indica Rawsonii Loudon, Gard. Mag. n. ser. II. 421 (1836).
Azalea Rawsonii Paxton, Mag. Bot. III. 123, t. (1837).
Rhododendron indicum y. purpureum De Candolle, Prodr. VII. pt. 2, 726 (1839),
in part, not Sweet.
Rhododendron ledifolium /3. phoeniceum De Candolle, Prodr. VII. pt. 2,
727 (1839), in part. — Render in Bailey, Stand. Cycl. Hort. V. 2944
(1916).
Rhododendron puniceum Planchon in Fl. des Serr. IX. 79 (1854), not Rox-
burgh; in Rev. Hort. 1854, 46, 61. — Maximowicz in Mem. Acad. Sci. St.
Petersburg, ser. 7, XVI. No. 9, 35 (Rhodod. As. Or.) (1870). — Schneider,
III. Handb. Laubholzk. II. 504 (1911).
Azalea phoenicea Hort. Paris apud Planchon in Fl. des Serr. IX. 79 (1854), as
a synonym; in Rev. Hort. 1854, 61.
Japan: ex Siebold comm. Zuccarini ex Herb. Zucc. 1842 (Herb.
Gray, doubtful specimen).
Cultivated: Hort. Holm Lea, March 30, 1917, A. Rehder.
Although introduced into European gardens as long ago as 1824 and used in
such vast quantities as a stock on which to graft the varieties of "Indian Azaleas"
62 THE AZALEAS OF THE OLD WORLD
BO-called, the origin of this plant is obscure. It appears to have been sent from
Canton, China, to the Horticultural Society's garden at Chiswick, probably by
John Reeves but the facts are not clearly known. One of these plants was figured
by Sims in the Botanical Magazine (t. 2667), and according to Poiteau it was known
in the gardens round Paris in 1829 but was rare. ,No wild species to which it can
be referred unhesitatingly has been discovered. In Japan I saw nothing just like
it but it is evident that the " Omurasaki-tsutsuji " is a glorified form of it. In its
vigorous habit, size of flower and shyness of blossoming R. phoeniceum G. Don
resembles R. scabrum G. Don, whilst in the calyx and character of pubescence it
suggests R. mucronatum G. Don; its viscid inner bud-scales agree with both species.
Possibly it is a hybrid between these two species though I incline to the belief
that it is nothing but an extreme form of R. scabrum G. Don. I have not been
able to discover just when it reached America but it was cultivated by Hovey &
Co., Boston, Mass., in 1835. In England attemps to hybridise this plant with all
sorts of species of Rhododendron were made and the books record a number of
presumed hybrids of remarkable parentage. For example Paxton's Azalea Raw-
sonii is said to be a cross between A. phoenicea and R. dauricum atrovirens
but an unbiased examination of the plate reflects nothing but a good colored form
of R. phoeniceum. Other presumed hybrids are dealt with hereunder and it is
evident that enthusiasm out-did the facts. It is probable that this plant has had
something to do in the evolution of the present-day race of " Indian Azaleas." In
Belgium R. phoeniceum and its variety concinnum are the principal stocks used in
grafting the "Indian Azaleas" of commerce.
A form of this is: —
Rhododendron phoeniceum f . semiduplex Wilson, n. f.
Azalea ledifolia var. /3. phoenicea Hooker in Bot. Mag. LX. t. 3239 (1833).
Rhododendron kdifolium ft. phoeniceum De Candolle, Prodr. VII. pt. 2, 727
(1839), in part.
G. Don and others have merged this into the type but its semi-double flowers
make it distinct as a garden plant. The color is poor. I have seen the specimen
preserved in Herb. Kew from which the Botanical Magazine figure was prepared
but no living material, and do not know if the plant is now in cultivation. In the
typical R. phoeniceum flowers are often seen in which the stamens show a tendency
toward becoming petaloid.
Another form is: —
Rhododendron phoeniceum f. Smithii Wilson, n. comb.
Rhododendron indicum 7. Smithii Sweet, Hort. Brit. ed. 2, 343 (1830).
Rhododendron pukhrum Sweet, Brit. Flow. Gard. ser. 2, II. t. 117 (1832). —
De Candolle, Prodr. VII. pt. 2, 726 (1839). — Maximowicz in Mem. Acad.
Sci. St. Petersbourg, se>. 7, XVI. No. 9, 36 (Rhodod. As. Or.) (1870).
Rhododendron indicum pulchrum G. Don, Gen. Syst. III. 845 (1834).
Azalea indica hybrida Loudon, Gard. Mag. n. ser. I. 326 (1835). — Hovey,
Am. Gard. Mag. II. 157 (1836).
This plant is stated variously to be " the produce of R. ledifolium Hook, im-
pregnated by the pollen of the Old Red R. indicum" and " a hybrid between R.
phoeniceum and R. ledifolium" but to me it appears to be nothing else than a form
of R. phoeniceum. Under Loudon's name it was introduced into America about
1835 and was exhibited for the first time before the Massachusetts Horticultural
Society on March 5, 1836, by Hovey & Co. For many years it was a favorite
ENUMERATION OF THE SPECIES 63
plant at exhibitions. It is still cultivated in the Magnolia Gardens, near Charles-
ton, South Carolina.
An old and obscure plant is: —
Rhododendron phoeniceum f . splendens Wilson, n. comb.
Rhododendron phoeniceum var. splendens D. Don in Sweet, Brit. Flow. Gard.
ser.2,IV.t.385(1837).
This is said to be a seedling raised from R. phoeniceum G. Don pollinated by
R. catawbiense Mich, but the figure shows no influence of the latter plant. That
it is a seedling may be accepted, but it is certainly nothing more than a good colored
form of R. phoeniceum with only from 5 to 8 stamens.
A common garden plant in Japan is: —
Rhododendron phoeniceum var. calycinum Wilson, n. comb.
Azalea indica calycina Lindley in Paxton, Flow. Gard. II. 169, t. 70 (1852).
Rhododendron calycinum Planchon in Fl. des Serr. IX. 81 (1854) ; in Rev. Hort.
1854, 65.
Rhododendron ledifolium /3. purpureum Maximowicz in Mem. Acad. Sci. St.
Petersburg, sSr. 7, XVI. No. 9, 36 (Rhodod. As. Or.) (1870), in part. —
Franchet & Savatier, Enum. PI. Jap. I. 291 (1875). — Matsumura, Ind.
PI. Jap. II. pt. 2, 462 (1912). — Render in Bailey, Stand. Cycl. Hort. V.
2944 (1916).
Azalea rosmarinifolia var. purpurea Rehder in Bailey, Cycl. Am. Hort. 1. 123
(1900).
Rhododendron rosmarinifolium var. purpureum Schneider, III. Handb. Laub-
holzk. II. 504 (1911). — Komatsu in Tokyo Bot. Mag. XXXII. [351 (1918).
Rhododendron rosmarinifolium var. speciosum Makino in Tokyo Bot. Mag.
XXVII. 110 (1913).
Rhododendron Oomurasaki Makino in Jour. Jap. Bot. I. 18 (1917).
Rhododendron Osakazuki Komatsu in Tokyo Bot. Mag. XXXII. [46] (1918) ;
in Icon. Koisikav. IV. 9, t. 217 (1918).
Japan: Kyushu, prov. Hizen, Nagasaki, cultivated, 1863, C. Max-
imowcz (Herb. Kew, Herb. Gray, co-types of R. ledifolium 0. pur-
pureum Maxim.); same locality, 1862, R. Oldham (No. 509, Herb.
Kew, Herb. Gray; No. 607, Herb. Kew); prov. Chikugo, Kurume, culti-
vated, May 3, 1918, E. H. Wilson. Hondo, prov. Choshu, Shimono-
seki, Sanyo Hotel garden, cultivated, May 17, 1917, E. H. Wilson
(No. 8425); prov. Musashi, Yokohama, cultivated, Hort. Suzuki,
May 15, 1918, E. H. Wilson; Tokyo, cultivated, May 11, 1902, K. Sa-
kurai; same locality, cultivated, May 12, 1910.
As pointed out by Lindley this variety is much superior to the type for it has
larger, more richly colored flowers. The corolla is rose-purple with crimson spots.
The calyx-lobes are larger and more acuminate but they vary. In Paxton's figure
the calyx is glabrous but this is a mistake. It is ciliate and sparsely or densely
clothed with long, straight, appressed hairs. Apart from the calyx Paxton's figure
is an excellent representation of the Omurasaki-tsutsuji (large purple Azalea) so
much grown in the gardens of Yokohama, Tokyo and elsewhere in Japan. At
64 THE AZALEAS OF THE OLD WORLD
Kurume in Kyushu it is known as the Kumagai-yodogawa. It is a vigorous free-
flowering plant of compact habit of growth, and its large, magenta-red flowers are
very handsome. Nothing definite appears to be known in Japan of the origin of
this Azalea but it has been cultivated for a long period. Maximowicz 's speci-
men undoubtedly belongs here, but those of Langsdorff, Wright and some of
Oldham's included by Maximowicz under his var. purpureum belong to R. sca-
brum G. Don. Recent botanists seem to have overlooked Lindley's name and
excellent figure. According to Planchon this variety was introduced from China
by Robert Fortune to the gardens of the Horticultural Society at Chiswick where
it flowered for the first time in 1851.
A very hardy form with carmine-red flowers much cultivated in
Europe and, to a less degree, in this country may be distinguished
as: —
Rhododendron phoeniceum var. calycinum f. Maxwellii Wilson,
n. comb.
Azalea Maxwelli Hort. Wezelenburg, Cat. 6, fig. (1915).
Rhododendron Maxwelli Millais, Rhodod. 208, fig. (1917).
Japan : Kyushu, prov. Chikugo, Kurume, cultivated, May 3, 1918,
E. H. Wilson.
Cultivated: Hort. Bobbink & Atkins, Rutherford, N. J., April, 1920.
At Kurume this bright-colored form is known as the " Aka-yodogawa."
To this variable species must be added : —
Rhododendron phoeniceum var. tebotan Wilson, n. comb.
Rhododendron Tebotan (Rh. Kaempferi X Rh. rosmarinifoliwri) Komatsu in
Tokyo Bot. Mag. XXXII. [46] (1918).
This variety has double flowers with small green leaves showing the centre,
and is remarkable for its color which is the same as that of Bougainvillaea glabra
Choisy, and quite unique among Azaleas. It is an old plant in Japanese gardens
but is now rare and Japanese nurserymen substitute for it Azalea " Fuji-manyo "
(R. mucronatum f. plenum Wils.). In 1919 I secured in Japan a living plant of
the true var. tebotan for the Holm Lea collection where it has flowered.
Rhododendron yedoense Maximowicz apud Regel in Gartenfl.
XXXV. 565, t. 1233 a-b (1886). — Millais, Rhodod. 264 (1917).
Azalea Yodogava Grignan in Rev. Hort. 1908, 425 t. fig. 2.
Rhododendron phoeniceum Matsumura, Ind. PL Jap. II. pt. 2, 463 (1912),
not G. Don.
Rhododendron Yodogawa Kunert in Gartenwelt XVI. 163, t. (1912). — Millais,
Rhodod. 264 (1917).
Rhododendron poukhanense var. yodogawa Render in Mitt. Deutsch. Dendr.
Ges. XXIV. 225 (1916); in Bailey, Stand. Cycl. Hort. V. 2943 (1916).
Rhododendron Poukhanense var. plenum Nakai in Tokyo Bot. Mag. XXXI.
245 (1917). — Komatsu in Tokyo Bot. Mag. XXXII. [12] (1918).
Azalea Tado Guno Hort. apud Millais, Rhodod. 264 (1917), as a synonym.
Rhododendron Matsumurai Komatsu in Tokyo Bot. Mag. XXXII. [13] (1918).
ENUMERATION OP THE SPECIES 65
Korea: prov. Keiki, cultivated, Forestry Experimental Garden,
Keijyo, May 21, 1917, E. H. Wilson (No. 8422).
Cultivated : Arnold Arboretum (No. 7345); ex Hort. E. G. Loder,
May, 1898 (Herb. Kew).
This double-flowered Azalea, in recent years exported from Japan in some quan-
tity to the gardens of Europe and America, is certainly nothing but a monstrous
form of R. yedoense var. poukhanense Nakai. My Korean specimens came from a
plant which had been found wild not far from Mt. Poukhan and transplanted to
the Government Forestry Experimental Garden, and are indistinguishable from
others taken from plants cultivated in the Arnold Arboretum. The habit is spread-
ing and more lax than in the type except when the latter grows among tall bushes.
The flowers are quite double, and the corolla is rose-purple and much less beautiful
than that of the type; the calyx is green, often larger than in the type, with oval
segments. The leaves are characteristic and have the impressed veins on the
upper surface.
This form seems to have become known in our gardens comparatively recently
and to have been first introduced into Petrograd by Japanese and exhibited at the
International Exhibition there in 1884. It is perfectly hardy in the Arnold Arbor-
etum. Matsumura gives " Botan-tsutsuji " (Paeony Azalea) as the vernacular
name of this plant.
The wild type of the species is: —
Rhododendron yedoense var. poukhanense Nakai hi Tokyo Bot.
Mag. XXXIV. (274) (1920).
Rhododendron indicum var. Simsii Palibin in Act. Hort. Petrop. XVIII. 150
(Consp. Fl. Kor. 11, 4) (1900), not Maximowicz. — Nakai in Jour. Coll.
Sci. Tokyo, XXXI. 76 (FL Kor. II) (1908).
Rhododendron poukhanense LSveille* in Fedde, Rep. Nov. Sp. V. 100 (1908). —
Nakai in Journ. Coll. Sci. Tokyo, XXXI. 76 (FL Kor. II) (1908); in
Tokyo Bot. Mag. XXXI. 244 (1917); FL Syl. Kor. VIII. 47, t. 18 (1919).
— Komatsu in Icon. PL Koi&ikav. II. 97, t. 133 (1915). — Render in
Mitt. Deutsch. Dendr. Ges. XXIV. 225 (1916); in Bailey, Stand. Cycl.Hort.
V. 2943 (1916).
Rhododendron hallaisanense LeveillS in Fedde, Rep. Nov. Sp. XII. 101 (1913).
Rhododendron coreanum Rehder in Mitt. Deutsch. Dendr. Ges. XXII. 259
(1913). — Millais, Rhodod. 148 (1917).
Korea: Quelpaert Island, sea-level to 1600 m. abundant, October
29, November 6, 1917, E. H. Wilson (Nos. 9396, 9458); same locality
April 14, October 25, 1908, June 1909, E. Taquet (Nos. 1090. 1091.
4679, 4680, 2972) ; prov. South Keisho, Fusan, May 18,1906, U.Faurie
(No. 670) : prov. Keiki, Kazan, near Suigen in Pine-woods, May 24,
1917, E. H. Wilson (No. 8472); Seoul, April 29, 1894, Miss A. Sontag
(Herb. Kew); same place, Mt. Poukhan, September 25, 1905, J. G.
Jack; province unknown, " Mt. Pomasa," May 21, 1906, U. Faurie
(No. 664).
Cultivated: Arnold Arboretum (No. 7254).
66 THE AZALEAS OP THE OLD WORLD
This Korean Azalea is usually a compact densely branched shrub from a few
inches to a metre high, but in shaded places it may be as much as two metres tall
and rather loosely branched; on wind-swept slopes and on the tops of rocks it hugs
the ground and forms broad mats. The branches are twiggy and clothed with
appressed gray hairs which disappear the second year. No part of the plant is
glandular; the winter-buds are ovoid, more or less pointed and covered with
appressed, gray-brown hairs. The leaves are quite or partially deciduous according
to climate and in the autumn are tinted from orange to crimson. The spring
leaves are membranous, oblanceolate to lanceolate or ovate-lanceolate, from 3 to
8 cm. long and from 1 to 2 cm. broad, acute and mucronate at apex, with a narrow
wedge-shaped base; they are dark green and have impressed veins on the upper
surface, and are pallid below where the principal veins are prominent, ascending
and arching inward but not extending to the margins of the leaf; both surfaces
are clothed with straight appressed gray to shining brown hairs. The summer
leaves are thicker, narrowly oblong-lanceolate, from 0.4 to 1 cm. wide, attenuate
at the base; the margins are often obscurely crenate-serrate, and the upper surface
is glabrous at maturity except for a few, short appressed, white bristles. The
flowers are in clusters of two to several, and are remarkably fragrant, with a
corolla rose to rosy purple. The calyx is ample, green and clothed with pubes-
cence similar to that of the leaves, the lobes are lanceolate to ovate-lanceolate,
from 5 to 10 mm. long, acute, obtuse or rounded. The pistil is exserted but the
stamens are included, 10 in number, with purple anthers. The fruit is erect,
ovoid, from 7 to 10 mm. long, clothed with strigose hairs and subtended by
the persistent calyx-lobes. This is the common Azalea of Korea from about the
latitude of Seoul (Keijyo), the capital city southward. It is partial to open country
and on grassy mountain-slopes and in thin Pine-woods it forms dense matlike
masses from a few inches to a yard high. On boulders in water-courses the growth
is low and dense but in thickets the plants are more loosely branched and often two
metres high. It grows from sea-level up to about 1600 m. altitude according to
latitude and in some places, like the foothills of Chiri-san, it is very abundant.
On Quelpaert it grows from sea-level to near the summit of Hallai-san and is
common on boulders in the water-courses and on the moorlands. On Poukhan-
san behind Keijyo from which it derives its specific name it is rare though
there are places not far from there where it is common.
This Azalea was introduced to the Arnold Arboretum by Mr. J. G. Jack who
sent seeds from Poukhan-san in the autumn of 1905. Plants flowered for the first
time in May, 1914. It has proved perfectly hardy here, grows freely and flowers
profusely. The flowers are distinctly and pleasantly fragrant and the plant is a
decided acquisition to the list of hardy species of its section.
Japanese botanists have recorded this plant from several places in Hondo, Japan,
and Komatsu (in Tokyo Bot. Mag. XXXII. [38] (1918) ) enumerates fourteen garden
forms. I have seen the Japanese material from wild plants referred to this species
in the herbarium of the Imperial Botanic Garden, Tokyo, but it is too fragmentary
to base a definite opinion upon. That from the Tokyo region has yellow anthers
and belongs to R. dbtusum var. Kaempferi f. mikawanum Wils. It certainly has
nothing to do with R. yedoense var. poukhanense. That from Bitchu province
collected by Z. Yoshino has purple anthers and the veins on the upper surface
are indistinctly impressed. It may represent Nakai's variety but the material is
too incomplete to judge by.
Rhododendron Oldhamii Maximowicz in Mem. Acad. Sci. St. Peters-
bourg, se"r. 7, XVI. No. 9, 34 (Rhodod. As. Or.) (1870). — Masters in
Gard. Chron. n. ser. XVII. 524 (1882). — Hemsley in Jour. Linn. Soc.
ENUMERATION OF THE SPECIES 67
XXVI. 28 (1889). — Henry in Trans. Asiat. Soc. Jap. XXIV. suppl.
57 (1896). — J. H. Veitch, Hortus Veitchii, 286 (1906). — Matsumura
& Hayata in Jour. Coll. Sci. Tokyo, XXII. 218 (Enum. PL Formos.)
(1906).— Hayata in Jour. Coll. Sci. Tokyo, XXV. art. 19, 153 (Fl.
Mont. Formos.) (1908). — Matsumura, Ind. PL Jap. II. pt. 2, 463
(1912). — Komatsu in Icon. PL Koisikav. II. 69, t. 119 (1914); in
Tokyo Bot. Mag. XXXII. [11] (1918). — Kanehira, Formos. Trees,
325, fig. 10 (1917). — Millais, Rhodod. 220 (1917).
Azalea Oldhamii Hort. Veitch. apud Masters in Gard. Chron. n. ser. XVII. 524
(1882).
Rhododendron Oldhamii var. glandulosum Hayata in Jour. Coll. Sci. Tokyo
XXV. art. 19, 153 (Fl. Mont. Formos.) (1908).
Rhododendron longiperulatum Hayata, Icon. PL Formos. III. 138 (1913).- —
Kanehira, Formos. Trees, 323, fig. 13 (1917). — Komatsu in Tokyo Bot. Mag.
XXXII. [14] (1918).
Formosa: prov. Taihoku, Jyukirin, sea-level to 1000m., April 8,
1918, E. H. Wilson (No. 10,316); Tamsui, 1864, R. Oldham (No. 212,
Herb. Kew, Herb. Gray); Sekitei, alt. 100-500 m. March 17, 1918,
E. H. Wilson (No. 10,165); prov. Nanto, round Lake Candidius,
March 11, December 7, 1918, E. H. Wilson (Nos. 9980, 11,175); be-
yond'Musha up to 2900 m. March 3, 1918, E. H. Wilson (No. 10,029);
prov. Kagi, beyond Ari-san, alt. 2800-2900 m. February 4, 1918,
E. H. Wilson (No. 9778); prov. Koshun, South Cape, Schmuser ex
A. Henry (Nos. 588, in part, 588A. Herb. Kew); prov. unknown,
" Okasaki," March, 1914, U. Faurie (No. 164, Herb. Bur. Sci. Ma-
nila); without locality ex Herb. Imp. Bot. Gard. Tokyo (Herb. Bur.
Sci. Manila).
This is the common red-flowered Azalea of Formosa, where it is endemic and
widely spread from sea-level up to 2800 m. altitude but is more abundant in the
north than elsewhere. On volcanic Mt. Daiton, not far from the capital city of
Taihoku, it is a feature on the wind-swept upper slopes. On sandstone cliffs east
of Taihoku it is common, and in thickets round Lake Candidius in central Formosa
it is a conspicuous shrub. On the grass-clad highlands beyond Musha and beyond
Ari-san it is plentiful. I did not see it in the extreme south, which is of coral forma-
tion, and suspect that Schmiiser's specimen cited really came from the savage
territory more to the north. The species is very glandular and very hairy, the
leaves shoots, pedicels and calyx being covered with a soft pubescence much of
which is long, villose and ferrugineous in color but on wind-swept mountains in
winter the pubescence may be bleached pale gray and the plant shaggy in appear-
ance. It is a much-branched shrub from 1 to 3 m. tall, bushy in habit with twiggy
branchlets densely clothed with glandular, spreading, red-brown hairs among
which are scattered flattened, paleaceous hairs spreading and less appressed
than is the rule in other red-flowered Azaleas. The leaves are persistent, and vary
in shape from elliptic or elliptic-oblong to elliptic-ovate or very rarely to lanceolate;
they are from 2 to 8 cm. long and from 1 to 4 cm. wide, rounded or subacute at the
68 THE AZALEAS OF THE OLD WORLD
apex which is furnished with a long gland-tipped mucro; the base is narrowed.
Both surfaces and the petiole are clothed with pubescence similar to that on
the shoots; on mature leaves the upper surface is scaberulous from the presence of
the tumid persistent base of deciduous hairs; the veins are impressed above,
raised and prominently reticulate below. The flowers are borne at the end of the
shoots, and at low altitudes appear every month in the year. The corolla is red,
funnel-shape, with spreading, rounded lobes, and from 3 to 5 cm. in diameter. The
calyx is green and variable in size, and the lobes may be rounded and less than 1 mm.
long or triangular-acuminate and as much as 8 mm. long. The ten stamens are of
unequal length, the longest almost equalling the corolla but overtopped by the
slender, glabrous, exserted style. The fruit is more or less erect, ovoid, from 6 to
10 mm. long, densely glandular-setose, on pedicels from 1 to 1.5 cm. long.
This species varies considerably in size of the leaves and calyx-lobes and some-
what in degree of hairiness and glandulosity but is well marked and easily recog-
nized among all the species of its section. At its altitudinal limits and on bleak
mountain-slopes the leaves, which are scattered on the free shoots and clustered at
the end of the branchlets, are tinted blackish purple. It was discovered by Rich-
ard Oldham round Tamsui in 1864, and introduced to gardens by Charles Maries
who sent seeds to Messers Veitch in 1878. Plants raised from these seeds were
exhibited in London in the spring of 1882. Whether plants of this origin are still
in cultivation I do not know. In 1918 I sent seeds to the Arnold Arboretum which
were distributed in America and Europe. As a greenhouse plant Oldham's Azalea
is worth cultivating.
In Tokyo I examined the type specimen of R. longiperulatum Hayata and could
find no characters by which to separate it from R. Oldhamii. On Mt. Daiton, the
type locality given by Hayata for his species, the variable R. Oldhamii is abundant
but 1 could find no other species of the group growing there. Mr. Shimada who
accompanied me told me it was all R. longiperulatum Hayata so-named from his
original specimen collected on this mountain.
Rhododendron mucronatum G. Don, Gen. Syst. III. 846 (1834).
Azalea rosmarinifolia Burmann, Fl. Ind. 43, t. 3, fig. 3 (1768). — Rehder in
Bailey, Cycl. Am. Hort. I. 123 (1900).
Azalea mucronata Blume, Cat. Gewass. Buitenz. 44 (1823); Bijdr. Fl. Nederl.
853 (1825).
Azalea indica alba Lindley, Bot. Reg. X. t. 811 (1824). — Loddiges, Bot. Cab.
XIII. t. 1253 (1827).
Azalea ledifolia Hooker in Bot. Mag. LVI. t. 2901 (1829). — Hovey, Mag.
Hort. IV. 135 (1838).
Azalea liliiflora Poiteau in Annal. de From. 104 (1829). — Loiseleur, Herb.
Amat. se*r. 2, I. t. 40 (1839). — Carriere in Rev. Hort. 1869, 299.
Azalea alba Sweet apud Poiteau in Annal. de From. 104 (1829), as a synonym.
Rhododendron leucanthum Bunge in Mem. Soc. £tr. Acad. Sci. St. Petersbourg,
II. 115 (Enum. PL Chin. Bor. 41) (1833).
Rhododendron ledifolium G. Don, Gen. Syst. 846 (1834). — Siebold and Zuc-
carini in Abh. Akad. Munch. IV. pt. III. 131 (Fl Jap. Fam. Nat. II. 7)
(1846). — Planchon in Rev. Hort. 1854, 48. — Boissier, Herb. Boiss. V. 918
(1897). — Bean, Trees and Shrubs Brit. Isl. II. 365 (1914). — Rehder in
Bailey, Stand. Cycl. Hort. V. 2943 (1916). — Millais, Rhodod. 201, t.
(1917).
Rhododendron Burmanni G. Don, Gen. Syst. III. 846 (1834).
Rhododendron macranthum var. albiflorum Souchetianum Lemaire in Loiseleur,
Herb. Amat. se*r. 2, III. t. 15 (1843).
ENUMERATION OF THE SPECIES 69
Rhododendron liliiflorum grandiflorum souchetianum Lemaire in Loiseleur,
Herb. Amat. ser. 2, III. sub. t. 15 (1843), as a synonym.
Rhododendron ledifolium a. leucanthum De Candolle, Prodr. VII. pt. 2, 727
(1839). — Miquel in Ann. Mus. Lugd.-Bat. I. 34 (1863); II. 164 (1865-66);
Prol. Fl. Jap. 96 (1866-67). — Maximowicz in Mem. Acad. Sci. St. Peters-
bourg, ser. 7, XVI. No. 9, 36 (Rhodod. As. Or.) (1870). — Franchet &
Savatier, Enum. PI. Jap. I. 291 (1875). — Matsumura, Ind. PL Jap. II.
pt. 2, 462 (1912).
Rhododendron rosmarinifolium Dippel, Handb. Laubholzk. I. 421 (1889), not
Vidal. — Voigtlander in Gartenwelt XV. 650, fig. (1911). — Schneider III.
Handb. Laubholzk. II. 503, figs. 330 f., 331 c-e (1911). — Komatsu in Tokyo
Bot. Mag. XXXII. [13] (1918).
Azalea rosmarinifolia var. alba Render in Bailey, Cycl. Am. Hort. 1. 123 (1900).
Rhododendron rosmarinifolium var. album Schneider, III. Handb. Laubholzk.
II. 504 (1911).
Rhododendron ledifolium var. album Render in Mitt. DeutschDendr. (?es.XXIV.
225 (1916).
Japan: Kyushu, prov. Hizen, Nagasaki, cultivated, April 25, 1903,
U. Faurie (No. 5434); prov. Chikugo, Kurume, cultivated, May 3,
1918, E. H. Wilson. Hondo, prov. Choshu, Shimonoseki, cultivated,
garden Sanyo Hotel, May 17, 1917, E. H. Wilson (No. 8426); prov.
Settsu, near Osaka, cultivated, May 7, 1918, E. H. Wilson; prov.
Kishu, May 15, 1911, K. Sakurai; prov. Musashi, Yokohama, culti-
vated, 1862, C. Maximowicz (Herb. Kew); Tokyo, cultivated, March
29, 1914, E. H. Wilson (No. 6339); same locality, cultivated, May 15,
1882, K. Miyabe; prov. Ugo, Akita, cultivated, May 20, 1888, U.
Faurie (No. 2133); prov. Mutsu, Hirosaki, May 27, 1905, U. Faurie
(No. 6786). Hokkaido, prov. Oshima, Hakodate, cultivated, 1855,
C. Wright (Herb. Gray, Herb. Kew); same locality, 1862, M.
Albrecht (Herb. Kew).
Japan: without locality, 1862-63, R. Oldham (No. 506); ex Herb.
Lugd.-Bat., 1863 (Herb. Gray, Herb. Kew).
China: prov. Hupeh, Ichang, cultivated, A. Henry (No. 3503,
Herb. Gray).
Cultivated: ex Herb. Bot. Bog. (Herb. Bur. Sci. Manila); Forest
Hills Cemetery, Boston, Mass., June 9, 1906, J. G. Jack; Butler Planta-
tion, West Feliciana Parish, La., March 28, 1910, C. S. Sargent; Hort.
Berckmans, Augusta, Georgia, March 18, 1909, C. S. Sargent; Hort.
Kew, May 28, 1901, A. Rehder.
This well-known plant is a much-branched compact, wide-spreading shrub usu-
ally from 1.5 to 2 m. tall but sometimes over 3 m. high and more in diameter.
The shoots in their first year, as well as the petioles and pedicels, are densely clothed
with gray to gray-brown, spreading, soft hairs and intermixed with them, espe-
cially on the shoots, are few or many appressed and spreading, flattened, bristle-like
hairs. On both shoots and pedicels occasional glandular hairs are present; the inner
70 THE AZALEAS OF THE OLD WORLD
scales of the flower-buds are also glandular. The spring leaves are light green,
deciduous and rather thin in texture, they are lanceolate to ovate-lanceolate, from
3 to 6 cm. long and from 1 to 2.5 cm. wide, acute or obtuse, mucronulate, clothed
on both surfaces witlj soft, straight, appressed, gray to rufous hairs; the summer
leaves are dark green, numerous, persistent and sub-coriaceous, oblong-lanceolate
to oblanceolate-oblong, from 1 to 4 cm. long and from 0.6 to 1.2 cm. wide, obtuse
or rounded, mucronate, somewhat rugulose above, prominently veined on the
lower surface, their margins more or less recurved; both surfaces are clothed with
soft, straight, appressed, gray to rufous hairs, and often mixed with these are
spreading, glandular, gray hairs. The flowers are in clusters of one or more at
the end of the branch, fragrant, pure white; occasionally an odd branch may have
rose-colored flowers, or flowers striped with rose. The calyx is green and ample,
the calyx-lobes are erect, lance-shaped, about 1 cm. long, often somewhat erose
and more or less densely glandular-pubescent. The corolla is wide-funnel shape
from 4 to 5 cm. long and broad; the stamens are usually 10 (occasionally 8) as
long as the corolla or nearly so, and are exceeded by the pistil which is slightly
exserted. The fruit is conic, with appressed setose hairs, and is shorter than the
persistent calyx-lobes which surround it.
This Azalea is a favorite plant in Japan and has a place in almost every garden
more especially from Tokyo southward, but its wild prototype was discovered
only quite recently.1 It is the " Jedogawa-tsutsuji with white flowers " mentioned
by Kaempfer (Amoen. Exot. 848 [1712]), and by Thunberg was included under his
Azalea indica as " Yedogawa Satsuke." It was cultivated in Java in the days
of Burmann and without doubt was brought there from Nagasaki, Japan, by Dutch
trading ships. In China it is grown in the gardens of the wealthy in many parts
of the Empire, but how it got there we do not know. According to Lindley (Bot.
Reg. X. t. 811 [1824]) it was first introduced into England to the nurseries of Mr.
Brookes at Ball's Pond through his collector Joseph Poole who sent it from China
in 1819. Like all introductions of this period it came, in all probability, either
from Canton or Macao. Probably there were other importations from China in
early times and during the last thirty years hundreds of thousands of plants have
been sent from Japan to America and Europe. Its fragrant, white flowers and
good constitution have made it a favorite and common plant in the greenhouses of
the west. In fairly recent years it has been found to be more hardy than was once
supposed, and it is now quite frequently seen as an outdoor garden shrub. I have
not been able to ascertain the exact date of its introduction into America, but
Hovey tells us that it was growing in the garden of J. P. Gushing, Belmont
Place, Watertown, Massachusetts, in February, 1838. It is scarcely hardy near
Boston but on Long Island, New York, and southward it is perfectly hardy. In
Japan it is known as the " Shiro-yodogawa," that is " White Yodogawa."
I am familiar with this plant in the gardens of Japan and China as well as in those
of Europe and America and in addition to the material enumerated I have seen
the many old specimens preserved in Herb. Kew and Herb. Gray, which include
several sent from Java many years ago. Every specimen in herbaria that I have
seen is definitely stated to have come from cultivated plants. That it is an albino
form of some species has long been suspected and it is satisfactory to be able to
identify it at last. After an exhaustive study I am of the definite opinion that this
old favorite garden plant is a white-flowered form of a plant wild near the banks
of rivers on the island of Shikoku, which has lilac-purple flowers and to which
Makino (in Tokyo Bot. Mag. XXII. 55 (1908) has given the name R. ripense.
1 Millais states that " Carles collected it on the Seoul mountains in Korea.'
This is incorrect; the plant is R. yedoense var. poukhanense Nakai.
ENUMERATION OF THE SPECIES 71
The specific name here employed to designate this species is the oldest valid
name but it seems to have been quite overlooked. Burmann named the plant
Azalea rosmarinifolia in 1768. This is the oldest name but unfortunately it was
neglected for over a century and became invalidated under Rhododendron by the
R. rosmarinifolium Vidal, a Philippine species, some years before it was taken up
for Burmann's plant by Dippel.
A form with larger flowers than the type is : —
Rhododendron mucronatum f. Noordtianum Wilson, n. comb.
Azalea japonica alba grandiflora van Noordt Pynaert in Rev. Hort. Belg. XXX.
133, t. (1904) . — Reuter in Mailer's Deutsch. Gdrtn. Zeit. XX. 73, fig. (1905) .
Azalea ledifolia var. Noordtiana Wittmack in Gartenfi. LIX. 310, fig. 32
(1910).
Rhododendron ledifolium var. Noordtianum Render in Mitt. Deutsch. Ges.
XXIV. 225 (1916).
Rhododendron rosmarinifolium f . Oriukiu Komatsu in Tokyo Bot. Mag. XXXII.
[35] (1918).
Japan: Hondo, prov. Kawachi, Ikeda, cultivated, May 8, 1918,
E. H. Wilson.
Pynaert states that this form was raised in the nursery of P. van Noordt &
Sons, Boskoop, from seeds collected from some plants introduced from Japan. I
can find no difference between it and the form long cultivated in Japan under
the name of 0-riukiu-tsutsuji (large Liukiu Azalea). It is considered in Europe
to be a very hardy form of the type.
Very similar to the last-named form is: —
Rhododendron mucronatum "Mattapan" Wilson, n. f.
Azalea "Mattapan" C. M. Hovey, Mag. Hort. XXVII. 190 (1861).
This plant was exhibited for the first time before the Massachusetts Horticul-
tural Society on March 23, 1861, by C. M. Hovey, and described as " a new seed-
ling, flowers white with a yellowish blotch on the upper petals which are fringed
in the way of A. crispiflora." This handsome form is still in the Holm Lea collec-
tion and in other gardens round Boston, Mass. In some gardens this Azalea is
known by the name of "America."
A form with double white flowers is : —
Rhododendron mucronatum f . narcissiflorum Wilson, n. comb.
Rhododendron narcissiflorum Planchon in Fl. des Serr. IX. 82 (1854) ; in Rev.
Hort. 1854, 67. — Hemsley in Jour. Linn. Soc. XXVI. 27 (1889). — Millais,
Rhodod. 216 (1917).
Azalea narcissiflora Fortune apud Planchon in Fl. des Serr. IX. 82 (1854), as
a synonym. — Hovey, Mag. Hort. XXII. 9 (1856).
Rhododendron ledifolium 7. narcissiflorum Maximowicz in Mem. Acad. Sci.
St. Petersburg, ser. 7, XVI. No. 9, 36 (Rhodod. As. Or.) (1870), in part. —
Franchet & Savatier, Enum. PL Jap. I. 291 (1875). — Matsumura, Ind.
PI. Jap. II. pt. 2, 462 (1912). — Bean, Trees and Shrubs Brit. Isl. II. 366
(1914). — Render in Bailey, Stand. Cycl. Hort. V. 2944 (1916).
Azalea rosmarinifolia var. narcissiflora Render in Bailey, Cycl. Am. Hort. 123
(1900).
72 THE AZALEAS OF THE OLD WORLD
Rhododendron rosmarinifolium var. narcissifiorum Schneider, III. Handb.
Laubholzk. II. 504 (1911).
Rhododendron rosmarinifolium f. narcissiflorum a. Shiromanyo Komatsu in
Tokyo Bot. Mag. XXXII. [36] (1918).
Japan: Kyushu, prov. Chikugo, Kurume, cultivated, May 3, 1918,
E. H. Wilson.
Under the name of " Shiro-manyo-tsutsuji " this double-flowered form has been
cultivated in Japan for a long time — probably centuries. It was introduced into
England by Robert Fortune who sent plants from China to Messers Standish &
Noble about 1850 or 1851. It was imported into this country by C. M. Hovey in
1855. Hovey (Mag. Hort. V. 25 [1839]) speaks of an Azalea ledifolia alba pleno
having been introduced into Boston in 1838. The name suggests that the form nar-
cissiflorum may have been in gardens prior to Fortune's introduction but I have
been unable to find any further reference to the plant mentioned by Hovey. Mil-
lais suggests this may be a hybrid R. indicum x R. linearifolium ? but it is
difficult to understand why it should be regarded as anything but the common
R. mucronatum G. Don (Azalea ledifolia Hook.) with double flowers. The habit,
fragrance, calyx and pubescence are identical. Maximowicz refers the double rose-
colored form (f . plenum Wils.) to this f . narcissiflorum and Millais does the same
but for horticultural purposes it is best kept distinct.
A fine garden form of the type is: —
Rhododendron mucronatum f. sekidera Wilson, n. comb.
Rhododendron rosmarinifolium f. Sekidera Komatsu in Tokyo Bot. Mag.
XXXII. [35] (1918).
Rhododendron Sekidera (Rhod. indicum X Rhod. Kaempferi) Komatsu in
Tokyo Bot. Mag. XXXII. [46] (1918).
Azalea magniflca Hort. Yokohama Nursery Co. Cat. 1918-19, p. 19.
Azalea indica roseum Hort. Andorra Nurseries, May, 1919.
Azalea japonica grandiflora superba Hort. Andorra Nurseries, May, 1919.
Azalea " Damask Rose " Hort. Andorra Nurseries, May, 1919.
Japan: prov. Musashi, cultivated, May 21, 1914, E. H. Wilson
(No. 6670).
This very handsome plant I saw cultivated in the grounds of the Yokohama
Nursery Company. The flowers are as large as those of f. Noordtianum, pure
white with the dorsal lobes spotted and splashed with rose, occasionally a flower is
rose-colored; the stamens vary in number from 6 to 10 but are usually 10. Under
the names Azalea indica roseum and Azalea "Damask Rose" slightly inferior
forms were sent to us for determination last year. The true variety is cultivated
by Mr. John S. Ames, North Easton, Mass., who imported it in 1917. In 1919 I
brought back plants from Japan to the Arnold Arboretum. This most desirable
addition to our gardens will probably prove to be as hardy as the typical white-
flowered R. mucronatum G. Don.
A spontaneous variety and undoubtedly the phylogenetic type of
the species is : —
Rhododendron mucronatum var. ripense Wilson, n. comb.
Rhododendron ripense Makino in Tokyo Bot. Mag. XXII. 55 (1908). — Schnei-
der, III. Handb. Laubholzk. II. 503 (1911). — Komatsu in Icon. PI. Koisi-
kav. II. 71, t. 120 (1914); in Tokyo Bot. Mag. XXXII. [12] (1918).
ENUMERATION OF THE SPECIES 73
Japan: Kyushu, prov. Hizen, Nagasaki, common in gardens,
March 19, 1914, E. H. Wilson (No. 6316); prov. Chikugo, Kurume,
cultivated, May 3, 1918, E. H. Wilson.
Cultivated: Garden of Butler Plantation, West Feliciana Parish,
Louisiana, March 28, 1910, C. S. Sargent.
I have examined the type of Makino's R. ripense and can find no character by
which it differs from R. mucronatum G. Don, except in the rose-purple color of its
flowers, and as is well known a branch bearing colored flowers is often found in
Don's species. Nevertheless, Makino's discovery is most interesting since it
enables us to place definitely the habitat and parentage of R. mucronatum G. Don
which has remained obscure for over a century and a half. Makino gives two
localities and says that it is found wild by the side of rivers in Tosa and lyo prov-
inces in Shikoku, and also that it is frequently cultivated. I have seen it only
as a cultivated plant in Japan where it is not by any means such a general favorite
as the pure white form. I saw more plants round Nagasaki than elsewhere. At
Kurume it is known as the " Momo-iro-yodogawa." Makino gives the vernacular
name in Tosa province as " Iso-tsutsuji."
There is in cultivation in this country an intermediate and very
lovely form in which the corolla is white, delicately flushed with pale
lilac-purple and has a few very faint rose-pink spots. As a garden
plant it is distinct and desirable and it may be called: —
R. mucronatum f. amethystinum Wilson, n. f.
Cultivated: Hort. Farquhar & Co., Boston, Mass., April 1, 1909,
(type). Hort. Andorra Nurseries, Chestnut Hill, Philadelphia, Pa.,
May 20, 1920, as Azalea japonica alba.
Rhododendron mucronatum f. plenum Wilson, n. comb.
Azalea indica var. /S. plena Suns in Bot. Mag. LI. t. 2509 (1824).
Azalea indica 7. purpurea Sweet, Hort. Brit. 264 (1827).
Azalea prolifera Poiteau in Annal. de From. I. 104 (1829).
Rhododendron phoeniceum var. p.flore pleno G. Don, Gen. Syst. III. 846 (1834).
Azalea purpurea pleno Hovey, Mag. Hort. V. 115 (1839).
Rhododendron indicum f . incamatum De Candolle, Prodr. 726 (1839).
Rhododendron ledifolium 7. nartissiflorum Maximowicz in Mim. Acad. Sci.
St. Petersburg, se>. 7, XVI. No. 9, 36 (Rhodod. As. Or.) (1870), in part.
Rhododendron ledifolium var. plena purpurea Regel in Gartenfl. XXXV. 565,
t. 1233, fig. c-d (1886).
Azalea indica purpurea plena Bretschneider, Hist. European Bot. Disc. Chin.
222 (1898).
Rhododendron rosmarinifolium f. narcissiflorum /3. Fujimanyo Komatsu in
Tokyo Bot. Mag. XXXII. [36] (1918).
Japan: Hondo, prov. Kawachi, Ikeda, cultivated, May 8, 1918,
E. H. Wilson.
Cultivated: Hort. Holm Lea, Brookline, Mass.
Round Tokyo and Yokohama this plant is known as Fujimanyo; round Osaka
it is the Murasaki-botan-tsutsuji (purple Paeony Azalea). It is an old plant even
74 THE AZALEAS OF THE OLD WORLD
in western gardens, having been sent by Joseph Poole from China to Samuel Brookes,
nurseryman, Ball's Pond, Newington Green, England, in 1819. The flower is rose-
purple, fragrant, quite, or only partially double, and with or without green rudi-
mentary leaves showing in the centre of the flower. Hovey tells us that this plant
was cultivated by Mrs. Hibbert and exhibited before the Pennsylvania Horticul-
tural Society on February 19, 1839.
Rhododendron linearifolium Siebold & Zuccarini in Abh. Akad.
Munch. IV. pt. III. 131 (Fl. Jap. Nat. II. 7) (1846).— Miquel in Ann.
Mus. Lugd.-Bat. I. 34 (1863); II. 165 (1864-66); Prol. FL Jap. 97
(1866-67). — Maximowicz in Mem. Acad. Sci. Petersbourg, se*r. 7,
XVI. No. 9, 34 (Rhodod. As. Or.) (1870). — Franchet & Savatier,
Enum. PL Jap. I. 290 (1875). — Boissier in Bull. Herb. Boiss. V. 918
(1897). — Schneider, III. Handb. Laubholzk. II. 504, figs. 330 g-k,
331 f. (1911). — Matsumura, Ind. PL Jap. II. pt. 2, 463 (1912).—
Bean, Trees and Shrubs Brit. Isl. II. 366 (1914). — Millais, Rhodod.
203 (1917).
Azalea linearifolia Hooker f. in Bot. Mag. XCV. t. 5769 (1869).
Rhododendron macrosepalum var. linearifolium Makino in Tokyo Bot. Mag.
XXII. 55 (1908). — Komatsu in Tokyo Bot. Mag. XXXII. [34] (1918).
Rhododendron linearifolium a. linearifolium Makino in Tokyo Bot. Mag.
XXVII. 108 (1913).
Cultivated: November, 1867, February, 1869, ex Hort. Standish
(Herb. Kew); 1876, ex Hort. Hunnewell (Herb. Gray).
This is a monstrous garden form cultivated in Japan but rather rare. The leaves
are narrow, strap-shaped, and the corolla is divided into narrow, ligulate segments.
An analogous plant is R. indicum f . polypetalum Wils. Maximowicz says it was in-
troduced into the gardens of Tokyo from the alpine regions of Sendai in north-
ern Japan. This is a mistake. It is unknown in a wild state and was first known
from the neighborhood of Nagasaki in Kyushu the southern island of Japan. Its
Japanese name is " Seigai-tsutsuji." It was introduced into England by Messers
Standish with whom it flowered in November, 1867, and again in February, 1869.
It is well figured in the Botanical Magazine. From England it appears to have
been sent to this country for it flowered in the garden of Mr. H. H. Hunnewell,
Wellesley, Mass., in 1876. According to Bean it is quite hardy at Kew. It is not
hardy in the Arnold Arboretum and I do not know whether it is now cultivated
in America.
Rhododendron linearifolium var. macrosepalum Makino in Tokyo
Bot. Mag. XXVII. 108 (1913).
Rhododendron macrosepalum Maximowicz in Gartenfl. XIX. 258, t. 662 (1870) ;
in Mem. Acad. Sci. St. Petersburg, s6r. 7, XVI. No. 9, 31 (Rhodod. As. Or.)
(1870) ; in Bull. Acad. St. Petersburg, se*r. III. XV. 227 (Mel Biol VII. 335)
(1871). — Franchet & Savatier, Enum. PL Jap. I. 290 (1875). — Dippel,
Handb. Laubholzk. I. 420, fig. 271 (1889). — Makino in Tokyo Bot. Mag.
IV. 151 (1890); XXII. 55 (1908). — Boissier in Bull Herb. Boiss. V. 918
(1897). — Schneider, III. Handb. Laubholzk. II. 503, figs. 330 e, 331 a-b
ENUMERATION OF THE SPECIES 75
(1911). — Matsumura, Ind. PL Jap. II. pt. 2, 463 (1912). — Millais, Rho-
dod. 205 (1917). — Komatsu in Tokyo BoL Mag. XXXII. [13] (1918).
Azalea macrosepala K. Koch, Dendr. II. pt. 1, 180 (1872). — O. Kuntze, Rev.
Gen. II. 387 (1891).
Rhododendron linearifolium /3. macrosepalum forma a. genuinum Makino in
Tokyo BoL Mag. XXVII. 108 (1913).
Japan: Kyushu, prov. Hizen, roadside, Nagasaki to Mogi, No-
vember 12, 1903, C. S. Sargent. Shikoku, prov. Tosa, thickets up to
300 m. alt. November 20, 1914, E. H. Wilson (No. 7794). Hondo,
prov. Settsu, near Kobe, April, 1875, H. N. Moseley (Herb. Kew);
prov. Kawachi, Yomomoto and Ikeda, May 8, 1918, E. H. Wilson
(No. 10,355); prov. Yamato, Koyasan, August 26, 1907, U. Faurie
(No. 124); Yoshino, April 22, 1914, E. H. Wilson (No. 6574, in part);
prov. Yamashiro, Kyoto, Temple Garden, October 16, 1892, C. S.
Sargent; Kyoto, J. Rein, ex Mus. Bot. Berol. (Herb. Bur. Sci. Manila) ;
prov. Omi, mountains round Lake Biwa, April 30, 1892, U. Faurie
(No. 7820, Herb. Kew) ; prov. Mino, Pine-barrens near Gifu, October
20, 1892, C. S. Sargent; prov. Mikawa, Pine-woods, Futagawa, May 9,
1918, E. H. Wilson (Nos. 10,346, 10,348, 10,349); prov. Shimotsuke
" alpe Niko," 1866-74, L. Savatier (No. 766, Herb. Kew).
This is the Mochi-tsutsuji (Glandular Azalea) of Japan, where it is common in
central Hondo at low altitudes from near Osaka north to Hamamatsu in Totomi
province; also in Tosa province, Shikoku. It is partial to gravelly soil and dry
situations such as Pine- woods and open thickets afford. A social plant it occurs
in great numbers either alone or with R. obtusum var. Kaempferi Wils. At Futa-
gawa, for instance, in Pine-woods these two species grow in thousands and in early
May when in full blossom they are conspicuous from the railway carriage windows.
The specimen from Nagasaki is probably from an escaped plant and there is no
other record of its growing in Kyushu. North of Totomi province I have not seen
it wild, and I think there is some mistake about it being indigenous in the Nikko
region, Maximowicz's statements and Savatier's specimens notwithstanding. It is
not mentioned by Matsumura in his Plants of Nikko nor by Hayata in his Vege-
tation of Mt. Fuji.
As usually seen R. linearifolium var. macrosepalum is a low, rather laxly branched
shrub spreading in habit and less than one metre high but in Shikoku I saw it
full three metres tall. It has the usual dimorphic leaves and these are mostly
deciduous. The shoots are terete and with the petioles are densely clothed with
gray to gray-brown pilose (some of them gland-tipped) hairs and a few flattened,
spreading bristles which disappear in the second season; the winter-buds are ovoid,
acute, densely covered with strigose, yellow-brown hairs. The leaves are mem-
branous, scattered on the free-growing shoots and crowded on others, short-
petioled, lanceolate-ovate to ovate-elliptic, sometimes lanceolate or ovate, short
acuminate, acute or merely mucronulate; those immediately beneath the winter-
buds oblanceolate to oblanceolate-oblong obtuse, or rounded, usually mucronulate,
the under surface clothed with soft, spreading, gray to gray-brown glandular hairs,
the upper surface sparsely glandular hairy, slightly rugulose and hispid; dull green
during summer changing to rich vinous purple in the autumn. The flowers are
76 THE AZALEAS OF THE OLD WORLD
fragrant, from 2 to 10 in terminal umbels, very variable in size and form. The
pedicels are from 2 to 4 cm. long, straight or spreading, densely glandular and
pilose. The calyx is green, glandular-pubescent and very variable in size, the
strap-shaped segments being from 1 to 3 cm. long and occasionally exceeding the
rose-pink to red-purple corolla, which is broad funnel-shape, sometimes 5 cm. but
often not more than 3 cm. across; it is glabrous without, and normally larger than
the calyx. Stamens normally 5, but at Ikeda I gathered specimens with from 6 to
10 stamens; they are shorter than the pistil and included within the corolla except
in abnormally small flowers. The fruit is narrow-ovoid, about 1 cm. long, glandu-
lar-pubescent, purplish-brown in color and subtended by the persistent calyx the
lobes of which are reflexed, brown without and wine-purple on the inside. There
can be no question of this being the phylogenetic type of the species and it is
B unfortunate that it should have to rank as a variety. Even in a wild state it is a
very variable plant, and a number of forms have been detected and are cultivated
in Japanese gardens; these are dealt with hereafter. The calyx, pedicels and inner-
most scales of the flower-buds are always glandular, usually densely so and com-
monly sufficiently viscid to hold gnats and small flies captive, but this viscosity
like everything else in this plant is variable. The flowers are pleasantly fragrant
and some of the color forms are very handsome. When the flowers have a com-
paratively small corolla and very long calyx-lobes the effect is curious. This
Azalea was introduced into Petrograd by Maximowicz who sent seeds in 1863. It
flowered for the first time in 1870 and is well figured in Gartenflora. Maximowicz
claims that the seeds and his two plants came from the Nikko alps but if this is
not a mistake it is strange that no other collector has seen the plant in this locality
which is fully two hundred miles north of where it has been seen wild by subse-
quent observers. Further, no one else has found it in alpine regions anywhere in
Japan. However, there is no doubt that the plant under discussion is Maxi-
mowicz's species. What happened to the original introduction I do not know
but neither Bean nor Millais mention its cultivation in England. In 1914 I sent
to the Arnold Arboretum seeds of this plant from Shikoku some of which were
sent to England. Plants raised from this seed in the Arnold Arboretum have not
proved very hardy.
A form with double flowers is: —
Rhododendron linearifolium var. macrosepalum f. dianthiflorum
Wilson, n. comb.
Azalea dianthiflora Carriere in Rev. Hort. 1889, 391; 1891, 60, fig. 18, t.
Rhododendron dianthiflorum Millais, Rhodod. 155 (1917).
Japan: Hondo, prov. Mikawa, Pine-woods, Futagawa, May 9,
1918, E. H. Wilson (No. 10,350).
Cultivated: ex Hort. James Veitch & Sons, June 28, 1904 (Herb.
Kew).
1 have seen at Futagawa one or two plants growing wild with double flowers.
The pedicels are more spreading than in the type and the calyx-lobes are variable
in length. Carriere's figures give a good idea of this form except that the color is
brighter and more pleasing than the plate shows. According to Carriere it was
introduced into France from Japan in 1889 by M. Wiesener, of Fontenay-aux-
Roses. The specimen in Herb. Kew shows that it was cultivated by Messers Veitch
in 1904. Bean does not mention it and Millais's account is abbreviated from Car-
riere's description. 1 have no knowledge of its being in the gardens of this country.
ENUMERATION OF THE SPECIES 77
Another spontaneous form is: —
Rhododendron linearifolium var. macrosepalum f . decandrum Wil-
son, n. f.
Japan: Hondo, prov. Kawachi, Yomomoto, roadside, Pine-woods,
May 8, 1918, E. H. Wilson (No. 10,355a, type); Ikeda, cultivated,
May 8, 1918, E. H. Wilson; prov. Yamato, near Yoshino, dry woods,
April 22, 1914, (No. 6574, in part).
This differs from the type in having 10 stamens; the Ikeda specimens have from
6 to 10 stamens and that from Yoshino (a fragment) has 6 only. The typical var,
macrosepalum is common round Yomomoto where it is known as the Yama-tsutsuji
(Mountain Azalea) and growing with it I found occasional plants with 10 or
from 6 to 10 stamens in each flower. I have seen none with from 5 to 10 stamens
and I do not remember whether the fragment from near Yoshino came from a
bush of the ordinary 5-stamen type.
An anomalous form is : —
Rhododendron linearifolium var. macrosepalum f. rhodoroides
Makino in Tokyo Bot. Mag. XXVII. 109 (1913).
Rhododendron macrosepalum /3. rhodoroides Maximowicz in Mem. Acad. Set.
St. Petersburg, ser. 7, XVI. No. 9, 31 (Rhodod. As. Or.) (1870). — Fran-
chet & Savatier, Enum. PI. Jap. I. 290 (1875). — Matsumura, Ind. PI
Jap. II.pt. 2, 463 (1912).— Komatsuin Tokyo Bot. Mag. XXXII. [34] (1918).
Rhododendron ledifolium var. Kochozoroi Komatsu apud Makino in Tokyo
Bot. Mag. XXVII. 109 (1913), as a synonym.
Japan: Hondo, prov. Kawachi, cultivated, Yamomoto and Ikeda,
May 8, 19J.8, E. H. Wilson; prov. Musashi, Okbo, cultivated, May 18,
1909, K. Onuma; Hatagaya, cultivated, April 29, 1914, E. H. Wilson
(No. 6596).
This is a curious form often seen in Japanese gardens. It has a deeply cleft
5-partite corolla only slightly longer than the calyx-lobes, and greenish-white shaded
with rose, exserted stamens with pale purple anthers exceeded in length by the
style. Maximowicz raised seedlings from this plant and states that in every in-
stance they reverted to typical var. macrosepalum. Makino gives " Kocho-zoroi "
as the Japanese name of this plant; in the nursery district near Osaka it is known
as " Seikan-tsutsuji."
Another anomalous form is: —
Rhododendron linearifolium var. macrosepalum f. hanaguruma
Makino in Tokyo Bot. Mag. XXVII. 109 (1913).
Rhododendron ledifolium var. leucanthum f. Hanaguruma Komatsu apud
Makino in Tokyo Bot. Mag. XXVII. 109 (1913), as a synonym.
Rhododendron macrosepalum var. Hanaguruma Makino in Tokyo Bot. Mag.
XXVII. 109 (1913), as a synonym. — Komatsu in Tokyo Bot. Mag. XXXII.
[35] (1918).
Rhododendron linearifolium var. macrosepalum f. polypetalum Makino in
Tokyo Bot. Mag. XXVII. 109 (1913), as a synonym.
78 THE AZALEAS OF THE OLD WORLD
Japan : Hondo, prov. Kawachi, cultivated at Yomomoto and Ikeda,
May 8, 1918, E. H. Wilson; prov. Rikuzen, Sendai, cultivated, May
27, 1888, U. Faurie (No. 2300, Herb. Kew).
Cultivated : ex Hort. Ball, March, 1879 (Herb. Kew).
In this form the corolla is rose-purple in color, deeply cleft and 5-partite, and
the stamens are usually shorter than the corolla-lobes which are from 2.5 to 4 cm.
long. Makino gives " Hana-guruma " as the Japanese name; in the nursery dis-
trict near Osaka it is known as " Oyeyama-tsutsuji." The specimen in Herb.
Kew proves that at one time it was in cultivation in England.
Komatsu (in Tokyo Bot. Mag. XXXII. [34] [1918]) enumerates
three other forms (" Usuyo," "Amaga-shita" and " Suruga-momyo ")
of this species, but these are unknown to me.
These are all the species of the section Tsutsutsi that are named or of which I
have seen sufficient material. There is, however, in this herbarium specimens (ex
Herb. Hongkong Nos. 7030, 5612) from Taimo-shan, Kowloon, Kwangtung prov-
ince, of a curious Azalea. It has narrow, linear-lanceolate, acuminate leaves and
inconspicuous subsessile flowers with the corolla deeply divided into five narrow
segments. It is in every way anomalous, and probably a monstrous condition of
some species not yet described, or possibly of the widespread R. Simsii Planch.
We have, also, a leafy fragment, collected in Kweichou province by Dr. Handel-
Mazzetti (No. 221, July 11, [1917]) which probably belongs to a new species re-
lated to R. Oldhamii Maxim.
SECT. II. SCIADORHODION REHD. & WILS., n. sect.1
Rhododendron section Tsutsutsi G. Don, Gen. Syst. III. 847 (1834),
as to species nos. 30, 31. — Render & Wilson in Sargent, PL Wilson.
I. 547 (1913), in part.
Rhododendron subgenus Tsutsia Planchon in Fl. des Serr. XI. 75 (1854); in
Rev. Hort. 1854, 43, as to R. Farrerae.
Rhododendron section Azalea Maximowicz in Mem. Acad. Sci. St. P&ersbourg,
s&r. 7, XVI. No. 9, 24 (Rhodod. As. Or.) (1870), in part.
Azalea subgenus Euazalea K. Koch, Dendr. II. pt. 1, 179 (1872), as to A.
reticulata.
Rhododendron section Rhodora Dippel, Handb. Laubholzk. I. 418 (1889), in
part.
Shrubs with rigid, usually verticillate, often ascending-spreading branches and
glabrous or villose shoots without bristle-like hairs. Flowers from terminal buds,
with leafy shoots from axils of lower scales of the same bud. Leaves deciduous,
in whorls of 3 to 5 at the end of the branchlets, on vigorous shoots scattered,
not dimorphic, usually rhombic to obovate, rarely ovate, without appressed
bristle-like hairs. Corolla rotate-campanulate, rarely rotate-funnel-form; stamens
from 6 to 10 (rarely 5 by abortion), unequal, sometimes declinate. Fruit oblong-
ovoid to cylindric, rarely conic-ovoid, often furrowed, villose or glandular, never
strigose.
This section is found only in eastern Asia, where it is represented by 6 species.
Rhododendron Farrerae Tate apud Sweet, Brit. Flow. Gard. ser. 2, 1.
t. 95 (1831). — G. Don, Gen. Syst. III. 846 (1834).— De Candolle,
Prodr. VII. 725, pt. 2 (1839). — Planchon in Fl. des Serr. XIX. 80
(1854); in Rev. Hort. 1854, 64. —Maximowicz in Mem. Acad. Sci. St.
Petersburg, se>. 7, XVI. No. 9,25 (Rhodod. As. Or.) (1870). — Hance
in Jour. Linn. Soc. XIII. 110 (1873). — Hemsley in Jour. Linn. Soc.
1 Sectio inter sect. Tsutsutsi et Rhodoram medium tenens, a priori indu-
mento piloso vel villoso pallido, non strigoso et fusco, foliis semper deciduis satis
magnis, corolla rotato vel rotato-campanulata, ovario villoso vel glabro, non stri-
goso, a posteriori gemmis terminalibus flores et folia simul proferentibus bene
differt, ab utraque sectione foliis in apice ramulorum subverticillatim congestis
quasi umbellam vel umbraculum (graece axids, a/ctdSos, unde nomen) formantibus
satis magnis plerumque late obovatis vel rhombico-ovatis distat.
In Sargent, Plantae Wilsonianae, I. 548 (1913), we suggested that with their
whorled leaves the species here enumerated formed a well-marked group easily
distinguished from Tsutsutsi, although agreeing in the character of the winter-
buds. Further investigation has brought to light other differences and we are of
the opinion that it is best to place them in a distinct section.
A. R. & E. H. W.
79
80 THE AZALEAS OF THE OLD WORLD
XXVI. 23 (1889); in Kew Bull. Misc. Inform. 1907, 245. — Dunn
& Tutcher in Kew Bull. Misc. Inform, add. ser. X. 155 (Fl. Kwang-
tung and Hongk.) (1912). — Millais, Rhodod. 163 (1917).
Azalea squamata Lindley in Jour. Hart. Soc. Lond. I. 152 (1846); in Bot. Reg>
XXXIII. t. 3 (1847). — Walpers, Ann. I. 481 (1848-49). — Bentham, Fl>
Hongk. 201 (1861).
Azalea Farrerae K. Koch, Dendr. II. pt. 1, 178 (1872). — O. Kuntze, Rev.
Gen. pt. 2, 387 (1891).
Azalea squamosa O. Kuntze, Rev. Gen. pt. 2, 387 (1891), as a synonym.
Rhododendron Farrerae S. typicum Diels in Bot. Jahrb. XXIX. 514 (1900).
China: prov. Kwangtung, Loh-fau-san, August 21, 1917, C. 6.
Levine (ex Canton Christian College Herb. No. 1533).
This species seems to be peculiar to Hongkong and the neighboring islands
and to the adjacent parts of Kwangtung province. It is a low, densely branched
shrub with short, rigid, shining brown, verticillate branchlets clothed with ap-
pressed, straight and villose hairs when young, becoming glabrous and gray in
their second year. The leaves are crowded, usually in threes at the end of the
branches, subcoriaceous, deciduous or semi-persistent, glabrescent, ovate, from
2 to 3 cm. long and from 1.2 to 2 cm. wide, acute or sub-acute, with a short mucro,
and a rounded base; they are dark green above and pallid below, reticulate, with
the principal veins impressed above and raised below. The petioles are from 1 to
3 mm. long and densely villose. The winter-buds are small, broadly ovoid, and
are densely clothed with gray or rufous pubescence. The flowers appear before
the leaves unfold, either solitary or in pairs at the end of the branches. The corolla
is pale to deep rose-color with red-purple spots, from 4 to 5 cm. in diameter; it has
a short, narrow, funnel-shape tube and spreacling, undulate lobes. The ring-like
calyx is minutely 5-toothed, and pubescent; and the pedicel and ovary are thickly
clothed with appressed and villose, ferrugineous or gray hairs. The stamens are
from 8 to 10 of unequal length and shorter than the corolla, and are equalled or
slightly overtopped by the slender, curved style. The fruit is conic-ovoid, from
0.5 to 1.5 cm. long and from 0.8 to 1 cm. in diameter and densely villose, and
is borne on a stout, curved, villose pedicel about 1 cm. long.
I have seen this Azalea growing wild in Hongkong and as Hemsley has pointed
out it is a very distinct species. It is characterized by its small, ovate leaves, its
very short villose petioles and by its relatively large fruit. It was first introduced
into England in 1829, by Captain Farrer of the East India Company's ship " Or-
well." It was reintroduced by Robert Fortune who in 1844 sent it to the garden
of the Horticultural Society of London where it flowered and was renamed by
Lindley. I have no knowledge of its having been in cultivation in America, and
Millais states that it is a rare plant in English gardens, and hardy only in the
south.
Rhododendron Mariesii Hemsley and Wilson in Kew Bull. Misc.
Inform. 1907, 244. — Hutchinson in Bot. Mag. CXXXIV. t. 8206
(1908). — Schneider, III. Handb. Laubholzk. II. 496, fig. 327 1-m
(1909). — Render & Wilson in Sargent, PL Wilson. I. 548 (1913).—
Bean, Trees and Shrubs Brit. I si. II. 377 (1914). —Millais, Rhodod.
207 (1917).
ENUMERATION OF THE SPECIES 81
Rhododendron Weyrichii Hemsley in Jour. Linn. Soc. XXVI. 32 (1889), not
Maximowicz.
Rhododendron Farrerae a. leucotrichum Franchet in Jour, de Bot. IX. 394
( 1895).— Diels in Bot. Jahrb. XXIX. 513 (1900). — Millais, Rhodod. 163
(1917).
Rhododendron Farrerae a. Weyrichii Diels in Bot. Jahrb. XXIX. 513 (1900).
Rhododendron Farrerae y. mediocre Diels in Bot. Jahrb. XXIX. 514 (1900).
Rhododendron rhombicum Diels in Bot. Jahrb. XXIX. 514 (1900), not Miquel.
Rhododendron Farrerae Kawakami, PI. Formos. 64 (1910), not Tate.
Rhododendron shojoense Hayata in Jour. Coll. Sci. Tokyo, XXX. art. 1, 174
(1911).
Rhododendron gnaphalocarpum Hayata, Icon. PL Formos. III. 132 (1913). —
Kanehira, Formos. Trees, 327, fig. 14 (1917).
China : without locality, 1845, R. Fortune (No. 122 (2), Herb. Kew);
prov. Fokien, April to June, 1905, Dunn's Exped. (Hongk. Herb. No.
2882); prov. Chekiang, Taihu Lake, near Huchau, April, 1881, W.
R. Carles (No. 117, Herb. Kew); prov. Kiangsi, Kuling, 1878, C.
Maries (Herb. Kew); same locality, alt. 1300 m. July 29, 1907, E. H.
Wilson (No. 1681) : prov. Hupeh, Changyang Hsien, A. Henry (Nos.
1422, 5274, 594p,Herb. Kew, Herb. Gray) ; Nanto and mountains to
northward, A. Henry (No. 3829, Herb. Kew, Herb. Gray); north and
south of Ichang, alt. 300-1300 m. May and November, 1907, E. H.
Wilson (No. 606, in part); south of Ichang, alt. 800 m. April and
October, 1900, E. H. Wilson (Veitch Exped. No. 29. type); Hsing-
shan Hsien, alt. 1300, May 12, 1907, E. H. Wilson (No. 606, in part);
prov. Szech'uan, Nanch'uan, A. von Rosthorn (No. 2164, Herb. Chris-
tiania).
Cultivated: ex Hort. Veitch, April, 1907 (Herb. Kew, type of
Bot. Mag. t. 8206).
This species is distributed from Fokien and Chekiang provinces of eastern
China westward to southeastern Szech'uan. On the Lushan mountains round
Kuling it is common and north and south of Ichang it is very plentiful on cliffs
and in thickets between altitudes of 300 and 1300 m. Its pleasing pink to rose-
colored flowers open before the leaves unfold and in late April and May it is a
conspicuous wayside shrub. Curiously this and R. molle G. Don are the only
deciduous leafed species in the whole of China except R. Farrerae Tate from
Hongkong and the adjacent territory. Maries' Azalea is an upright branching
shrub from 1 to 3 m. tall, rather narrow, with verticillate, twiggy, ascending
branches which are shining, yellow or chestnut-brown during the first year and
afterward pale gray. When young the shoots and leaves are covered with yellow-
ish, appressed silky hairs which usually fall away early or may in part persist on
the shoot through the entire season. The buds are conic, gray-purple, with ciliate
bud-scales glabrescent without and villose on the inner surface. The leaves at
maturity are chartaceous, dark green above, pallid below, prominently reticulate,
with the principal veins slightly impressed on the upper side and raised on the
lower side; they vary from 3.5 cm. to 7.5 cm. in length and from 2 to 4 cm. in
width, and are always the broadest below the middle. The prevailing shape is
82 THE AZALEAS OF THE OLD WORLD
ovate-lanceolate, with an acute mucronate apex and cuneate base, but occasion-
ally they are broad-ovate or elliptic. The petioles are from 0.4 to 1.2 cm. in length,
glabrescent, purplish, and often slightly glaucescent on the under-side. The flowers
are usually in pairs at the end of the naked branchlets, but are sometimes soli-
tary, and occasionally are in 4- or 5-flowered clusters; the corolla is from 4 to
5 cm. across, spotted with red-purple on the posterior lobes; it has a short, narrow,
funnel-shape tube and deeply cleft, spreading lobes. The pedicels are villose; the
minute, 5-lobed calyx and the ovary are clothed with gray or yellow-brown,
straight appressed hairs. The 10 stamens are of nearly equal length and as long
as the corolla, the filaments are glabrous, curved and the anthers purple. The
style is longer than the stamens and is curved upward and has a capitate, slightly
lobed stigma. The fruit is cylindric, from 1 to 1.5 cm. long, slightly furrowed,
and clothed with gray or yellow-brown, villose pubescence, and is borne on a
straight pedicel.
From those species with which R. Mariesii has been confused it is readily dis-
tinguished by its leaves. The flowers are of a different color from those of the
Japanese species, the corolla is differently shaped and there are other distinctions
of importance. In Tokyo I saw the types of Hayata's two species cited and could
find nothing by which to distinguish them from R. Mariesii.
This Chinese plant was discovered by Fortune, probably in Chekiang province,
and afterward by Charles Maries on the Lushan mountains behind Kiukiang in
the spring of 1878. It was introduced into Kew gardens through seeds sent from
the neighborhood of Ichang in 1886 by Augustine Henry; in 1900 I sent seeds
to Messers Veitch from south of Ichang. This Azalea flowered for the first time in
the Temperate House at Kew in April, 1907. Bean does not consider it to be
hardy. I have not heard of its being cultivated in America.
Rhododendron Weyrichii Maximowicz in Mem. Acad. Sci. St.
Petersbourg, ser. 7, XVI. No. 9, 26, t. 2, fig. 1-6 (Rhodod. As. Or.)
(1870). — Franchet & Savatier, Enum. PI. Jap. I. 288 (1875). —
Makino in Tokyo Bot. Mag. XVIII. 48 (1904). — Schneider, 111.
Handb. Laubholzk. II. 495 (1909), in a note. — Matsumura, Ind. PL
Jap. II. pt. 2, 464 (1912). — Nakai, Rep. Fl. Quelpaert Isl No. 999
(1915); in Tokyo Bot. Mag. XXXI. 243 (1917); Fl. Syl. Kor. VIII.
44, t. 16 (1919). — Millais, Rhodod. 261 (1917), excluding the Chinese
plant. — Komatsu in Tokyo Bot. Mag. XXXII. [10] (1918).
Azalea Weyrichii O. Kuntze, Rev. Gen. pt. 2, 387 (1891).
Rhododendron shikokianum Makino in Tokyo Bot. Mag. VI. 43 (1892); in IX.
Ill (1895).
Japan : Shikoku, prov. Tosa, round Kochi, sea-level to 800 m. al-
titude, November 17, 1914, E. H. Wilson (No. 7813). Kyushu, prov.
Hizen, near Nagasaki, 1862, R. Oldham (No. 511, Herb. Gray).
Korea: Quelpaert Island, between Saishu and the Monastery,
400-650 m. October 30, 1917, E. H. Wilson (No. 9411); same island,
Hallai-san, October, 1906, May, 1907, U. Faurie (Nos. 661, 1863 in
part, 1864); same place, May, 1909, April 14, June 6, 1908, E. Taquet
(Nos. 2970, 4678, 108S).
ENUMERATION OF THE SPECIES 83
This little known species has a very curious distribution. On the island of
Shikoku it is common round Kochi in Tosa province but does not grow on the
mainland of Kyushu, but it is found on the adjacent islands of Amakusa and Goto
south and west of Nagasaki. I do not know whether it grows on the island of
Tsushima in the Japan Sea — probably it does — but it is common on the Korean
island of Quelpaert although unknown on the mainland of Korea. In Shikoku I
found it to be fairly plentiful from near sea-level up to an altitude of 800 m.
growing in thickets and open woods. On Hallai-san, an extinct volcano on Quel-
paert Island, between 200 and 1000 m. altitude, and especially in thickets by the
sides of water-courses and on old lava flows, it is common.
This Azalea is a vigorous growing shrub from 1 to 5 m. tall, often decidedly
tree-like in habit, with moderately stout ascending to spreading often whorled
branches. These are yellow-brown, clothed with ferrugineous tomentum when
young, becoming glabrous, gray and finally dark purple in color. The winter-buds
are characteristic, being conic and sub-acute and clothed with yellow-brown,
matted and straight hairs and are unlike those of other species. The leaves are
distinctly petiolate, chartaceous, shining green and deciduous, changing to vinous
purple in the autumn; on the vigorous shoots the leaves are scattered and in pairs
or whorls but on the branchlets they are clustered in whorls of 3, or in pairs;
they vary from broad-ovate to semiorbicular or to rhombic, and in size from 3.5
to 8 cm. long and from 2 to 6 cm. wide; they are abruptly subacute or obtuse at the
apex which is mucronate, the base is broadly cuneate or rounded. The principal
veins are impressed above and slightly raised on the lower surface which is
venulose. When young the petioles and both surfaces of the leaf are covered
with rufous-brown pilose hairs but these soon disappear. The flowers are from
2 to 4 in terminal umbels, and open before or at the same time as the leaves
unfold. The pedicels, calyx and ovary are densely clad with rufous-brown pilose
hairs. The corolla is red, almost brick-red, from 3.5 to 6 cm. across, funnel-
shape, with a rather narrow expanding tube and spreading lobes. The calyx is
merely a ring with five minute teeth. The stamens vary from 6 to 10, and are
of unequal length, and like the curved style and its capitate stigma are in-
cluded. The fruit is cylindric or oblong-ovoid, from 1.5 to 2 cm. long, oblique,
furrowed and obtusely angled and clothed with appressed, villose pubescence.
This species was discovered on the Goto Islands in 1853 by Dr. Heinrich Wey-
rich, a surgeon on the Russian warship " Vostok " which formed part of Admiral
Putiatin's fleet. On Oldham's specimen the locality cited is Nagasaki but this is
a mistake; it probably came from the Amakusa Islands south by west of that city.
Makino first found it in Shikoku and Pere Faurie on Quelpaert Island. It was
unknown in gardens until 1914 when I sent the seeds from Shikoku to the Arnold
Arboretum which were distributed in America and Europe. Plants raised in this
Arboretum have not proved hardy but in another Massachusetts garden where
they have received the protection of a cold frame they have flowered. In 1917
I collected seeds on Quelpaert and hope that they will produce a hardier type. I
have never seen this Rhododendron in flower in a wild state and only a late flower
or two on cultivated plants. The color of the flowers is good and where it proves
hardy this species should be a welcome addition to gardens.
Rhododendron reticulatum D. Don apud G. Don, Gen. Syst. III.
846 (1834). -De Candolle, Prodr. VII. pt. 2, 727 (1839).
Rhododendron dilatatum Miquel in Ann. Mus. Lugd.-Bat. I. 34 (1863-64);
in II. 164 (1865-66); Prol. FL Jap. 96 (1866-67).
Rhododendron rhombicum Miquel in Ann. Mus. Lugd.-Bat. II. 164 (1865-66);
Prol. FL Jap. 96 (1866-67). — Regel in Gartenfl. X. XVII. 225, t. 586
84 THE AZALEAS OF THE OLD WORLD
(1868). — Maximowicz in Mem. Acad. Sri. St. Petersburg, ser. 7 XVI.
No. 9, 26 (Rhod. As. Or.) (1870). — Franchet & Savatier, Enum. PL Jap.
I. 288. (1875). — Hooker f. in Bot. Mag. CXIII. t. 6972 (1887). — Bean in
Gard. Chron. ser. 3, XX. 38, fig. 9 (1896); Trees and Shrubs Brit. Isl. II.
375, fig. (1914). — Boissier in Bull. Herb. Boiss. V. 918 (1897). — Dalli-
more in Garden, LXXII. 267, fig. (1908). — Mottet in Rev. Hort. 1909, 79,
fig. 28. — Schneider, III. Handb. Laubholzk. II. 497, figs. 327 f-g, 328 d-e
(1911). — W. Watson, Rhodod. and Azaleas, 111 (1911). — Matsumura,
Ind. PI. Jap. II. pt. 2, 463. (1912). — Render in Bailey, Stand. Cycl. Hort.
V. 2943 (1916). — Millais, Rhodod. 235 (1917). — Komatsu in Tokyo Bot.
Mag. XXXII. [10] (1918).
Azalea reticulata K. Koch, Dendr. II. pt. 1, 179 (1872).
Azalea dilatata O. Kuntze, Rev. Gen. pt. 2, 387 (1891).
Azalea rhombica O. Kuntze, Rev. Gen. pt. 2, 387 (1891). — Rehder in Bailey,
Cycl Am. Hort. I. 122 (1900).
Rhododendron dilatatum /3. decandrum Makino in Tokyo Bot. Mag. VII. 134
(1893).
Rhododendron decandrum Makino in Jour. Jap. Bot. I. 21 (1917).
Rhododendron Wadanum Makino in Jour. Jap. Bot. I. 21 (1917).
Japan : Kyushu, prov. Satsuma, Kagoshima in gardens, March 4,
1914, E. H. Wilson (No. 6158); Togo, in a garden, March 14, 1914,
E. H. Wilson (No. 6266); prov.Osumi, Mt. Kirishima, alt. 100-1 000m.
1917, Z. Tashiro; Nishi-Kirishima, alt. 1000 m. March 11, 1914,
E. H. Wilson (No. 6241); prov. Hizen, Nagasaki, Mt. Yuwaja, 1863,
C. Maximowicz (Herb. Gray). Shikoku, prov. Tosa, Nano-kawa,
May 12, 1889, K. Watanabe (Herb. Gray). Hondo, prov. Choshu,
between Habu and Asa, May 7, 1918, E. H. Wilson (No. 10,369);
prov. Aki, Miyajima, November 28, 1914, E. H. Wilson (No. 7842);
prov. Yamato, Yoshino, April 22, 1914, E. H. Wilson (No. 6573); prov.
Yamashiro, Kyoto, April 22, 1914, E. H. Wilson (No. 6568); prov.
Shinano, Ogawa, September 5, 1905, J. G. Jack; Nojiri to Nakatsu-
gawa, September 6, 1905, J. G. Jack; slopes of Mt. Komaga-take,
October 24, 1892, C. S. Sargent; prov. Suruga, lower slopes of
Mt. Fuji, alt. 800-1000 m. May 8, 1914, E. H. Wilson (No. 6640);
prov. Sagami, Hakone Mts. Kintoki, May, 1876, James Bissett (No.
237, Herb. Kew); prov. Shimotsuke, Nikko region, alt. 1000-1800 m.
May 18, October 24, 1914, E. H. Wilson (Nos. 6705, 7694), shores of
Lake Chuzenji, September 3, November 7, 1892, C. S. Sargent; same
locality, October 25, 1905, J. G. Jack. Hokkaido, prov. Hidaka, Shoya
village, August 17, E. Tokubuchi. Province unknown, " Mimasaka,"
May 10, 1904, S. Arimoto (Herb. Gray).
Cultivated: Arnold Arboretum (No. 3427-1).
This is a common plant throughout the greater part of Japan. In Kyushu,
Shikoku and Hondo it is everywhere abundant; in Hokkaido it is rather rare and
ENUMERATION OF THE SPECIES 85
finds the northern limits of its range in Hidaka province. On volcanic ash, lava-
flows and on cliffs in many places, as in the Nikko region, lower slopes of Mt. Fuji and
on the Hakone mountains for example, it is extraordinarily abundant both in open
country, in thickets, on the margins of woods and as undergrowth in thin forests.
It is in flower from early in March to late in June according to latitude and altitude
and produces in great abundance its rose- to red-purple or rich magenta-colored
blossoms. The richest colors are on plants in the open, and in dense shade the
color is quite pale. Nowadays magenta is not a popular color in the west but
massed and alone save for the varying shades of green the flowers of this Azalea
are impressive. The plant forms a much-branched bush or bushy tree from 1 to
8 metres tall, with numerous erect or erect-spreading verticillate, slender but
rigid branches, yellow-brown and sparsely or densely hairy when young, usually
soon becoming glabrous, and in the second year pale gray. In the shade the
branches are more sparse and the plants less compact and shapely in habit.
The winter-buds are conic and acute, with rufous- or gray-brown, villose and ciliate
scales, the inner ones being viscid. The leaves unfold as the corollas fall, and are
clustered in threes or in pairs at the end of the branchlets, and vary in shape from
broad-ovate to rhombic or occasionally to ovate, and terminate in a short mucro.
In size they vary from 3 to 6 cm. in length and from 2.5 to 5.5. cm. in width, with
petioles from 0.5 to 1.5 long. In the shade the leaves are membranous but in the
open they are firm and the reticulation is more prominent; they are dark green
above, pale even sub-glaucous below, and in the autumn change to vinous or
blackish purple or occasionally to yellow with splashes of red-purple. The
principal veins are impressed above and raised and usually more or less villose
on the under surface. When young the leaves are densely clothed with long,
or with short and long, appressed, gray to yellow-brown pilose hairs which dis-
appear early from the upper and entirely or partially from the lower surface. The
petiole is flattened and usually villose, but may be glabrous and glaucescent. The
flowers are borne at the end of the shoots in pairs or solitary or in clusters
of three or four. The corolla is from 3.5 to 5 cm. across usually unspotted,
with a short tube and spreading lobes which are often divergent and give the
corolla a two-lipped appearance. The pedicels are clothed with gray or brownish
appressed hairs, and the minute, 5-toothed calyx is ciliate, villose or glabrescent.
The stamens are normally 10, in two series, the longer equalling the corolla in
length, the shorter half as long, the filaments curving upward; the anthers are
purple. The ovary is covered with short straight hairs, or is lepidote, or lepidote and
hairy, and the style is hairy or glabrous; the stigma capitate and minutely 5-lobed.
The fruit is curved, cylindric, from 1 to 1.5 cm. long, furrowed, lepidote, glabrous,
or clothed with gray or brown soft hairs.
I have gone very minutely into the degree of variation exhibited by this plant
for I realize that those who compare the two figures in the Botanical Magazine
will find it difficult to appreciate that they represent the same species and really
only differ in the number of stamens. In the array of specimens before me and
cited above the variations mentioned are all shown and neither among them nor
in the field have I been able to distinguish two species. The distinguishing char-
acters emphasized by Maximowicz are inconstant except the number of stamens
and I am doubtful if careful examination among many plants would not reveal
flowers with five and others with ten stamens on the same plant. I have 10-
stamened flowers with a lepidote ovary and style, with a hirsute and lepidote
ovary and glabrous style; I have 5-stamened flowers which show exactly the same
variation. On both forms I find glabrous leaves and leaves more or less pubescent
below especially on the principal veins.
Miquel had only leaf specimens and founded his two species chiefly on the
difference in shape of the leaves. On every plant of this species as here understood
86 THE AZALEAS OF THE OLD WORLD
the leaves tend toward a rhombic shape, in fact this predominates and from this
they vary to broad-ovate and occasionally to ovate. An attempt to make leaf-
distinctions in this plant of specific value breaks down on the first bush examined.
Maximowicz who had flowering specimens and young leaves added to Miquel's
description of R. dilatatum the 5 stamens and glandular ovary which subsequent
authors have used to distinguish Miquel's two species. That Maximowicz was
not justified in this is abundantly proved by the material before me. As to
Makino's R. Wadanum I have specimens from Shikoku with slightly spotted
flowers but can find no other difference and do not consider that they can be
separated even as a variety. It is unfortunate that both Miquel's names should
have to be dropped but G. Don's description, brief as it is, leaves no doubt that
the plant he had was the same as that later described by Miquel. It has long been
accepted that Don's name belonged to one of Miquel's species but the question
remained to which? With the acceptance of the view first suggested by K. Koch
that both represent one species the question disappears and Don's name becomes
the valid, as it is the oldest, name. 1 have taken the form with ten stamens as
representing the type since it is by far the more common.
According to G. Don this Azalea was first introduced into England from Japan
by Messers Knight of Chelsea and evidently about 1832-33, but it must have been
lost. It was introduced by Maximowicz into the Petrograd Botanic Gardens in
1865, and is figured in the Gartenflora for 1868 but the color is poor. It was in-
troduced into the Arnold Arboretum by Professor Sargent who sent seeds from the
Nikko region in the autumn of 1892. The plants have grown slowly but have
proved perfectly hardy and each spring for a number of years past have flowered
profusely. Apparently it is rare in Europe and is one of the plants which will
probably thrive better in eastern North America than in England.
The specimen cited from Kintoki on the Hakone mountains is simply an ab-
normal condition of typical R. reticulatum G. Don in which the flowers have
been retarded and are open when the leaves are well grown. There are two
flowers and the pistil of a third, and a small deformed flower on the specimen, and
one flower with two unfolding leaves. The leaves have the characteristic rhombic
shape and the flowers have from 8 to 10 stamens. Branches bearing late flowers
and leaves together may be found occasionally on any species of precocious
flowering Rhododendron.
A variety with white flowers is : —
Rhododendron reticulatum var. albiflorum Wilson, n. comb.
Rhododendron rhombicum var. albiflorum Makino in Tokyo Bot. Mag. XVIII.
66 (1904). — Render in Bailey, Stand. Cycl. Hort. V. 2943 (1916).
Makino describes this plant from Tosa province in Shikoku and states that it
is very rare. It is unknown to me and is not cultivated in western gardens.
The form adopted by Maximowicz as the typical R. dilatatum
Miquel, and so considered by subsequent authors, and which is char-
acterised by having 5 stamens only may be distinguished as: —
Rhododendron reticulatum f . pentandrum Wilson, n. nom.
Rhododendron dilatatum Maximowicz in M6m. Acad. Sci. St. Petersbourg,
se~r. 7, XVI. No. 9, 27 (Rhodod. As. Or.) (1870), in part, not Miquel. —
Franchet & Savatier, Enum. PL Jap. I. 289 (1875). — Matsumura, PI.
Nikko 71 (1894); Ind. PL Jap. II. pt. 2, 459 (1912). — Boissier in Bull.
ENUMERATION OF THE SPECIES 87
Herb. Boiss. V. 918 (1897) . — Hooker f . in Bot. Mag. CXXV. t. 7681 (1899) . —
J. H. Veitch, Hortus Veitchii, 373 (1906). — Shirisawa, Icon. Ess. For.
Jap. II. t. 61, figs. 23-32 (1908). — Schneider, III. Handb. Laubholzk. II.
497, figs. 327 h, 328 a-b (1911). — Bean, Trees and Shrubs Brit. Isl. II.
353 (1914). — Millais, Rhodod. 155 (1917). — Komatsu in Tokyo Bot.
Mag. XXXII. [9] (1918).
Rhododendron dilatatum a. typicum Makino in Tokyo Bot. Mag. VII. 134 (1893).
Japan: Hondo, prov. Shinano, 1864, Tschonoski (Herb. Gray);
prov. Suruga, Mt. Fuji, May 12, 1907, (flowers), August 15, 1905,
(leaves); prov. Sagami, Hakone Mts., alt. 600-1000 m. April 16, 1914,
E. H. Wilson (No. 6448); in a garden, Miyanoshita, April 17, 1914,
E. H. Wilson (No. 6429).
Cultivated: Royal Gardens, Kew, May, 1880, G. Nicholson.
Of the characters proposed by Maximowicz only that of the 5 stamens seems
to hold and, as I have already mentioned, I am not convinced that this is con-
stant. This form is believed to have been introduced to England by Messers
Veitch in 1883, but that it was in cultivation in Kew as early as 1880 is shown by
Nicholson's specimens preserved in this herbarium. I have no record of its being
cultivated in America though it will probably appear among the seedlings raised
from Japanese seeds collected by me in 1914 and distributed by the Arnold
Arboretum.
Rhododendron quinquefolium Bisset & Moore in Jour. Bot. XV
292 (1877). — Franchet & Savatier, Enum. PI. Jap. II. 653 (1879). —
Matsumura, PI. Nikko, 71 (1894); in Tokyo Bot. Mag. XIV. 69
(1900); Ind. PL Jap. II. pt. 2, 463 (1912). — Komatsu in Icon. PL
Koisikav. I. 59, t. 30 (1912); in Tokyo Bot. Mag. XXXII. [8] (1918). —
Bean, Trees and Shrubs Brit. Isl. II. 374 (1914). — Rehder in
Bailey, Stand. Cycl. Hort. V. 2947 (1916). — Millais, Rhodod. 233
(1917).
Japan : Hondo, prov. Shimotsuke, Nikko region, alt. 600-1600 m.
May 14, May 18, October 20, 1914, E. H. Wilson (No. 6683, type,
6683A, 7676); Lake Chuzenji, October 21, 1914, E. H. Wilson (No.
7676A); same locality, August 11, October 25, 1905, J. G. Jack.
This very distinct species is well characterised by its corky, brown bark, its
broad-elliptic to obovate verticillate leaves and by its snow white, rotate-cam-
panulate corolla. In habit of growth, arrangement and shape of leaves and in
the shape of the flowers it superficially resembles R. pentaphyllum Maxim, but
the two belong to different sections. In Maximowicz's species the flowers and
leafy shoots originate from different buds, the flower-bud being terminal and the
leaf-buds lateral below it. In this new species both flowers and leafy shoots
issue from the same bud. This Azalea is abundant in shady, rocky ravines in the
Nikko region but is elsewhere unknown to me. It is a bush or small tree from 1.5
to 8 m. tall with gray-brown, corky bark, fissured into thick irregular plates; the
shoots are glabrous, terete, shining brown the first year and arranged partly in
verticils and partly alternate. The winter-buds are narrow-ovoid, acute, with
88 THE AZALEAS OF THE OLD WORLD
purple-brown ciliate scales, the basal ones having long aristate points. The leaves
are deciduous and unfold at the same time as the flowers open; they are clustered 4 or
5 together at the end of the shoots and vary from broad-elliptic to obovate, the apex
is mucronate and the base cuneate, the edges are ciliate and often margined with
red-purple; they are more or less villose, especially the lower half of the midrib;
the petiole is very short and villose. The flowers are either solitary, or two or
three together on slender, glandular-hairy pedicels; the corolla is pure white with
green spots within, rotate-campanulate, and the calyx is membranous, with 5
lanceolate or deltoid, glandular-ciliolate segments. The stamens are ten, with
greenish filaments of unequal length, dilated and villose at the base. The pistil
much exceeds the stamens and is glabrous except at the summit of the ovary. The
fruit is stout, cylindric, and from 1 to 1.5 cm. long.
According to Bean, this Azalea was introduced into English gardens by Lord
Redesdale about 1896, but it appears to be rare in gardens. To America it has
been sent by the Yokohama Nursery Company under the name of " Azalea quin-
quefolia white " and I have seen it growing fairly well in the garden of Mr.
T. A. Havemeyer, on Long Island. It is a woodland plant and needs shade and
a cool situation if it is to thrive. In 1905 Mr. J. G. Jack sent seeds from Lake
Chuzenji to this Arboretum but the resultant plants failed to prove hardy. The
plants raised from seeds sent from the same locality in 1914 have also proved
tender. Like many other woodland plants this Azalea is difficult to manage when
young.
Rhododendron Schlippenbachii Maximowicz in Bull. Acad. Sri.
St. Petersbourg, se>. 3, XV. 226 (Mel. Biol VII, 333) (1870); in Mem.
Acad. Sri. St. Petersbourg, se>. 7, XVI. No. 9, 29, t. 2, figs. 7-13
(Rhodod. As. Or.) (1870).— Herder in Act. Hort. Petrop. 1.347 (1871).—
Franchet & Savatier, Enum. PL Jap. 289 (1875). .— Hemsley in
Jour. Linn. Soc. XXVI. 30 (1889). — Hooker f. in Bot. Mag. CXX.
t. 7373 (1894).— Gard. Chron. ser. 3, XV. 462, fig. 58 (1894); XIX.
561, fig. 87 (1896); LV. 9, t. (1914). — W. Watson in Garden XL VI.
80, t. 972 (1894); Rhodod. and Azaleas, 112 (1911). — Palibin in Act.
Hort. Petrop. XVIII. 150 (Consp. Fl. Kor. II.) (1900). — J. H. Veitch,
Hortus Vritchii, 408 (1906). — Komarov in Act. Hort. Petrop. XXIV.
206 (Fl Mandsh. III.) (1907). — Schneider, III. Handb. Laubholzk.
II. 494, figs. 325 i-1 327 a-b (1909). — Nakai in Jour. Coll. Sri.
Tokyo, XXXI. 75 (Fl. Kor. pt. 2) (1911); Fl. Syl Kor. VIII. 43,
t. 15 (1919). — Matsumura, Ind. PI Jap. II. pt. 2, 464 (1912).—
W. Taylor in Garden, LXXVII. 136, fig. (1913). — Bean, Trees and
Shrubs Brit. Isl. II. 378 (1914). — Rehder in Bailey, Stand. Cycl.
Hort. V. 2943 (1916). — Millais, Rhodod. 239 (1917). — Komatsu in
Tokyo Bot. Mag. XXXII. [9] (1918).
Azalea Schlippenbachii O. Kuntze, Rev. Gen. pt. 2, 387 (1891).
Korea: prov. South Keisho, Herschel Island, 1863, R. Oldham
(No. 510, Herb. Gray); Chirisan, alt. 600-1845 m. November 16,
ENUMERATION OF THE SPECIES 89
1917, E. H. Wilson (No. 9592); Fusan, September 11, 1905, J. G-
Jack; prov. Keiki, East Park palace, Seoul, September 24, 1905,
J. G. Jack; Government Forestry Garden, Seoul, cultivated, May 21,
1917, E. H. Wilson (No. 8431); Kazan, near Suigen, May 24, 1917,
E. H. Wilson (No. 8472); prov. Kogen, Diamond Mts., July 7, 1918,
E. H. Wilson (No. 10,493); prov. South Kankyo, hills round Gensan
(Wonsan), September 5, 1903, C. S. Sargent; between Shinkori and
Eiko, September 20, 23, 1917, E. H. Wilson (Nos. 9201, 9223); prov.
North Heian, altitude 300-1000 m. June 16, 1917, E. H. Wilson
(No. 8603); province unknown, " Pomasa," altitude 800 m. May 21,
1906, U. Faurie (No. 66^) ; " Hoangheito," August, 1906, U. Faurie
(No. 668); northeast coast, 1854, Baron A. Schlippenbach (Herb. Gray).
Northeast Manchuria: shores of Possiet Bay, 1860, C. Maxi-
mowicz (Herb. Gray).
Japan: Hondo, prov. Ugo, Chokai-san, June 15, 1903, K. Sakurai.
Cultivated: Arnold Arboretum (No. 7258).
This is one of the commonest shrubs in Korea and in thin woods is often the
dominant undergrowth. It just crosses the border into northeast Manchuria on
the shores of Possiet Bay and in Japan is known from only two localities in north
Hondo. In Korea the southern limit of its range appears to be the Chiri-san range,
and Herschel Island in about the same latitude. Curiously it does not grow on
Quelpaert Island where the representative species is R. Weyrichii Maxim. On the
lower-middle slopes of Chiri-san and the lower slopes of the Diamond Mountains
R. Schlippenbachii is extraordinarily abundant. In June these regions are a
wonderful sight with literally miles and miles of the purest pink from the millions
of flowers of this Azalea. The plant grows from 1 to 5 m. tall and in open places
is sturdy and densely branched but in shade the branching is lax. The branches
are rigid, erect, verticillate or irregular, covered with curled glandular hairs when
young; pale brown the first year, becoming gray and glabrous the second. The
leaves are deciduous, thin, clustered in whorls of five at the end of the branches;
on strong shoots the whorl may be subtended by a pair of leaves and these by odd,
scattered leaves of small size; in shape they are all uniform being more or less
obovate (often broadly so), from 5 to 9 cm. long and from 3 to 7 cm. wide, the
apex is truncate or rounded, emarginate, with a glandular mucro, and the base is
narrowed to a short, broad petiole; the margins are slightly undulate, and both
surfaces are at first sparsely pubescent but later are glabrous except on the under-
side of the principal nerves. The leaves are dark green above, pale below and
in autumn change to yellow, orange and crimson. The flowers are fragrant, borne
in terminal 3- to 6-flowered umbellate clusters, and usually open as the leaves be-
gin to unfold. The corolla is pale- to rose-pink, broad-rotate, funnel-shape, from
6 to 8 cm. in diameter, with spreading, rounded lobes, the posterior marked with
red-brown spots. The pedicels and calyx are clothed with glandular hairs, and
the calyx-lobes are green, ovoid, about 5 mm. long and persistent. The stamens,
always 10 in number, are of unequal length, the longest equalling the corolla
but shorter than the style. The fruit is erect, oblong-ovoid, about 1.5 cm. long,
slightly oblique and covered with sessile glands; the seeds are angular, shining dark
brown.
90 THE AZALEAS OF THE OLD WORLD
This species was discovered by Baron A. von Schlippenbach of the Russian
navy on the shores of northeast Korea in 1854, and appears to have been culti-
vated sparingly in Japan for many years under the name of " Kurofune-tsutsuji."
James H. Veitch in 1893 saw it in a garden in Japan and sent it to England and
this was its first appearance in the west. Since then Japanese nurserymen have
exported it in small quantities to Europe and America but to this time it is by
no means so well known as its beauty warrants. The plants in this Arboretum
were raised from seeds collected in Korea in 1905 by Mr. J. G. Jack; they have
grown slowly but have been unaffected by winter-cold and summer-drought.
For two to three years past they have flowered freely and their large, pure pink
blossoms are lovely. This species has the second largest leaves and the most
beautiful flowers of its group and is worthy of a place in every garden. I collected
a quantity of seed in Korea in the autumns of 1917 and 1918, and this has been
widely distributed by the Arnold Arboretum and in a few years this Azalea should
be a prominent feature in New England gardens.
SECT. III. RHODORA G. DON*
Flowers from a terminal bud, the leafy shoots arising from separate, lower,
lateral buds; corolla rotate-campanulate, rarely campanulate or two-lipped;
stamens 10, rarely from 5 to 7. Leaves deciduous, scattered or whorled. Fruit
more or less cylindric, rarely conic-ovoid. Shrubs often of large size, usually with
rigid ascending or spreading branches; shoots glabrous or hairy.
This section contains 5 species; three of these grow in eastern Asia and two
(R. canadense Zabel and R. Vaseyi A. Gray) in eastern North America.
Rhododendron Albrechtii Maximowicz in Bull. Acad. Sci. St. Peters-
burg, se>. 3, XV. 227 (Mel. Biol. VII. 335) (1870); in Mem. Acad.
Sci. St. Petersburg, se>. 7. XVI. No. 9, 30, t. 2, figs. 14-20 (Rhodod.
As. Or.) (1870). — Franchet & Savatier, Enum. PL Jap. I. 290
(1875). — Matsumura, PL Nikko, 71 (1894); Ind. PL Jap. II. pt. 2,
458 (1912). — Boissier in Bull. Herb. Boiss. V. 917 (1897). — Schnei-
der, III. Handb. Laubholzk. II. 496, figs. 325 m-n, 327 e (1909). —
Millais, Rhodod. 112 (1917). — Komatsu in Tokyo Bot. Mag. XXXII.
[8] (1918).
Azalea Albrechtii O. Kuntze, Rev. Gen. pt. 2, 387 (1892). — Rehder in Bailey,
Cycl Am. Hort. I. 122 (1900).
Japan: Hondo, prov. Shinano, 1864, Tschonoski (Herb. Gray);
prov. Musashi, cultivated, Bot. Gard. Tokyo, April 2, 1914, E. H.
Wilson (No. 6363); prov. Shimotsuke, Nikko region, alt. 1600-2000 m.,
June 23, October 15, 1914, E. H. Wilson (Nos. 6858, 7638); prov. Uzen,
lower slopes of Adzuma-san, alt. 800-1100 m., July 19, October 24,
1914, E. H. Wilson (Nos. 7208, 7721); prov. Mutsu, Hirosaki, May,
1905, U. Faurie (No. 6785); Hakkoda-yama, alt. 1000-1600 m.,
July 5, 1914, E. H. Wilson (No. 7083); same locality, October 2, 1892,
C. S. Sargent. Hokkaido, prov. Oshima, Fuku-yama, June 3, 1889,
U. Faurie (No. 3831, Herb. Kew) ; Kakumi Hot Springs, September 29,
1892, C. S. Sargent; prov. Iburi, Nobori-betsu, July 2, 1914, E. H.
Wilson; prov. Ishikari, Sapporo, May 17, October 10, 1903, S. Ari-
moto (Herb. Gray); same locality, May 29, 1890, E. Tokubuchi (Herb.
Gray); Moiwa-dake, June 15, 1885, K. Miyabe (Herb. Gray); same
locality, June 23, 1891, E. Tokubuchi; cultivated, Bot. Gard. Sapporo,
August 22, 1905, J. G. Jack.
1 For synonyms and further details see page 119.
91
92 THE AZALEAS OF THE OLD WORLD
On the margin of forests and in thickets this species is widely distributed in
northern Japan from the mountains round Sapporo in central Hokkaido south-
ward to those of Shinano in central Hondo. I am familiar with it from the Nikko
region northward, but do not consider it a common plant. It is scattered here
and there and is partial to dense thickets on steep slopes of loose soil. It is a
shrub of loose and sparse habit, from 1 to 1.5 m. tall, with slender, smooth, purple-
brown branches which are brown and furnished when young with curled, partly
viscid, gray hairs. The leaves are deciduous, membranous, dark green and
change to yellow before they fall; they are scattered on the vigorous shoots, and
crowded, forming false whorls of fives, at the end of the branchlets; they are obo-
vate to oblanceolate, from 4 to 12 cm. long and from 1.5 to 6 cm. wide, acute or
subacute, with a glandular mucro; the base is narrowed to a short, winged petiole;
the margins are serrulate and ciliate, the upper surface is sparsely clad with ap-
pressed, flattened, hispid hairs and the under surface is more or less densely
clothed with short, pale gray tomentum. The flowers are about 5 cm. across, and
open in June and early July, according to climate, and immediately before or as
the leaves unfold; they are borne in terminal umbels, each containing from 3 to 5
flowers. The pedicels are moderately stout, from 1 to 2 cm. long, and are
clothed with curled, glandular, yellowish hairs; the calyx is small, with 5
purple and ciliate lobes; the corolla is rich red-purple, rotate-campanulate, with
a short, wide tube and spreading, rounded lobes; the stamens are 10 in number
in two series of unequal length, the longest equalling the corolla and over-
topped by the curved style, which has a bifid stigma. The fruit is erect, conic-
ovoid, from 1 to 1.2 cm. long, purple-brown, and clothed with yellow, viscid,
pilose hairs.
This species was discovered about 1860 by Dr. Michael Albrecht of the Russian
Consulate in Hakodate, and was found by Maximowicz also in the vicinity of
Hakodate in 1861. However, it does not appear to have been introduced into
western gardens until 1892, when Professor Sargent sent seeds to the Arnold
Arboretum from two localities in Hokkaido. Plants raised from these seeds grew
for several years in this Arboretum, but never really flourished. I sent seeds from
northern Hondo in 1914, and these were distributed by the Arboretum. Plants
raised from these seeds have grown fairly well, but it is too early to say whether
they will make themselves at home here. There is no apparent reason why this
Azalea should not thrive here. The habit is sparse and the flowers are not large,
but the color is intense and the plant is graceful and attractive.
Rhododendron pentaphyllum Maximowicz in Bull. Acad. Sd. St.
Petersburg, ser. 3, XXXI. 65 (MeT Biol. XII. 491) (1887).— Mat-
sumura, Ind. PI. Jap. II. pt. 2, 463 (1912). — Millais, Rhodod. 225
(1917). — Komatsu in Tokyo Bot. Mag. XXXII. [8] (1918).
Rhododendron pentaphyllum var. nikoense Komatsu in Icon. PL Koisikav.
III. 45, t. 168 (1916).
Rhododendron quinquefoliwn var. roseum Render in Bailey, Stand. Cycl. Hort.
V. 2947 (1916).
Japan: Kyushu, prov. Osumi, Tarumizu village, April and May,
1911, S. Kawagoe. Hondo, prov. Kozuki, Mt. Akagi, June 13, 1911,
as to flowers, May 17, 1921, K. Sakurai; prov. Musashi, Yokohama,
cultivated, April 11, 1914, E. H. Wilson (No. 6396); prov. Shimot-
ENUMERATION OF THE SPECIES 93
suki, Nikko region, alt. 1000-2000 m., May 18, May 25, May 31,
October 20, 1914, E. H. Wilson (Nos. 6698, 7683); same region,
shores of Lake Chuzenji, November, 1892, C. S. Sargent.
Cultivated: Hort. T. A. Havemeyer, Glenhead, Long Island,
New York, April 23, 1919.
This species is distributed in Japan from the extreme south of Kyushu through
Shikoku and Hondo to the Nikko region and beyond to Adzuma-san in Iwashiro
province but is nowhere abundant. I have seen it wild in the Nikko region
only and there, near the Hashimoto Tea House and on the mountain behind the
Lakeside Hotel at Chuzenji, it is common. It grows chiefly among deciduous trees
and shrubs and, flowering early, its pure rose-pink blossoms are conspicuous
from a long distance. My first view of it was across a deep ravine and I shall
never forget the charm of that splash of lovely color among the leafless plants of a
well-wooded steep slope. This Azalea is a large bush or small tree from 2 to 8 m.
tall, with a dense crown of twiggy ascending and spreading branches which are
arranged partly in verticils and partly in an alternate manner, and are sparsely
pilose when young but soon become glabrous; they are red-brown and more or less
angular the first year, later terete and gray. The trunk is clothed with pale gray-
brown bark. The winter-buds are short or elongated, acute, with shining purplish
brown, ciliolate, rather paleaceous scales. The leaves are clustered in a whorl of 5
at the end of the branchlet and are deciduous, chartaceous in texture, lustrous
green in the summer, changing to rich tints of orange and crimson in the autumn;
they are oval to elliptic-lanceolate in shape, from 3 to 6 cm. long and from 1.5 to 3 cm.
wide, acute and mucronulate, with a narrowed cuneate base; the margins are ciliate
and finely serrulate; they are reticulately veined with the midrib villose on both
surfaces, especially along the basal half. The petioles are from 3 to 8 mm. long,
usually sparsely bearded and glandular. The flowers are solitary or in pairs at
the end of the branchlets, and as the flower-buds expand the bud-scales fall. The
corolla is unspotted, bright rose-pink in color, about 4 to 5 cm. in diameter,
rotate-campanulate, with spreading, rounded, often emarginate lobes. The pedicels
are sparsely or densely glandularly pilose or quite glabrous and from 1 to 1.5 cm.
long. The calyx is glabrous, membranous, with 5 triangular or deltoid teeth
which are ciliate and from 1 to 5 mm. long. The stamens are unequal, 10 in
number, included; the base of the filaments is villose and the anthers are yellow.
The pistil slightly overtops the stamens and is glabrous. The fruit is spindle-
shaped, swollen about the middle, about 1.5 cm. long and 0.8 cm. wide, verruculose,
and subtended by the persistent calyx.
This lovely plant is very rare in gardens and appears to have been introduced
to Europe and America by the Yokohama Nursery Company, who list it under
the name of " Azalea quinquefolia pink." It is essentially a woodland species,
fond of partial shade. Where it grows at Nikko the soil is volcanic ash and lava
overlain with black leaf-mould. I collected seeds in 1914 for the Arnold Arbo-
retum and part of them were distributed. The plants raised in this Arboretum
have proved tender and difficult to manage, but older plants given a shady wood-
land site would probably thrive here as well as they do on Long Island, New York.
In Japan its autumn tints are singularly vivid and beautiful.
Rhododendron nipponicum Matsumura in Tokyo Bot. Mag. XIII.
17 (1899); in Icon. PL Koisikav. I. 9, t. 5 (1911); Ind. PL Jap. II.
pt. 2, 463 (1912). — Komatsu in Tokyo Bot. Mag. XXXII. [8] (1918).
94 THE AZALEAS OF THE OLD WORLD
Japan: Hondo, prov. Uzen, near Toge, alt. 1000 m., July 20,
October 23, 1914, E. H. Wilson (Nos. 7219, 7191).
This little known Japanese species is confined to the mountains of north-central
Hondo. It is very distinct in its flowers and fruit and also in its papery, cinnamon-
brown bark which shreds off and leaves polished brown stems and branches. No
other species with deciduous leaves has such attractive bark. In habit it forms an
upright, bushy shrub from 1 to 2 m. high, with rigid, red-brown branches clothed
with pilose and glandular hairs. The winter-buds are pale straw-color tinged
with purple, large, ovoid, with ciliate, eglandular bud-scales. The leaves are
scattered, sessile, membranous and deciduous; they have appressed, hispid hairs
on both surfaces and the margins are ciliate; in shape they are panduriform, from
6 to 18 cm. long and from 3.5 to 8.5 cm. wide, with the apex rounded or truncate,
usually emarginate, rarely obtuse, and are narrowed to the base, which is firmly
appressed to the stem and often has a curious shield-like protuberance continued
below the point of insertion; the veins are prominent and reticulate on the under
side and many are furnished with strigose hairs. In the autumn the leaves are
tinted from orange to crimson. The flowers are small and not conspicuous, and
open in late June and July with, or even after, the leaves. They are borne from
6 to 15 together in terminal, umbellate corymbs. The corolla is white, tubular or
campanulate, from 1.5 to 2 cm. long and from 0.8 to 1 cm. broad, with 5 short,
very slightly spreading lobes. The calyx is small, membranous, with lobes of
unequal size, and like the slender pedicel is covered with viscid hairs. The
stamens are of unequal length, 10 in number and are included, as is the style,
which is straight and slightly thickened below the capitate stigma. The fruit is
pendent, oval, from 8 to 10 mm. long, and has thin walls which open to the base
and have wavy margins.
This species in foliage suggests R. Schlippenbachii Maxim., but otherwise is
very distinct. On the hills round Toge, near the base of Adzuma-san, in 1914, I
found this species to be common in rather open country. The season of flowering
was almost past. In the autumn I gathered seeds for the Arnold Arboretum,
which distributed them in America and Europe. The plants raised from these
seeds have not yet flowered in the Arboretum. This Azalea was unknown to
Japanese nurserymen until I gave plants to the Yokohama Nursery Company in
1914. Its bark and foliage is striking, but the size of the flowers and the manner
in which they are hidden by the leaves and young shoots detracts from the plant.
As a flowering shrub it is one of the least desirable of Japanese Azaleas.
SECT. IV. PENTANTHERA G. DoN1
Flowers from a terminal bud, the leafy shoots from separate, lower, lateral buds;
corolla funnel-form-campanulate to funnel-form; stamens 5. Leaves deciduous,
scattered on the shoots. Fruit more or less cylindric. Shrubs usually with stiff,
ascending branches. Shoots villose or glabrous.
This section contains some 15 species and is the most widely distributed of the
four sections which we are discussing. Two species grow in eastern Asia, one in
Japan and the other in China; one species, R. luteum Sweet, grows on the Caucasus,
in the Pontus region in Asia Minor and in parts of eastern Europe. The others are
confined to North America, where they are widely distributed.
Rhododendron molle G. Don, Gen. Syst. III. 846 (1834).
Azalea mollis Blume, Cat. Gewass. Buitenz. 44 (1823); Bijd. Fl. Ned. Ind.
853 (1825).
Azalea sinensis Loddiges, Bot. Cab. IX. t. 885 (1824). — De Candolle, Prodr.
VII.pt. 2, 718 (1839).— Fortune, Wanderings in China, 154 (1847); Tea Coun-
tries of China 154 (1852) ; Residence among Chinese, 28 (1857) ; Suringar in
Gartenfl. LVII. 505 (1908).
Rhododendron sinense p. flavescens Sweet, Brit. Flow. Gard. ser. 1, III. t. 290
(1829).
Rhododendron sinense Sweet, Brit. Flow. Gard. ser. 1, III. sub. t. 290 (1829). —
Hovey, Am. Gard. Mag. II. 142, 179 (1836). — Hance in Journ. Bot. XVI.
109 (1878). — Hemsley in Jour. Linn. Soc. XXVI. 30 (1889), as to the
Chinese plant. — Suringar in Gartenfl. LVII. 516 (1908). — W. Watson,
Rhodod. and Azaleas, 112 (1911), in part. — Schneider, III. Handb. Laub-
holzk. II. 497, figs. 328 g-h, 329 a-b (1911). — Render & Wilson in Sargent,
PL Wilson. I. 549 (1913). — Bean, Trees and Shrubs Brit. Isl. II. 379
(1914). — Millais, Rhodod. (1917), in part.
Rhododendron sinense a. flammeum Sweet, Brit. Flow. Gard. ser. 1, III. sub. t.
290 (1829).
Azalea pontica var. sinensis Lindley in Bot. Reg. XV. t. 1253 (1829), poor
figure.
Azalea sinensis a. genuina Maximowicz in Suppl. Ind. Sem. Hort. Petrop.
1869, 11.
China: prov. Hupeh, stony hills and Pine-woods 15 miles below
Ichang on right bank of Yangtsze River, alt. 30-300 m., April 24, 1907
(flowers), January 18, 1908 (fruit), E. H. Wilson (No. 800); same
locality, A. Henry (No. 268); prov. Hunan, near Changsha, among
shrubs, alt. 70-400 m., April 7, 1918, Dr. Handel-Mazzetti (No. 2342);
prov. Chekiang, vicinity of Ningpo, 1908, D. MacGregor; near Chang-
hua, rocky banks, alt. 300 m., July 12, 1915, F. N. Meyer (No. 1543);
1 For synonyms and further details see page 124.
95
96 THE AZALEAS OF THE OLD WORLD
prov. Kiangsii, Nanking, April 23, 1914, Mary Strong Clemens (4226,
Herb. Bur. Sci. Manila).
This species is abundant in eastern China, especially on the mountains of the
Chekiang province, and appears to have the western limits of its range on the
conglomerate hills a little to the east of the city of Ichang where Henry and I col-
lected it. The plant is evidently common in the neighborhood of Ningpo, where
every collector since Fortune has gathered it. It grows among coarse grasses and
shrubs and in thin pine-woods. It is a sturdy, sparingly branched shrub from
half a metre to a metre and a half high, taller than broad, and has rich golden-
yellow flowers produced in large trusses before the leaves unfold. In habit and
floral characters in general it closely resembles its Japanese relative (R. japonicum
Suring.), but it has a smaller and less bristly calyx, flower-stalks without or with
few bristles, stamens as long or longer than the corolla and winter-buds densely
clothed with a short, nearly white, velvety pubescence. The leaves of the two
species are conspicuously different. Those of the Chinese plant are densely clothed
on the lower surface with soft, nearly white, matted pubescence which persists
through the life of the leaf; the upper surface is also softly pubescent but much of
this disappears before autumn. In late summer and autumn the leaves appear
glaucous below on account of the density of the pale gray pubescence. The leaves
of the Chinese species are also larger, up to 15 cm. long and 5.5 cm. wide, more de-
cidedly oblong-lanceolate, and only occasionally broadest above the middle. Sweet's
figure (Brit. Flow. Gard. ser. 1, III. t. 290 [1892]) clearly shows these essential
characters, and if it is compared with Hegel's figure (Gartenfl. XVI. 299, t. 556
[1867]) of the Japanese species the two plants cannot be confused. Since the two
may easily be distinguished by the leaves and other characters, behave differently
under cultivation and grow wild in widely separated geographical areas, I consider
that they are best kept under separate names without discussing the vexed question
of what constitutes a species.
I have not seen this Azalea in Chinese gardens but it must long ago have been
grown in those of Canton, Hanchow and Soochow. Loddiges received the plant
from China in 1823 and figured it in the Botanical Cabinet, IX. t. 885 (1824). This
plant in all probability was brought by some ship of the East India Company from
Canton. Others were introduced through the same agency during the succeeding
years but the species appears to have been lost, or nearly so, when it was sent to
the gardens of the Horticultural Society of London by Robert Fortune in 1845.
Fortune found it in gardens at Canton and wild on the hills near Ningpo, and in
his books he mentions this Azalea several times. According to Blume (Cat. Gewass.
Buitenz. 44 [1823]) it was introduced into gardens in Java before 1823. Of its
first introduction into America I can find no record, but Hovey tells us that it
flowered with him, and also in the garden of Mr. J. P. Gushing, Watertown, Mass.,
in April, 1836. Later it became lost and it was not cultivated in America when
in January, 1908, 1 sent seeds from China to the Arnold Arboretum. Some of these
seeds were sent to England, where the species appears again to have been lost. In-
deed, in western gardens the pure species never seems to have established itself,
and like its Japanese relative soon got lost under a mass of hybrid and seminal
forms. In this Arboretum the Chinese Azalea is doubtfully hardy, but it is an ex-
cellent pot plant and forces well. This tenderness, which is to be expected when
the climate of the region in which it grows is taken into consideration, explains its
frequent disappearance from gardens. The habit and fine yellow flowers make it
a very decorative garden plant but it lacks stamina. Its great use has been in
hybridising, notably with the Japanese speqies, from which has sprung a race of
hybrids popularly known as " Mollis Azaleas," correctly X R. Kosterianum*
ENUMERATION OF THE SPECIES 97
It is a pity to have to discontinue the use of Sweet's name R. sinense in favor
of one which has been so much misused, but this cannot be avoided. Blume's
description is perfectly good, but this publication seems to have been entirely over-
looked, all authors quoting him in his Bijdragen Flora Nederlandsch Indie, which
was published two years later. Siebold and Zuccarini in 1846 were the first to apply
Blume's name to the Japanese plant and initiated the confusion which has existed
ever since.
X Rhododendron Kosterianum Schneider, III. Handb. Laubhohk.
II. 499 (1911).
Azalea mollis x sinensis Pynaert & van Geertin Rev. Hort. Belg. XVII. 121, fig.
18 (1891); XX, 277, t. (1894). — Rodigas in Tijd. Boomt. 1893, 183, fig. 25.
Rhododendron sinense W. Watson, Rhodod. and Azaleas, 77 (1911), in part,
not Sweet.
Rhododendron sinense X R. molle Schneider, III. Handb. Laubholzk. II. 499
(1911), as a synonym.
Rhododendron molle Millais, Rhodod. 211 (1917), in part, not G. Don, nor
Miquel.
Rhododendron molle X sinense Millais, Rhodod. 212 (1917).
It appears to be the concensus of opinion that Anthony Koster & Sons of Bos-
koop, Holland, began to cross R. sinense Sweet and R. japonicum Suring. about
1880 and to raise hybrids in commercial quantities. They were closely followed by
Anthony Waterer, Knap Hill, Surrey. But apparently neither were the first in
this field, for in the Florist and Pomologist for 1875, p. 282, William Tillery writes:
" In 1872 1 had six varieties of the showy hardy Azalea mollis from M. van Houtte
named as follows: — 'Isabellevan Houtte, 'dark nankeen color, 'Madame Camille
van Langenhone,' white striped with rose and carmine, 'Nonpareil,' white bordered
with rose, 'Ebenezer Pyke,' half yellow, 'Centi Striatella' and 'Baroness Roth-
schild.' I find that all the varieties cross very readily with Azalea sinensis — the
yellow and white varieties, and I have many healthy seedlings this year from these
crosses." This would appear to be the beginning of the race. The work of these
pioneers has been emulated by others in Holland, Belgium and England and the re-
sult is a wealth of popular Azaleas with lovely flowers in exquisite shades of color.
For indoor decoration they are, in normal times, forced by the million hi Europe
and America. As garden plants out-of-doors they thrive hi many parts of England
and Millais is loud in their praise. While hardy in the gardens of New England the
plants are usually short lived, lack constitution and are even less satisfactory than
the " Gandavensis hybrids." The tender strain derived from the Chinese species
(R. molle) is unfortunately too potent, and though the plants struggle along for
a few years they are rarely satisfactory and generally at the end of a few years die.
It is a pity, for they are beautiful plants. In Horticulture, XXX. 71 (1919), there
is described a hybrid (" Miss Louisa Hunnewell ") raised in 1913 by Mr. T. D.
Hatfield, superintendent of the estate of Walter Hunnewell, Esq., Wellesley, Mass.,
which is a cross between the pure species R. japonicum Suring. and R. molle G.
Don obtained from the Arnold Arboretum. It first flowered in 1917, and has an
orange-yellow corolla similar to that of "Anthony Koster" but even richer in
color; it proved "bud hardy " in the exceptionally severe winters of 1917-18 and
1919-20, and is a free grower. If this new Azalea fulfils expectations it will be a
most valuable addition to New England gardens.
Another hybrid is : —
X Rhododendron albicans Waterer apud Zabel in Mitt. Deutsch.
98 THE AZALEAS OF THE OLD WORLD
Dendr. Ges. XI. 30 (1902). — Schneider, III Handb. Laulholzk.il.
499 (1911).
Rhododendron occidental* X sinense Zabel in Beissner, Schelle & Zabel, Handb.
Laubholzk-Ben. 380 (1903), as a synonym.
Rhododendron motte x ocddentale Schneider, III. Handb. Laubholzk. II. 499
(1911), as a synonym.
Azalea occidental™ "Hybrids" Hort. Wezelenburg, Cat. 9 (1915).
Rhododendron occidentak X R. molle x " Ghent Azaleas" Millais, Rhodod. 220,
fig. (1917).
Many varieties of this hybrid have been raised by Anthony Waterer and by
Koster & Sons, among the best being "Superba," "Graciosa," "Exquisite" and
"Magnifica." The parentage is, apparently, very mixed; a majority have large
white flowers with the usual yellow blotch characteristic of the flowers of the
American species, but some have cream and others yellow flowers with a darker
blotch. They flower between early June and mid-July and are very hardy.
In quite recent years X R. Kosterianum has been hybridised with a
variety of forms of X R. gandavense and the result is a race with
double flowers, for which I propose the name of: —
X Rhododendron mixtum Wilson, n. nom.
Azalea rustica flore-pleno Hort. ex Vandervoorde in Rev. Hort. Belg. XIX.
232, t. (1893), not Van Houtte. — Cat. A. Waterer, 10 (1911-12.) — Cat.
Wezelenburg, 10 (1915). — Millais, Rhodod. 213 (1917).
It appears to be safer to give a new name to this race than to risk confusing it
with the double-flowered " Gandavensis hybrids " (Azaleas rustique de Gand)
first raised by Louis van Houtte, who figures four varieties in Flore des Serres XIX.
tt. 2021-2024 (1873), and of which " Graf von Meran," " Narcissiflora " and
"Louis A. van Houtte," may be considered types. Typical forms of x R. mixtum
are " Murillo " with rose-colored flowers, " Virgile " with yellow flowers, " II
Tasso " with red flowers, " Milton " with white flowers, and " Racine " with pale
pink flowers. According to Millais (Rhodod. 213 [1917]) there are hybrids raised
by Vuylsteke between R. molle and Azalea altaclarense. These are unknown
to me.
Rhododendron molle G. Don has been crossed with one or more
of the broad-leafed Rhododendrons and the oldest of these is : —
X Rhododendron "Smithii aureum" Paxton, Mag. of Bot. IX. 79,
t. and fig. (1842).— Gard. Chron. II. 352 (1842). — Robinson, Fl
and Sylva II. 152, t. (1904). — Bean, Trees and Shrubs Brit. Isl.
II. 346 (1914).
Rhododendron "Hardy Seedling" X Azalea sinensis Paxton, Mag. of Bot. IX. 79
(1842.)
" Norbiton hybrids " Hort. ex Masters in Gard. Chron. ser. 3, XIII. 665
(1893).
Rhododendron sinense X Eurhododendron spec. Zabel in Beissner, Schelle &
Zabel, Handb. Laubholz.-Ben. 379 (1903).
I have given the parentage as set down by Paxton but Robinson says " between
a yellow form of the Chinese Azalea and Rhododendron caucasicwn, the latter of
ENUMERATION OF THE SPECIES 99
which it resembles in habit." This interesting Azaleodendron was raised by a
nurseryman at Norbiton, Surrey, named W. Smith, and exhibited before the Horti-
cultural Society of London in the spring of 1842. It is not now in cultivation in
this Arboretum, not being sufficiently hardy to withstand the winter's cold. A
specimen in this herbarium under the name of Rhododendron " Victoria regina "
and from an exhibition held by the Massachusetts Horticultural Society on April
19, 1889, evidently belongs here, but whether the name it was exhibited under has
any standing I do not know.
Another hybrid between a broad-leaf evergreen Rhododendron
and R. molle G. Don is: —
X Rhododendron "broughtonii aureum" Hort. apud W. Watson,
Rhodod. and Azaleas 93 (1911). — Osborne in Gard. Chron. ser. 3,
LI. 53. fig. 29 (1912). — Bean, Trees and Shrubs Brit. I si. II. 345,
fig. (1914).
Osborne in his account of this plant says it " obtains its name from the village
of Broughton in Peebleshire, where it was raised by crossing a yellow Azalea and
a seedling evergreen Rhododendron." Both Osborne and Bean regard this as the
best of its class. It has been in cultivation in this Arboretum since 1910 but does
not thrive. More recently M. G. Vander Meulen has raised hybrids between R.
molle and the evergreen Rhododendrons " Prince Camille de Rohan " and " Leo-
pard " which he names " Edouard AndrS," "Director Rodigas" and "Dr.
Masters." Mr. White of Sunningdale has raised similar hybrids. Millais (Rhodod.
214 [1917]) says that they retain their leaves in winter, and are quite hardy and
very floriferous.
Rhododendron japonicum Suringar in Gartenfl. LVII. 516 (1908). —
Schneider, III Handb. Laubholzk. II. 1046 (1912). — Rehder & Wil-
son in Sargent, PL Wilson. I. 549 (1913), in a note. — Rehder in
Bailey, Stand. Cycl. Hort. V. 2942 (1916). — Arnold Arb. Bull. Pop-
ular Inform, n. ser. III. 26 (1917); IV. 20, 28 (1918). — Komatsu in
Tokyo Bot. Mag. XXXII. [6] (1918). — E. G. Loder in Rhodod. Soc.
Notes, I. No. 4, 197 (1918).
Rhododendron molle Siebold and Zuccarini in Abh. Akad. Munch. IV. pt. 3,
131 (Fl. Jap. Fam. Nat. II. 7) (1846), not G. Don. — Miquel in Ann. Mus.
Lugd.-Bat. 1. 33 (1864); II. 164 (1865-66); Prol. Fl. Jap. 96 (1866-67).—
Schneider, III. Handb. Laubholzk. III. 499, figs. 328 i-k, 329 c-d (1911).—
Bean, Trees and Shrubs Brit. Isl. II. 368 (1914). — Millais, Rhodod. 211
(1917), in part.
Azalea japonica A. Gray in Mem. Am. Acad. n. ser. VI. 400 (1858-59). —
Hemsley in Garden, XI. 420, t. (1877), in part.
Rhododendron molle var. glabrior Miquel in Ann. Mus. Lugd.-Bat. I. 33 (1864).
Azalea mollis /3. glabrior Regel in Gartenfl. XVI. 289, t. 556 (1867).— Van
Houtte in Fl. des Serr. XIX. 177 tt. 2034-2035 (1873).
Azalea sinensis 0. glabrior Maximowicz in Suppl. Ind. Sem. Hort. Petrop.
(1869) 11.
Rhododendron Sinense Maximowicz in Mem. Acad. Sci. St. Petersbourg, se'r. 7,
XVI. No. 9, 28 (Rhodod. As. Or.) (1870), not Sweet. — Hooker f. in
100 THE AZALEAS OF THE OLD WOULD
Bot. Mag. XCVII. t. 5905 (1871). — Franchet & Savatier, Enum. PL Jap.
I. 289 (1875). — Matsumura & Yatabe, Nippon Shokub. 163 (1884).—
Matsumura, PL Nikko, 71 (1894); Shokub. 250 (1895); Ind. PL Jap. II.
pt. 2, 464 (1912). — Shirasawa, Icon. Ess. For. Jap. II. t. 62, figs. 19-27
(1908).— Hayata, Veget. Mt. Fuji, 66 (1911). — Ito, Icon. PL Jap. I. No.
5, 1, t. 17 (1913). — W. Watson, Rhodod. and Azaleas, 112 (1911), in
part.
Azalea mollis Andr6 in III. Hort. XVIII. 132, t. 68 (1871), not Blume. —
Suringar in Gartenfl. LVII. 505 (1908).
Japan: Hondo, prov. Suruga, Mt. Fuji, alt. 600-1000 m., open
country, May 8, 1914, E. H. Wilson (No. 6657); same locality, July
28, 1891, K. Watanabe (Herb. Gray); prov. Shinano, Karuizawa,
alt. 1000 m. May, 1903, B. Hayata; prov. Shimotsuke, between Lake
Chuzenji and Yumoto, open country, alt. 1600-1800 m., June 24,
1914, E. H. Wilson (No. 6872); same locality, September 5, 1892,
C. S. Sargent; same locality, August 11, 1905, J. G. Jack; Nikko re-
gion, alt. 500-18QO m., May 22, flowers, October 19, fruit, 1914, E.
H. Wilson (Nos. 6727, 7670) ; prov. Uzen, foot of Adzuma-san, grassy
slopes, alt. 1000 m., October 23, 1914, E. H. Wilson (No. 7192);
without locality, June 7, 1913, K. Sakurai; prov. Rikuchu, round base
of Hayachine-san, June 4, 1905, U. Faurie (No. 6784). Hokkaido,
prov. Oshima, Hakodate, cultivated, 1855, C. Wright (Herb. Gray).
Cultivated: Arnold Arboretum (Nos. 861-1, 861-4, 861-5,
861-6); Hort. Kew, May 18 (flowers), August 7 (leaves), 1880,
G. Nicholson (No. 807, Herb. Arnold Arboretum).
This handsome species is common over a great part of Hondo, the main island
of Japan. I am familiar with it from the neighborhood of Kamo, on the Kwan-sai
railroad beyond Nara, northward to the foot-hills of Hayachine-san. It is a special
feature of the moorlands round the base of sacred Fuji-san and of Ontake-san, and
of open grass and scrub-clad places in the Nikko region and elsewhere. Matsu-
mura reports it from Higo province in Kyushu but I have not seen it wild anywhere
in this southern island. It is cultivated in and around Hakodate in Hokkaido but
I can find no record of its growing wild in that island. Wherever I have seen this
Azalea wild it was scattered in open grass and scrub-clad country, never in woods
or dense thickets and obviously it is sun-loving. It is a sturdy-growing plant, with
fairly stout, erect shoots, as much as two metres high and a metre through; usually,
however, it is less than a metre high and broad. The flowering season is from
about the last week in April to the end of June, according to locality. The flowers
appear before the leaves, and the corolla varies in color from orange-red to flame-
red or almost red; they are broad funnel-shape, from 5 to 6 cm. across and the
flowers are produced 6 to 12 together in umbellate corymbs at the end of shoots.
The calyx is small, obtusely 5-lobed with many (rarely few) straight, bristle-like
gray hairs; the flower-stalk and annual shoot are also clothed with similar bristles,
though occasionally these are wanting on the foot-stalks. The outside of the
corolla is velutinous. The stamens, five in number and of unequal length, are
shorter than the corolla, with pilose filaments and dark brown anthers. The
ovary is villose, and the fruit is erect, oblong-ovoid to cylindric, from 2 to 2.5
ENUMERATION OF THE SPECIES 101
cm. long, grooved, shining brown, often bloomy in color, pilose and villose
with scattered hairs, and is subtended by the persistent calyx. The winter-buds
are ovoid, acute or subacute, gray-brown and very slightly puberulous, but
the scales are margined with a row of white, nearly straight hairs. The leaves
are more or less spatulate to oblanceolate, from 5 to 10 cm. long and from
1.5 to 3 cm. broad; when mature they are green on both surfaces, strongly veined
and have scattered, appressed, bristly hairs pointing toward the apex of the
leaf on the upper surface and on the under-surface of the primary and secondary
veins; the margins are ciliate, the apex is tipped by a glandular mucro and the
base is narrowed to the short petiole. When unfolding, both surfaces of the leaf,
but more especially the lower, are often sparsely covered with a short, soft pubes-
cence, but this is soon thrown off. In late autumn the leaves are quite glabrous
except for the appressed bristles and the cilia on the margins, and change to red
and red-purple. The character of the leaves is important, since it affords an
easy and accurate means of distinguishing the species from its Chinese relative
(R. molle G. Don).
The history of the introduction of this Japanese Azalea into western gardens is
considerably involved. A Hollander, J. B. Groenewegen, in Sempervirens, XIX.
532 (1890), states that he received seeds of this plant direct from Japan in 1861,
and raised many plants which he afterward sold to a Belgian friend, by whom they
were distributed among Belgian nurserymen, including Louis van Houtte. Later
these plants were hybridised with other cultivated species and varieties and many
beautiful plants were raised. In 1863 Maximowicz introduced seeds to Petrograd,
where plants were raised which flowered and were figured by Regel in the Garten-
flora, XVI. 289, t. 556 (1867). In 1869 seeds were distributed from Petrograd.
Hooker in figuring it in the Botanical Magazine, XCVII. t. 5905 (1871), states that
the specimens were communicated by William Bull, nurseryman, Chelsea, with
whom it flowered for the first time in March, 1870. Seeds were received at the
Arnold Arboretum on April 3, 1876, from the Jardin des Plantes, Paris, and plants
flowered in Professor Sargent's garden in the spring of 1880. Seedlings raised from
this stock flowered in the Arboretum in 1884. In 1890 Dr. W. S. Bigelow sent
seeds from Japan to this Arboretum, and in 1892 Professor Sargent also sent seeds
of it in quantity. Plants raised from this latter source have for many years been
well established here and seeds from them have been widely distributed. In the
Arnold Arboretum R. japonicum is perfectly hardy, grows freely and vigorously
and flowers profusely every season. With its large trusses of bright to dull flame-
colored flowers it is strikingly handsome and is worthy of a place in every garden.
That in the past it has been neglected is undoubtedly due to its having been con-
fused with its less hardy Chinese relative and with hybrid and seminal forms of
both species. The error was started by Siebold and Zuccarini in 1846 and Miquel
followed them; Gray was first to give the Japanese plant specific rank under a new
name. Miquel, Regel and Maximowicz in the 60's all recognised it as distinct from
the Chinese plant and ranked it as a variety. After this for about forty years
botanists merged it under the Chinese species and until Suringar in a critical,
painstaking account in the Gartenflora, LVII. 516 (1908) established its right to be
considered a good species. From even a cursory glance at the literature it is evi-
dent that the nurserymen of Belgium and Holland, at any rate, all along recognised
the two plants as distinct.
The Japanese name for R. japonicum is " Renge-tsutsuji," and a form with
slightly different colored flowers is " Beni-renge-tsutsuji." To the latter the
name var. rosea has been given by Ito (Icon. PL Jap. I. No. 5, 4 [1913]). The
colors indicated by the two Japanese names are merely extremes and merge in-
extricably into each other. Though this Azalea is now grown in some quantity in
102 THE AZALEAS OF THE OLD WORLD
the nurseries round Tokyo and Osaka for export it is but little used by the Japanese
in their own gardens, probably because it is not amenable to clipping.
In western gardens the first to raise and name varieties of R. japonicum from
seed was Louis van Houtte of Ghent, Belgium, who published (in the FL des Serr.
XIX. 177 [1873]) an article, accompanied by four plates. Enthusiastic on the future
possibilities of this plant, he named and described twenty kinds. Among these are
some of the best seminal kinds of this Azalea yet produced. The first of them to
attain popularity was " Comte de Gomer," which is figured in the Revue Horti-
culture Beige, I. 97, t. (1875), by Kerchove de Denterghen under the name of Azalea
mollis " Comte de Gomer." In 1879, Messers James Veitch & Sons exhibited it be-
fore the Royal Horticultural Society under the same name and it received a First
Class certificate. It is figured by Richard Dean in the Floral Magazine, XVIII. t.
367 (1879), and is still among the best kinds raised. Others of the same stock are
" Alphonse Lavalle"e," " Baron Edmond de Rothschild," " Comte Papadopoli,"
" Consul Pdcher " and " Charles KSkuleV' In his article Van Houtte makes no
mention of using the Chinese plant but his figure 2033 suggests that plant. His
t. 2035, depicting white flowers with yellow blotch on upper petal is presumably the
variety " Chevalier A. de R6ali," and suggests an albino form of the Chinese plant
rather than of the Japanese species. I have seen no specimen of this, but the leaves
should tell its origin. In this connection, however, it is well to remember that
although only recently definitely known, the yellow-flowered form (f . aureum) of
the Japanese species might have been raised from the seedlings distributed by
Groenewegen or from the Petrograd stock. I saw the f . aureum in the British Con-
sulate garden in Hakodate in 1914 and the plant might well have been growing
somewhere in the town when Maximowicz was there in 1861. In reading Van
Houtte's account the inference certainly is that all the forms he mentions and
figures are of the Japanese plant, and Van Houtte, of course, knew the Chinese
plant well. At this late date it is not possible to be sure, but I incline to the belief
that the yellow-flowered form of the Japanese species appeared among the seed-
lings raised from Groenewegen's or Maximowicz's seeds.
Rhododendron japonicum f. aureum Wilson, n. f .
Rhododendron sinense Tanaka, Useful PL Japan, 74, No. 652, fig. (1891), not
Sweet.
Rhododendron sinense var. flavescens Ito, Icon. PI. Jap. I. No. 5, p. 4 (1913),
not Sweet.
Japan : Hondo, prov. Musashi, brought from Chichibu mountains,
cultivated, Botanic Gardens, Tokyo, May 11, 1917, E. H. Wilson
(No. 8414, type); prov. Kawachi, between Yomomoto and Ikedo,
cultivated, said to have been brought from round Tokyo, May 8,
1918, E. H. Wilson (No. 10,351).
Except for its rich, deep yellow flowers there is nothing to distinguish this* form
from the typical R. japonicum. I was informed by Dr. Nakai that this form grows
wild mixed with the type on Chichibu mountains in the northwestern part of Mu-
sashi province and that the plant my specimens are from came from there. I did
not see it wild but Dr. Nakai' s statement was confirmed to me by various horti-
culturists. I saw it in gardens in Hakodate in 1914, and in nurseries not far from
Osaka in 1918. The winter-buds are pale colored and afford an easy means of dis-
tinguishing it from the type. The Japanese name for this plant is " Ki-tsutsuji "
or " Ki-renge-tsutsuji " and Tanaka's figure cited above is quite good. As far as I
ENUMERATION OF THE SPECIES 103
can discover it was first introduced to America in the spring of 1917 among plants of
the type imported from the Yokohama Nursery Company by Mr. J. S. Ames, North
Easton, Mass. In 1919 I brought back plants from Japan to the Arnold Arbore-
tum. Whether this plant has reached Europe I do not know, but there is no men-
tion of it in Millais's recent work on Rhododendrons. In this connection it should
be mentioned that Maximowicz (in Mem. Acad. Sri. St. Petersbourg, s6r. 7, XVI.
No. 9, 29 (Rhodod. As. Or.) [1870]) speaks of the form with yellow flowers as rare,
but it must be remembered that he confuses the Japanese and Chinese species and
calls both R. sinense. Maximowicz identifies this plant with the " Rjuku Tsutsusi,
lillifera Insulae Luconiae, flore languide luteo, petalis, surrectis, punctis satura-
tioribus variegatis " and with " Rjuku Tsutsusi flore igneo, punctis petalorum
croceis, apicibus rufis " (Kaempfer, Amoen. Exot. 848 [1712]). What the first
named of Kaempfer' s plant is I do not know, neither can I find out the " Insulae
Luconiae;" the description, however, would fit our new form (aureum) or the
Chinese species. The " Rjuku Tsutsusi fl. igneo " is R. scabrum G. Don (R. sub-
lanceolatum Miquel). Personally I doubt if Kaempfer saw or heard of R. japoni-
cum or its form aureum, since they are not favorite garden plants in Japan, neither
do they grow wild by the road he traversed from Nagasaki to Tokyo.
A recently raised hybrid between R. japonicum Suring. and R.
canadense Zabel is : —
X Rhododendron Fraseri W. Watson in Gard. Chron. ser. 3, LXVII.
225 (1920). l
Rhododendron luteum Sweet, Hort. Brit. ed. 2, 343 (1830), not
Azalea lutea L. — Schneider, III Handb. Laubholzk. II. 1046 (1912), not
II. 500 (1911). — Render in Bailey, Stand. Cycl Hort. V. 2942 (1916).
Azalea pontica Linnaeus, Spec. 150 (1753), not R. ponticum Linnaeus, —
Pallas, Fl. Ross. II. 51, 1. 19 (1788). — Andrews, Bot. Rep. 1. 1. 16 (1797). —
Schmidt, Qster. Baumz. III. 44, t. 169 (1800). — Marschall a Bieberstein,
Fl. Taur.-Caucas. I. 144 (1808); 111. 136 (1819). — -Hovey, Mag. Hort. IV.
276, 367 (1838). — De Candolle, Prodr. VII. pt. 2, 718 (1839).
t Azalea flava Hoffmannsegg, Verz. Pflanzenkult. 61 (1826).
Anthodendron ponticum Reichenbach in Mosseler, Handb. Gewachsk. II. aufl.
1. 309 (1827); Fl. Germ. Excur. I. 416 (1830).
Rhododendron flavum G. Don, Gen. Syst. III. 847 (1834), not Pallas. — Nyman,
Consp. Fl. Europ. 491 (1878-82). — Schneider, III Handb. Laubholzk. II.
499, figs. 328 n-q, 329 e-h (1911). — Bean, Trees and Shrubs Brit. Isl II.
356 (1914). — Millais, Rhodod. 165 t. (1917). — Boissier, Fl. Or. III. 972
(1875). — Kuzentzof, Fl. Caucas. Crit. IV. pt. 1, 31, 488 (1901, 1906).
Rhododendron flavum var. coronarium Sweet, Brit. Flow. Gard. ser. 2, IV. t.
331 (1836).
Azalea arborea Linnaeus apud De Candolle, Prodr. VII. pt. 2, 718 (1839), as a
synonym.
Rhododendron ponticum Schreber apud De Candolle, Prodr. VII. pt. 2, 718
(1839), not Linnaeus, as a synonym.
Azalea Pontica a. flava De Candolle, Prodr. VII. pt. 2, 718 (1839).
Azalea pontica var. autumnalis K. Koch in Linnaea XVII. 281 (1843).
Anthodendron flavum Reichenbach apud K. Koch, Dendr. II. pt. 2, 184 (1872),
as a synonym. — Schneider, III. Handb. Laubholzk. II. 499 (1911).
Azalea pontica "Goldlack" Hesse in Gartenfl. LII. 48 (1903).
1 See page 185.
104 THE AZALEAS OF THE OLD WORLD
Caucasus, near summit of Dariel Pass, south side 2000 m. alt.,
July 24, 1903, C. S. Sargent; Vladikavkaz, April 22, 1902, A. Famine;
Mt. Beschtau, June, July, R. F. Hohenacker; prov. Ossetia, Alagir,
swamps, May 10, Sept. 12, 1901, R. Marcowicz. Pontus region, "Ci-
ganadagh," July 20, 1889, P. Sintenis (No. 1357); Sumila, in woods,
July 31, 1889, P. Sintenis (No. 2017).
Cultivated: Arnold Arboretum (No. 3159-1) from seeds collected
on the Caucasus by C. Schneider, June, August 28, 1917, A.
Rehder; Hort. Holm Lea, May and September, 1880; Bot. Gard.
Cambridge, Mass., May 31, 1916, A. Rehder; Hort. Kew, May 19,
August 9, 1880, G. Nicholson (No. 835); Breslau, Schneitniger Park,
June 13, July 23, 1902, C. Baenitz; Hort. Bot. Gottingen, May 22,
1893, A. Rehder (No. 1574).
This well-known species is geographically isolated from its relatives and has a
rather remarkable distribution. It is native of the Caucasus Mountains, the Pontus
region of the Black Sea, of Cilicia, and also of eastern Europe (Lithuania, south-
eastern Poland, Volhynia and in southwestern Russia). It is a broad, densely
branched shrub from 2.5 to 4 m. high and as much as 6 m. in diameter. The
branches are twiggy and clothed when young with glandular, villose hairs. The
leaves are scattered, oblong-lanceolate often broadest above the middle, from 4 to
12 cm. long and from 1.5 to 3.5 cm. long, acute or obtuse, mucronate, narrowed to
the base, the margin is serrulate and ciliate, and on both surfaces are scattered,
appressed, short glandular bristles and short curled pale gray pubescence which
later disappears. The petioles, calyx and outside of the corolla tube are glandular.
The richly fragrant flowers are borne from 10 to 12 together in clusters at the end
of the naked shoots. The calyx is green, deeply divided into 5 oblong or ovate,
glandular-ciliate lobes from 2 to 5 mm. long. The corolla is yellow, from 4.5 cm.
in diameter with a narrow, cylindric tube from 1.5 to 2 cm. long. The stamens are
long exserted but overtopped by the pistil which has a glandular ovary, slender
style and capitate stigma. The fruit is cylindric, from 2 to 2.5 cm. long and from
0.5 to 0.8 cm. wide, furrowed and glabrescent.
This Azalea was discovered by Tournefort on the eastern side of the Black Sea
during his voyage to the Levant (1700-02) and is described in his Corollarium In-
stitutionum rei herbariae, p. 42 (1703), as " Chamaerhododendros Pontica, maxima,
Mespili folio, flore luteo "; he also figures it in Mimoires de VAcademie royale des
sciences, 348 (1704). A long account of it is given in his Voyage du Levant, II. 99
(1718). Buxbaum in his Plantarum minus cognitarum ceniuria V. 36, fig. 69 (1740)
gives a crude figure of it under Tournef ort's name. It was on this description and
figure that Linnaeus based his Azalea pontica. The plant was introduced into
England from the Caucasus by Pallas, who sent seeds to Messers Lee & Kennedy
of Hammersmith in 1792, with whom they germinated the following year. In 1796,
Mr. Anthony Hove of Warsaw found this Azalea on the north side of the Black
Sea near Oczakow in marshy places, on the banks of the rivers Dnieper and Dniester,
and on the Asia Minor side of the Black Sea round Trebizond. Mr. Hove sent
seeds to Watson, a nurseryman of Islington, and plants flowered in a greenhouse in
1798. According to Schmidt it was found in Volhynia by Dr. Besser, and was in-
troduced to the Botanic Garden at Vienna before 1800. I have not been able to
ascertain exactly when it was introduced into this country, but according to Hovey
ENUMERATION OF THE SPECIES 105
it was a familiar plant in gardens round Boston, Mass., in 1838. In this Arboretum
the Pontic Azalea is not properly hardy. This Azalea has been much used in
hybridising and crosses between it and various American species have originated
the popular " Ghent Azaleas " of gardens which should be known as x R. ganda-
vense Render.1 According to Millais (Rhodod. [1917]) A. Waterer has crossed R.
luteum and R. molle and such a hybrid is figured by Millais opposite page 198.
A variety with large flowers is : —
Rhododendron luteum var. macranthum Wilson, n. comb.
Rhododendron flavum var. macranthum Bean, Trees and Shrubs Brit. Isl. II. 357
(1914). — Millais, Rhodod. 165 (1917).
The flowers of this variety are described as being 6.5 cm. wide.
There is also the obscure: —
KHODODENDRON LouREiRiANA G. Don, Gen. Syst. III. 846 (1834). —
Maximowicz in Mem. Acad. Sci. St. Petersbourg, se*r. 7, XVI. No. 9,
49 (Rhodod. As. Or.) (1870). — Millais, Rhodod. 204 (1917).
Azalea punctata Loureiro Fl. Cochinch. 113 (1790).
This is said to be native of Cochinchina and was described with lanceolate,
glabrous leaves scabrous at the margin and with a white corolla dotted with red,
as are also the calyx, anthers and ovary. No Azalea answering this description has
since been found, and very probably Loureiro made a mistake in referring his plant
to that genus.
These are all the Azaleas at present known from the Old World but Dumont
de Courset (Bot. Cult. ed. 2, III. 337 [1811]) mentions Azalea fimbriata, A. lugens
and A. vittata. He gives no descriptions but says the first two are from China,
the third from the Indies, and that they are growing in English gardens. Probably
they are referable to R. Simsii or R. indicum but it is impossible to identify them
with certainty. In Iwasaki's Japanese Herbal, Phonzo Zoufou, issued in 1828, a
number of colored pictures of Azaleas are given. These figures are so crudely
drawn that I find it impossible to determine, with any degree of certainty, what
species and forms they represent. However, in the new edition, now being issued
under the editorship of Messers Shirai & Onuma, technical names are given, and
in Volume XX (Poisonous Plants, pt. 3) K. Onuma makes three new combina-
tions. If his determinations are correct his R. macranthum var. polypetalum should
be referred as a synonym to R. indicum f . polypetalum Wile., his R. macranthum
f . semperflorens to R. indicum f . variegatum DC., and his R. Nakaharai var. line-
arifolium to R. linearifolium S. & Z.
1 See page 178.
THE AZALEAS OF NORTH AMERICA
BY
ALFRED REHDER
THE AZALEAS OF NORTH AMERICA
INTRODUCTION
THE Azaleas, as the term is generally understood, are the
deciduous species of the genus Rhododendron, which, as far as
concerns the American species, seem well separated from the
evergreen Rhododendrons; this explains to some extent the tend-
ency of many recent American botanists to consider the two
groups generically distinct, but if we take into consideration
the Asiatic species, the differences become less pronounced, and
therefore it seems better to limit the genus as proposed by
Salisbury, D. and G. Don, Maximowicz and most recent authors.
In dealing with the American Azaleas we restrict the term to the
species of the sections Pentanthera and Rhodora which both
belong to the same subgenus and exclude Azaleastrum and
Therorhodion, though they, too, have deciduous leaves, but they
differ considerably in their inflorescence and are best considered
distinct subgenera; they are, moreover, not Azaleas in the usual
sense of the word. The subgenus Azaleastrum differs chiefly in
its usually one-flowered lateral inflorescences, and Therorhodion
in the flowers being borne in terminal racemes at the end of
leafy shoots, while in the subgenus Anthodendron to which
Pentanthera and Rhodora belong the flowers are borne in leaf-
less umbel-like racemes, or rarely solitary, at the end of the
shoots of the previous season. I prefer to use the name Antho-
dendron first proposed by Reichenbach as a generic name and
later used by Endlicher as a subgeneric name instead of Azalea,
as it is an older subgeneric name and as, moreover, Azalea of
Linnaeus upon which that subgeneric name is based does not
belong here but to another genus, as explained on page 116
under Anthodendron.
A short history of the genus, as far as it concerns the American
species with which we are dealing, may be given here; more
detailed accounts will be found under the different species. The
109
110 THE AZALEAS OF NORTH AMERICA
first American species recorded is Rhododendronviscosum, of which
we find a figure published in 1691 by Plukenet (Phytogr. 1. t. 161,
fig. 4) under the name Cistus virginiana flore et odore Peri-
clymeni after a drawing made from nature by John Banister, an
English missionary in Virginia who took great interest in botany
and sent in 1680 a catalogue of Virginian plants to Ray. A few
years later Plukenet (Mant. 49) mentioned the plant now known
as R. nudiflorum under the name Cistus virginiana Periclymeni
flore ampliore minus odorato. Both species were introduced into
England by Peter Collinson before 1730 and of R. nudiflorum a
good colored plate was published by Trew in 1750 (PL Select.
Ehret. t. 48), while the first colored plate of R. viscosum was pub-
lished by Meerburgh in 1798 (PL Select. Icon. t. 9). Linnaeus
when publishing his Species plantarum in 1753 knew only these
two species which he referred to the genus Azalea and named
A. viscosa and A. lutea, changing the latter name to A. nudiflora
in the second edition of his work. In the same edition, in 1762,
he described Rhodora canadensis introduced some time before
the year 1756 from Canada to Paris and figured first by Duhamel
in 1760 (Sem. PL Add. 10, t. 27, fig. 2). In 1763 Adanson (Fam.
PL 164) proposed the name Tsutsusi based on Kaempfer's t. 846
which is R. obtusum var. Kaempferi, and cites " Azalea L." as
a synonym; though not an American plant, this is mentioned
here, because Small in the North American Flora considers
A. indica L., under which Linnaeus cites Kaempfer's tab. 846, the
type of the genus Azalea. In 1766 Crantz (Inst. II. 468) pro-
posed the new name Hochenwartia for Rhodora, because it was
not the Rhodora of Pliny. Gmelin (Syst. Nat. II. pt. 1, 694) in
1791 united Rhodora with Rhododendron, and Salisbury in
1796 (Prodr. 286) first recognized the close relationship of most
Azaleas to the genus Rhododendron; he referred the American
Azaleas and Rhodora to the genus Rhododendron, retaining the
name Azalea for A. procumbensj one of the two species upon
which Linnaeus founded the genus. In 1803 Michaux (FL
EOT. -Am. I. 150) described two new species, A. calendulacea and
A. canescens; the former had been mentioned as long before as
1749 by Golden but without sufficient description. It was men-
tioned again hi 1791 by W. Bartram, who discovered it in 1776
and describes its beauty in glowing terms. The second species
is possibly identical with one of Aiton's varieties of A. nudiflora
INTRODUCTION 111
and its introduction would be in that case prior to 1789. In 1811
Willdenow (Berl. Baumz. ed. 2, 49) described from cultivated
plants A. speciosa identical with one of Aiton's varieties of
A. nudi flora and the following year Loiseleur Deslongchamps
(Nouv. Duhamel. V. 224) described A. rosea also from culti-
vated plants. Pursh in 1814 describes as a new species A.
arborescens and raises three of Aiton's varieties of A. viscosa
and one of A. nudiflora to specific rank. In 1822 D. Don (in
Edinb. Philos. Jour. VI. 47) transferred, like Salisbury twenty-
six years before, the species of Azalea except A. procumbens to
Rhododendron. In this he was followed by Torrey, G. Don,
Endlicher, Maximo wicz, Bentham & Hooker and most recent
authors, except that Maximowicz, Bentham & Hooker and
later authors took up Desvaux's name Loiseleuria for Azalea
procumbens. In 1827 Reichenbach, who like the two Dons and
Endlicher retained the name Azalea for A. procumbens, proposed
the genus Anthodendron (in Moessler, Handb. Gewachsk.
I. 244) for A. pontica, A. nudiflora and A. viscosa. G. Don (Gen.
Syst. III. 84) in 1834 was the first botanist to subdivide the
genus Rhododendron into sections and he proposed the sections
Pentanthera and Rhodora with which we are here concerned.
After 1814 no new species were added until the year 1855,
when A. calif ornica Torr. & Gray (Rh. occidentale Gray) from
California was described; it was introduced by Lobb about 1850.
The very distinct R. Vaseyi was discovered in 1878 by George
Vasey and described the following year by A. Gray; it was in-
troduced into cultivation about the same time. In 1891 Greene
(m.Pittonia, II. 172) described R. sonomense as a new species,
but this is only a form of R. occidentale. In 1892 Otto Kuntze,
who took the year 1737 as the starting point for generic nomen-
clature and consequently considered Azalea the older generic
name, transferred all the species of Rhododendron known to him
to Azalea. In 1901 Small (in Bull. Torr. Bot. Club, XXVIII.
360) described as a new species A. Candida now referred to
R. canescens as a variety, and in 1903 (Fl. S. E. U. S. 883) he
described A. oblongifolia and A. serrulata and separated R.
Vaseyi as a distinct genus under the name Biltia. In 1913 (I. c.
ed. 2, 1356) he adds two new species A. austrina and A. pruni-
folia, and in 1914 (in N. Am. Fl. XXIX. 42) A. prinophylla
identical with A. rosea Loisel. (R. roseum Rehd.). In 1917 Ashe
112 THE AZALEAS OF NORTH AMERICA
(in Bull. Charleston Mus. XIII. 26) published A. atlantica as a
new species and three years later A. neglecta (in Bull. Torr.
Bot. Club, XLVII. 581 [1920]) here referred to R. atlanticum
as a form. One new species and several new varieties are
described in this paper. Of these recent species R. austrinum was
introduced into cultivation in 1914, R. oblongifolium in 1917 and
R. serrulatum and R. prunifolium in 1918, all through the agency
of the Arnold Arboretum. Rhododendron atlanticum has been
cultivated for several years by W. W. Ashe in Washington and
by Professor Coker in the Arboretum of the University of
North Carolina at Chapel Hill. Rhododendron alabamense is the
only species not yet in cultivation.
Soon after the introduction of the first American Azaleas to
England about 1730 they become favorite garden plants and at
the beginning of the last century there were already several
species and many varieties in cultivation which played an
important part among the so-called American plants. By
hybridization between themselves and with the Rhododendron
luteum introduced at the end of the 18th century and also with
evergreen Rhododendrons the garden forms began rapidly to
increase in numbers and in 1836 Loddiges cultivated in his
nursery near London, according to his catalogue, 107 varieties
and hybrids of R. viscosum and 43 varieties of R. nudiflorum and
several other species and varieties. The delicate coloring of some
and the brilliancy of 'others, combined with a delicate fragrance in
several species and the hardiness of almost all these Azaleas,
made them very desirable and favorite garden plants both in
England and on the Continent. Hybridization in the seventies
with R. japonicum added a new race of hybrids which are per-
haps even more showy in some respects but weaker in constitu-
tion than the older hybrids generally known as Ghent Azaleas.
It is, however, doubtful if any of these hybrids surpass in the
brilliancy of their flowers the true species like R. calendulaceum
and R. speciosum which had almost disappeared from European
gardens until recently reintroduced.
The American Azaleas are chiefly confined to the Appalachian
Mountains and the adjoining regions and to the Atlantic and
Gulf coast region; only one species, Rhododendron occidentale,is
found in the Pacific states from southern Oregon to southern
California. No Azalea occurs south of the United States bound-
INTRODUCTION 113
ary; the most southern species are R. serrulatum which reaches
middle Florida and R. canescens which extends in Texas nearly as
far south. In the North R. canadense is found as far north as
Labrador. The western limit of the Atlantic Azaleas runs from
southern Quebec to northeastern Ohio, then through southeast-
ern Indiana, extreme southeastern Missouri, central Arkansas and
extreme eastern Oklahoma to the coast of eastern Texas. The
greatest development of the group is on the Appalachian
Mountains and as the centre of segregation we must consider
Georgia, where eight species, half of all American species, occur.
The Azaleas are shrubs from one half to two metres or rarely
to 7 metres in height and are essentially inhabitants of the
temperate deciduous forest; they are mostly moisture and shade
loving shrubs and most species are found on the wooded slopes
of hills and mountains growing in scattered individuals inter-
mingled with other shrubs and trees. Like most Ericaceae they
are calciphobous and therefore are absent from limestone
regions, although R. roseum is found in western New York and
R. oblongifolium in Oklahoma on limestone soil. In spring when
in bloom they form a most conspicuous feature of the woods,
particularly species like R. calendulaceum on the mountains
from Pennsylvania to Georgia with its brilliant orange or scarlet
flowers and R. speciosum in Georgia with bright red or scarlet
flowers; also R. nudiflorum, R. roseum and R. canescens with
white to pink flowers are conspicuous, the latter being widely
distributed in the woods of the southern coastal plain. The late
flowering species, as R. viscosum and R. serrulatum, are less showy
but deliciously fragrant and inhabit chiefly swamps and moist
woods of the coastal plains from New England to Louisiana,
though the northern species R. viscosum also grows on the
mountains. The related R. arbor escens with white and fra-
grant flowers is likewise a mountain plant. Only R. atlanticum
is a predominant feature over large areas as it grows in open
pine woods of the coastal plain chiefly in North and South
Carolina. Most species have a wide distribution, particularly
R. nudiflorum, R. canescens, R. viscosum and R. serrulatum',
others, like R. speciosum, R. oblongifolium and R. atlanticum,
occupy an area not more than about two to three hundred
miles in length and R. Vaseyi, R. alabamense and R. pruni-
folium are more limited in distribution.
114 THE AZALEAS OF NORTH AMERICA
The present study of American Azaleas is based chiefly on the
collections of the Arnold Arboretum. For many years Professor
Sargent has taken special interest in Azaleas and has succeeded
in assembling a large amount of material, particularly from the
southern states usually poorly represented in most herbaria.
Besides having this material at my disposal, I have consulted
the collections of the Gray Herbarium at Cambridge and of the
National Herbarium at Washington and the herbaria of the
New York Botanic Garden, the Academy of Natural Sciences of
Philadelphia, and of the New England Botanical Club ; specimens
for further study were kindly loaned to me from most of these
institutions and from the herbaria of the State University of
Ohio, of the Missouri Botanical Garden and of the Academy of
Sciences at Rochester. I also am under obligation for specimens
to Professor W. C. Coker of the University of North Carolina, to
Dr. K. M. Wiegand of Cornell, Mr. W. W. Ashe of Washington
and Mr. John Dunbar of Rochester. I have further had the op-
portunity to see most of the species in their native habitats dur-
ing various journeys, and the living collections of Azaleas of this
Arboretum supplied me with material to study many of the
species and a large number of garden forms and hybrids in the
living state. The great variability of most species together with
the absence of strong morphological characters within this group
makes it difficult to assemble the numerous forms into well
defined species and varieties. The difficulty is considerably in-
creased if one tries to elucidate the innumerable garden forms
and hybrids, as few of these forms are adequately described
or figured and herbarium or living material of only a small per-
centage of them is available.
The Azaleas form a distinct subgenus of the Rhododendron
for which we propose to use Endlicher's subgeneric name Antho-
dendron, as we do not believe that the name Azalea used for it
by most authors can be correctly applied to this subgenus, as
will be seen from the following enumeration of synonyms and
the appended remarks.
THE SUBGENUS ANTHODENDRON ENDL.
Rhododendron subgen. Anthodendron Endlicher, Gen. 759 (1839),
emended.
Azalea Linnaeus, Spec. 150 (1753), as to species 1-4. — Desvaux in Jour.
Bot. Appl. I. 35 (1813). — Roemer & Schultes, Syst. IV. 374 (1819), ex-
cluding species 12 and 13. — Gray, Man. 268 (1848). — K. Koch, Dendr.
II. 1, 171 (1872). — Render in Bailey, Cycl. Am. Hort. I. 119 (1900), ex-
cluding A. albiflora, semibarbata, kamschatica. — Britton & Brown, III. Fl.
11.558 (1897). — Britton, M an. 698 (1901). — Small in N. Am. Fl. XXIX.
41 (1914).
Anthodendron Reichenbach in Moessler, Handb. Gew&chsk. I. 244, 308 (1827);
FL Germ. Exc. 416 (1831).
Rhododendron sect. Pentanthera G. Don, Gen. Syst. III. 846 (1834). — See
also page 124.
Rhododendron a. Anthodendron, Endlicher, Gen. 759 (1839).
Rhododendron subgen. Azalea Planchon in Rev. Hort. 1854, 43; with Tsusia as
distinct subgenus. — Maximowicz in Bull. Acad. Sci. St. PStersbourg, XV.
229 (1870); in Mem. Acad. Sci. St. Pttersbourg, s<§r. 7, XVI. 9, 24 (1870),
as section, with Tsusia as distinct section. — Bentham & Hooker, Gen.
II. 601 (1876), as series, with Tsusia as distinct group. — Gray, Syn. Fl.
N. Am. II. 1, 40 (1878). — Dippel, Handb. Laubholzk. I. 410 (1889), with
Tsusia as distinct subgenus. — Drude in Engler & Prantl, Nat. Pflan-
zenfam.IV. 1,37 (1889). — Koehne, Deutsch. Dendr. 454 (1893), exclud-
ing Azaleastrum and Therorhodion. — Rehder & Wilson in Sargent, PI.
Wilson. I. 516 (1913), excluding Chionastrum and Azaleastrum. — Rehder
in Bailey, Stand. Cycl. Hort. V. 2937 (1916), excluding Azaleastrum.
Shrubs or occasionally small trees with deciduous or half evergreen rarely
evergreen leaves, usually more or less strigose- or villose-pubescent, sometimes
glabrous, never lepidote-glandular. Flowers from a terminal bud, one or several
to many in umbel-like racemes. Corolla funnel-form to rotate, rarely campanu-
late, usually with a distinct often long and slender tube, rarely two-lipped and
divided partly almost to the base. Stamens 5 to 10, of unequal length. Ovary
5-celled, usually strigose and pubescent, rarely glabrous, never lepidote.
The type section of the subgenus is Pentanthera and the type species Rhodo-
dendron luteum Sweet (Azalea pontica Linnaeus). In North America this subgenus
is represented by sixteen species.
Our conception of the subgenus coincides exactly with that of Drude (I. c.),
while all other authors draw its limits narrower or wider, as shown in the syn-
onomy given above. In former publications I had included Azaleastrum and
Therorhodion in this subgenus, but as the inflorescens of these two groups is en-
tirely different from that of the type of this subgenus, I prefer to consider these
two groups as coordinate subgenera and restrict the sections belonging to Antho-
dendron to Tsutsutsi G. Don, Sciadorhodion Rehd. & Wils., Rhodora G. Don
and Pentanthera G. Don, of which the first two are exclusively Asiatic, while the
last two contain American and Asiatic species. It does not seem advisable to
115
THE AZALEAS OF NORTH AMERICA
maintain Tsutsutsi as a distinct subgenus, since it is closely connected with Rho-
dora by the new section Sciadorhodion.
As the name Azalea used first by Planchon as a subgeneric name is not the
oldest subgeneric name for the group, and as, moreover, the generic name Azalea
upon which the name of the subgenus is based properly belongs as a synonym to
Loiseleuria,1 either Don's Penthanthera or Endlicher's Anthodendron must take its
place. As Pentanthera has been proposed originally as a sectional name and used
as such by later authors it may be retained as the name for the section to which it
should apparently be restricted by the meaning of its name, and Anthodendron
first published in 1827 as a genus may be adopted in an enlarged sense as the
proper name for the subgenus.
See Jour. Arnold Arboretum, II. 156 (1921).
KEY TO THE AMERICAN SPECIES OF THE SUBGENUS
ANTHODENDRON
Corolla rotate or rotate-campanulate, more or less two-lipped; stamens 7 to 10,
rarely 5 or 6. (Sect. Rhodora).
Stamens 10; corolla two-lipped with the two lower lobes divided to the base,
rose-purple; leaves tomentulose beneath, glaucous.
R. canadense, p. 120.
Stamens 5 to 7; corolla with short tube, slightly two-lipped, pink or whitish,
spotted; leaves glabrous and green beneath R. Vaseyi, p. 122.
Corolla funnel-form, subregular, the tube longer or little shorter than the lobes;
stamens 5. (Sect. Pentantherd).
Color of corolla yellow or orange to scarlet and red, rarely white or pinkish with
a large yellow blotch.
Corolla white or pinkish with large yellow blotch, the tube gradually dilated
above the middle; flowers with or after the leaves.
R. occidentale, p. 125.
Corolla orange or yellow to scarlet or red.
Flowers with or shortly after the leaves; winter-buds glabrous.
Corolla-tube more or less glandular outside, about as long or shorter
than the lobes, yellow to scarlet R. calendulaceum, p. 127.
Corolla- tube finely pubescent and glandless outside, longer than the lobes,
red to scarlet R. spedosum, p. 131.
Flowers before the leaves; winter-buds pubescent; corolla yellow, the tube
often reddish R. austrinum, p. 146.
Color of corolla white to deep pink or carmine, crimson in R. prunifolium, with-
out a conspicuous yellow blotch.
Flowers before or with the leaves.
Flower-buds without prominent rows of stipitate glands at apex; much
branched shrubs usually more than 0.5 m. tall, rarely low.
Corolla-tube more or less pilose, glandular or eglandular, gradually dilated
near the apex.
Corolla-tube about as long as the lobes, dilated above the middle;
stamens declinate; corolla usually pink.
Leaves glabrous beneath except the strigose midrib, bright green;
corolla hirsute and glandless or glandular-pilose outside; winter-
buds glabrous rarely thinly pubescent . . R. nudiflorum, p. 134.
Leaves pubescent beneath, sometimes nearly glabrous except along
the midrib beneath, often bluish green; corolla glandular out-
side; winter-buds pubescent R. roseum, p. 138.
Corolla-tube distinctly longer than the lobe, glandular or eglandular;
corolla white; winter-buds glabrous; leaves pubescent and glauces-
cent beneath R. alabamense, p. 141.
Corolla-tube densely and finely villose and sparingly stipitate-glandu-
lar or eglandular, slender and abruptly expanded at apex; winter-
buds pubescent; leaves usually pubescent beneath.
R. canescens, p. 143.
117
118 THE AZALEAS OF NORTH AMERICA
Flower-buds with prominent rows of conspicuous long-stipitate glands at
apex; corolla glandular-pilose, not or slightly villose outside, the tube
abruptly expanded at apex; low stoloniferous shrub with simple or
little branched stems R. atlanticum, p. 147.
Flowers expanding after the leaves are fully developed; the flower-buds with
prominent rows of stipitate glands at apex, rarely quite glabrous.
Branchlets and leaves more or less strigose or pubescent; style usually
pubescent.
Calyx-lobes oblong to oblong-lanceolate, rarely short; corolla finely
villose; leaves usually large, 4 to 10 cm. long; winter-buds pubescent;
flowers appearing before the terminal buds are formed.
R. oblongifolium, p. 150.
Calyx-lobes short, semi-orbicular to ovate; corolla villose and glandular-
pilose; leaves usually 2 to 6 cm. long; winter-buds glabrous or
pubescent; flowers appearing usually when the terminal buds are
forming.
Winter-buds with many (usually more than 15) aristate-mucronate
scales, usually pale with conspicuous dark margin; branchlets
bright red-brown, usually densely strigose, specially toward the
apex; leaves often pubescent beneath, particularly at the end of
shoots, serrulate-ciliate R. serrulatum, p. 153.
Winter-buds with fewer (usually less than 15) obtusish or acutish,
usually pale brown scales; branchlets usually pale, strigillose, his-
pid or glabrescent; leaves glabrous, strigose on midrib beneath,
pubescent only in one rare variety .... JR. viscosum, p. 157.
Branchlets and leaves glabrous or the leaves sometimes strigillose on mid-
rib beneath; style usually glabrous; winter-buds glabrous.
Corolla white or pinkish, tube glandular-pilose outside; leaves glaucous
beneath, generally obovate, acute or obtusish.
R. arborescens, p. 166.
Corolla crimson, tube glabrous or nearly glabrous outside; leaves light
green beneath, elliptic to oblong-lanceolate, acuminate.
R. prunifolium, p. 169. **
ENUMERATION OF THE SPECIES
SECT. I. RHODORA G. DoN1
Rhododendron sect. Rhodora G. Don, Gen. Syst. III. 848 (1834).—
Endlicher, Gen. 759 (1839). — Dippel, Handb. Laubholzk. I. 417
(1889), as section of subgenus Azalea, excluding his Nos. 29 and 31. —
Koehne, Deutsch. Dendr. 455 (1893), as section of subgenus Azalea,
excluding his No. 36. — Zabel in Mitt. Deutsch. Dendr. Ges. XI. 26
(1902), in part.
Rhodora Linnaeus, Spec. ed. 2, 561 (1762); Gen. ed. 6, 218 (1764). — Will-
denow, Spec. I. pt. 2, 866 (1798). — De Candolle, Prodr. VII. 719 (1839). —
Gray, Man. 267 (1848); ed. 5, 309 (1867). — Britton & Brown, III. Fl. II.
560 (1897). — Britton, Man. 699 (1901). — Small in N. Am. Fl. XXIX. 44
(1914).
Hochenwartia Crantz, Inst. II. 468 (1766).
Rhododendron sect. Azalea, ser. 2, [subser.J b, Maximowicz in M6m. Acad.
Sci. St. Petersb., se"r. 7, XVI. No. IX. 28 (1870). — Bentham & Hooker,
Gen. PI. II. 601 (1876), as subser. 2, in part. — Drude in Engler & Prantl,
Nat. Pflanzenfam. IV. 1, 37 (1889), as subgenus Azalea, § 4.
Biltia Small, Fl. S. E. U. S. 884 (1903); in N. Am. Fl. XXIX. 48 (1914).
Deciduous upright shrubs without strigose pubescence, densely or loosely
branched, sometimes irregularly dichotomous, but not whorled; branchlets gla-
brous or pilose to hirsute, winter-buds of many imbricate scales, glabrous or pu-
berulous. Leaves scattered or crowded at the end of the branchlets. Flowers
from a terminal bud, the leafy shoots from separate lateral buds; corolla two-
Lipped, or rotate-campanulate, rarely campanulate; stamens 10, or in one species
7 or occasionally 5 or 6, not or jonly little longer than the corolla, usually declinate;
ovary pubescent or glabrous and stipitate-glandular. Capsule usually with rather
thin valves.
The type species of this section is R. canadense Torr. The section contains five
species, of which two are native of eastern North America and three are Japanese.
All these species are very distinct from each other and may be divided into three
groups. The first group, containing only R. canadense, is characterized by the
deeply two-lipped corolla, the lower lip divided nearly to the base, the glandular-
pubescent and sparingly setose ovary, the puberulous branchlets and the to-
mentulose under side of the usually oblong leaves and the glandular-puberulous
narrowly oblong capsule. The second group with three species, of which R. Vaseyi
is one, has a rotate-campanulate slightly two-lipped corolla, a stipitate-glandular
but otherwise glabrous or sometimes quite glabrous ovary, an ovoid to oblong
glandular-hirsute or stipitate-glandular or glabrous capsule, and glabrous or pilose
leaves and branchlets. The third group, consisting only of R. nipponicum, has a
campanulate nearly regular corolla, with the lobes shorter than the tube, a glandu-
1 See page 91 for the Old World species of this section.
119
120 THE AZALEAS OF NORTH AMERICA
lar-pilose but otherwise glabrous ovary, hirsute branchlets and hirsute large obo-
vate leaves, a very thin-valved oblong-ovoid capsule almost destitute of glands at
maturity; its flowers appear after the full development of the leaves, while in all
the other species of this group they open before the leaves unfold. The petiole
of the shoot-leaves in R. Vaseyi, R. nipponicum and R. Albrechtii is somewhat de-
current on the stem, leaving an elongated scar distinctly longer than broad.
In the section Rhodora I have included R. Vaseyi as suggested by Gray and
as done by Dippel and by Koehne; by Small this has been made the type of a new
genus Biltia, chiefly distinguished by the exterior aestivation of the middle lobe of
the upper lip of the corolla. This position of the posterior lobe is without doubt
unusual in the genus, but can be observed at least occasionally in species related
to R. Vaseyi. Among flowers of R. canadense I have found a small percentage
with the middle lobe of the upper Up exterior and in R. Schlippenbachii, which
belongs to the section nearest to Rhodora and is very similar in its flowers to
R. Albrechtii and R. quinquefolium, both closely related to R. Vaseyi, I have found
after examining numerous fresh flowers just before opening that about 15 per cent
of the flowers had the middle lobe of the upper lip completely exterior and 25 to
30 per cent had one side exterior and the other side covered. This shows that the
position of the upper lobe cannot be used as a reliable character to separate Biltia
generically. As there is no other character to separate R. Vaseyi from the other
species of the section Rhodora except the number of stamens, which also cannot
be considered a reliable character in the genus Rhododendron, it seems best to
retain it in this section.
Rhododendron canadense Torrey, Cat. PL 151 (in Geol. Surv. New
York Assembly, No. 50) (1839). — Oakes, Cat. Vermont PL 190 (in
Thompson, Hist. Vermont) (1842).— Wood, Classb. Bot. 235 (1845).—
Zabel, Syst. Verz. Muenden, 26 (1878). — Britton, Sterns, Poggenburg,
Prelim. Cat. New York, 33 (1888). — Britton, Cat. PL N. Jersey, 162
(1889). — Dippel, Handb. Laubhokk. I. 418 (1889). — Robinson &
Fernald, Gray's New Man. ed. 7, 631 (1908). — Schneider, III. Handb.
Laubholzk. I. 494, fig. 327 i-k, 328 f (1909). — Jackson, Cat. FL Worces-
ter Co., Mass. 76 (1909). — Graves & others, Cat. Flow. PL Conn. 308
(1910). — Twining, FL N. E. Pennsylv. 56 (1917).
Rhodora canadensis Linnaeus, Spec. ed. 2, 561 (1762). — Willdenow, Spec. I.
pt. 2, 866 (1798). — Michaux, FL Bor.-Am. I. 259 (1803). — Pursh, FL Am.
Sept. I. 298 (1814). — Bigelow, FL Boston, 104 (1814). — De Candolle,
Prodr. VII. 719 (1839). — Gray, Man. 267 (1848); ed. 5, 309 (1867).—
Tracy, Stud. Essex FL 49 (1858). — Britton & Brown, III. FL 560, fig. 2748
(1897). — Clute, FL Upp. Susquehanna, 70 (1898). — Britton, Man. 699
(1901). — Small, Fl. Pennsylv. 238 (1903); in N. Am. FL XXIX. 44 (1914).
Hochenwartia canadensis Crantz, Inst. II. 469 (1766).
Rhododendron Rhodora G. F. Gmelin, Syst. Nat. II. pt. 1, 694 (1791).—
Sweet, Hort. Brit. ed. 2, 343 (1830). — G. Don, Gen. Syst. III. 848 (1834).—
Gray, Syn. FL II. 1, 41 (1878). — J. Robinson, FL Essex Co., Mass. 73
(1880). — Macoun, Cat. Canad. PL II. 302 (1884). — Dame & Collins, FL
Middlesex Co., Mass. 63 (1888). — Perkins, Cat. FL Vermont, 33 (1888). —
Bennett, PL Rhode Isl. 26 (1888). — Coulter & Watson, Gray's Man.
ed. 6, 321 (1890). — Rand & Redfield, FL Mt. Desert Isl. 127 (1894).—
ENUMERATION OF THE SPECIES 121
Deane, Fl. Metrop. Park, Mass. 53 (1896); in Rhodora, I. 94 (1899). —
Millais, Rhodod. 235, pi. (1917).
Azalea canadensis O. Kuntze, Rev. Gen. II. 386 (1891). — Rehder in Bailey,
Cycl. Am. Hort. I. 122 (1900) .*
A much-branched shrub 1 m. tall or lees, with slender upright or ascending
branches; young branchlets puberulous when young, bright yellowish red or
pinkish and often slightly bloomy at the end of the first season, becoming light
yellowish gray or gray the second year, later grayish brown; floral winter-buds
with about 10 ovate, acuminate to acute pinkish, finely pubescent and ciliolate
scales. Leaves elliptic to oblong, obtuse or acutish, cuneate at base, 2 to 4.5 rarely
to 6 cm. long and 0.8 to 1.8 cm. broad, ciliate and revolute at the margin, dull
bluish green above, usually somewhat strigillose and finely villose on the midrib,
thinly grayish tomentulose beneath and usually with scattered fulvous hairs and
scattered glands, and sparingly strigose on the midrib, the secondary veins diverg-
ing at nearly right angles; petioles slender, 2 to 5 mm. long, puberulous and spar-
ingly strigose. Flowers appearing before the leaves, in April or May or in the
North in June, in 3- to 7-flowered umbel-like racemes; pedicels 3 to 7 mm. long,
puberulous, glaucous and usually sparingly glandular-pilose; calyx-lobes very
short, unequal, puberulous and setosely ciliate; corolla rose-purple, two-lipped,
1.5 to 2 cm. long, glabrous, the lower lip divided nearly or quite to the base into
two nearly distinct narrow-oblong lobes, the upper lip with three short ovate lobes
at apex; stamens 10, about as long as the corolla, unequal; anthers broadly ellip-
soidal, 0.15 mm. long, purple; the filaments pubescent at the lower third; style
slightly longer than the stamens, 1.5 to 1.8 mm. long, glabrous or minutely pilose
near the base; ovary pubescent and slightly glandular, sparingly setose. Capsule
ovoid-oblong, curved near the base, 1 to 1.5 cm. long, slightly grooved, setose and
finely puberulous, light red-brown with a pinkish bloom.
This is the most northern species of the group in North America and its range
extends from Labrador and Newfoundland to southwestern Quebec and south
through New England and central New York to northeastern Pennsylvania and
northern New Jersey. It grows along river banks, in moist woods and in swamps.
In spring it is a beautiful feature of the northern woods and swamps and its charm
has inspired Emerson to a well known poem in which he calls Rhodora a rival of
the Rose.
Rhododendron canadense differs from all other species of the genus by the deeply
divided corolla, but in all other characters it is so closely related to the species here
associated with it, that its generic separation would appear artificial, and its close
1 PRELINN. STNON. : Chamaerhododendros Duhamel, Semis Plant. Arb. Add. 10,
tab., fig. 2 (1760); Abh. Bdume Stand. Str&uch, ed. Oelhafen, I. 119, t. (1762).
ADDITIONAL ILLUSTRATIONS. COLORED PLATES: Meerburgh, PL Select. Icon.
t. 23 (1798). — Bot. Mag. XIV. t. 474 (1800). — Nouv. Duhamel III. t. 53 (1806).—
Guimpel, Otto & Hayne, Abb. Fremd. Holzgew. t. 14 (1825). — Emerson, Trees &
Shrubs Mass. ed. 2, II. t. opp. p. 441 (1875). — BLACK FIGURES: L'He*ritier, Stirp.
Nov. t. 68 (1796). — Lamarck, Encycl. Meth. Rec. PL II. t. 364 (1823). — Newhall,
Shntb* N.E.Am.&g. 85 (1893). — Mdller's Deutsch. Gdrtn.-Zeit. XVII. 286, fig.
(1902). — Keeler, Our North. Shrubs, 359 (1903). — Garden Mag. V. 221 (1907).—
Country Life Am. XL 496 (1907). — Millais, Rhodod. pi. opp. 234 (1917). — HABIT
FIGURES: Mdller's Deutsch. Gdrtn.-Zeit. XVII. 287, fig. (1902); XXI. 73, fig.
(1906). — Silva-Tarouca, Uns. Freil.-Laubgeh. fig. 65 (p. 81) (1913). — GartenweU,
IX. 474 (1905); XIV. 85 (1910); XX. 378 (1916). — Gartenschonheit, I. 33 (1920). —
The figures 31, 32 in Jardin, XX. 57 (1905) named Rhodora canadensis represent
Rhododendron dahuricum L.
122 THE AZALEAS OF NORTH AMERICA
relation to Rhododendron was perceived as early as 1791 by Gmelin who referred
it to that genus. The species was first described and figured by Duhamel from a
cultivated plant which flowered the first time in March, 1756, in the Botanic Gar-
den at Paris, where it had been brought from Canada a few years earlier. Into
England it was introduced by Joseph Banks in 1767.
Observations on the pollination of this species have been made by F. Hildebrand
(Flora, LXIV. 501, t. 10, fig. 6, 7 (1881) ), who describes the peculiar arrangement
to avoid self-fertilization. When the flower opens, the apex of the style with the
stigma remains enclosed in a little hood formed by the lobes of the upper lip,
while visiting insects carry away pollen from the anthers; further elongation of the
style forces it out of the hood and the bent style stretches itself, extending the
stigma beyond the stamens, and is then in a position to be fertilized by insects
carrying pollen from other flowers.
Rhododendron canadense f. albiflorum Rehder, comb. nov.
Rhododendron Rhodora f. alUflora Rand & Redfield, Fl. Mi. Desert IsL 127
(August, 1894).
Rhododendron canadense f. album Voss, Vilmorin's Blumengdrt. I. 587 (Sept.
or Oct., 1894). — Zabel in Mitt. Deutsch. Dendr. Ges. XI. 31 (1902).
A form with white flowers, occasionally found wild under the typical form, e.g.
Maine, Mt. Desert, Southwest Harbor.
Rhododendron canadense f. viridifolium Fernald, n. forma.
Ramulis glabriusculis; foliis subtus sparse pilosis supra atroviridibus lucidis
nee glaucis.
NOVA SCOTIA: boggy thickets bordering Trefry's Lake, Arcadia,
July 29, 1920, Fernald & Long, No. 22,150 (TYPE in Gray Herb.).
This shrub occurs in scattered clumps on the shore of Trefry's Lake, the only
place we met it, the ordinary form of the species with glaucous foliage being
generally common in the province. — M. L. FERNALD.
Rhododendron Vaseyi A. Gray in Proc. Am. Acad. XV. 48 (1879) ; in
Bot. Gaz. VIII. 282 (1883); Syn. Fl. ed. 2, II, 1, 398 (1886).—
Donnell Smith in Bull. Torr. Bot. Club, XV. 164 (1888). — Sargent in
Gard. & For. I. 376, fig. 60 (1888). — Dippel, Handb. Laubholzk.
I. 419 (1889). — Skan in Bot. Mag. CXXXII. t. 8081 (1906).—
Schneider, III. Handb. Laubholzk. II, 495, fig. 325o,327 c-d (1909).—
Millais, Rhodod. 257, t. opp. p. 10 and 20 (1917).
Azalea Vaseyi Rehder in Moller's Deutsch. Gartn.-Zeit. XIV. 332, fig. (1899) ;
in Bailey, Cycl. Am. Hort. I. 122 (1900).
Biltia Vaseyi Small, Fl. S. E. U. S. 884 (1903); in N. Am. Fl. XXIX. 49
(1914) -1
1 ADDITIONAL ILLUSTRATIONS. COLORED PLATES: Meehan's Monthl. VII. 121,
t. 7 (1897). — Garden, LIV. t. 1191, opp. p. 282 (1898). — BLACK FIGURES: Gard.
Chron. ser. 3, XX. 71 (1896); LI. 313 (1912). — Mover's Deutsch. Gartn.-Zeit. XIV.
332 (1899) . — Gard. LVI. 122 (1899) ; LXXVI. 332 (1912) ; LXXXIV. 239 (1920) . —
Gard. Mag. V. 219 (1907). — Country Life Am. XI. 499 (1907). — Bean, Trees &
Shrubs Gt. Brit. II. 384 (1914) . — Bailey, Stand. Cycl Hort. V. fig. 3391 (1916) , after
Gard. & For.— HABIT FIGURES: Mailer's Deutsch Gartn.-Zeit. XIV. 333 (1899).—
ENUMERATION OF THE SPECIES 123
An upright, rather irregularly branched shrub with spreading branches, occa-
sionally 5 m. tall; young branchlets puberulous and sparingly pilose at first, soon
glabrous, light red-brown at the end of the season, becoming brown or grayish
brown the second year; older branches grayish brown with flaky or shredding
bark; floral winter-buds large, broadly ovoid, obtuse, with 7 to 10 orbicular-ovate
scales, rounded or the upper ones truncate or slightly emarginate at apex, mu-
cronulate, the basal ones acuminate, glabrous or the upper and inner ones minutely
puberulous, white-ciliate and sometimes glandular on the margin. Leaves elliptic
or elliptic-oblong, acuminate, cuneate at base, 5 to 12 cm. long and 2 to 5 cm.
broad, usually slightly undulate on the margin, ciliate, dark green and glabrous above
except the sparingly and finely villose midrib, rarely sparingly strigillose, light
green beneath and glabrous or sparingly pilose on the midrib; petioles slender, 3 to
7 mm. long, glabrous or sparingly pilose. Flowers appearing in May before the
leaves, in 5- to 8-flowered umbel-like racemes; pedicels 0.5 to 1.5 cm. long, with
short-stipitate glands, sometimes sparingly so; calyx oblique, with shallow rounded
lobes, erose-glandular on the margin; corolla rotate-campanulate 2.5 to 3 cm. long,
two-lipped, light rose-colored with orange or red-orange dots at the base of the
upper lobes, glabrous, tube very short, about 5 mm. long, the lobes oblong, rounded
at apex, the upper lip less deeply divided, with the middle lobe exterior in bud;
stamens usually 7, sometimes 5 or 6, unequal, the longer ones exceeding the
corolla; filaments glabrous; anthers ellipsoid, 1 to 2 mm. long, pinkish; style 2.5 to
3 cm. long, longer than stamens, glabrous or with few stipitate glands near the
base. Capsule narrow-oblong, 1.2 to 1.5 cm. long, with a thin narrow keel on
back of the rather thin valves.
This species is very distinct from all other American Azaleas and seems most
nearly related to the Japanese R. Albrechtii Maxim, which, however, differs con-
siderably in its 10 stamens, the more pubescent obovate leaves and the shorter
and thicker more woody, hispid capsule. It is restricted to the higher mountains
of western North Carolina, where it grows at an altitude of from 3000 to 5500 feet
on mountain slopes, in ravines and sometimes in swamps. It was first discovered
in 1878 on Balsam Mountain near Webster, Jackson County, by George Vasey
and soon afterward introduced into cultivation, for in 1880 the Arnold Arboretum
received a living plant from G. C. Woolson & Co. of Passaic, New Jersey. It has
proved perfectly hardy near Boston and is now well known in gardens in this
country as well as in Europe and valued for its handsome pale pink flowers appear-
ing in great profusion in spring before the leaves unfold. It has been found escaped
from cultivation near Halifax, Mass., as shown by the following specimens in the
herbarium of the New England Botanical Club: swamp near an abandoned nur-
sery, May 30, 1907, A. S. Pease (No. 9998); sandy soil, probably part of old
nursery, May 30, 1907, J. A. Cushman (No. 653).
Rhododendron Vaseyi f. album Nicholson in Kew Hand-list Arb. II.
57 (1896), as var., name only. — Bean, Trees & Shrubs Gt. Brit. II. 384
(1914), as var. — Rehder in Mitt. Deutsch. Dendr. Ges. XXIV. (1915),
225 (1916).
This form with white flowers was found at the Arnold Arboretum and also in
Kew Garden^ among seedlings of the typical form; all transitions from pure pink
to white can be found among seedlings of this species.
Gard. LVI. 119 (1899). — Gartenwelt, XVI. 231 (1912); XXII. 363 (1918). — Silva-
Tarouca, Urn. Freil-Laubgeh. fig. 64 (1913). — Gard. LXXIX. 302 (1915). — Gard.
Mag. XXX. 259 (1920). — Gar tenschonheit, I. 33 (1920).
SECT. II. PENTANTHERA G. DON
Rhododendron sect. Pentanthera G. Don, Gen. Syst. III. 846
(1834). — Render & Wilson in Sargent, PL Wilson. I. 549 (1913).
Azalea Linnaeus, Spec. 150 (1753), as to species 2 to 4. — De Candolle, Prodr.
VII. 715 (1838), excluding species 13, 14, 16. — Britton & Brown, III. Fl.
II. 558 (1897).
Rhododendron a. Anthodendron Endlicher, Gen. 759 (1839). — Zabel in Mitt.
Deutsch. Dendr. Ges. XI. 28 (1902), as section.
Theis "Salisb. in coll. 1817" ex De Candolle, Prodr. VII. 715 (1839), synonym.
Rhododendron sect. Azalea Regel in Act. Hort. Petrop. I. 162 (1871), exclud-
ing species 5 and 8.
Azalea subgen. Pentanthera K. Koch, Dendr. II. 1, 186 (1872).
Azalea subgen. Euazalea K. Koch, Dendr. II. 1, 179 (1872), as to species 11, 12.
Rhododendron sect. Euazalea Dippel, Handb. Laubholzk. I. 411 (1889).—
Koehne, Deutsch. Dendr. 458 (1893).
Deciduous upright shrubs, rarely almost tree-like, sometimes stoloniferous,
with usually irregularly whorled branches; branchlets usually more or less strigose
or hirsute, sometimes glabrous. Winter-buds with many imbricate scales.
Leaves scattered. Flowers several to many from a terminal bud, the leafy shoots
from separate lateral buds; corolla funnel-form, subregular, the tube about as long
or longer than the limb; stamens 5, usually much exserted; ovary more or less
strigose or setose. Capsule with woody valves.
The type species of this section is Rhododendron luteum Sweet. The section con-
tains besides the sixteen American species enumerated below, two species from
eastern Asia, R. molle Miq. and R.japonicum Suring., and one from southeastern
Europe and western Asia, R. luteum Sweet. In America it occupies two distinct
geographical areas: one on the Atlantic coast, extending from southern Quebec to
central Florida and west to Vermont, eastern Ohio, southeastern Missouri,
central Alabama, extreme eastern Oklahoma and eastern Texas; and one on the
Pacific coast from southern Oregon to southern California.
From the section Rhodora this section is easily distinguished by the funnel-form
subregular corolla with a distinct cylindric tube longer or little shorter than the
lobes and by the 5 stamens; the ovary is always densely villose and strigillose,
with or without glands. Most species show a wide range of variation particularly
in the pubescence of the leaves and in the color of the flowers. The leaves vary
from nearly glabrous to pubescent in R. oblongifolium, R. serrulatum, R. canescens,
R. roseum, R. occidentale and R. atlanticum; they are always glabrous except the
midrib in R. nudiflorum, R. arborescens and R. prunifolium and usually so in
R. viscosum; they are always pubescent in R. alabamense and, though usually only
slightly so, in R. calendulaceum and R. speciosum. The pubescence of the winter-
buds which affords a character hitherto neglected, shows less variation; they vary
from glabrous to finely pubescent in R. nudiflorum, R. viscosum, R. serrulatum, R.
atlanticum and R. occidentale; they are always glabrous in R. calendulaceum,
R. speciosum, R. arborescens, R. alabamense and R. prunifolium and always pu-
bescent in R. canescens, R. roseum and R. oblongifolium. The branchlets are in
most species more or less pubescent, usually villose and strigillose, but are always
124
ENUMERATION OF THE SPECIES 125
glabrous in R. arborescens and R. prunifolium and sometimes nearly glabrous in
R. nudiflorum, R. atlanticum, R. viscosum and R. occidentale. The sepals vary in
most species from semi-orbicular or nearly obsolete to oval or oblong, but usually
are rather small; in R. oblongifolium they are mostly oblong and usually well de-
veloped in R. arborescens and R. occidentale. The corolla is usually glandular-
pubescent outside, glabrous or nearly glabrous in R. prunifolium, finely villose
and nearly destitute of glands in R. oblongifolium and R. canescens, pilose and
eglandular in typical R. nudiflorum and in R. speciosum. The tube is in most
species pubescent inside, glabrous or nearly so in R. atlanticum, R. viscosum, R.
serrulatum, and usually in R. oblongifolium. The color of the corolla is in most
species white to pinkish or pink, pale yellow in R. austrinum, bright yellow to
scarlet or bright red in R. calendulaceum, bright red in R. speciosum and crimson
in R. prunifolium. The stamens are always pubescent, usually for two-thirds of
their length. The style is pubescent at the base in most species and only occa-
sionally glabrous or nearly glabrous, but always glabrous in R. prunifolium and
usually so in R. arborescens. The pubescence of the ovary is mostly villose, more
or less overlaid by strigose or setose hairs which are at least partly gland-tipped in
R. calendulaceum, occasionally glandless in R. austrinum, R. oblongifolium, R. ser-
rulalum, R. viscosum, R. arborescens, but glandless or nearly so in R. speciosum,
typical R. nudiflorum, R. canescens, occasionally glandular in R. atlanticum and
R. prunifolium. In R. canescens there are often only a few strigose hairs at the
base and the whole ovary appears clothed with silky white hairs. The pubescence
of the capsule is similar to that of the ovary; the shape varies much in the same
species and is generally ovoid-oblong; the most distinct capsule is that of R.
canescens, which is slender and nearly cylindric, almost destitute of bristles, but
covered with a fine grayish pubescence.
The species of this section may be divided into four fairly distinct groups.
The first group contains R. occidentale, R. calendulaceum and R. speciosum. The
corolla is rather large with a tube dilated gradually above the middle, spreading
into a wide limb with broad, ovate lobes; the color is bright yellow to scarlet or
white to pink and the upper lobe is marked by a large orange blotch. The flowers
appear with or in R. occidentale often after the leaves. The second group contains
R. roseum, R. austrinum, R. nudiflorum, R. alabamense and R. canescens. The
corolla is generally smaller with a narrow cylindric tube rather abruptly dilated
at the apex into a distinctly oblique limb with comparatively narrower lobes; the
color is white to pink or pale yellow in one species, without a conspicuous yellow
blotch; the stamens are distinctly declinate. The flowers appear shortly before
the leaves expand or with the leaves. The third group contains R. atlanticum,
R. oblongifolium, R. serrulatum, R. viscosum and R. arborescens. The corolla is
similar in shape to that of the preceding group but often larger and its color is
white to pink without a yellow blotch and the tube is often glabrous inside. The
flower-buds are marked by conspicuous rows of long-stipitate glands on the back
of the corolla-lobes. The flowers are very fragrant and appear after the leaves
are fully grown or with the leaves in R. atlanticum, which thus forms a connecting
link with the preceding group. The fourth group contains only R. prunifolium.
The flowers are comparatively large and shaped like that of the preceding group,
but of crimson color, and appear after the leaves are fully formed. The whole
plant including the corolla tube is glabrous except the pedicels and a few hairs
on the midrib and veins of the under side of the leaves which are distinctly
acuminate, while they are acute to obtusish in all other species of this group.
Rhododendron occidentale A. Gray, Bot. Calif. 1. 458 (1876) ; Syn. Fl.
II. 140 (1878).— Behr, Fl. Vicin. San Francisco, 173 (1888).— Dippel,
126 THE AZALEAS OF NORTH AMERICA
Handb. Laubholzk. I. 415, fig. 268 (1889). — Jepson, Fl. W. Middle Cal.
369 (1901); ed. 2, 311 (1911). — Schneider, III. Handb. Laubholzk. II.
501, fig. 328 1-m, 329 i-k (1911). — Millais, Rhodod. 220 (1917).
Azalea calendidacea Hooker & Arnott, Bot. Capt. Beechey Voy. 362 (1841), not
Michaux. — Bentham, PL Hartweg. 321 (1849).
Azalea nudiflora var. ciliata Kellogg in Proc. Calif. Acad. Sci. I. 60 (1855).
Azalea calif ornica Torrey & Gray apud Durand in Jour. Acad. Philadelphia,
ser. 2, III. 94 (1855). — Small in N. Am. Fl. XXIX. 44 (1914).
Azalea occidental-is Torrey & Gray in Rep. Explor. Surv. Miss. Pacif. Ocean,
IV. 116 (1856). — Hooker in Bot. Mag. LXXXIII. t. 5005 (1857).—
Howell, Fl. N. W. Coast, I. 422 (1901).1
A shrub to 3 m.; young branchlets soft-pubescent or glabrous, brown at the
end of the first season; floral winter-buds finely pubescent or sometimes nearly
glabrous with numerous ovate to ovate-lanceolate, acuminate and aristate-mu-
cronate or mucronulate scales. Leaves elliptic to oblong-lanceolate, acute or ob-
tusish, gland-tipped, cuneate or attenuate at base, 3 to 9 cm. long, ciliate, thinly
pubescent on both surfaces, rarely nearly glabrous, at maturity chartaceous,
glabrous or nearly glabrous except pubescent on the midrib above and sparingly
strigose on the midrib and sometimes on the veins beneath; petioles rather stout,
1 to 5 mm. long. Flowers appearing with or after the leaves or rarely before the
leaves, 6 to 12 in umbel-like racemes; pedicels 0.5 to 1.5 cm. long, pubescent and
more or less glandular, sometimes pilose and glandless, rarely nearly glabrous;
sepals broadly ovate to oblong-ovate, obtuse, 1.5 to 4 or sometimes 5 mm. long,
densely ciliate with usually setose, gland-tipped or glandless hairs; corolla white
or sometimes pink with a yellow blotch on the upper lobe or on the three upper
lobes, the tube about 2 cm. long, or sometimes shorter, gradually dilated upwards,
villose and glandular-pilose outside, the lobes about as long as the tube, broad-
ovate, acute or acutish; stamens exserted, more than twice as long as the tube;
filaments pilose below the middle; anthers 2.5 to 3 mm. long, whitish; style about
as long or longer than stamens, finely pubescent or sometimes villose above the
base, rarely nearly glabrous; ovary pilose and glandular. Capsule ovate-oblong,
1 to 2 cm. long, setosely pilose or sometimes furnished with short gland-tipped hairs.
This species is distributed from southern Oregon to southern California, grow-
ing by brooks among the mountains up to 5000 or sometimes 5800 feet altitude.
It is the only Azalea west of the Rocky Mountains and was first discovered during
the Expedition of Captain Beechey in 1827 and was also collected later by Douglas,
Hartweg and Burke. Hooker as well as Bentham referred it to A. calendulacea,
and it was not recognized as a distinct species until named in 1855 by Torrey &
Gray A. calif ornica and a year later by them A. occidentale.
Rhododendron occidentale seems most closely related to R. calendulaceum, from
which it is easily and chiefly distinguished by the color of its flowers, which other-
wise in size and shape resemble those of that species more than those of other Amer-
ican species. It is very variable in the shape and size of its leaves, in the pubescence
of all its parts and also to some extent in the size of the flowers; the sepals are appar-
ently always well developed, never nearly obsolete, as is often the case in the Eastern
1 ADDITIONAL ILLUSTRATIONS. COLORED PLATES: FL des Serres, XIV. t. 1432
(1861). — Gard. XXXIV. 416, t. 673 (1888).— BLACK FIGURE: Gard. Chron. ser. 2,
XXVI. 105, fig. 21 (1886) .2— HABIT FIGURES: Gartenwelt, XI. 8 (1906); XV. 650
(1911).
2 The legend under the wood-cut reads "flowers orange and crimson, fragrant"
which is hardly correct; in the text the flowers are described as deep rosy-red.
ENUMERATION OF THE SPECIES 127
species. It exhibits a remarkable latitude in the time of blooming; I have before
me a specimen collected by Orcutt in San Diego County in April without any leaf
buds developed and in northern California I collected it myself in full bloom as
late as August 25 with the winter-buds of the new growth fully developed; gen-
erally it flowers between the middle of June and the middle of July, just when
the young leaves are fully grown. The autumnal tints of this species are very
brilliant. In Garden and Forest (III. 626 [1890] ), E. W. Hammond says "in the
fall of the year its leaves glow with such a profusion of scarlet and crimson mingled
with the gold and green, that it produces the most delightful effects."
Behr (Fl. Vicin. San Francisco, 173) states that the root contains a powerful
narcotic, and according to Jepson (FL W. Middle Calif, ed. 2, 311) the plant is
feared by sheepmen as poisonous.
Rhododendron occidentale was introduced into cultivation by William Lobb, who
sent seeds from California about 1850 to the Veitchian Nurseries, where it flow-
ered in 1857. It is tenderer than many other American Azaleas and has not
proved hardy at the Arnold Arboretum.
Rhododendron occidentale var. sonomense Rehder, var. nov.
Rhododendron sonomense Greene in Pittonia, II. 172 (1891). — Zabel in Mitt.
Deutsch. Dendr. Ges. XI. 29 (1902). — Millais, Rhodod. 245 (1917).
This variety differs from the type according to Greene chiefly in its smaller
narrower leaves, smaller rose-colored and very fragrant flowers; the odor of typical
R. occidentale is mephitic according to Greene. It occurs on dry slopes in the
mountains of Sonoma County. It does not seem to be in cultivation outside of
California.
Rhododendron calendulaceum Torrey, Fl. U. S. 425 (1824).—
G. Don, Gen. Syst. III. 847 (1834). — Bigelow & Hor, FL Lancast. 56
(in Trans. Med. Convent. Ohio) (1841); Reprint, p. 10 (1841). — Gray,
Syn. Fl. N. Am. II. 1, 41 (1878). — Dippel, Handb. Laubholzk. I. 413,
fig. 266 (1889). — Millspaugh/Preftm. Cat. Fl. W. Va. 402 (1892). —
Blake in Rhodora, XX, 53 (1918).
Azalea lutea Linnaeus, Spec. 150 (1753), only as to Colden's synonym. —
Weston, Bot. Univ. I. 16 (1770). — Michaux, Jour. ed. C. S. Sargent,
111, 116 (in Proc. Am. Philos. Soc. XXVI.) (1889). — Britton & Brown,
III. Fl II. 559, fig. 2745 (1897). — Gattinger, Fl. Tenn. 131 (1901).—
Britton, Man. 698 (1901). — Porter, FL Pennsylv. 238 (1903). — Mills-
paugh, Liv. Fl. W. Va. 323 (W. Va. Geol. Surv.) (1913). — Small, Fl. S. E.
U. S. 883 (1903); in N. Am. FL XXIX. 41 (1914). — Shreve & others, PL
Life Maryland, 466 (1910). — Schaffner, Cat. Ohio Vase. PL 204 (in Ohio
Biol. Surv. I.) (1914). — Griggs, Bot. Surv. Sugar Grov. Reg. 328 (Ohio BioL
Surv. I.) (1914). — Taylor, FL Vicin. N. Y. 489 (in Mem. N. Y. Bot.
Gard. V.) (1915).
Azalea nudiflora Linnaeus, Spec. ed. 2, 214 (1762), as to Colden's synonym only.
Azalea flammea Bartram, Travels, I. 327 (1791), name only.
Azalea calendulacea Michaux, FL EOT. -Am. I. 151 (1803), excluding var. a. —
Pursh, FL Am. Sept. 151 (1814). — Elliott, Sketch Bot. I. 238 (1821), ex-
cluding var. a. and c. — De Candolle, Prodr. VII. 717 (1839). — Gray,
Man. 268 (1848) ; ed. 5, 299 (1872). — M. A. Curtis, Descript. Trees & Shrubs,
98 (in Geol. Nat. Hist. Surv. N. Car. III. Bot.) (1860).
128 THE AZALEAS OF NORTH AMERICA
Azalea aurantiaca Dietrich, Darst. Vorz. Zierpfl. 4, t. 1 (1803) .l
Azalea pontica ft. A. calendulacea Persoon, Syn. I. 212 (1805).
? Azalea nudiflora var. h. lutea Elliott, Sketch Bot. I. 241 (1821).
? Azalea flava Michaux, Jour. ed. C. S. Sargent, 111 (in Proc. Am. PhUos.
Soc. XXVI.) (1889), name only.
Rhododendron luteum Schneider, III. Handb. Laubholzk. II. 500, fig. 329 q-r,
320 a (1911), not Sweet.2
A shrub with erect and spreading branches, usually 1.5 to 3, rarely to 5 m.
tall; young branchlets pubescent and strigillose; floral winter-buds with broadly
ovate scales, rounded or even emarginate at the apiculate apex, brown, glabrous
except the densely white-ciliolate margin. Leaves broadly elliptic to elliptic-
oblong or obovate-oblong, rarely obovate, 4 to 8 cm. long, and 1.5 to 3.5 cm. broad,
acute and gland-tipped, broadly cuneate at base, finely pubescent above and more
densely so beneath when young, particularly on and along the midrib; petioles
2 to 5 mm. long, pubescent. Flowers in May and June, in usually 5- to 7-flowered
umbels, expanding with or shortly after the leaves; pedicels setulose and usually
glandular; calyx-lobes usually oblong and 3 to 4 mm. long or ovate and 1 to 2 mm.
long, obtuse, setulose outside, ciliate with long gland-tipped hairs; corolla funnel-
form, yellow or orange to scarlet, with orange blotch on the upper lip, the cylindric
tube gradually dilated above the middle, 1.5 to 2 cm. long, glandular-pilose, and
pubescent outside, the lobes ovate, about 2 cm. long and 1.5 cm. broad, usually
wavy at the margin, abruptly contracted into a short point, slightly pubescent
outside; stamens nearly three times as long as corolla-tube; the filaments pubescent
below the middle or on the lower third, the anthers about 3 mm. long; style pilose
toward the base, sometimes glabrous, 6 to 7 cm. long, about as long or longer than
stamens; ovary covered with long setose, partly gland-tipped hairs. Capsule
ovoid-oblong, 1.5 to 2 cm. long, setose and pubescent.
This species is confined to the Appalachian Mountain region from Pennsyl-
vania to northern Georgia; according to the herbarium material seen, its western
limit runs from western Pennsylvania (Venango County) through southeastern
Ohio (Fairfield County),3 eastern Kentucky (Rockcastle County), eastern Tennes-
see (Knox County) to northern Georgia (Gwinnett County); its eastern limit
1 Dippel and Schneider cite 1801 as date of publication, which would give Die-
trich's name priority over A . calendulacea, but the part which contains A . aurantiaca
is dated 1803 as well on the title-page as on the cover. The cover bears the title
" Modeblumen fur Botaniker . . . Sechstes Heft." The first part of the latter pub-
lication is the one which is dated 1801. There is no technical description given,
and this together with the fact that the part was published during the second half
of the year, as it contains a letter dated July 1, 1803, makes it advisable to give
Michaux's name the preference.
8 PRELINNEAN NAME: Azalea erectafoliis ovatis integris alternis fiore luteo piloso
praecoci Golden in Act. Soc. Sri. Upsala, IV. 93 (1749).
ADDITIONAL ILLUSTRATIONS. BLACK FIGURES: Loudon, Arb. Brit. II. 1142,
fig. 946 (1838); reproduced in Gard. XXIX. 550 (1886). — Britton & Brown, III.
Fl. II. fig. 2745 (1897); ed. 2, II. fig. 3217 (1913). — Keeler, Our North. Shrubs,
351 (1903).— Gard. Mag. V. 218 (1907). — Country Life Am. XI. 496 (1907).—
Stevens, III. Guide Flow. PL t. 114, fig. 3 (1910). — Schneider, III Handb. Laub-
holzk. I. fig. 329 q-r, 330 a (1911).
3 This station, interesting on account of its isolation, was first discovered in
1841 according to Bigelow & Hor, Fl. Lancast. 56 (1841): "For the discovery of
this splendid plant ... we are indebted to the hospitality of Mr. Jacob Greene,
who had found it a few days previously at the mouth of Clear Creek."
ENUMERATION OF THE SPECIES 129
extends from southern Pennsylvania (Somerset County), through West Virginia
(Pocahontas County), western North Carolina (Ashe, Mitchell and Buncombe
Counties), northwestern South Carolina (Spartanburg County) to northeastern
Georgia (Rabun County). The type locality is the Blue Ridge Mountains in North
Carolina. In most Floras the range of the species is given as extending to southern
New York but I have not seen a single specimen in support of this statement which
is apparently based on "Azalea erect a foliis ovatis integris alternis flore luteo piloso
praecoci" enumerated by Cadwallader Golden in his Plantae Coldenghamiae (in
Act. Soc. Sci. Upsala, IV. 93 [1749]). This plant has not been found again by
any botanist in the state of New York; the report by Dr. Barnhart in 1895 (in
Bull. Torr. Bot. Club, XXII. 282) that he discovered it in an apparently native
state near Tarrytown was based on a single shrub which belonged to a planta-
tion in a private estate, a fact Dr. Barnhart found out on the occasion of a later
visit to the locality, as he himself has told me. Rhododendron calendulaceum is
usually found growing scattered in open woods on mountain sides as undergrowth
and along the banks of watercourses in the mountains. With its brilliant flowers
ranging from yellow to scarlet it enlivens the mountain woods in early summer,
and as well in its natural habitat as in the garden it must be considered one of the
most gorgeous of American shrubs.
Rhododendron calendulaceum was first mentioned by Cadwallader Golden in
1749 from southern New York, as already stated, and his account was referred by
Linnaeus to his Azalea lutea, which was chiefly based on material belonging to the
species we now call Rhododendron nudiflorum. It was also discovered in northern
Georgia at the confluence of the Savannah and Broad River, the most southern
point of the range of the species, in 1774 by William Bartram, who describes its
beauty in glowing terms (Travels, I. 322 [1790]); he called it "Flame Azalea" and
named it incidentally Azalea flammea in his book, but without giving a technical
description. The elder Michaux collected it on the Blue Ridge Mountain in
North Carolina on May 11, 1795, and called it Azalea lutea in his Journal.
When JR. calendulaceum was first introduced into cultivation cannot be stated
with certainty. If the plant figured as Azalea aurantiaca by Dietrich in 1803 and
said to have been procured from England belongs to our species, it must have
been sent to England before 1800. It is certain, however, that the yellow form
was growing in the nurseries of J. Fraser and of Loddiges and Sons in 1812, as
stated by Sims in Botanical Magazine under tab. 1721. Their plants were received
from John Lyon, who brought over a large shipment of American plants in 1806.
The nomenclature of the species is somewhat involved and the name Azalea
lutea which Linnaeus gave in 1753 to an American species incompletely known to
him and based on citations belonging to three different species, namely R. nudi-
florum, R. canescens and R. calendulaceum, has been recently taken up by several
American botanists for our species. In the second edition of his Species plan-
tarum, however, he changed the name to A. nudiflora, but retained the descrip-
tions and the citations unchanged, augmented only by references to Kalm and
Duhamel; he had then in his possession specimens collected by Kalm and repre-
senting R. nudiflorum which apparently induced him to change the name, noticing
that the color of the flowers was not yellow. As both names Azalea lutea and A.
nudiflora are based on the same citations and on the same description, they cannot
be used for different plants, as has been done by Britton and by Small, and as they
are chiefly based on R. nudiflorum and R. canescens, A. lutea cannot be taken up
for our species, as Blake has shown in Rhodora. The next oldest name A. flammea
Bartram being a nomen nudum, A . calendulacea becomes the correct name for the
species, after excluding A . aurantiaca Dietr. for the reasons given in the footnote
on page 128.
130 THE AZALEAS OF NORTH AMERICA
Small in North American Flora gives "Savannah River" as the type locality
for his A. lutea, but if A. lutea of Linnaeus is taken up as the name for R. calendu-
laceum it could be based only on Cadwallader Colden's enumeration of the plant
from southern New York and not on the locality given by Michaux for var. a. of
his A . calendulacea. Unfortunately Michaux's specimen collected on the Savannah
River near Two-Sisters Ferry and cited by him under a. flammea does not belong to
A. calendulacea as described by him, but to R. speciosum, and therefore the speci-
men labeled in his herbarium ft. crocea must be considered the type specimen and
the high mountains of Carolina or more particularly the Blue Ridge Mountains
of North Carolina, the type locality. Though it is against general usage to take
var. p. as the type of a species which is divided into varieties, the specific descrip-
tion in this case appears to be chiefly based on the specimen designated var. /S.,
particularly the character "corolla tubo hirsute, laciniis breviore" must have been
taken from var. /3., for in var. a. (R. speciosum Sweet) the tube is distinctly longer
than the lobes and less conspicuously hirsute, also the color "floribus . . . calen-
dulaceis" referring to Calendula which has yellow to orange flowers, indicates the
mountain form, var. £., rather than var. a., which has bright red to scarlet flowers.
Rhododendron calendulaceum does not show much variation except in the color of
the flowers and in the length of the sepals, which are usually oblong, but sometimes
rather small; the style is normally pilose near the base, but sometimes glabrous,
as in Harbison's No. 171 from Macon County, North Carolina, in Small's speci-
men from White Rock Mountains, Smyth County, Va., and in Britton's & A. M.
Vail's specimen from the same locality. There are also forms with partly salmon-
colored flowers of which I collected a specimen myself on Roan Mountain of North
Carolina, and I have before me a specimen from North Carolina stated to have
pink flowers. The two following forms have been described, of which the first
represents the typical form, though probably more color forms could be distin-
guished but this cannot be done satisfactorily without copious living material of
undoubtedly spontaneous origin.
Rhododendron calendulaceum f. croceum Sweet, Hort. Brit. ed. 2,
343 (1830), as var. a. — Rehder in Mitt. Deutsch. Dendr.Ges. XXIV.
(1915), 225 (1916), as forma; in Bailey, Stand. Cycl. Hort, V. 2942
(1916), as var.
Azalea calendulacea /3. crocea Michaux, FL Bor.-Am. I." 151 (1803). — Sims in
BoL Mag. XLI. t. 1721 (1815). — Rehder in Bailey, Cycl. Am. Hort. I.
121, (1900) .1
Flowers yellow to orange-yellow with a darker blotch, sometimes partly
salmon-colored. As stated before there are all kinds of intermediate shades be-
tween the plants with scarlet flowers and those with yellow flowers.
Rhododendron calendulaceum f. aurantium Rehder, comb. nov.
Azalea calendulacea a. Ker in Bot. Reg. II. t. 145 (1816), not var. a. flammea
Michaux.
Azalea aurantiaca Dietrich, Darst. Vorz. Zierpfl. 4, t. 1 (1803). — Hort. apud
Dumont de Courset, Bot. Cult, ed 2, III. 333 (1811), as var. of A. nudiflora.
? Azalea coccinea major Dumont de Courset, I. c. (1811), as var. of A. nudiflora.
1 ADDITIONAL REFERENCE TO COLORED PLATE: Mag. Bot. & Gard. II. 119,
t. 36, fig. 7 (1834).
ENUMERATION OF THE SPECIES 131
Azalea speciosa f. aurantia Sweet, Hort. Brit. 265 (1826), name only.
Azalea coccinea aurantia Loddiges, Bot. Cab. XIII. t. 1255 (1827).
Rhododendron calendulaceum var. a. flammeum Sweet, Hort. Brit. ed. 2, 343
(1830). — Zabel in Beissner, Schelle & Zabel, Handb. Laubholz.-Ben. 380
(1903).
Rhododendron speciosum f. aurantium Sweet, Hort. Brit. ed. 2, 343 (1830).
Azalea speciosa /3. aurantia De Candolle, Prodr. VII. 117 (1838).
Azalea speciosa a. aurantiaca Kirchner in Petzold & Kirchner, Arb. Muse.
479 (1864).
Azalea calendulacea var. flammea Render in Bailey, Cycl. Am. Hort. I. 121
(1900), in part.
Rhododendron calendulaceum aurantiacum Zabel in Beissner, Schelle & Zabel,
Handb. Laubholz-Ben. 380 (1903).
Rhododendron luteum var. flammeum Schneider, III. Handb. Laubholzk. II.
500 (1911), in part.
Flowers deep orange-red to scarlet, with large orange blotch.
Rhododendron speciosum Sweet, Hort. Brit. ed. 2, 343 (1830), not
Salisbury.1 — G. Don, Gen. Syst. III. 847 (1834).
Azalea nudiflora a. coccinea Aiton, Hort. Kew. I. 202 (1789). — Sims in Bot.
Mag. V. t. 180 (1792).
Azalea coccinea Sims in Bot. Mag. text to 1. 180 (1792), as synonym. — Michaux,
Jour. ed. C. S. Sargent, 9 (in Proc. Am. Philos. Soc. XXVI.) (1889).
Azalea fulva Michaux in Jour. Hist. Nat. I. 410 (1792), name only.2
Azalea calendulacea a. flammea Michaux, Fl. Bor.-Am. I. 151 (1803). —
Pursh, Fl. Am. Sept. 152 (1814).
Azalea speciosa Willdenow, Berl. Baumz. ed. 2, 49 (1811); Enum. Hort. Berol.
Suppl. 10 (1813). — Guimpel, Otto & Hayne, Abb. Fremd. Holzart. I. 37,
t. 31 (1825). — Watson, Dendr. Brit. II. t. 116 (1825).
Azalea periclymenoides var. coccinea Pursh, Fl. Am. Sept. I. 152 (1814).
Azalea nudiflora Loiseleur-Deslongchamps, Herb. Amat. IV. 213, t. (1820),
not Linnaeus.
Azalea calendulacea var. a. Elliott, Sketch Bot. I. 239 (1821).
Azalea coccinea major Loddiges, Bot. Cab. VII. t. 624 (1822).
Azalea speciosa a. major Sweet, Hort. Brit. 265 (1826).
1 Rhododendron speciosum Salisbury, Prodr. 287 (1796) cannot invalidate Sweet's
combination, as it is a straight synonym, being only a new name for R. ponticum L.
2 This is apparently the Azalea which he calls Azalea coccinea in his Journal
(ed. C. S. Sargent, p. 9) and describes under the entry of the following day (p. 10)
as "1'Azalea couleur de feu. La couleur de cet Azal. qui est dans toutes les
parties de la fl. aussi fonce"e, Corolla, Etam. et Pistille, est celle de Hemerocallis
fulva mais dans les lieux plus de"couverts et moins ombrages cet couleur est encore
plus forte." This Azalea Michaux collected on April 26 and 27, 1787, after having
crossed the Savannah River at Two-Sisters Ferry; in his Flora it is referred to under
A . calendulacea a. flammea. In comparing the color of this plant with that of Heme-
rocallis fulva Michaux must have had in mind the color form figured by Redoute"
in his Liliaceae, tab. 16, which has red-purple flowers and was probably at that
time well known in France. The color of this form agrees very well with that of
R. speciosum, while the plant now generally cultivated as Hemerocallis fulva has
orange flowers.
132 THE AZALEAS OF NORTH AMERICA
? Azalea nudiflora var. thyrsiflora Gowen apud Lindley in Bot. Reg. XVI.
t. 1367 (1830).
Rhododendron speciosum a. major Sweet, Hort. Brit. ed. 2, 343 (1830).
Rhododendron nudiflorum f. cocdneum Sweet, Hort. Brit. ed. 2, 343 (1830). —
G. Don, Gen. Syst. III. 847 (1834).
Azalea speciosa a. coccinea De Candolle, Prodr. VII. 717 (1839).
Azalea calendulacea Darby, Bot. S. States, 422 (1855), in part.
Rhododendron cakndulaceum Chapman, Fl. S. U. S. 265 (1860), in part.
Rhododendron calendulaceum f . speciosum Voss, Vilmorin's Blumengdrt. I. 588
(1894). — Zabel in Beissner, Schelle & Zabel, Handb. Laubholz-Ben. 380
(1903).
Rhododendron flammeum Sargent in Rhodod. Soc. Notes, I. 120 (1918), name
only, not Azalea flammea Bartr.1
A shrub 0.3 to 2 m. tall with slender, irregularly whorled branches; the young
branchlets finely pubescent and rather densely strigillose, becoming grayish brown
the second year; floral winter-buds glabrous, with generally ovate, ciliolate scales,
usually rounded and mucronate at apex. Leaves obovate or elliptic to oblong,
acute or obtusish, mucronulate, broad-cuneate at base, 3 to 6 cm. long and 1.2 to
2 or sometimes to 3 cm. broad, strigillose above, finely pubescent beneath, more
densely on the leaves of the shoots and particularly on the veins, often strigose
on the midrib, sometimes nearly glabrous except on the midrib beneath, setosely
ciliate, subchartaceous at maturity, with prominent lateral veins; petioles 3 to 5 mm.
long, pubescent and strigillose. Flowers appearing with the leaves end of April and
beginning of May in 6- to 15-flowered umbel-like racemes, scarlet or bright red,
with a large orange blotch on the upper lobe; pedicels strigillose, not glandular;
sepals roundish ovate to oblong, 0.5 to 3 mm. long, long-ciliate, pubescent or
nearly glabrous outside; corolla funnel-form, tube cylindric, rather slender, 2 to
2.5 cm. long, longer than the limb, rather abruptly dilated at the apex, covered
outside with fine villose pubescence interspersed with long pilose not gland-tipped
hairs, pubescent inside, lobes ovate, abruptly acuminate, 1.5 to 2 cm. long; stamens
much exserted, more than twice as long as tube and slightly shorter than the style,
the filaments pubescent below the middle; style 5 to 6 cm. long, finely pubescent at
the lower third, usually purplish above; ovary covered with long setose hairs, not
glandular. Fruit ovoid to narrow-oblong narrowed toward the apex, 2 to 3 cm.
long, strigose.
This species is distributed through central Georgia from the Savannah River
to the Chattahoochee River, its range extending north to Gwinnett County and
to Oconee County of South Carolina, south to Screven County in the east and to
Muscogee County in the west.2 It is usually a low shrub and grows in open dry
woods and on sand hills, often covering large stretches and is very conspicuous
when in bloom on account of the brilliant color of its flowers.
1 ADDITIONAL ILLUSTRATIONS. COLORED PLATES: Drapiez, Herb. Amat. 1. t. 51
(1828), as A. nudiflora.— ? Audubon, Birds Am. II. t. 198 (1831); Quarto ed.
II. 86 & 104 (1841), poorly colored. — BLACK FIGURES: Dippel, Handb. Laubholzk.
I. fig. 266 (1889), after Watson, Dendr. Brit., as R. calendulaceum. — Voss,
Vitmorin's Blumengdrt. I. 588 (1894), same as preceding.
2 Mohr mentions under A. nudiflora (PL Life Ala. 653 [1901] ) a form with flame
or deep orange-colored flowers from Springhill, Mobile County, which he refers to
A. nudiflora var. rutilans Pursh; this may be either an undescribed color form of
R. canescens or it may be R. speciosum and in this case the range of R. speciosum
would extend to southwestern Alabama. I have not seen any specimen of this
form.
ENUMERATION OF THE SPECIES 133
SOUTH CAROLINA. Oconee County : Newry, April 26, 1906, H. D.
House (No. 1934, 1935, 1936; in Nat. Herb.).
GEORGIA. Gwinnett County : Thompson's Mills, May 2, 1909,
H. A. Allard (No. 181, in Nat. Herb.). Dekalb County: on and
about Stone Mountain, May 1-18, 1895, J. K. Small; base of Stone
Mountain, May 3, 1899, C. S. Sargent and Wm. M. Canby; without
precise locality, May 23, 1897, H. Eggert (in N. Y. Bot. Gard. Herb.).
Fulton County : Atlanta, May, 1869, Wm. M. Canby (in Nat. Herb.).
Baldwin County : Milledgeville, Samuel Boykin (in Herb. Philadelphia
Acad. Nat. Sci.); south of Milledgeville, May 6, 1914, T. G. Harbison
(Nos. 1561-1570). Muskogee County : Columbia, above the falls,
1912, T. G. Harbison. Richmond County : sand hills at Belair,
A. Cuthbert, April 26, 1903; near Bath, April 29, 1914, C. S. Sargent;
near Augusta, April 29 and October 7, 1914, C. S. Sargent; near
Hephzibah, May 9, 1920, A. Rehder (No. 930). Screven County:
Ogeechee River, 1847, H. C. Pater (in Gray Herb.). — Middle Georgia,
Dr. Leavenworth; Ocmulgee River, April, 1847, T. C. Porter (both in
Herb. Philadelphia Acad. Nat. Sci.).
Though this species was introduced into cultivation more than a century ago
and described and figured by early European botanists it has never been recognized
by an American botanist. The exact date of its first discovery and of its introduc-
tion into cultivation is not known with certainty. It was first mentioned without
adequate description by Aiton in 1789 as Azalea nudiflora var. cocdnea and figured
three years later by Sims in the Botanical Magazine under the same name; Sims says
"whether it was originally introduced to the country by Mrs. Norman of Bromley
or by Mr. Bewick of Clapham in Surrey we cannot with certainty assert; true it is
that Azalea cocdnea was little known here till the sale of Mr. Bewick's plants in
17 "; and he adds that the plants were sold at high prices, one of them produc-
ing 20 guineas. Possibly plants were sent before 1789 by William Bartram, who
must have known this plant, as it grows in a region traversed by him in search of
plants. Later, in 1811, the plant was described by Willdenow as Azalea speciosa
from cultivated plants growing in the Berlin Botanic Garden, the origin of which is
not stated and it was figured by Guimpel in 1825. By Michaux it was collected near
Two-Sisters Ferry on the Savannah River, about twenty-five miles above Savannah,
and his are the first wild specimens we know. In Michaux's Flora they were con-
fused with Azalea calendulacea and enumerated under his var. flammea. Pursh
also in 1814 confused the two, though he was the first to refer Aiton's A. nudiflora
var. cocdnea to Michaux's var. flammea and thus identified the plant growing near
Savannah with Aiton's plant. I have no doubt that Aiton's, Willdenow's and
Michaux's plants are identical. Of Azalea nudiflora var. cocdnea there is a speci-
men in the British Museum which probably served for Sims's figure in the Botanical
Magazine. Mr. W. J. Bean kindly compared flowers of Rhododendron spedosum
from the specimens collected by me near Augusta, Georgia, with that specimen and
states that they agree with it and that A. nudiflora var. cocdnea certainly is not
R. calendulaceum with which it had been confused. Of A. speciosa there is a speci-
men in the Berlin Botanical Museum, of which Professor L. Diels obligingly sent me
a flower, which also agrees with the Georgia plant and not with R. calendulaceum.
134 THE AZALEAS OF NORTH AMERICA
Of Michaux's specimens of var. a. flammeum collected according to his Journal near
Two-Sisters Ferry, Georgia, on April 27, 1787, and of his specimens of var. 0. cro-
ceum I have photographs before me which show that the latter variety is R. calen-
dulaceum, while a. flammeum differs chiefly in its slenderer corolla-tube distinctly
longer than the limb and not conspicuously glandular-hairy and in the smaller
corolla-lobes and thus agrees with the plant here called R. spedosum.
Rhododendron spedosum has been usually confused with R. calendulaceum, and
particularly with the scarlet-flowered form of it, from which it may be chiefly dis-
tinguished by the slenderer corolla-tube more abruptly enlarged at the apex into
the limb and longer than the limb, by the absence of glandular hairs on the
corolla-tube which is covered with a short villous pubescence interspersed with
pilose hairs and by the generally smaller and comparatively broader leaves. The
color of the flowers is always scarlet or bright red and never varies to yellow, as
it does in R. calendulaceum and the flowers are more numerous in each inflorescence.
It shows little variation except in shape and size of sepals, which may be oblong
and up to 3 mm. long or nearly obsolete, and in the shape and size of the capsules.
Geographically the two species are well separated; R. calendulaceum is essentially
an Alleghanian plant, while R. spedosum belongs to the Piedmont region of Geor-
gia, but in northern Georgia the ranges of the two species touch and at Thompson's
Mill, Gwinnett County, both species have been collected by H. A. Allard.
Though the species was well known in cultivation at the beginning of the last
century, it later almost disappeared from the gardens until it was reintroduced in
1916 through the Arnold Arboretum, though in 1881 it was still cultivated at
Kew as Azalea cocdnea major according to a specimen before me. There is also
in the herbarium of the Arnold Arboretum a specimen collected by H. Zabel in
the Botanic Garden at Muenden, Hanover, from a plant received as Azalea cocdnea
from Booth's nursery at Flottbeck near Hamburg in 1872. It is certainly as hand-
some as R. calendulaceum, but probably more tender and not suited for cultivation
in the open ground in the North.
Rhododendron nudMorum, Torrey, /<7. J7./S.424 (1824) ;FJ. N. Y.I.
438 (1843). — Gray, Sun. FL II. 1, 41 (1878). — J. Robinson, Fl.
Essex Co. Mass. 73 (1880). — Dame & Collins, Fl. Middlesex Co. Mass.
63 (1888). — Britton, Cat. PL N. Jersey, 162 (1889). — Dippel,
Handb. Laubholzk. I. 414, fig. 267 (1889). — Coulter & Watson,
Gray's Man. ed. 6, 320 (1890). — Dudley & Thurston, Cat. PL Lacka-
wanna & Wyoming Valleys, 38 (1892). — Beckwith & Macauley, PL
Monroe Co. N. Y. 83 (in Proc. Rochester Acad. Sci. Ill) (1894), in
part. — Deane in Rhodora, I. 94 (1899); III. 196 (1901). —Robinson
& Fernald, Gray's New Man. 631 (1908). — Graves & others, Cat.
Flow. PL Conn. 308 (1910). — Schneider, III. Handb. Laubholzk. 502,
fig. 329 s-t (1911).
Azalea lutea Linnaeus Spec. I. 150 (1753), excluding the synonyms of Golden
and Gronovius.
Azalea nudiflora Linnaeus, Spec. ed. 2, 214 (1762), excluding the synonyms of
Golden and Gronovius. — Wangenheim, Beytr. Forstwiss. 67 (1787). —
Willdenow, Spec. I. pt. 2, 831 (1798).— Eaton, Man. Bot. ed. 2, 165 (1818).—
Elliot, Sketch Bot. I. 241 (1821), in part. — Bigelow, FL Boston, ed. 2, 82
ENUMERATION OF THE SPECIES 135
(1824). — De Candolle, Prodr. VII. 716 (1839). — Gray, Man. 268 (1848);
ed. 5, 299 (1872). — M. A. Curtis, Descript. Trees & Shrubs, 98 (Geol. Nat.
Hist. Surv. N. Car. III. Bot.) (I860). — Willis, Cat. PL N. Jersey, 33
(1874). — Kellermann, Cat. Ohio PL 129 (in Rep. Geol. Surv. Ohio, VII.
pt. 2) (1893), in part. — Britton & Brown, III. Fl. II. 558, fig. 2743
(1897). — Clute, FL Upp. Susquehanna, 69 (1898). — Britton, Man. 698
(1901). — Gattinger, FL Tennessee, 131 (1901).— Porter, Fl. Pennsylv. 238
(1903). — Small, FL S. E. U. S. 883 (1903); in N. Am. Fl. XXIX. 42
(1914). — Shreve & others, PL Life Maryland, 466 (1910). — Stone in Ann.
• Rep. N. J. State Mus. 1910, 612, t. 95 (1911). — Millspaugh, Liv. FL W.
Virginia, 323 (in W. Va. GeoL Surv.) (1913). — Schaffner, Cat. Ohio Vase.
PL 204 (inOhioBiol. Surv. I.) (1914), in part. — Taylor, FL Vicin. N. Y. 488
(in Mem. N. Y. Bot. Gard. V.) (1915).
Rhododendron venustum Salisbury, Prodr. 287 (1796), in part.
Azalea peridymenoides Michaux, FL BOT. -Am. I. 151 (1803). — Pursh, Fl.
Am. Sept. I. 152 (1814).
Azalea peridymena Persoon, Syn. I. 212 (1805).
Azalea nudiflora /3. peridymenoides, Heynhold, Nomend. Bot. Hort. I. 108
(1840).
Anthodendron nudiflorum Reichenbach in Moessler, Handb. Gewachsk. ed. 2,
I. 309 (1827) .*
An upright shrub, usually 1 to 2, rarely to 3 m. tall; young branchlets slightly
pubescent and sparingly strigose or nearly glabrous, becoming dull brown or
grayish brown; winter-buds brown, glabrous or slightly pubescent, with ovate
abruptly acuminate finely ciliate scales; leaves elliptic to oblong or obovate to
oblong-obovate, acute or abruptly acuminulate, rarely obtusish, gland-tipped,
cuneate at base, 3 to 8 cm. long and 1.5 to 3 cm. wide, finely pubescent on the
midrib above, strigillose and sometimes sparingly pubescent on the midrib beneath,
finely ciliate on the margins, bright green above and scarcely paler beneath;
petioles 2 to 4 mm. long, strigillose and sometimes slightly pubescent. Flowers
1 PRELINNEAN SYNONYMS: Azalea scapo nudo floribus confertis terminatridbus
staminibus dedinatis, Linnaeus, Hort. Cliff. 69 (1737). — Chamaerhododendros Vir-
giniana Peridymeni flore ampliori minus odorato, Duhamel, Traite Arb. 1. 160 (1755)
and doubtfully Cistus Virginiana Peridymeni flore ampliori et minus odarato [sic]
Plukenet, Mant. 49 (1700).
ADDITIONAL ILLUSTRATIONS. COLORED PLATES: Trew, PL Sel. Ehret. t. 48
(1750). — Schmidt, Oester. Baumz. III. t. 170 (1800), good plate of the typical
form. — Bot. Reg. II. t. 120 (1816), as A. nudiflora var. carnea. — Loddiges, Bot.
Cab. I. t. 51 (1818), as A. nudiflora var. rubra. — Guimpel, Otto & Hayne, Abb.
Fremd. Holzgew. t. 110 (1825), apparently var. glandifera with white flowers. —
Emerson, Trees & Shrubs Mass. ed. 2, II. 440 t. (1875), pink flowers. — Jour.
N. Y. Bot. Gard. XIV. 79, pi. (1913).— House, Wild Fl. N. Y. II. 200, pi. 154
(1920). — BLACK FIGURES: Loudon, Arb. Brit. II. 1140, fig. 943 (1838), after Bot.
Reg. t. 120. — AndrS, PL Terre de Bruybre, 179, fig. 6 (1864). — Gard. XXIX. 550
(1886), same as London's. — Mottet, Diet. Prat. Hort. I. 303, f. 359 (1892), after
Andre. — Newhall, Shrubs N. E. Am. fig. 83 (1893). — Miller & Whiting, Wild
Flow. N. E. St. 379 (1895). — Bailey, Cyd. Am. Hort. I. fig. 172, 173 (1900); Stand.
Cyd. Hort. V. fig. 3389, 3390 (1916). — Keeler, Our North. Shrubs, 347 (1903). —
Stevens, III. Guide Flow. PL, t. 114, fig. 2 (1910). — Rep. N. Jersey St. Mus.
1910, t. 15 (1911). — Amer. For. XXII. 655, fig. (1916). — HABIT FIGURES:
Gard. Mag. V. 218, fig. (1907). — Country Life Am. XI. 496 (1907).
136 THE AZALEAS OF NORTH AMERICA
expanding in April and May just before the leaves, scentless or nearly scentless,1 in
6- to 12-flowered umbel-like racemes; pedicels 0.5 to 1 cm. long, strigose-pilose and
sometimes finely pubescent, rarely sparingly glandular; calyx-lobes semi-orbicular
or ovate, rarely oblong, 0.5 to 2 mm. long, long-ciliate; corolla usually light pink or
whitish with pink tube, funnel-form, tube 1.5 to 2 cm. long, rather gradually
dilated above, finely pubescent and pilose or strigose-pilose outside; lobes ovate
to oblong-ovate, abruptly acuminate, 1.2 to 1.6 cm. long, finely pubescent outside
or glabrescent toward the apex, pilose along the middle; stamens nearly three
times as long as the corolla-tube, declinate, the filaments pubescent below the middle;
anthers 2 to 2.5 mm. long, usually brownish yellow; style 5 to 6 mm. long, some-
what exceeding the stamens, finely pubescent at the lower third, usually purple
or purplish above; ovary usually densely covered with long setose glandless hairs,
rarely sparingly setose and nearly entirely white-tomentose. Capsule oblong to
narrow-oblong, narrowed upward, 1 to 2 cm. long, finely pubescent and usually
strigose.
This species has the center of its distribution in the Appalachian mountains
from Massachusetts to northwestern North Carolina and ascends to an altitude
of 3800 feet; its range extends east to the coast from Massachusetts to southern
North Carolina and west to central New York (Monroe County), central Pennsyl-
vania, southern Ohio, eastern Kentucky and eastern Tennessee. According to
Small it extends into northern Florida, but I have seen no specimens from south
of North Carolina. It inhabits chiefly dry open woods and is also found along
mountain streams.
Rhododendron nudiflorum in its typical form is chiefly characterized by the
glabrous bright green, usually elliptic or obovate leaves pubescent only on the
midrib above, strigose along the midrib below and ciliate, by the glabrous winter-
buds, by the pink, scentless flowers with a cylindric tube slightly longer than the
lobes rather gradually dilated above the middle into the spreading limb and cov-
ered outside with a fine pubescence and pilose glandless hairs. The species shows,
however, considerable variation and in some forms it approaches R. roseum.
The most striking variation is that with the hairs of the corolla gland-tipped
instead of glandless; this is separated below as a distinct variety. There are
slighter variations in the shape of the leaves, in the pubescence of the winter-
buds which are sometimes, particularly in the form with glandular corolla,
finely pubescent, in the color of the flowers which varies from almost white to
deep carmine. The sepals are occasionally well developed as in specimens of var.
glandifera from Somerset, Massachusetts, collected by J. G. Jack, May 21, 1903,
where they are up to 5 mm. long. In one specimen, Harbison's No. 35 (1919)
from Wilmington, North Carolina, the filaments are pubescent beyond the
middle and the ovary is only sparingly setose.
Rhododendron nudiflorum was first discovered probably by Banister and men-
tioned by Plukenet as "Cistus virginiana Periclymeni flore ampliori et minus
odarato." It was introduced into England together with R. viscosum in the first
half of the 18th century, probably between 1725 and 1730 by Peter Collinson,
who had received it from John Bartram, for in a letter to Dr. Golden dated Ridge
Way House, Feb. 25, 1764, speaking of the plants in his garden he says, "Regard
the variety of trees and shrubs in this plantation, as Mountain Magnolia, Sarsi-
fax, Rhododendrons, Kalmias and Azaleas, etc. etc.; all are the bounty of my
curious botanic friend, J. Bartram of Philadelphia." 2 According to Aiton it was
1 Clute (FL Upp. Susquehanna, 69), however, calls the flowers very fragrant.
2 Gray, Selections from the Scientific Correspondence of Cadwallader Golden
with Gronovius, Linnaeus, Collinson, p. 48 (1843); reprinted from Ann. Jour. Sci»
Arts, LXIV.
ENUMERATION OF THE SPECIES 137
introduced in 1734, but Catesby says in 1731 that "it has for several years pro-
duced its beautiful and fragrant flowers at Mr. Bacon's at Hoxton and at Mr.
Collinson's at Peckham," though it is somewhat doubtful whether the plant re-
ferred to is this species or R. viscosum or R. canescens, the species figured by Catesby.
It is certain, however, that it was in cultivation about 1750 in England, for Ehret's
colored plate in Trew, Plantae Selectae Ehretianae (t. 48) is certainly our species,
and about 1800 it was known on the Continent, as the excellent colored plate of
the typical form in Schmidt's Oesterreichische Baumzucht (III. t. 170) shows.
The first detailed description was given in 1787 by Wangenheim, who describes
the typical form, for he states that the leaves are glabrous and that the hairs on
the outside of the corolla-tube have no glands; he also mentions two pubescent
varieties and a form which he saw only cultivated in two gardens in the state of
New York with fringed or erose corolla-lobes.
The nomenclature of the species presents some difficulties discussed by Blake
in Rhodora (XX. 53 [1918]). The oldest name for the species is A. lutea Linnaeus,
of which A . nudiflora is merely a synonym, but fortunately the name lutea cannot
be transferred to Rhododendron on account of the older R. luteum Sweet which is
the valid name of A. pontica Linnaeus under Rhododendron. Therefore the syn-
onym A. nudiflora takes the place of A. lutea. Those, however, who retain Azalea
as a distinct genus must, as pointed out by Blake, either adopt A. lutea for the
pink-flowered species or discard altogether both A. lutea and A. nudiflora and
adopt Michaux's A. peridymenoides.
The form with pink or pinkish flowers should be considered the type of this
species *; it seems to be the most common and the one originally cultivated under
this name, as Trew's plate of 1750 which shows pink flowers tends to prove. The
form with white or nearly white flowers may be distinguished as f . album? Most
of the more highly colored forms probably belong to var. glandiferum, though this
variety also includes light colored forms.
1 This is probably the form distinguished as :
Rhododendron nudiflorum S. carneum Sweet, Hort. Brit. ed. 2, 343 (1830). —
G. Don. Gen. Syst. III. 847 (1834).
Azalea nudiflora y. carnea Aiton, Hort. Kew. I. 202 (1789). — Ker in Bot. Reg.
II. t. 120 (1816). — De Candolle, Prodr. VII, 717 (1839).
? Azalea carnea Dumont de Courset, Bot. Cult. III. 332 (1811), as var. of A,
nudiflora.
Azalea peridymenoides y. carnea Pursh, Fl. Am. Sept. 152 (1814).
Ker's figure and description represent apparently the typical pink-flowered
form of R. nudiflorum with pilose corolla and nearly smooth leaves; but it differs
from the original description in the calyx, which is described as f oliaceous by Aiton,
while Ker calls it small. Dumont de Courset describes the leaves as pubescent,
which would remove his plant from R. nudiflorum.
2 Rhododendron nudiflorum a. album Sweet, Hort. Brit. ed. 2, 343 (1830) . — G. Don,
Gen. Syst. III. 847 (1834), as var. 5.
Azalea nudiflora d. alba Aiton, Hort. Kew. I. 202 (1789).
Azalea alba Dumont de Courset, Bot. Cult. ed. 2, III. 332 (1811), as var. of
A. nudiflora. — Michaux, Jour. ed. C. S. Sargent, 111 (in Proc. Am. Philos.
Soc. XXVI (1899).
Dumont de Courset's description of the tube of the corolla as covered with short
hairs and of the scales of the winter-buds as glabrous shows that a form of typical
R. nudiflorum was cultivated under that name.
138
THE AZALEAS OF NORTH AMERICA
Rhododendron nudiflorum var. glandiferum Rehder, comb, nov.1
Azalea nudiflora glandifera Porter in Bull. Torr. Bot. Club, XXVII. 508 (1900);
Fl Pennsylv. 238 (1903). — Keller & Brown, Handb. Fl. Phila. 246 (1905). —
Stone in Ann. Rep. N. Jersey State Mus. 1910, 613 (1911).
This variety differs from the type in having the pedicels and the outside of the
corolla-tube furnished with more or less numerous gland-tipped hairs of usually
nearly equal length, and the color of the corolla is usually of a deeper pink or
carmine color. The variety was based originally on specimens collected in eastern
Pennsylvania, but it is found frequently within the range of the type from Massa-
chusetts to northwestern South Carolina and often grows together with the typical
form. It seems, however, nearly absent from the southeastern part of the range,
that is from the coastal plain from New Jersey to North Carolina and more common
West, for the plants I have seen from the extreme Western localities, western Ten-
nessee and southern Ohio, represent this variety though from the last named local-
ity (Lawrence County) and from western New York (Monroe County) I have
seen specimens of the typical form.
A form with double flowers is mentioned by Pursh (FL Am. Sept. 152 [1814])
under his A. periclymenoides, but he does not state where he saw it. In 1826 Sweet
enumerated a double white form (Azalea nudiflora /3. albo-plena Sweet, Hort. Brit.
265 [1826]), name only. — Rhododendron nudiflorum /3. albo-plenum Sweet, Hort.
Brit. ed. 2, 343 (1830) and a semi-double white form (Azalea nudiflora w. semi-
duplex Sweet, Hort. Brit. 265 [1826]. — Rhododendron nudiflorum w. semiduplex
Sweet, 1. c. ed. 2, 344 [1830]), also a double purple form (Azalea nudiflora 65. pur-
pureo-plena Sweet, 1. c. 265 [1826]. — Rhododendron nudiflorum 66. purpureo-plenum
Sweet, I. c. ed. 2, 344 [1830]) and a double red form (Azalea nudiflora KK. rubro-
plena Sweet, 1. c. 265 [1826]. — Rhododendron nudiflorum KK. rubro-plenum Sweet,
I. c. ed. 2, 344 [1830]). Probably Azalea nudiflora flore pleno Loddiges Cat. 1836
(ex Loudon, Arb. Brit. II. 1142 [1838]) is the same as the double white form of
Sweet. Two different forms Azalea periclymenoides "alba pleno" and "rubra
pleno" were offered in 1831 by R. Carr (Cat. Am. Trees Bartram Bot. Gard. 64).
All the double-flowered forms in cultivation which I have seen seem to be of
hybrid origin, but from Kew Gardens I have seen a specimen collected by
G. Nicholson in 1880 as Azalea " Double Blush " which is probably a double-
flowered R. nudiflorum; it has the leaves perfectly glabrous beneath except the
strigose midrib and the corolla is pilose and villose outside but not glandular.
Several other varieties and forms have been described or mentioned by Aiton,
Loddiges and others, but as the descriptions are inadequate and I have not seen
the type specimen or other reliable material of them, I am in doubt whether they
belong here or to R. roseum or to R. canescens; they will therefore be enumerated
under the doubtful names.
Rhododendron roseum Rehder, comb. nov.
Azalea rosea Loiseleur-Deslongchamps in Duhamel, Traite Arb. Arbust.
ed. 2, V. 224, t. 64 (1812). — ? Michaux, Journal, ed. C. S. Sargent, 111 (in
Proc. Am. Philos. Soc. XXVI. (1889)).
1 Azalea nudiflora rubra Loddiges, Bot. Cab. I. t. 51 (1817). — De Candolle,
Prodr. VII. 717 (1839), as var. — Rhododendron nudiflorum var. rubrum Sweet,
Hort. Brit. ed. 2, 343 (1830); G. Don, Gen. Syst. III. 847 (1834) is probably identi-
cal with this variety, judging from Loddiges' figure, but as long as one cannot be
positively sure I prefer to keep Porter's name.
ENUMERATION OF THE SPECIES 139
Azalea canescens Pursh, Fl. Am. Sept. 1. 152 (1814), in part, as to the specimen
from Virginia^1 not Michaux. — Eaton, Man. Bot. 165 (1818). — Britton &
Brown, Itt. FL II. fig. 2744 (1897). — Clute, FL Upp. Susquehanna, 70
(1898). — Britton, Man. 698 (1901). — Porter, Fl. Pennsylv. 238 (1903). —
Millspaugh, Liv. FL W. Virginia, 322 (in W. Va. GeoL Sum.) (1913).—
House, Wild FL N. Y. II. 201 (1920), excl. figure.
Azalea nudiflora «-. rosea Sweet, Hort. Brit, 265 (1826), name only. — Loddiges
apud Loudon, Arb. Brit. II, 1142, fig. 945 (1838), name and figure only.
? 'Azalea calendulacea 5. cupraea Sweet, Hort. Brit. 265 (1826), name only. —
Loddiges, Bot. Cab. XIV. t. 1394 (1828).
? Rhododendron calendulaceum d. cupreum Sweet, Hort. Brit. ed. 2, 343 (1830),
name only.
Rhododendron nudiflorum e«. roseum Sweet, Hort. Brit. ed. 2, 344 (1830).
Rhododendron nudiflorum Darlington, FL Cestrica, ed. 2, 262 (1837), not
Torrey.2 — Oakes, Cat. Vermont PL 190 (in Thompson, Hist. Vermont)
(1842); reprint p. 18 (1842). — Dudley, Cayuga FL 59 (in Bull. Cornell
Univ. II.) (1886).— Perkins, Cat. FL Vermont, 33 (1888). — Beckwith &
Macauley, PL Monroe Co. N. Y. 83 (in Proc. Rochester Acad. Sci. III.) (1894),
in part.
Azalea nudiflora Darlington, FL Cestrica, 26 ( 1 826) .2 — Wright & Hall, Cat.
PL Troy, 8 (1836). — Clinton, Prelim. List PL Buffalo, 7 (1864). — Payne,
Cat. PL Oneida Co. 51 (in Rep. Regents Univ. N. Y.) (1865). —Patterson,
Cat. PL Illinois, 25 (1876). — D. F. Day, PL Buffalo, 115 (in Bull. Buffalo
Nat. Sci. IV.) (1882). — Meehan inMeehan's Monthly, II. 17, t. 2 (1892).3 —
Kellerman, Cat. Ohio PL 129 (in Rep. GeoL Surv. I.) (1914), in part. —
Schaffner, Cat. Ohio Vase. PL (in Ohio Biol. Surv. I.) (1914), in part.
Rhododendron canescens Porter in Bull. Torr. Bot. Club XVI. 220 (1889), not
Sweet. — Dudley & Thurston, Cat. PL Lackawanna & Wyoming Valleys,
38 (1892). — Deane in Rhodora, III. 196 (1901). — Fernald & Robinson,
Gray's New Man. 631 (1908). — Jackson, Cat. PL Worcester Co. Mass.
76 (1909). — Graves & others, Cat. Flow. PL Conn. 308 (1910). — Stone,
List PL Frankl. Hampshire, Hampden Cos. Mass. 48 (1913). — Rehder in
Bailey, Stand. Cycl. Hort. V. 2942 (1916). — Twining, FL N. E. Pennsylv. 56
(1917).
Azalea prinophylla Small in N. Am. FL XXIX. 42 (1914). — Taylor, FL Vicin.
N. Y. 488 (in Mem. N. T. Bot. Gard. V.) (1915).
Rhododendron prinophyllum Millais, Rhodod. 229 (1917). — Millais & Williams
in Rhodod. Soc. Notes, I. 125 (1918).4
A shrub 1 to 3, rarely to 5 m. tall, with irregularly whorled branches; the young
branchlets finely pubescent, and usually sparingly strigose, becoming grayish
brown or light brown the second year; buds grayish pubescent with numerous,
1 The phrase in the description " staminibus vix exertis " also refers to R. roseum
rather than R. canescens.
2 As the leaves are described as pubescent beneath, the species must be R. roseum
rather than R. nudiflorum.
3 As Meehan describes the leaves as pubescent beneath and the corolla as glan-
dular, the plant figured must be R. roseum rather than R. nudiflorum.
4 ADDITIONAL ILLUSTRATIONS. COLORED PLATES: Goodale, Wild Flow. Am.
t. 36 (1882). — Meehan' s Monthly, II. t. 2 (1892). — BLACK FIGURES: Loudon,
Arb. Brit. II. fig. 945 (1838), as R. nudiflorum var. rosea, after Nouv. Duhamel. —
Keeler, Our North. Shrubs, 349, fig. (1903), as Azalea canescens. — Stevens, III.
Guide Flow. PL t. 114, fig. 1 (1910), as A. canescens.
140 THE AZALEAS OF NORTH AMERICA
generally ovate, obtusish and mucronulate scales. Leaves elliptic or obovate to
obovate-oblong, acute or short-acuminate, gland-tipped, cuneate at the base,
3 to 7 cm. long and 1.2 to 3.3 cm. broad, sparingly pubescent above, densely grayish
villose beneath or sometimes thinly villose rarely nearly glabrous except along
the midrib, sparingly strigillose on the midrib, ciliolate, thinnish at maturity, usually
more or less bluish green or dull green; petioles 2 to 5 mm. long, soft-pubescent and
sparingly strigose. Flowers expanding in May with the leaves in usually 5- to 9-
flowered umbel-like racemes, fragrant; pedicels 0.5 to 1.5 cm. long, finely villose
and glandular-setose; calyx-lobes semiorbicular to ovate, unequal, scarcely exceed-
ing 1 mm., finely pubescent, glandular-ciliate; corolla funnel-form with oblique
limb, usually bright pink, rarely whitish, the tube 1.5 to 2 cm. long, cylindric,
rather gradually dilated toward the apex, covered with a thin villose tomentum
interspersed with numerous gland-tipped hairs of unequal length, pubescent inside,
the lobes about as long or slightly shorter than tube, ovate, abruptly pointed;
stamens little more than twice as long as tube, filaments pubescent below the
middle, the anthers about 2 mm. long, ochraceous; style exceeding the stamens,
4 to 5 cm. long, sparingly or sometimes rather densely pubescent below, purple
above; ovary finely covered with a villous pubescence overlaid with numerous
appressed white, setose, partly gland-tipped hairs. Capsule oblong, narrowed
toward the apex, 1.5 to 2 cm. long, sparingly puberulous and setosely glandular.
Rhododendron roseum is distributed from southwestern New Hampshire, cen-
tral Vermont and southwestern Quebec l through western New York, eastern Ohio,
southern Illinois to southeastern Missouri, and through western and central
Massachusetts, northwestern Connecticut, northern Rhode Island, New York,
Pennsylvania, and northern New Jersey to southwestern Virginia and western
Tennessee. Its range lies chiefly west of the Appalachian Mountains, except in
the north, and does not extend into the coastal plain.
This species is closely related to R. nudiflorum and particularly to its variety
glandiferum and I was for some time inclined to refer it as a variety to the latter
species, as it seems to be connected with it by intermediate forms. It differs, how-
ever, in several important characters from typical R. nudiflorum, as in the pubescent
winter-buds, the more or less densely villous branchlets, the pubescent bluish-green
leaves, in the shorter stamens and in the glandular corolla with larger and broader
lobes and a wider tube, and as the two are easily distinguished in their typical
forms, I think it better to keep them as distinct species. Glabrescent forms with
the leaves pubescent only along the midrib might be confused with R. nudiflorum,
but can be distinguished from it by the flowers, the pubescent winter-buds and
the finely villous branchlets. Rhododendron roseum has also been confused with
R. canescens Don, with which it agrees in the pubescence of the leaves, but differs
in the shorter, gradually dilated pilose-glandular corolla-tube, in the shorter sta-
mens and in the thinner, not reticulate leaves.
This species was first mentioned in 1787 as a variety of Azalea nudiflora "with
broad rough leaves" by Wangenheim (Beytr. Forstwiss. 68), who observed it in the
state of New York. When it was introduced into cultivation cannot be stated with
certainty. It may be one of the varieties mentioned by Aiton in 1789, and without
doubt Pursh's specimen from Cacapoon Springs near Winchester, West Virginia,
referred by him to R, canescens belongs here. According to a note by Loudon (Arb.
Brit. II. 1143) this has been found in Virginia "on the mountains of the Cacapoon
Springs, near Winchester, where it forms a shrub growing 3 feet or 4 feet high and
producing its rose-coloured flowers in May and June. Introduced in 1812 and
1 Near Hull, Quebec, June 5, 1916, John Dunbar (Herb. Park Dept., Rochester,
N. Y.)
ENUMERATION OF THE SPECIES 141
cultivated in several of the London nurseries." Loddiges states under A. calen-
dulacea cuprea, which possibly belongs to this species, that it was introduced in 1806
by John Lyon. It must have been in cultivation in Europe before 1812, for I have
little doubt that Loiseleur's description and figure in the Nouveau Duhamel
represents this species, though he himself identifies it with Azalea canescens Michx.
by quoting that name as a synonym. The colored plate in Nouveau Duhamel well
shows its difference from R. canescens in the dense flower-cluster, the bright rosy-
pink corolla, its wide limb and short tube furnished with conspicuous glandular
hairs, the comparatively short stamens and the bluish green leaves. Loiseleur's
figure and name, however, have been entirely overlooked by later authors, and
after Pursh had described it as A. canescens, the species was not mentioned again,
until Porter described it in 1889, clearly pointing out its difference from R, nudiflorum
and from R. calendulaceum; but he also referred it to Azalea canescens Michx.,
naming it R. canescens (Michx.). As a distinct species it was recognized by Small,
who described it in 1914 as A. prinophylla in the North American Flora, overlooking
the name A. rosea, which is not enumerated in the Index Kewensis nor mentioned
in any systematic work after 1812.
Rhododendron alabamense Rehder, spec. nov.
Azalea nudiflora var. alba Mohr, PL Life Ala. 653 (1901), not Pursh.
Frutex humilis ramis subverticillatis; ramuli juniores satis dense vel sparse
pallide strigoso-pilosi, annotini griseo- vel flavido-brunnei; vetustiores plerique
fusco-brunnei; gemmae florales multiperulatae perulis ovatis apice rotundatis
mucronatis glabris fuscis margine dense albo-ciliolatis. Folia obovata vel elliptica
ad elliptico-oblonga v. obovato-oblonga, acuta vel obtusiuscula et glanduloso-
mucronulata, basi cuneata, 3-6 cm. longa et 1.4-3 cm. lata, supra initio sparse
vel sparsissime villosula et saepe minute strigillosa; subtus glaucescentia vel
pallida et tota facie satis dense villosula, costa media supra villosula subtus pleraque
sparse strigosa, margine ciliata, utrinque nervis 10-12; petioli villosuli et strigillosi,
breves. Flores odorati, simul cum foliis, mense Aprili et Maio; plerumque 6-10,
subumbellati; pedicelli 0.5-1 cm. longi, sparse villosuli et plerique satis dense
hirsutis pilis partim glanduliferis vel eglandulosis; sepala inaequalia, semiorbicularia
ad ovata, 0.5-1.5 mm. longa, extus et margine pilis longis setosis eglandulosis
instructa; corolla infundibuliformis, alba, tubo cylindrico apice sensim dilatato,
2-2.8 cm. longo, rarius breviore, extus sparse villosula et plus minusve pilosis
pilis partim glanduliferis vel interdum omnibus eglandulosis et longioribus, lobis
ovatis acutis circiter 1.5 vel fere 2 cm. longis, tubo manifeste brevioribus, stamina
tubum duplo superantia, vix declinata, filamentis infra medium villosis albidis,
antheris flavidis 2-3 mm. longis; stylus stamina longiora vix superans, 5-6 cm.
longus, basin versus villosulus, albidus; ovarium dense setoso-strigosum setis glandu-
losis vel fere eglandulosis. Capsula (immatura) cylindrico-oblonga, circiter 1.5 cm.
longa, sparse villosula et glandulosa vel fere eglandulosa.
Low shrub with irregularly whorled branches; young branchlets densely or
sparingly furnished with pale strigose hairs; one-year old branchlets grayish or
yellowish brown, older branches usually dark brown; floral winter-buds glabrous,
brown, of many ovate scales rounded and mucronate at apex, densely white-
ciliolate. Leaves obovate or elliptic to elliptic-oblong or obovate-oblong, acute or
obtusish and gland-tipped, cuneate at base, 3 to 6 cm. long and 1.4 to 3 cm. wide,
above sparingly or very sparingly puberulous and often finely strigillose, glaucescent
or sometimes pale green beneath and usually rather densely, sometimes more spar-
ingly short-villose, the midrib villose above and usually sparingly strigose beneath,
ciliate on the margin, with 10 to 12 pairs of veins; petioles finely villose and strigil-
142 THE AZALEAS OP NORTH AMERICA
lose, short. Flowers fragrant, appearing with the leaves, in April and May, in
usually 6- to 10-flowered umbel-like clusters; pedicels 0.5 to 1 cm. long, sparingly
villose and rather densely hirsute, glandless or glandular; sepals unequal, roundish
to ovate, 0.5 to 1.5 mm. long, densely setose, glandless; corolla funnel-form, white,
tube cylindric, gradually dilated at apex, 2 to 2.8 cm. long, rarely slightly shorter,
outside sparingly and more or less glandular-pilose or sometimes hirsute without
glands, lobes ovate or sometimes ovate-oblong, acute, 1.5 to 1.8 cm. long, distinctly
shorter than the tube; stamens twice as long as tube, scarcely declinate, the fila-
ments villose below the middle, the anthers yellowish, 2 to 3 mm. long; style
scarcely exceeding the longer stamens, 5 to 6 cm. long, finely villose toward the
base, whitish; ovary densely setose-strigose, glandular or nearly glandless. Capsule
(immature) cylindric-oblong, about 1.5 cm. long, sparingly and finely villose and
glandular-setulose or nearly glandless.
ALABAMA . C u 1 1 m a n C o u n t y : Pine woods, May 2 1 , 1 902 , Biltmore
Herb. H/62921 (Nat. Herb. No 980,507, type); on rocky slope in woods
of Oak, Hickory and Pine, May 21, 1902, Biltmore Herb. H/6293
(Nat. Herb. No. 980,506); dry rocky hillside, May 19, 1902, Biltmore
Herb. H/6258 (Nat. Herb. No. 980,524); dry woods, May 19, 1902,
Biltmore Herb. H/6267, 6268 (Nat. Herb. Nos. 980,528, 980,511);
without special locality, May 19, 1902, Biltmore Herb. H/6259, 6262-
6265 (Nat. Herb. Nos. 980,525, 980,510, 980,523, 980,509, 980,527);
dry rocky open woods on the high tablelands, May 2, 1883, C. Mohr
(as R. (Azalea) nudiflora alba; "flowers snowy white, highly fragrant ").
Marshall County: Albertville, May 8, 1901, Biltmore Herb.
H/4290, 4292, 4293, 4295, 4297 (Nat. Herb. 969,632, 969,628, 969,682,
969,634, 969,658) ; dry woods, August 27, Biltmore Herb. H/2452 (Nat.
Herb. 969,617); October 12, 1900, Biltmore Herb. H/3321 (Nat. Herb.
969,649). Henry County : Abbeville, April 15, 1902, Biltmore Herb.
H/6112 (Nat. Herb. 980,513).
As it appears from these specimens this species is known to me only from two
counties in northern and from one county in southeastern Alabama, but probably
it is more widely distributed through the northern and central part of the state; it
inhabits dry open woods and rocky hillsides and thus agrees in its habitat with the
northern R. roseum, while R. canescens, the other common Alabama species, prefers
damp woods and swamps.
This new species is closely related to R. nudiflorum Torr., R. roseum Rehd. and
R. canescens G. Don. From the first species it is easily distinguished by the
much longer and slenderer corolla-tube, the pure white fragrant flowers, less long-
exserted scarcely declinate stamens and the pubescent leaves; from R. roseum
it differs in the glabrous winter-buds, the longer and slenderer corolla-tube, the
glandless setae of the sepals, in the white color of the flowers and in the glau-
cescent under side of the leaves; from R. canescens it is distinguished by the
glabrous winter-buds, the much less villose and more or less pilose corolla-tube,
less slender and more gradually dilated at the apex, by the less exserted stamens,
the larger limb, the densely strigose ovary, the less villose and more setose capsules,
1 "H " stands for T. G. Harbison who collected for the Biltmore Herbarium.
ENUMERATION OF THE SPECIES 143
and the generally broader leaves. Rhododendron alabamense shows some variation
chiefly in the size and pubescence of its flowers. The type specimen has large
flowers with a glandular-pilose tube, while in Nos. 6258 and 6259 the tube has
longer and quite glandless hairs; the specimens from Albertville have generally
smaller flowers, the tube sometimes scarcely 2 cm. long and the lobes longer and
narrower, sometimes nearly oblong and acuminate, the leaves are also smaller and
less glaucescent and often less pubescent beneath. The Abbeville specimen from
southeastern Alabama is again much like the type in its flowers, but the leaves are
less densely pubescent and less glaucescent beneath. In the National Herbarium
is a sheet (No. 770,587) labeled "R. viscosum Torr., borders of stream in thickets,
Pointclear (not quite legible), C. Mohr, June 16, 1889," which contains a specimen of
R. arborescens and two specimens which suggest a glabrous form of R. alabamense,
but as apparently the locality and the date do not belong to these two specimens, I
consider them for the present as doubtful.
Rhododendron alabamense was apparently first observed in 1883 by Dr. C. Mohr,
who recognized it as distinct from the more widely distributed R. canescens which
he included under his A. nudiflora; this probably induced him to identify this
particular form with A. nudiflora var. alba Aiton. The species has not yet been
introduced into cultivation; it may be hardy North, and for southern gardens it
would be superior to R. canescens on account of its very fragrant larger flowers,
which are "snowy white" according to Dr. Mohr.
Rhododendron canescens Sweet, Hort. Brit. ed. 2, 343 (1830).—
G. Don, Gen. Syst. Ill, 848 (1834), excl. the reference to plant of
Winchester. — Loudon, Arb. Brit. II, 1143 (1838), in part. — Millais,
Rhodod. 136 (1917).
Azalea lutea Linnaeus, Spec. 150 (1753), as to the synonym of Gronovius only.
Azalea nudiflora Linnaeus, Spec. ed. 2, 214 (1762), as to the synonym of
Gronovius only. — Walter, Fl. Car. 97 (1788). — Elliott, Sketch Bot. I. 240
(1821), in part. — Mohr, PL Life Ala. 653 (1901).
? Azalea nudiflora e. bicolor Aiton, Hort. Kew. I. 203 (1789).
Azalea canescens Michaux, Fl. BOT. -Am. I. 150 (1803). — Pursh, Fl. Am. Sept.
152 (1814), in part. — Elliott, Sketch Bot. I. 239 (1821). — De Candolle,
Prodr. VIII. 717 (1838). — Small, Fl. S. E. U. S. 883 (1903); Shrubs Fla.
93 (1913); in N. Am. Fl. XXIX. 42 (1914).
Azalea bicolor Pursh, FL Am. Sept. I. 153 (1814). — Elliott, Sketch Bot. I.
239 (1821). — De Candolle, Prod. VII. 717 (1839).
Rhododendron bicolor Sweet, Hort. Brit. ed. 2, 344 (1830). — G. Don, Gen.
Syst. III. 847 (1834). — Loudon, Arb. Brit. II. 1142 (1838).
Rhododendron nudiflorum Chapman, FL S. U. S. 265 (1865), not Torrey.
Azalea nudiflora var. canescens Rehder in Bailey, Cycl. Am. Hort. 1. 121 (1900),
in part.1
A shrub to 4 or 5 m. tall with irregularly whorled upright branches; young branch-
lets finely villous-pubescent and usually sparingly strigose; winter-buds with
broadly ovate, acuminulate and densely grayish pubescent scales. Leaves usually
1 PRELINNEAN SYNONYM : Cistus Virginiana flore et odore Periclymeni, Catesby,
Nat. Hist. Car. I. 57, t. 57 (1731), not Banister apud Plukenet.
ADDITIONAL ILLUSTRATIONS. COLORED PLATES: Abbot, Nat. Hist. Lepidopt.
Georgia, I. t. 27 (1797). — Audubon, Birds of Am. IV. t. 398 (1835-38).
144 THE AZALEAS OF NORTH AMERICA
oblong-obovate to oblanceolate or oblong, rarely elliptic or obovate, acute, rarely
obtusish, gland-tipped, cuneate at base, 4 to 9 cm. long and 1.5 to 3.5 cm. broad,
setosely ciliate, sparingly pubescent above or glabrescent except at the finely vil-
lose midrib, densely pubescent or grayish tomentulose beneath particularly on the
veins and midrib, usually sparingly strigose on the midrib toward the base, of firm
texture and slightly reticulate beneath at maturity; petioles 2 to 7 mm. long, finely
pubescent and sparingly strigose. Flowers expanding before or with the leaves in
April and May, in 6- to 15-flowered clusters, slightly fragrant; pedicels 0.5 to 1 cm.
long, villose-pubescent and hirsute, sometimes stipitate-glandular; calyx-lobes,
unequal, semi-orbicular to ovate, scarcely exceeding 1 mm., ciliate or sometimes
glandular-ciliate; corolla-tube cylindric, abruptly dilated at apex, 1.5 to 2.3 cm.
long, distinctly longer, sometimes nearly twice as long as lobes, densely and finely
villose outside and stipitate-glandular, rarely somewhat pilose, pubescent inside;
lobes ovate, acute or obtusish, 1.2 to 1.5 cm. long; stamens much exserted, nearly
3 times as long as tube, pubescent below the middle, anthers 1.5 to 2 mm. long,
ochraceous; style 4 to 6 cm. long, finely villose toward the base, slightly longer or
about as long as stamens; ovary densely white pubescent with appressed silky hairs
and sparingly setulose, without glands. Capsule cylindric-oblong, narrowed up-
ward, slender, 1.5 to 2 cm. long, pubescent and sparingly setose.
This species is chiefly a plant of the southern Atlantic and the Gulf coastal
plain, but extends into the Piedmont region of North Carolina, Georgia and
Tennessee; it ranges from southwestern Tennessee and southern central North
Carolina to eastern South Carolina and northeastern Florida to extreme south-
eastern Texas, central Louisiana and northeastern Alabama. It usually grows in
woods on moist sandy soil, often along streams, rarely in swampy soil.
Rhododendron canescens is chiefly characterized by the more or less pubescent
leaves firm at maturity and slightly reticulate beneath, by the slender corolla-tube
abruptly enlarged into a comparatively small limb and clothed outside with a
fine dense villose tomentum interspersed with rather short and small stipitate
glands, by the long exserted stamens being nearly three times as long as the tube
and by the grayish pubescent eglandular and not strongly setose ovary and cap-
sule. The color of the flowers is usually pink or perhaps more often the tube only
is pink and the limb white or only slightly pinkish; a form with nearly purple
flowers differing further from the type in the comparatively short and wide corolla-
tube has been collected by T. G. Harbison at Valleyhead, Alabama (No. 530;
May 2, 1911). There is considerable variation in the pubescence of the leaves; in
one extreme they are nearly white tomentose beneath, while in the other ex-
treme they are nearly glabrous. The glabrous or glabrescent form has been con-
fused with R. nudiflorum, but it is easily distinguished from that species by the
shape and pubescence of the corolla and by the pubescent winter-buds.
Rhododendron canescens was discovered by Catesby, who published a character-
istic and fairly good figure of it in 1731. In 1797 an excellent colored plate of it,
drawn by J. Abbot, was published as A . nudiflora in his work on tjhe Lepidopterous
insects of Georgia. It was also collected by Michaux in South Carolina between
1784 and 1796, and first recognized by him as a distinct species and described in
his Flora as R. canescens. Pursh in 1814 confused Michaux's A. canescens with
R. roseum; he identified a plant collected near Winchester, West Virginia, which
apparently was R. roseum, with Michaux's A. canescens and redescribed the true
A . canescens under the name A . tricolor.
It was probably introduced into cultivation about the middle of the 18th cen-
tury and it may be one of the varieties enumerated by Aiton in 1789 and possibly
his var. bicolor, cited by Pursh as a synonym of his A. bicolor which is identical with
R. canescens, but it apparently soon disappeared again from the gardens.
ENUMERATION OF THE SPECIES 145
Rhododendron canescens f. subglabrum Rehder, forma nov.
A typo recedit foliis costa media utrinque villosa et margine ciliato exceptis
fiubglabris; ceterum ut in typo.
MISSISSIPPI . HindsCounty: Jackson, April 1 5 and 30, 1 9 1 5, T. G.
Harbison (No. 16, type, No. 38). Tishomingo County : luka, May
5, 1915, T. G. Harbison (No. 6). Lauderdale County: Meridian,
April 12, 1900, C. S. Sargent; April 16, 1915, T. G. Harbison (Nos. 5, 13).
Harrison County: Mississippi City, March 31, 1900, C. S. Sargent.
GEORGIA. Habersham County: Cornelia, bank of small stream,
May 6, 1920, T. G. Harbison (No. 40). Randolph County: Cuth-
bert, pine woods, March 29, 1918, T. G. Harbison (No. 19, low shrub).
ALABAMA. Cullman County: May 3, 1901, Biltmore Herb.
H/4246 (Nat. Herb. 969,666). Chilton County: Mapleville, April
13, 1912, T. G. Harbison (No. 849). Dallas County: Selma, April
9, 1912, T. G. Harbison (No. 825). Lee County: Auburn, April 6
and 8, 1913, T. G. Harbison (Nos. 817, 807). Mobile County:
Mobile, March 18, 1894, C. Mohr.
LOUISIANA. Natchitoches Parish: Natchitoches, wet sandy
banks, April 15, 1915, E. J. Palmer (No. 7228). Calcasieu Parish :
Lake Charles, April 2, 1913, C. S. Sargent. East Baton Rouge
Parish : Baton Rouge, April 15, 1920, R. S. Cocks (No. 3321).
TEXAS. Hardin County : Fletcher, March 17, 1918, E. J. Palmer
(No. 13,095, in part).
This form differs from the type in its glabrescent or nearly glabrous leaves;
they may be either glabrous on both sides except the ciliate margin and the mid-
rib which is finely villous above and beneath and often also sparingly strigillose
beneath, or sometimes they are finely pubescent on the upper surface while young
and rarely also sparingly pubescent beneath. In the pubescence of the winter-
buds, of the branchlets and of the flowers, this form does not differ from the type
and is thus easily distinguished from R. nudiflorum with which it has been confused.
This form is distributed from northern and western Georgia through Alabama
to northeastern Mississippi, western Louisiana and southeastern Texas, and south
to the coast of Alabama, Mississippi and Louisiana. Its range lies wholly within
the range of the type, but is apparently chiefly restricted to the western portion
of it. The only stations known to me east of Alabama are near Cuthbert, Randolph
County, in western, and near Cornelia, Habersham County, in northeastern Georgia.
It has been usually confused with R. nudiflorum, and the extension of the range of R.
nudiflorum beyond Tennessee and South Carolina given in those floras which keep
R. nudiflorum distinct from R. canescens refers apparently to this form. It is con-
nected by intermediate forms with the type and generally the pubescence on the
leaves of specimens of the type from the western part of the range of the species
is much thinner than that of the eastern specimens.
Rhododendron canescens f. subglabrum has only recently been introduced into
cultivation through the Arnold Arboretum, where it was raised from seed sent by
E. J. Palmer in 1916 from Fletcher, Texas. It will probably not be hardy in the
northern states and does not differ from the type in its ornamental qualities.
146 THE AZALEAS OF NORTH AMERICA
Rhododendron canescens var. candidum Rehder, var. nov.
Azalea Candida Small in Bull Torr. Bot. Club XXVIII. 360 (1901); FL S. E.
U. S. 883 (1903); Shrubs of Fla. 93 (1913); in N. Am. FL XXIX. 43 (1914).
Rhododendron candidum Render in Bailey, Stand. Cycl. Hort. V. 2945 (1916);
VI. 3574 (1917). — Millais, Rhodod. 136 (1917).
This variety differs from the typical form in the glaucous or glaucescent, densely
pubescent under side of the leaves and in the mostly denser pubescence of the
branchlets usually interspersed with numerous short gland-tipped setae. The
white or whitish color of the under side is not caused by the dense tomentum, as
one might suppose, but by the glaucous or glaucescent epidermis, which is coated
with a waxy exudation as in glaucous forms of R. viscosum.
GEORGIA. Decatur County: Climax, Nov. 6, 1917, T. G. Harbi-
son (No. 14). Brooks County: Quitman, April 2, 1918, T. G.
Harbison (No. 3). Lowndes County: near Valdosta along the With-
lacoochee River, June 6-12, 1895, J. K. Small (type) ; in low sandy soil
along the Withlacoochee River, April 2, 1918, T. G. Harbison (Nos. 1,
2); near Ousley, Oct. 21, 1910, T. G. Harbison (Nos. 247, 250).
Charlton County : Folkston, July 16, 1918, T. G. Harbison (No. 76).
Tattnall County: rock outcrop near Choopee River, June 24, 1903,
R. M. Harper (No. 1858).
FLORIDA. Hamilton County: White Springs, May 11, 1901,
H. H. Blume.
This variety is restricted to southern Georgia and northern Florida and I have
seen no specimen farther north or south than about twenty miles from the border line
except a specimen from Tattnal County about one hundred miles north of Florida,
but that specimen is not a typical var. candidum, as it lacks the glandular pubescence
of the branchlets, and the under side of the leaves though densely villous or almost
whitish tomentose, is not very glaucous. Besides the character already mentioned
I can find no difference between this variety and R. canescens and I therefore pre-
fer to consider it only a variety of that species. I do not understand why Small
places it among the species with the flowers appearing after the leaves; the flower-
ing specimens before me, collected April 2, differ in no way as regards the de-
velopment of leaves from typical R. canescens.
The variety seems to have been first observed and collected in 1895 by Dr.
Small on the Withlacoochee River. It is doubtful whether it is in cultivation; the
plant introduced under this name a few years ago raised from seed collected near
Folkston, Georgia, is possibly typical R. canescens.
Rhododendron austrinum Rehder in Bailey, Stand. Cycl. Hort. VI.
3571, 3574 (1917). — Millais, Rhodod. 125 (1917).
Rhododendron nudiflorum var. luteum Curtiss in herb, sub No. 1718.
Azalea austrina Small, FL S. E. U. S. ed. 2, 1356 (1913); Shrubs Fla. 94
(1913); in N. Am. FL XXIX. 42 (1914).
Slender branched shrub to 3 m. tall; young branchlets covered with a short
soft pubescence interspersed with usually copious gland-tipped hairs and spar-
ingly strigose, particularly toward the apex, becoming red-brown in autumn and
grayish brown the second year; floral winter-buds with ovate scales, rounded to
ENUMERATION OF THE SPECIES 147
acutish and acuminulate at the apex and densely grayish pubescent. Leaves
elliptic to obovate or oblong-obovate, 3 to 9 cm. long and 1.5 to 3.5 cm. broad,
acute or obtusish and gland-tipped at apex, cuneate at base, setosely ciliate, finely
pubescent on both sides, more densely beneath, particularly on the veins, rarely
glabrescent above at maturity; petioles 3 to 8 mm. long, pubescent and glandular
and usually sparingly strigose. Flowers appearing shortly before or with the
leaves, end of March or in April in 8- to 15-flowered umbel-like racemes; pedicels
0.5 to 1 cm. long, pubescent and glandular-setose; sepals broadly ovate to oblong,
unequal, 1 to 2.5 mm. long, glandular-ciliate, pubescent outside; corolla yellow and
orange, the tube usually more or less purplish or with 5 longitudinal purplish
stripes, slightly fragrant, the tube cylindric, abruptly dilated at the apex, 1.5 to
2 cm. long, finely pubescent and stipitate-glandular, the lobes ovate 1 to 1.5 cm.
long and 0.6 to 1 cm. broad, short-acuminate with recurved point, finely pubes-
cent outside; stamens nearly three times as long as tube, the filaments pubescent
below the middle, the anthers ochraceous, 2 to 3 mm. long; style slightly exceeding
the stamens, 5 to 6 cm. long, short-pilose near the base; ovary covered with long
whitish strigose, partly gland-tipped hairs. Capsule oblong-cylindric, slightly nar-
rowed toward the apex, 1.5 to 2.5 cm. long, covered with a thin fine pubescence
interspersed with long strigose partly gland-tipped hairs.
This species has a very restricted distribution; it has been found only in Gads-
den County, in northern Florida, near River Junction and Chattahoochee, close
to the Georgia state line and about ten miles farther south at Aspalaga near Rock
Bluff, Liberty County (Biltmore Herb. 6088). It was apparently first discovered
by Dr. Chapman some time before 1865, as he refers to it in his Flora under R.
nudiflorum as a color variation of that species; there is also a specimen collected
by him in the National Herbarium without date and locality with the note "flowers
orange." The species was again collected in 1880 by A. W. Curtiss and distributed
as R. nudiflorum var. luteum, but that name was never published and this Azalea
was not recognized as distinct until described as a species by Dr. Small in 1913.
Rhododendron austrinum is so closely related to R. canescens that one might be
induced to consider it only a color form of that species, but aside from the fact
that the yellow color is a disconnected deviation from the pink color tones of
R. canescens, R. austrinum differs further in the glandular ovary and capsule,
entirely destitute of glands in R. canescens, and in the copious glandular pubescence
of the calyx and pedicels which are usually, though not always, glandless in R.
canescens. In their general appearance, however, I could see no difference except
the color between the two species, when I saw them growing side by side in Mr.
H. H. Hume's garden in Jacksonville, who had brought the plants of both species
from River Junction the year before.
The species was first introduced into cultivation through the Arnold Arboretum,
where plants were raised from seed collected in 1914 by Mr. T. G. Harbison near
River Junction. It cannot be expected to thrive in northern gardens, but for
southern gardens it may be desirable on account of its yellow flowers.
Rhododendron atlanticum Rehder, comb. nov.
Azalea nudiflora M. A. Curtis in Boston Jour. Nat. Hist. I. 100 (Enum. PI.
Wilmington) (1834), not Linnaeus.1 — Groom, Cat. PI. Newbern, 21 (1837).—
Wood & McCarthy, Wilmington Fl. 34 (1886).
1 I have seen in the herbarium of the Academy of Natural Science at Phila-
delphia a specimen collected by Curtis at Wilmington and named by him A. nudi-
flora, which proves to be R. atlanticum. The true R. nudiflorum has not been found
near Wilmington.
148 THE AZALEAS OF NORTH AMERICA
Azalea atlantica Ashe in Bull. Charleston Mus. XIII. 26 (1917). — Coker in
Jour. Elisha Mitchell Soc. XXXVI. 97, pi. 1, 7 (1920).
Low stoloniferous shrub rarely more than 0.5 m. tall, with slender upright
usually sparingly branched or simple stems; young branchlets sparingly strigillose
and sometimes glandular hirsute, otherwise glabrous, occasionally slightly glau-
cescent, reddish brown at the end of the season, becoming grayish brown and
glabrous the second year; floral winter-buds with ovate, mucronulate, light brown
and white-ciliolate, glabrous or slightly silky-pubescent scales. Leaves obovate
to oblong-obovate, rarely elliptic, rounded or acutish and gland-tipped at apex,
cuneate at base, 3 to 6 cm. long and 1.5 to 2 cm. broad, setosely ciliate or minutely
serrulate-ciliate, glabrous above except the villose midrib and bright green or
bluish green, glabrous and sparingly strigillose and sometimes pubescent on the
midrib beneath, rarely strigillose on the surface, and glaucescent or bright green,
chartaceous at maturity, the secondary veins scarcely prominent beneath and
the veinlets obscure; petioles 1 to 5 mm. long, sparingly strigillose. Flowers ap-
pearing before or with the leaves in April or beginning of May in clusters of 4 to
10; pedicels about 1 cm. long, hirsute or glandular-hirsute, otherwise glabrous,
rarely minutely and slightly villose; sepals broadly ovate, small or occasionally
oblong and 2 to 4 mm. long, glandular-ciliate or sometimes eglandular; corolla
funnel-form, white, usually flushed pink or purple outside, very fragrant, the tube
cylindric, rather gradually dilated at apex, 2 to 2.5 cm. or rarely to nearly 3 cm.
long, outside with numerous short gland-tipped hairs, otherwise glabrous or only
slightly villose, glabrous or nearly so inside, the lobes ovate to ovate-oblong, acute,
1.3 to 2 cm. long, stipitate-glandular along the middle; stamens exserted, about
twice as long as the tube, the filaments hairy below the middle, the anthers 2 to 3 mm.
long; style exceeding the stamens, 4.5 to 5.5 cm. long, pubescent below the middle,
usually purplish above; ovary with setose, gland-tipped or glandless hairs. Cap-
sule ovoid-oblong, 1.5 to 2 cm. long, setose, the setae glandless or gland-tipped.
DELAWARE. Kent County: Choptank Mills, May 29-30, 1904,
Witmer Stone (Herb. Acad. Nat. Sci. Phila.).
DISTRICT OF COLUMBIA. Washington, Takoma Park, May 11, 1900,
T. A. Williams.
VIRGINIA. Princess Anne County: May 9, 1898, Th. H.
Kearney (No. 1062; Nat.Herb. No.355,802). Nansemond County :
near Suffolk, April 30, 1898, Fr. Coville & Th. H. Kearney (No. 49;
Nat. Herb. No. 355,681).
NORTH CAROLINA. Johnston County: Selma, April 23, 1918,
and November 19, 1919, T. G. Harbison (Nos. 1-8, 10). Craven
County : Newbern, April 7 and 18, 1918, April 20 and Nov. 20, 1919,
T. G. Harbison (Nos. 7, 14, 17, 23, 30, 101, 102, 115, 116, 117, 121, 131,
132). New Hanover County: Wilmington, April 2, 1880, C. S.
Sargent; April 14 and 15, 1911, C. S. Williamson; April 18 and 19, 1919,
T. G. Harbison (Nos. 36-41, 47, 48), without date, M. A. Curtis.
Eastern N. Carolina, without precise locality, April, 1888, G. McCarthy
(Nat. Herb. 42,633).
SOUTH CAROLINA. Florence County : Ebenezer, wet Pine barren,
ENUMERATION OF THE SPECIES 149
Sept. 26, 1911, H. H. Bartlett (No. 2857; Nat. Herb. No. 586,340);
three miles east of Florence, April 17, 1897, L. F. Ward (Nat. Herb. No.
284,925); GeorgetownCounty: Georgetown (type locality), April
25, 1918, T. G. Harbison (Nos. 11, 14).
This species is restricted to the coastal plain region from Delaware to South
Carolina. It is characteristic of the low pine lands, where it forms extensive colonies
almost to the exclusion of the other shrubs and often occupies large stretches; the
low stoloniferous shrubs, rarely more than half a meter high, dotted over the grassy
forest floor, form in spring with their white or pinkish very fragrant flowers a
conspicuous feature of these woods. I noticed it from the railroad train from north-
ern South Carolina to Virginia for a distance of more than 150 miles almost every-
where in the pine woods and often spreading into the adjacent fields.
Rhododendron atlanticum seems to be most closely related to R. viscosum, with
which it agrees perfectly in its leaves, in the shape of the corolla with its slender
cylindrical tube, glabrous inside and glandular-hirsute outside, in the strong frag-
rance of its flowers and in the densely setose but scarcely villose capsule, but usually
it can be easily distinguished by its low stoloniferous habit, its early appearing
flowers, the usually nearly glabrous branchlets and the absence of the fine pubes-
cence on the outside of the corolla and the less abrupt expansion of its tube into
the limb. There are, however, particularly in the coastal plain region from Mary-
land to South Carolina, forms of R. viscosum of low and somewhat stoloniferous
habit (see page 159) which might be confused with R. atlanticum and in the south
R. viscosum begins to flower often about or sometimes before the middle of May,
but the flowers of that species always appear after the leaves are nearly fully
developed and the fine villose pubescence of the outside of the corolla, absent or
nearly absent in R. atlanticum, and the generally slenderer corolla more abruptly
dilated at the apex afford characters to separate the two species. Rhododendron
atlanticum has been also confused with R. nudiflorum, but from that species it is
readily distinguished by the low stoloniferous habit, by the smaller obovate leaves
chartaceous at maturity, the very fragrant flowers, the much longer tube of the
corolla glandular-hirsute outside and lacking the fine villose pubescence of the
corolla of R. nudiflorum, by the glabrous inner surface of the corolla-tube and
the conspicuous rows of stipitate glands at the apex of the flower-bud.
Rhododendron atlanticum has always been confused with the two species just
mentioned until Ashe described it in 1917 as a new species. The oldest specimens
I have seen are those collected as Azalea nudiflora by M. A. Curtis, one on Society
Hill, South Carolina, representing at least partly the variety luteo-album, and one
collected near Wilmington, North Carolina, probably in the early thirties while
he was residing at Wilmington. The species is in cultivation at the Arnold Arbore-
tum, where a plant was received in 1920 from Mr. Ashe who had grown it in his
garden at Washington for several years; it is doubtful, however, if this species
proves hardy in the northern states.
Rhododendron atlanticum f. neglectum Rehder, comb. nov.
Azalea neglecta Ashe in Bull Torr. Bot. Club, XLVII. 581 (1920).
This form, based by Ashe on specimens collected by him near Georgetown,
South Carolina, May, 1916, is hardly specifically distinct from R. atlanticum; it
differs chiefly in the purplish pink color of its flowers, the somewhat shorter and
wider tube and the usually more villose pubescence of the corolla. Specimens of
his new species collected near Kinlock, South Carolina, on May 1, 1920, kindly sent
150 THE AZALEAS OF NORTH AMERICA
by Mr. Ashe, show well the purplish pink color of the flowers; the corolla tube is
slightly shorter and wider than in the typical R. atlanticum and is furnished outside
with numerous gland-tipped stiff hairs, which are more numerous in one of the
specimens sent and less numerous in the other, but in the latter the tube is
also thinly covered with a fine villose pubescence, which in typical R. atlanticum is
absent or nearly absent, though occasionally, as in Harbison's No. 14 from George-
town, South Carolina, the type locality of the species, and in his Nos. 38 and 41
from Wilmington, North Carolina, this villose pubescence is present. To f. ne-
glectum I also refer Harbison's No. 14 from Newbern, North Carolina, collected
April 17, 1918, though this differs in its narrow-oblong calyx-lobes, up to 5 mm.
long, and possibly also his Nos. 7, 101, 102 from the same locality, Nos. 37, 40 and
47 from Wilmington, and his Nos. 3 and 5 from Selma, North Carolina, may belong
to this form, if we consider the color its chief distinguishing character.
Rhododendron atlanticum var. luteo-album Rehder, comb. nov.
Azalea atlantica var. luteo-alba Coker in Jour. Elisha Mitchell Sti. Soc. XXXVI.
98, pi. 1, fig. (at right) (1920).
This variety differs from the type in the dull bluish green leaves finely pubescent
on both surfaces and strigillose above, in the finely villose petioles and in the stipi-
tate glandular young branchlets; the flowers white, when open, are sometimes
yellowish in bud without any trace of pink.
SOUTH CAROLINA. Darlington County: Ditch bank southeast of
Hartsville plantation of J. L. Coker & Co., spring of 1918, J. L. Coker,
Jr. (co-type); flat woods south of Hartsville plantation, April 29, 1915,
W. C. Coker; without precise locality, in sandy soil (No. 8), in sandy
soil near roadside (No. 14), in cultivated field (No. 13), April 24, 1918,
T. G. Harbison; in low sandy pine woods, November 22, 1919, T. G.
Harbison (Nos. 31, 32) ; Society Hill, no date, M. A. Curtis (Gray Herb.,
partly typical R. atlanticum).
This variety was based originally on the color of the flowers, but as a specimen
kindly sent me by the author of the variety shows, it is at the same time rather
densely pubescent and differs in this respect from the type of the species. As the
pubescence seems to me the more important character, I prefer to include in this
variety all the specimens with pubescent leaves without regard to the difference in
the color of the flowers, which, moreover, seems to be not very pronounced, for I
can hardly see any difference between the two forms as represented on the colored
plate cited above.
Rhododendron oblongifolium Millais, Rhodod. 219 (1917). — Millais
& Williams in Rhodod. Soc. Notes, I. 125 (1918).
Azalea oblongifolia Small, Fl. S. E. U. S. 883, 1336 (1903) ; in N. Am. Fl. XXIX.
43 (1914).
Shrub to 2 m. high or less, with irregularly whorled branches; young branchlets
with short and rather sparse villose pubescence and usually with sparse strigose
hairs or sometimes nearly glabrous; floral winter-buds with ovate, acuminulate or
obtuse, grayish pubescent scales. Leaves obovate or elliptic-obovate to oblong-
oblanceolate, rarely oblong, 4 to 10 cm. long and 1.5 to 3.8 cm. broad, acutish
or acute, gland-tipped, cuneate, ciliate, dull green and glabrous above except the vil-
ENUMERATION OF THE SPECIES 151
lose midrib or sometimes strigillose and minutely pubescent, light green, or rarely
glaucescent beneath, pilose and strigillose on the midrib, more or less pubescent on
the whole under surface or nearly glabrous ; petioles 2 to 3 mm. long, finely pubescent.
Flowers expanding at the middle or end of May or in southeastern Texas at the end
of April, after the leaves are fully formed, and borne in 7- to 12-flowered clusters;
pedicels 1.5 to 2 cm. long, sparingly villose and glandular-hirsute; calyx-lobes
unequal, ovate to oblong or lanceolate, obtuse to acute, 1 to 3 mm. long, long-
ciliate and sparingly villose outside; corolla funnel-form, white, the tube cylindric,
abruptly dilated at the apex, 2.5 to 3 cm. long, thinly villose and sparingly gland-
ular-hirsute outside or more densely villose and destitute of stipitate glands except
on the outside of the lobes, sparingly pubescent above the middle or glabrous inside,
the lobes oblong-ovate, acute, 1.8 to 2 cm. long, glandular-hairy along the middle
outside; stamens about twice as long as the tube, slightly exceeding the corolla-
lobes, villose below the middle, the anthers ochraceous, 2.5 to 3 mm. long; style
exceeding the stamens, 5 to 6 cm. long, finely pubescent at the lower third, or
sometimes glabrous; ovary usually not or little longer than the sepals, covered with
upright setose hairs partly glandular. Capsule oblong or ovoid-oblong to narrow-
oblong 1.2 to 1.8 cm. long, finely villose and glandular-setose.
ARKANSAS. Newton County: rocky woods, Jasper, October 28,
1914, E. J. Palmer (No. 6932). Cleburne County: sandy woods,
Heber Springs, October 31, 1914, E. J. Palmer (No. 6973); Pulaski
County: Little Rock, H. E. Hasse. Pike County: Delight,
May 20, 1910, A. H. Howell (No. 659; Nat. Herb. No. 514,206).
Hempstead County : Fulton, sandy woods, May 21 and Oct. 5, 1909,
B. F. Bush (Nos. 5684, 5955); Washington, moist sandy woods, Sept.
4, 1916, E. J. Palmer (No. 10,583); Columbus, along sandy streams,
July 17, 1916, E. J. Palmer (No. 10,505). Ouachita County: Cam-
den, 1850, A. Fendler. Miller County : Doddridge, moist sandy
woods, July 19, 1916, E. J. Palmer (No. 10,515). " National Forest,"
1907 (Nat. Herb. No. 615,731).
OKLAHOMA. Leflore County: near Page, near mountain creek,
April 20 and September 7, 1913, G. W. Stevens (Nos. 1390, 2658), on
low creek branch, June 20, 1914, D. W. Blakeley (G. W. Stevens, No.
1418; Nat. Herb. No. 589,543); rocky woods, valleys in limestone and
lower levels of sandstone hills, July 27, 1917, E. J. Palmer (No. 12,644).
McCurtain County : Idabel, May 29, 1916, H. W. Houghton (G. W.
Stevens, No. 3925).
TEXAS. Harrison County: Marshall, common in swamp, Oct. 5,
1901, B. F. Bush (No. 983). San Augustine County: San Augus-
tine, margin of sandy swamps, September 10, 1917, E. J. Palmer
(No. 12,710). Houston County: Grapeland, 1879, Frank Tweedy1;
1 This is the type specimen collected at " Grapelands," as stated in a letter by
F. Tweedy accompanying the specimen and dated March 15, 1899. On the label,
which is not in Mr. Tweedy's handwriting, however, Tom Green County is given as
the locality, which is apparently a mistake, for there are no Rhododendrons
152 THE AZALEAS OF NORTH AMERICA
sandy bogs, May 28, 1917, September 22 and 28, 1917 (Nos. 12,830,
12,831), March 26 and April 2, 1918, E. J. Palmer (Nos. 13,181,
13,265). Hardin County: Silsbee, sandy pine lands, April 25 and
September 10, 1916, E. J. Palmer (No. 9568; shrub 4-6 cm. high,
flowers pure white, No. 10,689). Without definite locality and date;
C. Wright (in Gray Herb.).
This is the most western species of the eastern group of Rhododendrons and is
distributed from northern Arkansas (Newton and Cleburne Counties) to south-
eastern Oklahoma and through southeastern Arkansas to southeastern Texas
(Houston and Hardin Counties). It is a low shrub growing in moist sandy woods
or on the margins of sandy bogs and along streams.
Rhododendron dblongifolium is most nearly related to R. viscosum and R. serrula-
tum, but differs chiefly in the finely villose, sparingly strigose branchlets, the pubes-
cent winter-buds, in the larger leaves of thinner texture and usually more or less
pubescent, in the larger corolla finely villose and glandular outside and in the usually
longer calyx-lobes; the flowers appear earlier, in May or even at the end of April, while
R. serrulatum flowers in July and August and R. viscosum from the end of May to the
beginning of July. Without flowers the pubescent forms of it have some resemblance
to R. canescens and have been sometimes confused with that species. It shows
considerable variability in some characters, particularly in the pubescence of the
leaves, which may be glabrous or more or less pubescent beneath; the extreme forms
look very distinct but they are closely connected by numerous intermediates and
both forms frequently occur at the same locality and have been distributed by
the collectors even under the same number as Bush's No. 5955 * from Fulton,
Arkansas, and Palmer's No. 12,644 from Page, Oklahoma. The upper surface of
the leaves also varies from being quite glabrous, except the pubescent midrib,
to strigillose and with or without a minute villose pubescence. Sometimes the
under side of the leaves is more or less covered with a glaucous bloom, as in part of
Palmer's No. 12,644 from Oklahoma and in his 12,062 and part of 12,830 from Texas.
The young branchlets may be puberulous all over and sparingly strigose toward
the apex or nearly glabrous; the winter-buds are always densely pubescent. The
calyx-lobes are sometimes very short and semi-orbicular or ovate, as in Palmer's
Nos. 9568, 12,062 and 12,063 from Texas and in his No. 10,583 from Arkansas. The
outside of the corolla is usually covered with a thin villose pubescence interspersed
with numerous stipitate glands but sometimes, as in Palmer's Nos. 9568 and 12,063,
the tube is more densely villose and destitute of glands, which are present only
toward the apex of the corolla on the outside of the lobes; in the same numbers the
style and the inside of the tube are glabrous. These characters together with the
rather dense villose pubescence of the under side of the leaves of No. 12,063 might
induce one to make this number the type of a distinct variety, but considering the
great variability of the species even in the same locality and the apparent absence
of any correlation of the different forms with their geographical distribution, I
think it wiser to defer a subdivision of the species into varieties or forms until a
careful field study has been made and more copious material is available.
known growing as far west as Tom Green County, Houston County marking the
farthest western limit of the genus in the Eastern States.
1 The glabrous form of this number looks very distinct, the leaves are broad and
generally obovate, quite glabrous except sparingly strigillose on the midrib beneath,
even the branchlets are quite glabrous and the specimen, which is in fruit, might be
taken for R. arborescens but for the pubescent winter-buds.
ENUMERATION OF THE SPECIES 153
Some of the specimens enumerated above are rather poor and do not show clearly
he distinguishing characters of the species and might be taken for forms of R. vis-
cosum, but they have been placed here chiefly for geographical reasons, since we have
no knowledge that R. viscosum extends farther west than eastern Tennessee. The
species was apparently first collected by A. Fendler near Camden, Arkansas, in 1850
and about the same tune by C. Wright in Texas. Later it was found by Frank
Tweedy at Grapeland, Houston County, Texas, and upon his specimen Dr. Small
based his Azalea oblongifolia published in 1903. It was introduced into cultivation
through the Arnold Arboretum, where plants were raised from seeds collected in
1917 by E. J. Palmer near Washington, Arkansas.
Rhododendron serrulatum Millais, Rhodod. 241 (1917). — Millais
& Williams in Rhodod. Soc. Notes, I. 125 (1918).
Azalea viscosa Hooker in Comp. Bot. Mag. I. 100 (1835),1 not Linnaeus. —
Mohr, PL Life Ala. 653 (1901), in part. — Small, Fl. S. E. U. S. 883 (1903),
in part; Shrubs Fla. 94 (1913); in N. Am. Fl. XXIX. 42 (1914), in part.
Rhododendron viscosum Chapman, Fl. S. U. S. 265 (1865), not Torrey.
Azalea serrulata Small, FL S. E. U. S. 883 (1903); in N. Am. FL XXIX. 43
(1914).
Shrub to 7 m. tall, with irregularly whorled branches; young branchlets usually
copiously strigose toward the apex and finely villose or nearly glabrous, becoming
soon bright red-brown, changing to dull brown or grayish the following year; floral
winter-buds glabrous or sometimes grayish pubescent with numerous usually
15 to 20 ovate scales mucronate or mucronate-aristate, usually light yellowish brown
with a sharply marked dark brown band along the white-ciliolate margin. Leaves
elliptic to obovate or obovate-oblong, rarely oblanceolate, 4 to 8 cm. long and 1.5
to 3.8 cm. broad, on vigorous shoots often oblanceolate and 8 by 2 cm. large,
usually acute, rarely obtuse, gland-tipped, cuneate at the base, serrulate-ciliate
on the margins, glabrous above except sparingly short-villose on the midrib,
glabrous beneath and strigose on the midrib, or on the upper leaves of shoots
soft-pubescent beneath and strigillose and more or less puberulous above, firm at
maturity; petioles 1 to 4 mm. long, strigose. Flowers appearing after the leaves
and after the winter-buds are at least partly formed from the middle of June to the
beginning of August, in 6- to 10-flowered umbel-like racemes; pedicels slender, 1 to
2 cm. long, glandular-hirsute and sparingly villose; calyx-lobes semiorbicular to
ovate, rarely exceeding 1 mm., eiliate with long glandular hairs; corolla white,
funnel-form, very fragrant, the tube cylindric, slender, 2.5 to 3.3 cm. long and about
2 mm. wide, slightly dilated at apex, rather copiously glandular-pilose and spa-
ringly villose outside, glabrous inside, the lobes ovate-lanceolate, acuminate, 1.2
to 1.5 cm. long; stamens exserted, about 1% times as long as tube, exceeding the
lobes, glabrous in the upper third, villose below; anthers oblong, 2 to 2.5 mm.
long, ochraceous; style considerably exceeding the stamens, 4.5 to 5.8 cm. long,
slightly short-pubescent near the base or nearly glabrous, purple above; ovary
densely covered with gland-tipped setae. Capsule ovoid-oblong, 1 to 1.3 cm. long,
minutely villose and densely glandular-setose.
GEORGIA. Wayne County : Jessup, October, 1916, T. G. Harbison
(No. 240). Charlton County: near Folkston, April 3 (No. 10),
1 Drummond's No. 190 named A. viscosa by Hooker is represented in the Gray
Herbarium by a sheet consisting of two specimens, one with mature leaves, which
is R. serrulalum, and one in flower, which is R. canescens. Hooker quotes this
number as 198, but No. 198 belongs to Vaccinium dumosum (Gaylussada dumosa).
154 THE AZALEAS OF NORTH AMERICA
July 15-17 (Nos. 62, 63, 64, 65, 67, 70, 81, 82, 84, 87) and December 15,
1918 (No. 93), June 16 and 18 (Nos. 97, 99) and November 26 and 27,
1919 (Nos. 100, 102, 103, 110, 111, 112, 114, 115), T. G. Harbison;
without locality, May 17, 1918, T. G. Harbison (Nos. 29, 33, 34, 46,
57). Lowndes County: Ousley, October 21, 1910, T. G. Harbison
(Nos. 242, 246, 251); near Valdosta, June 6-12, 1895, J. K. Small.
Brooks County : Quitman, April 2, 1918, T. G. Harbison (No. 5).
FLORIDA. Lake County: Eustis, June 1-15, 1894, G. V. Nash
(No. 967, type); June 16-31, G. V. Nash (No. 1306); same locality,
December 12, 1919, T. G. Harbison (Nos. 21, in part, 26, 27). Semi-
nole County: near Wekiva Springs, May 9, 1918, C. H. Baker
(No. 499 a-c). Orange County: near Maitland, February 27 (Nos.
478 a-b), June 20 (No. 529 a) and July 12, 1918, C. H. Baker (Nos.
529 b, 478 c, d, f); swamps, July 10, 1902, A. Fredholm (No. 5379;
in Gray Herb.). Polk County: Lakeland, August 1, 1918, T. G.
Harbison. De Soto County : Sebring, July 28, 30, 1918, T. G.
Harbison (Nos. 19, 20, 21, 47). Escambia County: Pensacola,
April 18, 1899, Biltmore Herb. (Nat. Herb. No. 969,619). Calhoun
County : Apalachicola, T. Drummond (in Gray Herb.). Without pre-
cise locality: 1842-49, F. Rugel (No. 237; Nat. Herb. 512,161); with-
out date, Herb. Chapman (Nat. Herb. No. 955,093).
ALABAMA. Mobile County : near Mobile, July, 1887, C. Mohr;
same locality, December 4, 1919, T. G. Harbison (Nos. 1, 2); Spring
Hill, August 6, 1897, B. F. Bush (No. 12); same locality, December 4,
1919, T. G. Harbison (Nos. 1-4).
MISSISSIPPI. Jackson County: Ocean Springs, June 19, 1895,
J. Skehan. Harrison County: Biloxi, July 29, 1896, C. L. Pollard
(No. 1097; Nat. Herb. 271,755); August 21, 1898, S. M. Tracy (No.
4395; Nat. Herb. 770,586) ; October 30, 1917, T.G. Harbison (No. 6),
April 1 (No. 1), May 6 (Nos. 2, 3, 24) and July 19, 1918, T. G. Harbison
(No. 25-33).
LOUISIANA. St. Tammany Parish: Pearl River, July 9, 1909,
R. S. Cocks (No. 2222); New Orleans (Covington), 1832, T. Drummond
(No. 190). !
This Azalea is distinctly a species of the southern coastal plain region and extends
from southern Georgia or, including the variety georgianum, from middle Georgia
to central Florida (De Soto County) and westward along the coast to southeastern
Louisiana. Its type locality is Eustis, Lake County, Florida. It inhabits swamps
or moist sandy soil and is usually a tall shrub 2 to 7 m. high.
Rhododendron serrulatum is closely related to R. viscosum and takes its place south
1 See footnote on page 153.
ENUMERATION OF THE SPECIES 155
of central Georgia. It is chiefly distinguished by the brown-red branchlets usually
conspicuously and densely covered toward the ends with strigose red-brown hairs,
by the aristate or at least distinctly mucronate more numerous scales of the winter-
buds, usually glabrous and with a conspicuous dark band along the margin, by the
long and slender corolla-tube about twice as long as the comparatively small
lobes, and by the stamens considerably exceeding the lobes; the leaves are of firmer
texture and more distinctly serrulate on the margin and are not unfrequently,
particularly those toward the end of vigorous shoots, more or less densely pubescent
on the under side; it is usually a tall shrub, while R. viscoswn, particularly in the
southern part of its range, is usually a low, sometimes even stoloniferous shrub.
Small in his description and keys lays much stress on the oval shape of the leaves,
but though the type specimen which has only short and weak branchlets and no
vigorous shoots happens to have most of its leaves of elliptic shape, this is the more
unusual shape, while the prevailing shape of the leaves varies from obovate to
oblong-obovate or sometimes oblanceolate. Until Small described it as a new
species, R. serrulatum had been always confused with R. viscosum and even he
understood under that name only the uncommon form with oval or elliptic leaves
and referred the forms with obovate leaves to R. viscosum, making it a very local
species, while really it has a rather wide distribution. Like the other related species
it varies in the pubescence of its leaves, which may be glabrous except strigose hairs
on the midrib beneath, as in the type, or more or less, sometimes densely pubescent
on their under side and strigillose and puberulous above; the pubescence may appear
either on all the leaves or chiefly on upper leaves of the more vigorous shoots, while
the leaves appearing earlier in the season are glabrous or nearly glabrous. The
form with the leaves always pubescent is described below as a distinct form. Some-
times the leaves of the glabrous form are glaucescent beneath, as in some specimens
from Folkston, Georgia. Also the winter-buds vary in their pubescence; typically
they are perfectly glabrous, but sometimes they are more or less densely pubescent
and these specimens I have referred to a distinct variety, described below. In
the shape of the corolla, in its pubescence and in its color, which is apparently
always white or nearly white, I find little variation except that the tube varies
somewhat in length.
This species was apparently first collected by T. Drummond about 1830 near
New Orleans in Louisiana and near Appalachicola in Florida; it also was collected
in Florida by T. Rugel in the forties and by Chapman in the fifties or sixties, but
it was not distinguished until Dr. Small in 1903 described his Azalea serrulata,
based on a specimen collected by G. V. Nash near Eustis, Florida, which had most
of the leaves of distinctly oval or elliptic shape. The shape of the leaves, however,
cannot be considered a reliable character, as already stated.
Rhododendron serrulatum was introduced into cultivation through the Arnold
Arboretum, where plants were raised in 1919 from seeds collected by T. G. Harbison
in December, 1918, near Folkston, Georgia. It will probably not be hardy north
and as an ornamental shrub it will not be superior to R. viscosum, but for southern
gardens it may be valuable on account of its late appearing fragrant flowers.
Rhododendron serrulatum f . molliculum Rehder, forma nova.
A typo recedit ramulis annotinis apicem versus densius villosulis v. glabrius culis
minus strigosis, foliis subtus molliter subaccumbenti-villosis supra sparsius villosulis
et saepe praecipue in foliis superioribus strigillosis, pedicellis magis villosulis.
FLORIDA. Lake County: Eustis, June 23, 1919, T. G. Harbison
(No. 17, type, 19, 20, 21, partly); December 12, 1919 (No. 25); June
16-30, 1894, G. V. Nash (No. 1104; Nat. Herb. 223,237).
156 THE AZALEAS OF NORTH AMERICA
GEORGIA. Charlton County : Folkston, June 16 and July 16,
1918, T. G. Harbison (No. 69, 98); without precise locality, May 18,
1918, T. G. Harbison (No. 58).
This form differs from the type in all the leaves being densely soft-pubescent
beneath and slightly puberulous and often strigillose above; also the branchlets are
usually more or less puberulous and the pedicels are more densely villose, while
the winter-buds are glabrous as in the type. Pubescent leaves are also found
occasionally in the typical form, but they are restricted to the upper part of the
more vigorous branchlets, while the leaves of the short branchlets which are usually
terminated by floral winter-buds and the lower leaves on the shoots are glabrous or
nearly so. Such pubescent leaves are present, e. g. in Chapman's specimen, in
Harbison's No. 6 from Lakeland, Florida, in his Nos. 21 (partly) and 27 from Eustis,
in Nash's No. 1306 from the same locality, in Baker's No. 529 a from Maitland and
in his No. 499 a from Wekiva Springs, in Harbison's No, 20 from Sebring, Florida,
in his No. 84 and 100 from Folkston, Small's specimen from Valdosta, Harbison's
No. 2 from Mobile, Alabama, and his Nos. 24, 27, 28 from Biloxi, Mississippi, and
Cock's No. 2222 from Pearl River, Louisiana.
Rhododendron serrulatum var. georgianum Render, var. nov.
A typo recedit gemmis dense sericeo-pubescentibus perulis paucioribus et
tantum mucronatis vix aristatis.
GEORGIA. Charlton County: Folkston, July 16, 1918, T. G.
Harbison (No. 68, type; shrub 10 ft. tall; No. 77), July 15 (No. 66),
July 17, 1918 (No. 86, shrub 18 ft. tall) and Nov. 27, 1919, T. G.
Harbison (No. 118, low shrub) ; without precise locality May 17 and 18,
1918, T. G. Harbison (Nos. 34 and 57; tall late-blooming species).
Richmond County : Augusta, sand hills, swamp, July, 1904,
A. Cuthbert. Bryan County: boggy places in sand hills of Canoochee
River near Groveland, June 22, 1903, R. M. Harper (No. 1850).
Screven County : near Oliver, July 9, 1901, A. H. Curtiss (No. 6837;
8 to 12 feet high). Appling County: swamps near Baxley, August
10, 1901, Biltmore Herb. No. 4823 (Nat. Herb. 980,173). Lowndes
County: Ousley, October 21, 1910, T. G. Harbison (Nos. 244, 248).
Randolph County: Cuthbert, December 1, 1919, T. G. Harbison
(Nos. 31, 32; low shrub). DecaturCounty: moist pine barrens
near Climax, August 13, 1903, R. M. Harper (No. 1929).
SOUTH CAROLINA. Beaufort County: Bluffton, 1893, J. H.
Mellichamp.
This variety differs from the type only in the densely grayish pubescent winter-
buds with usually less numerous and only mucronate, not aristate scales from the
type. It approaches thus in its winter-buds R. viscosum and may be considered an
intermediate form not only on account of its characters but also in regard to its
distribution, occupying as it does an area between R. viscosum and typical R. ser-
rulatum. I have not yet seen any specimens of this variety from Florida or from
localities west of Georgia, while typical R. serrulatum does not seem to extend farther
ENUMERATION OP THE SPECIES 157
north than Wayne County; from Lowndes and Charlion Counties I have seen both,
the type and this variety. The fact that this form occupies a fairly well-defined
range chiefly induced me to consider it a distinct variety though differing only in
the minor character of the pubescent winter-buds. Except in the amount of pu-
bescence of the winter-buds it shows little or no variation. Harper's No. 1929 from
Climax is the only specimen of this variety which shows part of the leaves pubescent;
it differs also in its small nearly ovoid capsules less than 1 cm. long. Whether
Mallichamp's specimen from South Carolina really belongs here or is perhaps a
form of R. viscosum I am not quite sure.
Rhododendron viscosum Torrey, Fl. U. S. 424 (1824) ; FL N. Y. I.
439, t. 66 (1843). — G. Don, Gen. Syst. III. 847 (1834). — Loudon,
Arb. Brit. IV. 1143, fig. 947 (1838). — Gray, Syn. Fl. II. 1, 40
(1878).— J. Robinson, FL Essex Co. Mass. 73 (1880). — Owen, PL
Nantucket, 39 (1888). — Dame & Collins, FL Middlesex Co. Mass. 62
(1888). — Bennett, PL Rhode Isl. 26 (1888). — 'Dippel, Handb. Laub-
holzk. I. 416, fig. 269 (1889). — Britton, Cat. PL N. Jersey, 162
(1889). — Coulter & Watson, Gray's Man. ed. 6, 320 (1890). — Deane,
FLMetrop. Park, Mass. 53 (1896) ; in Rhodora, I. 94 (1899).— Robinson
& Fernald, Gray's New Man. ed. 7, 631 (1908). — J. Jackson, Cat. PL
Worcester Co. Mass. 75 (1909). — Graves & others, Cat. FL PL Conn.
308 (1910). — Schneider, III. Handb. Laubhohk. II. 502, fig. 329 n-p,
330 c-d (1911). — Stone, List PL Franklin, Hampshire and Hampden
Cos. Mass. 48 (1913). —Twining, FL N. E. Pennsylv. 56 (1917).—
Millais, Rhodod. 259 (1917).
Azalea viscosa Linnaeus, Spec. I. 151 (1753). — Wangenheim, Beytr. Forst-
wiss. 66, t. 25, fig. 52 (1787). — Willdenow, Spec. I. pt. 2, 831 (1798).—
Michaux, FL Bar. -Am. 150 (1803). — Pursh, FL Am. Sept. 153 (1814).—
Eaton, Man. BoL 25 (1817). — Bigelow, FL Bost<m, 52 (1814). — Barton,
Fl. Phila. 113 (1818). — Elliott, Sketch Bot. S. C. I. 241 (1821). — M. A.
Curtis, Enum. PL Wilmington, 100 (1834).— Groom, Cat. PL New Bern, 21
(1837).— De Candolle, Prodr. VII. 715 (1839). — Gray, Man. 268 (1848) ; ed.
5, 299 (1872). — Tracy, Stud. Essex FL 50 (1858). — M. A. Curtis, DescripL
Trees & Shrubs, 98 (in GeoL Nat. Hist. Surv. N. Car. III. Bot.) (I860). —
Willis, Cat. PL N. Jersey, 33 (1874). — Wood & McCarthy, Wilmington
FL 34 (1886). — Britton & Brown, III. FL II. 559, fig. 2747 (1897).—
Jelliffe, FL Long Island, 124 (1899). — Britton, Man. 698 (1901). — Gat-
tinger, FL Tenn. 131 (1901). — Porter, FL Pennsylv. 238 (1903). — Small,
FL S. E. U. S. 883 (1903), in part; in N. Am. FL XXIX. 42 (1914), in part. —
Shreve & others, PL Life Maryland, 466 (1910). — W. Stone in Ann. Rep.
N. J. State Mus. 1910, 613, t. 58, fig. 2 (1911). — Millspaugh, Liv. FL
W. Virginia, 323 (in W. Va. GeoL Surv.) (1913). — Taylor, FL Vicin. N. Y.
489 (Mem. N. Y. Bot. Gard. V.) (1915).
Azalea viscosa palustris Marshall, Arbust. Am. 16 (1785).
Rhododendron venustum Salisbury, Prodr. 287 (1796), in part.
Azalea virens Dumont de Courset, Bot. Cult. ed. 2, III. 335 (1811), as var. of
A. viscosa.
Azalea nitida Lindley in BoL Reg. V. t. 435 (1819), not Pursh.
158 THE AZALEAS OF NOKTH AMERICA
Anthodendron viscosum Reichenbach in Moessler, Handb. Gewdchsk. ed. 2, I.
309 (1827).1
Shrub to 3 or nearly 5 m. tall, sometimes low, rarely stoloniferous, with irregu-
larly whorled branches; young branchlets, particularly toward the apex, with
hirsute or strigose loosely appressed, rarely spreading hairs, otherwise glabrous,
yellowish, or grayish brown, rarely red-brown at the end of the first season, the older
branches light grayish brown; winter-buds glabrous sometimes pubescent, usually
brown, with 8 to 12 broadly ovate rounded at apex and usually mucronate or
sometimes without mucro, the basal scales sometimes long-pointed, ciliolate on the
margin. Leaves ovate or elliptic-obovate to oblong-oblanceolate, acute or rounded
and gland-tipped at apex, cuneate at base, 2 to 6 cm. long and 0.7 to 2 cm. broad,
ciliate, glabrous on both sides except the midrib slightly villose above and more
or less strigose beneath, sometimes strigillose above, particularly on leaves at the
end of the shoots, usually dark green above, lighter green or glaucescent beneath,
at maturity firm but rather thin; petioles 1 to 3 mm. long, strigillose. Flowers
appearing after the leaves in June or July or farther south in May, in clusters of
4 to 9; pedicels 0.5 to 1, rarely to 1.5 cm. long, pubescent and glandular-hirsute;
calyx-lobes semi-orbicular to ovate, about 1 mm. long, setosely glandular-ciliate;
corolla white or more or less suffused with pink, rarely deep pink, cylindric, the
tube somewhat dilated near apex, 1.5 to 2.5 cm. long, about one and one half times
as long as the lobes or sometimes little longer than lobes, rarely almost twice
as long, finely villose and glandular-hirsute outside, slightly pubescent inside above
the middle, the lobes ovate-oblong, acuminate, about 1.5 cm. long, glandular-
hirsute along the middle outside and finely villose; stamens exserted, somewhat
longer than the lobes; the filaments villose except the upper third; style 4 to 5 cm.
long, exceeding the stamens, finely pubescent below the middle or on the lower
third, pale or sometimes purplish toward the stigma; ovary glandular-setose or
sometimes setose and glandless. Capsule oblong-ovoid, 1.3 to 2 cm. long, glandu-
lar-setose and finely pubescent or sometimes glandless.
The species is distributed from southwestern Maine through the coastal plain
to southeastern South Carolina, extending inland to central Massachusetts, north-
western Connecticut and up the valley of the Hudson River to the neighborhood
of Albany,2 northern New Jersey, central and southwestern Pennsylvania, eastern
1 PRELINNEAN SYNONYMS: Cistus Virginiana flore et odore Peridymeni Banister
apud Plukenet, Phytog. t. 161, fig. 4 (1691); Almag. 106 (1696). — Azalea ramis
infra foliosis Gronovius, Fl. Virg. 21 (1739). — Colden in Act. Soc. Sci. Upsala, IV.
92 (PL Coldengh.) (1749).
ADDITIONAL ILLUSTRATIONS. COLORED PLATES: Kerner, Darst. Vorz. Ausl.
Baum. t. 57 (1796). — Meerburgh, PL Select. Icon. t. 9 (1798). — Schmidt, Oesterr.
Baumz. III. t. 171 (1800). — Savi, FL Ital. II. t. 66 (1822).— Audubon, Birds Am.
II. 115 (1831-34) ; Quarto ed. 1. 1. 64 (1840) . — Emerson, Trees & Shrubs Mass. ed. 2,
II. t. opp. p. 438 (1875). — Meehan's Monthl. X. 81, t. 6 (1900). — BLACK FIGURES:
Loudon, Arb. Brit. II. figs. 947, 949 (1838), 947 after Loddiges t. 44, and 949
after Bot. Reg. t. 414. — Newhall, Shrubs N. E. Am. fig. 82 (1893). — Miller &
Whiting, Wild Flow. N.E.St.381 (1895) . — Keeler, Our North. Shrubs, 355 (1903) . —
Stevens, III. Guide Flow. PL t. 114, fig. 5 (1910). — Schneider, III. Handb.
Laubholzk. II. figs. 329 n-p, 330 c-d (1911). — Country Life Am. XI. 496 (1907).—
House, Wild. FL N. Y. II. fig. 22 (1920), as A. canescens.
2 In the state of New York R. viscosum has been reported as far west as Oneida
County by Payne, Cat. PL Oneida Co. 50 (in Rep. Regents Univ. N. F.) (1865),
but I have seen so specimens from that locality and Professor K. M. Wiegand
writes me that he does not know it west of the Albany region and the Catskills.
ENUMERATION OF THE SPECIES 159
West Virginia, western North Carolina and southeastern Tennessee and south-
western South Carolina (Oconee County). It also has been reported from north-
eastern Ohio.1 It forms a densely-branched shrub from 1 to 5 meters tall and grows
almost exclusively in swamps together with other swamp-loving shrubs and trees;
it is rather common in the swamps of the coastal plain from southwestern Maine
to South Carolina, but it also is found in swamps on the higher mountains.
Rhododendron viscosum is a very variable species, but it is never pubescent except
in one rare variety and in this respect differs from the otherwise very closely related
R. serrulatum from which it is often difficult to distinguish. With the latter
species and with R. arborescens, R. oblongifolium and R. atlanticum, it forms
a group of very closely connected species which have been frequently confused and
are sometimes not easily distinguished from each other. The most distinct and
least variable is R. arborescens, which differs from all these related species in the
glabrous branchlets, glabrous leaves and usually glabrous style; R. atlanticum
differs in its early flowers appearing before or with the leaves, in the absence of
the villose pubescence of the corolla and in its low stature and stoloniferous habit;
R, oblongifolium differs chiefly in its usually more or less pubescent, larger and
narrower, acute or sometimes almost acuminate leaves, in the usually larger calyx-
lobes, the larger more villose and less glandular corolla and in the always pubescent
winter-buds. The most closely related species is R. serrulatum which might be
considered only a southern variety of R. viscosum and in fact was not separated
at all from the latter species until recently; it may be chiefly distinguished by the
more chartaceous, setosely serrulate, somewhat reticulate, often pubescent leaves
never glaucous beneath, the more numerous always distinctly mucronate, often
aristate scales of its floral winter-buds, the longer and slenderer corolla-tube
about twice as long as the lobes and the bright red-brown branchlets usually
densely strigose toward the apex. Rhododendron viscosum varies in the pubescence
of its winter-buds, in the amount and character of the strigose or hirsute pubes-
cence on the branchlets and leaves, in the color and shape of the leaves which may
be bright green or more or less glaucous and vary from obovate to oblong-lance-
olate, in the size and color of the flowers which may be almost pure white or more
or less pink, rarely deep pink. Sometimes it has the low stoloniferous habit of
R. atlanticum; e. g. I. Tidestrom's No. 7080, from between Berwyn and Lanham,
Maryland, June 8, 1914, L. F. Ward's specimen from Terra Cotta Swamp,
Washington, D. C., June 13, 1880 (Nat. Herb. No. 14,480), E. S. Steele's specimen
from Hyattsville, Maryland, May 31, 1915 (Nat. Herb. No. 835,633) and Witmer
Stone's No. 571, from Tyndalls Mill, south of Manning, South Carolina, May 5,
1917; also P. C. Standley's No. 11,547 from Hyattsville Swamp, May 27, 1915,
1 Newberry, Cat. PL Ohio, 24 (1860). — Kellerman, Cat. Ohio PL 129 (in Rep.
Geol. Surv. Ohio, VII. pt. 2) (1893). — Schaffner, Cat. Ohio Vase. PL 204 (in Ohio
BioL Surv. I.) (1914). — Rhododendron viscosum was first reported from Ohio by
Newberry in 1860 without definite locality except "East." Kellerman in 1893
quotes it from Beardslee's Catalogue of 1874, where it is recorded from near Paines-
ville. Schaffner in 1914 gives Ashtabula County as the only locality for the species.
Among the Azaleas from the herbarium of the Ohio State University received
through the kindness of Professor J. H. Schaffner I found only one specimen
labeled A zaleaviscosa L., Pymatuming Swamp, Ashtabula County, August 11, 1900,
C. A. Davis, A. Dachnowski, F. Detmers. This specimen has neither flowers nor
fruits and is apparently some form of R. roseum; it is certainly not R. viscosum.
Beardslee's record is probably based on a similar form; Professor Schaffner writes
me that there are a few of Beardslee's specimens in the herbarium of the Ohio
State University, but none labeled Azalea viscosa, and that Newberry 's Catalogue
was not based on specimens that could be verified.
160 THE AZALEAS OP NORTH AMERICA
which belongs to var. glaucum and a specimen from Fayetteville, North Carolina,
Biltmore Herb. (Nat. Herb. No. 969,586) which belongs to var. nitidum. Several
forms and varieties have been distinguished but on account of their mostly in-
sufficient description and in the absence of type specimens it is not always pos-
sible to recognize them with certainty and the numerous intermediate forms make
their distinction still more difficult.
Rhododendron viscosum was apparently first observed by John Banister, an
English missionary who sent a drawing of it to Dr. Compton, Bishop of London.
Dr. Compton communicated it to Plukenet, who published it in 1691 in his Phyto-
graphia. The plant was introduced into England apparently in the first half of the
18th century by John Bartram, who sent seeds or plants to Peter Collinson,1 but
the exact date is not known. According to Aiton it was introduced in 1734, but
Catesby in 1731 speaks of this shrub in the text to the figure of his Cistus vir-
giniana, which is R. canescens, as "having for some years past produced its beau-
tiful and fragrant blossoms at Mr. Bacon's at Horton and at Mr. Collinson's at
Peckham." I suppose Catesby confused several species, as appears from the fact
that he applied Plukenet's name belonging to R. viscosum to his figure which repre-
sents R. canescens. His reference to fragrant blossoms seems to indicate that the
shrub in cultivation was R. viscosum. In any case this species must have been
well known about 1789 when Aiton enumerated five different varieties in cultiva-
tion. Wangenheim in 1787 published the first detailed description and char-
acteristic figure; he mentions three varieties observed by him in the state of New
York.
From the type (R. viscosum a. odoratum Sweet, Hort. Brit. ed. 2, 344 [1830]. —
Azalea viscosa a. odorata Aiton, Hort. Kew. I. 203 [1789]. — Azalea viscosa a. virens
Michaux, Fl. Bor.-Am. 1. 151 [1803]), which has green leaves and the flowers white
or sometimes striped pink outside along the middle of the lobes (Azalea viscosa /3.
vittata Aiton, Hort. Kew. 203 [1789]. — Rhododendron viscosum /3. vittatum Sweet,
Hort. Brit. ed. 2, 344 [1830]), the following varieties and forms may be distinguished:
Rhododendron viscosum f. rhodanthum Rehder, forma nova.
A typo recedit floribus intense roseis.
MARYLAND. Prince Georges County: opposite Hyattsville,
eastward, May 31, 1915, E. S. Steele (Nat. Herb. No. 835,633).
DISTRICT OP COLUMBIA. North of Washington, June 15, 1909,
Professor Cook (Nat. Herb. No. 615,776).
This is a form of the typical variety with bright pink flowers very glandular
outside. In the type specimen, which is from a low stoloniferous shrub, the very
young winter-buds are glabrous outside; in Professor Cook's specimen they are
silky-pubescent. This bright pink form occurs occasionally with the type, but
seems to be less common than the pink form of var. glaucum.
Rhododendron viscosum var. glaucum Torrey, Fl. U. S. I. 425
(1824). — Gray, Syn. FL II. 1, 41 (1878).— J. Robinson, Fl. Essex
Co. Mass. 73 (1880). — Dame & Collins, FL Middlesex Co. Mass. 62
(1888). — Britton, Cat. PL N. Jersey, 162 (1889). — Coulter & Wat-
son, Gray's Man. ed. 6, 320 (1890). — Dudley & Thurston, Cat. PL
1 See R. nudiflorum on page 136.
ENUMERATION OF THE SPECIES 161
Lackawanna & Wyoming Valleys, 38 (1892). — Voss, Vilmorin's
Blumengart. I. 588 (1894), as forma. — Deane, Fl. Metrop. Park,
Mass. 53 (1896); in Rhodora, I. 94 (1899). — Robinson & Fernald,
Gray's New Man. ed. 7, 631 (1908). — J. Jackson, Cat. PL Worcester
Co. Mass. 75 (1909). — Graves & others, Cat. Flow. PL Conn. 308
(1910). — Stone, List PL Franklin, Hampshire, Hampden Cos. Mass.
48 (1913).
Azalea viscosa var. 5. floribunda Alton, Hort. Kew. I. 203 (1789). — Willde-
now, Spec. I. 832 (1798).
Azalea viscosa var. c. glauca Alton, Hort. Kew. I. 203 (1789). — Willdenow,
Spec. I. 832 (1798). — Michaux, Fl. Bor.-Am. I. 151 (1803). — Gray, Man.
268 (1848). — M. A. Curtis, Descript. Trees & Shrubs (in Geol Nat. Hist.
Surv.N.Car. III. Bot.98 (I860).— Britton& Brown, 7tt.Fi.II.660 (1897).—
Jelliffe, Fl. Long Island, 124 (1899). — Britton, Man. 699 (1901).—
Porter, Fl. Pennsylv. 239 (1903). — Keller & Brown, Handb. FL Phila. 246
(1905). — Shreve & others, PL Life Maryland, 466 (1910). — Stone in
Ann. Rep. N. Jersey State Mus. 1910, 614 (1911). — Millspaugh, Liv. FL
W. Virginia, 322 (in W. Va. Geol. Surv.) (1913).
Azalea glauca Lamarck, Tab. Encycl. Meth. I. 493, t. 110, fig. 2 (1791). —
Pursh, FL Am. Sept. I. 154 (1814). — De Candolle, Prodr. VII. 716 (1839).
Azalea scabra Hort. ex Michaux, FL Bor.-Am. I. 151 (1803), as synonym.
Azalea floribunda Dumont de Courset, Bot. Cult. ed. 2, III. 334 (1811), as
var. of A. viscosa.
Rhododendron glaucum Sweet, Hort. Brit. ed. 2, 344 (1830). — G. Don, Gen.
SysL III. 848 (1834) .1
This variety differs from the type in its glaucous leaves, which may be glaucous
only below and green or more or less glaucescent above. Sometimes, particularly
at the end of the shoots, the leaves are strigose above; the latter form was distin-
guished by Aiton as var. glauca from his var. floribunda with the leaves glaucous
beneath and smooth above, but these two forms can hardly be kept distinct and
in uniting them I follow Torrey (FL U. S. I. 425 [1824]) in giving preference to
the name glauca which has been used for this form by all subsequent authors,
though var. floribunda precedes it on the page. The flowers are either white or
more or less suffused with carmine outside, often very intensely so before opening;
the form with the more intensely pink or carmine flowers may be distinguished as
f. rubescens, comb. nov. (? Azalea viscosa pubescens 2 Loddiges, Bot. Cab. V. t. 441
[1820]). — A. viscosa TJ. rubescens Sweet, Hort. Brit. 266 (1826), name. — Loddiges,
I. c. XVI. t. 1518 (1829). — Rhododendron viscosum rj. rubescens Sweet, Hort. Brit.
ed. 2, 344 (1830). — G. Don, Gen. Syst. III. 847 (1834). — ?#. viscosum 6. pubescens
Sweet, Hort. Brit. ed. 2, 344 (1830). — Azalea glauca vox. purpurascens Jager,
Ziergeh. 118 (1865). — Azalea glauca var. rosea Jager, 1. c. (1865). — Rhododen-
dron viscosum f. roseum Hollick in Bull. Torr. Bot. Club, XVIII. 256 (1891).
The var. glaucum both with white and red flowers is found frequently growing
together with the typical form throughout its range, at least in the coastal plain
1 ADDITIONAL ILLUSTRATIONS. COLORED PLATES: Meerburgh, PL Select. Icon.
t. 6 (1798). — Schmidt, Oester. Baumz. III. 1. 172 (1800). —Watson, Dendr. Brit. I.
t. 5 (1825).
2 This is probably a mistake for rubescens; there is apparently nothing pubescent
about this plant and the red color is the chief character by which it is distinguished.
162 THE AZALEAS OF NORTH AMERICA
region, but I have seen no specimens of it from Maine, New Hampshire, nor from
North and South Carolina. A specimen from Lee County, Alabama, seems
doubtful.
Rhododendron viscosum var. nitidum A. Gray, Syn. Fl. II. 1, 41
(1878). — Ward, Guide FL Wash. 95 (1881). — Owen, PL Nantucket,
39 (1888). — Britton, Cat. PL N. Jersey, 162 (1889). — Coulter &
Watson, Gray's Man. ed. 6, 320 (1890). — Voss, Vilmorin's Blu-
mengart. I. 588 (1894), as forma. — Deane in Rhodora, I. 94 (1899);
III. 197 (1901). — Fernald & Robinson, Gray's New Man. 631 (1908).
— Graves & others, Cat. FL PL Conn. 308 (1910).
? Azalea lucida Meerburgh, PL Select. Icon. t. 7 (1798).
? Azalea spathulata Dumont de Courset, Bot. Cult. III. 335 (1811), as "sous-
var." of A. viscosa.
Azalea nitida Pursh, FL Am. Sept. I. 153 (1814). — De Candolle, Prodr. VII.
716 (1839).
Rhododendron nitidum Torrey, FL U. S. I. 425 (1824). — G. Don, Gen. Syst.
III. 847 (1834).
Azalea viscosa var. nitida Gray, Man. ed. 2, 257 (1856). — Wood, Classb. Bot.
489 (1870); Am. Bot. FL 203 (1870). — Nicholson, III. Diet. Gard. I. 150
(1887). — Britton in Mem. Torr. Bot. Club, V. 248 (1894) ; Man. 699 (1901). —
Britton & Brown, III. FL 560 (1897). — Jelliffe, FL Long Island, 124
(1899). — Porter, FL Pennsylv. 239 (1903). — Keller & Brown, Handb. Fl.
Phila. 246 (1905). — Millspaugh, Uv. FL W. Virginia, 323 (in W. Va. Geol.
Surv.) (1913).
This form differs from the type chiefly in its dwarfer habit and in its smaller
leaves obovate-oblong or narrowly elliptic to oblanceolate, acute at the ends or
abruptly acuminate, green on both sides, sometimes strigose above. The flowers
are usually more or less pinkish.
This form occurs with the type from Massachusetts to eastern North Carolina
and is apparently a coastal plain form; the most southern specimens I have seen
are from Newbern, Craven County, North Carolina (T. G. Harbison, Nos. 45, 46,
47, 49, 53, 55, 56, June 6, 1918); a specimen collected near the same locality (May
26, 1919; No. 129) by the same collector is typical R. viscosum.
Rhododendron viscosum var. tomentosum Rehder, comb. nov.
Azalea tomentosa Dumont de Courset, Bot. Cult. ed. 2, III. 336 (1811), as var.
of A. viscosa. — Bosse, Vollst. Handb. Blumengart. I. 341 (1840).
? Azalea tomentosa Dur. ex Steudel, Nomencl. 1. 96 (1821), as var. of A. pro-
cumbens.1
Azalea viscosa tomentosa Hort. Angl. ex Bosse, I. c. (1840), as synonym.
MARYLAND. Prince Georges County: Hyattsville, June 27,
F. H. Knowlton (Nat. Herb. 335,818); June 4, 1905, H. D. House
(No. 925 a, Nat. Herb. No. 492,824, in part).
1 The author citation "Dur." is possibly a mistake for "Dum." Duroi describes
only Azalea viscosa in his Harbkesche Baumzucht. Why Steudel refers A. tomen-
tosa to A. procumbens is not clear to me.
ENUMERATION OF THE SPECIES 163
DISTRICT OF COLUMBIA. Bancroft, Four Mile Run, June 6, 1915,
E. S. Steele (Nat. Herb. No. 835,632).
NORTH CAROLINA. Cumberland County: Manchester, June 25,
1902, Biltmore Herb. No. 6610 (Nat. Herb. No. 969,584; shrub
6-8 ft.).
Cultivated. A specimen in the Gray Herbarium without locality
labeled " 28. A. tomentosa Loddiges."
This variety differs from the type chiefly in its leaves being finely but rather
densely pubescent beneath and more or less so above. No reference to such a form
appears in any American flora, but the plant must have been introduced to Europe
more than a hundred years ago and was first described by Dumont de Courset,
who was in doubt whether it was a distinct species or a variety of A . viscosa and
describes it as having wooly branches, lanceolate-oval leaves soft-pubescent on
both sides and late appearing white, fragrant flowers. Of the plant cultivated in
England as A. tomentosa there is a sterile specimen in the Gray Herbarium which
was probably incorporated in the herbarium between 1840 and 1850, as "Torr.
and Gray, Flora N. Am." appears on the label. This specimen agrees exactly with
the spontaneous specimens cited above and especially with the specimen from
Hyattsville. The leaves are generally oblong-obovate, 2.5 to 5.5 cm. long, acute
or acutish, sparingly strigillose above, sparingly strigose on the midrib beneath;
the petioles and young branchlets are puberulous and sparingly strigose. The
leaves in the specimen from Manchester are slightly shorter and broader and more
densely pubescent above and not strigillose; the corolla-tube in this specimen is
slender, about 2.8 cm. long, rather densely villose and sparingly glandular-pilose.
The specimen from the District of Columbia has less densely pubescent leaves and
a more glandular and less villose corolla as has the specimen from Hyattsville.
This is a rather remarkable variety, as I have not observed in any of the numer-
ous specimens of R. viscosum that I have seen any tendency to have the leaves
pubescent, although the midrib may be sometimes slightly pubescent below.
Rhododendron viscosum var. hispidum Voss, Vilmorin's Blumen-
gdrt. I. 588 (1894), as forma. — Schneider, III. Handb. Laubholzk. II.
502 (1911), as var. — Rehder in Bailey, Stand. Cycl Hort. V. 2942
(1916).
? Azalea scabra Dumont de Courset, Bot. Cult. ed. 2, III. 335 (1811), as var.
of A. viscosa.
Azalea hispida Pursh, Fl. Am. Sept. I. 154 (1814). — Watson, Dendr. Brit. t. 6
(1825). — De Candolle, Prodr. VII. 2, 716 (1839).
Rhododendron hispidum Torrey, FL U. S. I. 425 (1824). — Loudon, Arb. Brit.
II. 1144, fig. 948 (1838). — G. Don, Gen. Syst. III. 847 (1834).
Azalea glauca /3. hispida Heynhold, Nomencl. Bot. Hort. I. 108 (1840).
Azalea viscosa var. hispida Wood, Classb. Bot. 490 (1870) ; Am. Bot. Flor. 203
(1870). — Britton in Mem. Torr. Bot. Club, V. 248 (1894); Man. 699
(1901). — Britton & Brown, III. Fl. II. 559 (1897). — Porter, FL Pennsylv.
239 (1903).
This form differs from the type chiefly in its hispid young branchlets, the glau-
cous rather narrow leaves usually strigose above and in the hispid pedicels. The
flowers are usually more or less carmine and have according to Pursh frequently
ten stamens. The habitat of this form which is described as a shrub 3 to 5 m. tall
164 THE AZALEAS OF NORTH AMERICA
is given by Pursh as occurring "on the borders of lakes on the highest parts of the
Blue Mountains: New York and Pennsylvania"; by Britton it has been reported
from Shawangunk Mountain, Ulster County, New York, and Montauk Point, Long
Island, and by Porter from Monroe County, Pennsylvania, but I have not yet seen
a specimen which agrees with Pursh's description. The specimen from Montauk
Point I consider a rather copiously strigose specimen of typical R. viscosum.
Rhododendron viscosum var. montanum Render, var. nov.
A typo recedit gemmis floriferis perulis paucioribus sericeo-pubescentibus praedi-
tis, ramulis minute-villosulis et praesertim apicem versus pilis longis patentibus
pallidis instructis ut petioli, foliis subtus ad costam sericeo-strigillosis v. subpaten-
tim hirsutis et satis dense v. interdum sparsissime minute villosulis vel interdum
fere glabris, pedicellis dense glanduloso-pilosis.
NORTH CAROLINA. Macon County: Highlands, alt. 3825 and
3900 ft., July 9 and September 30, 1918 (No. 58, type, No. 60); alt.
3900 ft., June 20 and September 30, 1918 (Nos. 40, 41), July 9, 1918
(No. 63), June 13, 1918 (No. 38), June 20, 1918 (Nos. 31, 36), Sep-
tember 2, 1910 (No. 117), June 10, 1911 (No. 650), July 2, 1911 (No.
656), T. G. Harbison-, Mt. Satuloh, June 21, 1898, A. P. Anderson
(No. 1507; Nat. Herb. No. 344,433). Buncombe County: Bilt-
more, June 12, 1897 (Biltmore Herb. No. 1399 a), vicinity of Black
Mountain, Sept. 8, 1913, P. C. Standley & H. C. Bollman (No. 10,453;
Nat. Herb. No. 689,191). Wake County: Raleigh, June 11, 1918,
T. G. Harbison.
This variety differs from the type chiefly in its pubescent winter-buds with
comparatively few scales, in the spreading hairs and the minute pubescence of the
branchlets and pedicels and of the midrib of the under side of the leaves. It is a
low densely branched shrub, usually not exceeding 1.25 m. in height. The silky-
pubescent winter-buds have only 5 to 7 larger broad rounded scales with 3 to 4
small acuminate scales at the base. The young branchlets are minutely puberu-
lous and toward the apex more or less densely furnished with long spreading pale
hairs not brown and loosely accumbent as on the otherwise glabrous branchlets
of the typical plant. The leaves are obovate to oblong-obovate, 2.5 to 4 cm. long,
glabrous and bright green somewhat lustrous above, the terminal leaves very rarely
strigose, lighter or paler green beneath, the midrib with long pale subaccumbent
or sometimes more or less spreading hairs and besides usually minutely villose
particularly toward the base; the very short petioles have a pubescence similar to
that of the branchlets. The flowers appear from the middle of June to the begin-
ning of July; their pedicels are finely villose and rather densely glandular-pilose;
the corolla is finely villose and furnished with numerous red long-stipitate glands
and seems to be usually more or less suffused with pink; the calyx-lobes are very
short; the style is purplish above, with purple stigma. The capsule is oblong-
ovoid, 0.8 to 1.5 cm. long, finely villose and glandular-setose. The variety seems
to be similar to and may be identical with Azalea hispida of Pursh, which is also a
mountain form of R. viscosum; but Pursh describes his plant as 10 to 15 feet tall,
the leaves as hispid above and the calyx-teeth as oblong, while this variety is a
low shrub, with the leaves smooth above or only very exceptionally strigillose
above, and the calyx- teeth very short.
ENUMERATION OF THE SPECIES 165
This variety is apparently restricted to the mountains of North Carolina and
grows in swamps or sometimes in woods or on mountain slopes. It was introduced
into cultivation through the Arnold Arboretum, where plants were raised from
seed collected in January, 1919, by Mr. T. S. Harbison near Highlands. With it
grows a form with glaucescent leaves and often more intensely pink flowers which
may be distinguished as:
Rhododendron viscosum var. montanum f. coerulescens Rehder,
f. nov.
A typo recedit foliis subtus glaucis et supra glaucescentibus vel opace coeruleo-
viridibus et floribus saepius plus minusve roseis.
NORTH CAROLINA. Macon County: Highlands, alt. 3825 and
3900 ft., July 9 and September 30, 1918 (No. 66, type, Nos. 57 and 65),
June 17, 1918 (No. B 39), June 19, 1918 (No. 35), September 2, 1920
(No. 116), July 14, 1920 (No. 5845), T. G.Harbison. Avery County,
Linville (Plant collected by H. H. Richardson and cultivated in his
garden; specimen June 28, 1918). Transylvania County: Little
Pisgah Mountain, alt. 5100ft., June 24, 1909, H. D. House (No. 4311;
Nat. Herb. No. 513,348). Buncombe County: Asheville, May,
1888, G. McCarthy (Nat. Herb. No. 42,623).
This form appears quite distinct with its bluish green leaves glaucous beneath
and the more or less pink flowers which are in the plant brought by Mr. Richard-
son from Linville in 1913 carmine in bud and suffused with rosy pink all over when
open. As an ornamental shrub it is certainly one of the handsomest forms of
Rhododendron viscosum.
Rhododendron viscosum var. aemulans Rehder, var. nov.
A typo praecipue recedit foliis majoribus latioribusque ad 6 cm. longis et ad
3.5 cm. latis, subtus glaucescentibus v. pallidis plerumque obovatis saepe obtusius-
culis, ramulis praesertim apicem versus dense ferrugineo-strigosis, floribus majori-
bus, tubo fere 3 cm. longo satis dense villoso, perulis dense griseo-sericeis.
GEORGIA. Randolph County: in low woods near Cuthbert,
May 9, 1918, T. G. Harbison (No. 39, type, Nos. 36, 37, 38). Here
may also belong Harbison's Nos. 17 and 20, Cuthbert, low shrub in
burned-over pine woods, March 29, 1918.
This is a very perplexing form and seems to be equally closely related to R. vis-
cosum, R. serrulatum var. georgianum and R. oblongifolium. From the first it differs
chiefly in the larger leaves glaucescent beneath, the densely rufous-strigose branch-
lets, the larger rather densely villose flowers and the densely pubescent winter-
buds; from the second it differs in its early flowering time, the more villose corolla,
and from the third in the densely rufous-strigose branchlets, destitute or nearly
destitute of villose pubescence, in the more densely glandular corolla and in the
small sepals. The winter-buds are densely grayish pubescent. The leaves are
obovate to nearly elliptic often almost rounded at the apex, mucronulate, 3 to 6
cm. long and 1.5 to 3.5 cm. broad, glabrous above, the upper ones narrower and
acute and strigillose above, pale or glaucescent beneath and glabrous except the
166 THE AZALEAS OF NORTH AMERICA
strigillose midrib, and slightly reticulate. The flower-clusters are large and many-
flowered; the sepals semiorbicular and minute; the corolla-tube is about 3 cm. long,
villose and glandular-hirsute; the setose hairs of the ovary are tipped with purple
glands. Part of No. 36 consists of a branch with the leaves narrower and puberu-
lous above and short-villose beneath. Whether the numbers 17 and 18 collected
in bloom on March 29 belong here is doubtful. The leaves are half -grown, glauces-
cent on both sides and glabrous except the strigillose midrib beneath, the corolla is
less pubescent and the tube somewhat more gradually dilated at the apex. It has
some resemblance to R. atlanticum, but the corolla is less glandular and more vil-
lose, the winter-buds are pubescent and the habit is apparently different. Some
specimens from Lee and Dallas Counties, Alabama, which I have referred to typi-
cal R. viscoswn, may belong rather to this variety than to R. viscosum.
Aiton's Azalea viscosa y. fissa (Hart. Kew. I. 203 [1789]. — Rhododendron vis-
cosum t.fissum Sweet, Hort. Brit. ed. 2, 344 [1830]) described as "floribus albis ad
basin usque divisis, foliis saturate viridibus lucidis " is apparently not a form with
a regularly five-parted corolla like his A. nudiflora rj. partita, for Dumont de Cour-
set describes the same form under Azalea serotina N., A. fissa H. K. (Bot. Cult. ed. 2,
III. 336 [1811]), as follows: "Le tube de la corolla est plus court; le limbe se fend
quelquefois dans une des ses divisions jusqu'au tiers ou la moitiS du tube, meme
jusqu'a sa base; dans plusieurs corolles il ne se fend pas." Such split corollas may
be seen occasionally and seem to occur in certain individuals more frequently than
in others; for instance Harbison's No. 656 of var. montanum shows a large per-
centage of more or less deeply split corollas, but this can be considered only as an
abnormality and not as a taxonomic form.
A form with double flowers is mentioned by Dumont de Courset in 1814 (Bot.
Cult. VII. 166) as "Azalea visqueuse a fleurs doubles," and in 1864 Kirchner (in
Petzold & Kirchner, Arb. Muse. 479 [1864]) enumerates an Azalea viscosa flare
pleno. I have seen neither a plant nor a specimen of a double-flowered true R. vis-
cosum; the forms I have seen under this name were apparently of hybrid origin.
There is also an Azalea glaucaflore semipleno Jager (Ziergeh. 118 [1865]). — Azalea
viscosaglauca sousv&T.flore pleno Mouillefert, Arb. Arbriss. II. 1021 [1897]. — ? Azalea
glauca plena Hort. Kew. [in herb. Arnold Arb.]. Under the last named synonym a
specimen was collected by G. Nicholson in Kew Gardens in 1880; the leaves are
glaucescent beneath and the corolla has the shape of that of R. viscosum, but it is
almost destitute of villose pubescence, the sepals are well developed and oblong
and the young branchlets are almost glabrous except stipitate glands. These
characters, together with the early flowering time (June 1) when the leaves were
only partly developed, suggest R. atlanticum.
Rhododendron arborescens Torrey, Fl. U. 8. 425 (1824). — G. Don,
Gen. Syst. III. 847 (1834). — Loudon, Arb. Brit. IV. 1145 (1838).—
Gray, Syn. FL II. 1, 40 (1878). — Sargent, Gard. & For,!. 400, fig. 64
(1888). — Dippel, Handb. Laubholzk. I. 416, fig. 269 (1889). — Coul-
ter & Watson, Gray's Man., ed. 320 (1890). — Robinson & Fernald,
Gray's New Man. ed. 7, 631 (1908). —Schneider, III. Handb. Laub-
holzk. II. 500, fig. 329 1-m, 330 b (1911). — Millais, Rhodod. 115
(1917).
? Azalea viscosa Marshall, Arbust. Am. 15 (1785), not Linnaeus.
Azalea arborescens Pursh, Fl. Am. Sept. 152 (1814). — De Candolle, Prodr.
VII. 2, 716 (1839). — Gray, Man. 268 (1848); ed. 5, 299 (1867). — M. A.
ENUMERATION OF THE SPECIES 167
Curtis, Descript. Trees & Shrubs (in Geol. Nat. Hist. Surv. N. Car. III. Bot.)
(I860). — Britton & Brown, III. Fl. II. 559, fig. 2746 (1897). — Britton,
Man. 698 (1901). — Gattinger, Fl. Term. 131 (1901). — Porter, Fl. Penn-
sylv. 238 (1903). — Keller & Brown, Handb. Fl. Phila. 246 (1905). — Small,
Fl. S. E. U. S. 883 (1903); in N. Am. Fl. XXIX. 43 (1914). — Millspaugh,
Uv. Fl. W. Virginia, 322 (in W. Va. Geol. Surv.) (1913).
Azalea vertidllata Carr, Cat. Trees & Shrubs Bartram's Bot. Gard. 11 (1814),
name only. — Loddiges, Bot. Cab. XVII. t. 1632 (1830).
Azalea arborea Bartram ex Pursh, Fl. Am. Sept. 152 (1814), as synonym.
Azalea fragrans Rafinesque, Ann. Nat. 12 (1820), not Adams.1
Upright shrub to 3 m., rarely a small tree 6 m. tall; young branchlets glabrous
or rarely with a few scattered strigose hairs, often slightly bloomy, yellowish brown
or reddish brown at the end of the first season, becoming light gray or light gray-
ish brown the second year; floral winter-buds glabrous, light brown, with broadly
ovate rounded and usually mucronulate ciliate scales. Leaves obovate or some-
times elliptic to oblong-oblanceolate, acute or obtuse and gland-tipped at the apex,
cuneate at base, 3 to 8 cm. long and 1.3 to 3 cm. broad, ciliate, lustrous bright
green above, glaucous or glaucescent or sometimes nearly green beneath, glabrous
except sparingly short-villose on the midrib above and sparingly strigose on the
midrib beneath or sometimes quite glabrous beneath; petioles slender, 3 to 7 mm.
long, glabrous or rarely with a few strigose hairs. Flowers very fragrant, appear-
ing the end of June or beginning of July in 3- to 6-flowered, umbel-like clusters;
pedicels slender, 0.8 to 2 cm. long, glandular-hirsute or without glands, sometimes
glabrous; sepals ovate to linear-oblong, usually obtuse, 3 to 6 mm. long, glandu-
lar-ciliate, otherwise glabrous or sometimes villose; corolla funnel-form, white or
pinkish, the tube 2.5 to 3 cm. long, slightly dilated at the apex, usually sparingly,
rarely densely glandular-hirsute outside, otherwise glabrous or slightly, rarely
rather densely villose, pubescent inside except on the lower third, lobes ovate-
oblong, acuminate 1.5 to 2 cm. long; stamens exserted about twice as long as the
tube, the filaments purple above, pubescent below the middle; anthers 2 to 3 mm.
long, ochraceous; style as long or somewhat longer than the stamens, 5.5 to 7 cm.
long, purple above, glabrous or sometimes finely pubescent near the base, rarely
villose on the lower third; ovary glandular-setose, with reddish glands. Capsule
oblong-ovoid, 0.8 to 1.7 cm. long, densely glandular-hispid.
This species is distinctly a species of the Appalachian Mountain regions and
does not occur in the coastal plane but along the Susquehanna it descends to the
southern part of Lancaster County, Pennsylvania, along the Potomac to Fairfax
County, Virginia, along the Savannah River to Richmond County, Georgia,
and along the Chattahoochee River to Decatur County, Georgia; it is distributed
from southern Pennsylvania through western Maryland, northern and western
Virginia, eastern West Virginia, and eastern Kentucky, western North Carolina,
northwestern South Carolina, eastern Tennessee to northern (Winston County)
and eastern Alabama (Talladega and Clay Counties) 2 and to eastern (Richmond
County) and southwestern Georgia (Decatur County). It grows chiefly on the
banks of mountain streams, rarely on the borders of swamps and ascends to an
altitude of 5200 feet on the mountains of North Carolina.
1 ADDITIONAL ILLUSTRATIONS. COLORED PLATE: Lounsberry, Guide to Trees, t.
75 (1900). — BLACK FIGURES: Keeler, Our North. Shrubs, 353, fig. (1903). — Garden
Mag. V. 219, fig. (1907). — Country Life Am. XL 496 (1907). —Bailey, Stand.
Cyd. Hort. V. f. 3388 (1916), after Gard. & For.
a Sheet No. 770,587 in the National Herbarium labeled "Rhododendron visco-
sum, borders of stream in thickets, Pointclear, C. Mohr, June 16, 1889," contains
168 THE AZALEAS OF NORTH AMERICA
Rhododendron arborescens is most nearly related to R. viscosum, but is easily
distinguished from this and other Azaleas by the glabrous branchlets, glabrous
leaves glaucous beneath and the large white or pinkish flowers. It shows little
variation except in the length and shape of the sepals, in the amount of pubescence
on the outside of the corolla, in the pubescence of the pedicels occasionally quite
or nearly glabrous, in the pubescence of the style, which is glabrous or sometimes
more or less pubescent below.
Rhododendron arborescens was probably discovered by John or William Bartram
and appeared, according to Pursh, in Bartram' s catalogue as Azalea arborea, while
in the catalogue issued by Robert Carr in 1814 it appears as A. vertidllata; also
"Azalea caroliniana, Sweet Honeysuckle," in an undated "Catalogue of American
trees and shrubs ... in John Bartram's Garden" may possibly be the same
species. Also Humphrey Marshall seems to have known it, for his Azalea viscosa
(Arbust. Am. 15 [1785]), which he describes as a shrub five or six feet high growing
in rich rocky places near streams of water, is probably R. arborescens, while his
A. viscosa palustris is the true R. viscosum.
Michaux observed it in May, 1795 (see his Jour. ed. Sargent, 116), on the Blue
Ridge in North Carolina, but there seems to be no specimen of it in his herbarium.
Loddiges, who published an excellent colored plate of this species under the name
Azalea vertidllata, states that it was received "many years since from our old
friend Bartram under this name," which tends to show that it was introduced
before the plant was known as A. arborescens and before 1818, the date given by
Sweet in his Hortus Britanicus under A . arborescens as the date of its introduction
to England, but neither Sweet nor Loudon say who introduced it at that date;
probably it was John Lyon, who was an active collector in North America up
to that time. It was first described in 1814 as a new species by Pursh, who dis-
covered it on the Blue Mountains of Pennsylvania, and also saw it cultivated in
John Bartram's garden at Philadelphia; he called it the finest ornamental shrub
he knew. It certainly is a very handsome shrub and it seems strange that it is
still so little known in cultivation; the dry leaves have a very pleasing smell of
coumarin, like Melilotus and Anthoxanthum, and retain it for many years in her-
barium specimens.
Rhododendron arborescens var. Richardsonii Rehder, var. nov.
A typo praecipue recedit statu humiliore plerumque 0.60-1.5, rarius ad 2.5 m.
altum, foliis paulo minoribus et magis glaucescentibus, corolla densius villosa et
magis glanduloso-hirsuta, sepalis plerisque brevibus ovatis vel semiorbicularibus
extus villosis, stylo plerumque in triente inferiore dense villoso.
NORTH CAROLINA. Macon County: on Wayoh Bald, alt. 5200
feet, June 7, 1919, T. G. Harbison (No. 170, type, compact shrub,
4 feet tall, growing in dense patches), alt. 4800 feet (No. 176); High-
lands, on mountain side in moist soil, alt. 4400 or 4500 feet, June 23,
1918, T. G. Harbison (Nos. G 34, D 42); alt. 4000 feet, July 9, 1918,
T. G. Harbison (No. 62) ; without precise locality, alt. 3800 feet, July 2,
1911 (No. 655); high mountains, Sept. 2 and 6, 1910 (Nos. 114, 132),
two different species, one being R. arborescens. If the locality, which is not clearly
written, is Pointclear, Baldwin County, the range of R. arborescens would extend
to the coast of Alabama, but until the occurrence of the species there is confirmed
by other collections I consider it doubtful.
ENUMERATION OF THE SPECIES 169
alt. 48,500 feet (No. 5788), alt. 4800 feet (No. 5790), July 1, 1920,
alt. 3800 feet (Nos. 5841, 5842), alt. 4000 feet (No. 5843), alt. 4500
feet (No. 5844), T. G. Harbison.
This is the form of the high mountain which replaces the typical tall-growing
form at altitudes of from 3800 to 5200 feet. It is a low compact or wide-spreading
shrub, usually about 1 m. but occasionally up to 2.5 m. tall. The leaves are some-
what smaller and more glaucous. The corolla is rather densely villose and copi-
ously glandular-pilose outside, but slightly villose in Nos. 5790, 5841 and 5842;
the sepals are usually short, but sometimes, as in Harbison's Nos. G. 34 and D. 42,
they are as long as in the type; the style is densely villose on the lower third except
in Nos. 62, 655, 5790, 5841, 5842, and 5844, which have a glabrous or nearly glabrous
style; the leaves are glaucous beneath, but green in No. 5843.
What appears to be the same form has been collected near Great Falls, Fairfax
County, Virginia, by Mr. W. W. Ashe (see Bull. Torr. Bot. Club, XLVII. 582 [1920]),
who kindly sent us a specimen which agrees in every respect with the mountain
form described above.
The variety Richardsonii was introduced into cultivation in 1917 by Mr. H. H.
Richardson, who has in his garden at Brookline, Mass., an interesting collection of
spontaneous forms of American Azaleas.
Rhododendron prunifolium Millais, Rhodod. 230 (1917). — Millais &
Williams in Rhodod. Soc. Notes, I. 125 (1918) .x
Azalea prunifolia Small, FL S. E. 17. S. ed. 2, 1356 (1913) ; in Fl. N. Am. XXIX.
44 (1914).
Slender shrub to 3 m. tall with irregularly whorled branches; young branchlets
glabrous, dark purplish red, rarely light grayish brown at the end of the first season,
becoming light grayish brown or grayish the second year; winter-buds glabrous,
light brown or reddish brown, with broadly ovate scales rounded and mucronulate,
sometimes nearly aristate at the apex and ciliolate. Leaves elliptic, or sometimes
obovate to oblong, acute or short-acuminate and gland-tipped, cuneate or broadly
cuneate at base, 3 to 10 cm. or occasionally to 13.5 cm. long and 1.7 to 4 cm. broad,
ciliate, dark or bright green, glabrous above except the slightly villose midrib and
dull green, very rarely sparingly strigillose, lighter green beneath and sparingly
strigose on the midrib and sometimes on the veins, midrib and secondary veins
often rather prominent beneath and light-colored, slightly impressed above; peti-
oles 3 to 6 mm. long, glabrous or rarely sparingly strigose. Flowers about the
middle of July in 4- to 5-flowered umbel-like clusters; pedicels about 5 mm. long,
hirsute; sepals semi-orbicular to ovate, about 1 mm. long, long-ciliate; corolla
funnel-form, crimson, the tube gradually widened above the middle, 2 to 2.5 cm.
long, glabrous or sparingly hirsute, pubescent inside, the lobes broadly ovate,
abruptly acuminulate, about 1.5 cm. long and 0.9 to 1.3 cm. broad and more or less
finely villose and sometimes slightly glandular-pilose outside; stamens much ex-
serted, nearly three times as long as the tube, 5 to 6.5 cm. long, villose on and
below the middle; anthers 2 to 3 mm. long, ochraceous; style much exceeding the
stamens, about 8 cm. long, glabrous, purple above; ovary covered with long se-
tose, glandless hairs. Capsule ovoid-oblong, about 2 cm. long, strigose and finely
puberulous.
1 Rhododendron prunifolium Forbes, Hort. Woburn, 91 (1833), is a nomen nudum
and cannot invalidate Millais' combination.
170 THE AZALEAS OF NORTH AMERICA
This plant is known only in southwestern Georgia and eastern Alabama and
grows in shady ravines on the banks of streams. The type locality is about two
miles northwest of Cuthbert, where it was collected by R. M. Harper in 1903 and
first described by Small in 1913. It is the most distinct of the American species of
the section Pentanthera and shows no very close relation to any species of this
section. It is the most glabrous of all American species and entirely destitute of
any glandular pubescence except occasionally some glands on the outside of the
corolla-lobes; in its glabrousness it comes nearest to the preceding species, but that
has generally obovate smaller leaves distinctly glaucous beneath and a glandular
and pubescent corolla; in the leaves, the winter-buds and in the branchlets it re-
sembles R. Vaseyi so much that it is not easy to distinguish sterile specimens,
but the flowers are entirely different. The shape of the corolla of R. prunifolium
is much like that of R. calendulaceum and R. occidentals, but these species differ
widely from R. prunifolium in most other characters.
Rhododendron prunifolium was introduced into cultivation through the Arnold
Arboretum, where plants were raised in 1918 from seeds collected by T. G. Harbison
near Cuthbert, Georgia, in November, 1917.
ENUMERATION OF THE SPECIES
SPONTANEOUS HYBRIDS
No spontaneous Azalea hybrids have been as yet recorded, but I
have before me several specimens which may possibly be of hybrid
origin. There are some specimens collected by Professor C. S. Sar-
gent near Bath, Georgia, on April 29, 1914, which appear interme-
diate between R. canescens and R. spedosum. They differ from the
former in the red flowers with shorter more dilated corolla-tube desti-
tute of glands and with larger limb and from R. spedosum in their
smaller flowers, more densely pubescent leaves and more or less pubes-
cent winter-buds. As the two supposed parent species have been
collected at the same locality, and flower at about the same time, the
occurrence of such a hybrid is not improbable. Possibly of the same
origin is T. G. Harbison's No. 900 from Stone Mountain, De Kalb
County, April 29, 1912; it much resembles R. speciosum, but the flow-
ers are apparently of much lighter color and the winter-buds are
pubescent; both supposed parent species occur in the region.
On the Nantahala Mountains, Macon County, North Carolina,
T. G. Harbison collected a specimen (No. 186; June 7, 1919) similar
to R. calendulaceum but with narrower and longer corolla-tube and
pink flowers; it may possibly be a hybrid between R. calendulaceum
and R. nudiflorum, but I am not aware whether the latter species is
found in that particular locality, though it occurs in Macon County.
On the Chilhowee Mountain, Tennessee, A. H. Curtiss collected an
Azalea (No. 1719) which resembles closely R. arborescens, but has
pubescent branchlets; whether this is a hybrid possibly with R. vis-
cosum} I am not prepared to say.
171
GARDEN HYBRIDS
There exists in gardens, especially in Europe, on the Continent as
well as in England, a bewildering variety of Azaleas which are un-
doubtedly of hybrid origin; in fact almost all of the so-called hardy
Azaleas in cultivation are hybrids, the true species having almost
entirely disappeared from gardens. The parentage of most of these
forms is so mixed that it is impossible to recognize their origin with
certainty, particularly if one is not sure of at least one of the parents.
The difficulty is increased, as pointed out before, by the absence of
strong morphological characters between the different species of this
group, so that it is sometimes difficult to separate even the spontane-
ous forms satisfactorily. Many of the older hybrids have been figured,
but usually without adequate description and with often vague and
indefinite indication of the parentage; and as no herbarium material
is available to supplement the illustrations, we have to depend on the
figures and the indication of the parentage as given. Some of these
older forms may still be in cultivation, and if one were able to observe
and compare a large collection of them in cultivation, many of the
problems might be solved, though the only sure way to elucidate the
origin of these hybrids would be by raising plants from seed of self-
fertilized flowers, that is from flowers carefully protected from foreign
pollination and fertilized by pollen from the same plant. In some
cases it may be necessary to raise more than one generation to arrive
at satisfactory results. All I can do here is to assemble the more im-
portant literature relating to these hybrids as a basis for further
studies.
It seems rather strange that the first hybrids known to have been
raised in this genus are not between species of the Azalea group, but
between Azaleas and true Rhododendrons. The very first hybrid
which we know is one raised between Rhododendron ponticum and some
form of Azalea; it originated at Thompson's Nursery at Mile End near
London before 1800 and was figured by Andrews in 1801 as R. ponti-
cum var. deciduum. This is possibly the plant Distributed afterwards
as R. azaleoides by English nurserymen, for in 1811 and 1814 Dumont
de Courset describes an identical or very similar form under that
name, giving " Hort. lond." as author citation. Similar crosses have
172
HYBRIDS 173
been made afterwards during the first quarter of last century, for dis-
tinct forms of similar origin appeared in horticultural literature at
that time, e. g., a cross between R. viscosum and R. maximum pub-
lished by Ker in Botanical Register (t. 195) in 1817 and a cross between
R. viscosum and R. ponticum published by Suns in Botanical Magazine
(t. 2308) in 1822, both raised by Wm. Herbert at Spofforth, England,
and other forms of unknown origin partly cultivated under the name
R. azaleoides. Many such hybrids were raised at Coombe Wood and at
Highclere, as a report in the Edinburgh New Philosophical Journal (VI.
193) in 1829 shows: " It has been found that different species in the
genera Azalea, Rhododendron and Rhodora fertilize each other . . .
this has occurred at the Earl of Liverpool's collection at Coombe Wood
and still more remarkably at the Earl of Caernarvon's [sic] extensive
collection at High Clerc [sic]," and at the same place Mr. Gowen men-
tions that there are hundreds of seedlings of different varieties of
Azalea nudiflora and A. viscosa fertilized with pollen of a Rhododen-
dron intermediate between R. ponticum and R. catawbiense.
The raising of hybrids between different species of Azaleas seems to
have been started almost simultaneously in England and in Belgium.
In England it was chiefly at Highclere in the Earl of Carnarvon's
gardens where these hybrids were raised. In a report in the Edin-
burgh New Philosophical Journal (X. 185) in 1831 it is stated that Mr.
Gowen raised seedlings of Azalea coccinea var. major, minor and
rubescens1 " dusted with pollen of a late A. pontica" and of A.
coccinea rubescens2 "impregnated with pollen of A. calendulacea
triumphans." In Belgium it was a baker at Ghent, P. Mortier, who
conceived about 1825 the idea of retarding the early flowering varie-
ties, which are often injured by late frosts, by crossing them with late
flowering varieties, and he achieved splendid results. In 1834 he sold
his last seedlings to Louis Verschaffelt of Ghent, who continued the
work. By Sweet, who figured one of these hybrids in 1831, they were
called R. Mortieri and later by Spae and Morren Azalea Mortieriana.
These hybrids were chiefly crosses between the American Azaleas,
1 This is probably a mistake and should read A. viscosa var. rubescens, for in
1832 Sweet states (Brit. Flow. Gard. ser. 3, II. t. 137) under R. ornatum, that the
specimen figured was received in 1830 and that "the seeds were raised by Lord
Carnarvon's gardener from Azalea viscosa rubescens fertilized by A. pontica under
Mr. Gowen's own inspection."
2 Lindley (in Bot. Reg. XVI. t. 1366 [1830]) states under A. calendulacea sub-
cuprea, quoting from Mr. Gowen's letter, that this form was raised at Highclere
between A. nudiflora rubescens and A. calendulacea triumphans. There is no such
name as A. coccinea rubescens known to me.
174 THE AZALEAS OF NORTH AMERICA
R. calendulaceum, R. nudiflorum, R. speciosum, R. viscosum and the
Old World R. luteum. An interesting hybrid was raised by the Rev.
William Herbert at Spofforth by crossing R. luteum and R. canadense,
the species representing two different sections; it was figured by Lind-
ley in 1838 as Azalea Seymouri, but apparently disappeared soon
from cultivation, as it had no particular ornamental merits.
After R. molle G. Don (Azalea sinensis Lodd.), introduced in 1823
from China, had found its way into the gardens it also was used to pro-
duce new hybrids, and a hybrid with R. viscosum was figured as Azalea
altadarense in 1842, one with R. speciosum as Azalea marginata in 1835
and one with a form of R. Mortieriw&s figured in 1845 as A. sinensis
var. Bylsiana. The influence of R. molle, however, does not seem to
have left a perceptible trace among the older Azalea hybrids, but
when crossed with R. occidentals A. Gray introduced about 1850,
which was used by Anthony Waterer of Knap Hill and by others in
hybridization work with this and other hardy Azaleas, a very hand-
some race of hardy free-flowering Azaleas with large flowers of prevail-
ingly light colors was developed, classed here under R. albicans. A
still greater influence on the development of hybrid Azaleas took place
when R. japonicum was introduced into the gardens in the early six-
ties. It became soon widely known under the name Azalea mollis
and by hybridizing it with other hardy Azaleas a distinct race known
as " Azalea mollis hybrids " (R. mixtum) was raised, characterized
by low compact habit and dense clusters of large scentless flowers
with a wide limb and short tube. Among the " Mollis hybrids " are
often included the hybrids of R. japonicum with R. sinense for which
the name R. Kosterianum has been proposed; the first hybrids of this
kind appear to have been raised in the seventies (see p. 97). About
1890 another race of hybrids was raised by crossing R. japonicum
with evergreen Rhododendrons (see p. 99) ; these were called by Andre"
" Azaleodendron." Recently an interesting hybrid between two dif-
ferent sections was raised by G. Fraser of Ucluelet, Vancouver, B. C.,
by crossing R. japonicum with R. canadense. This promises to be a
very ornamental plant unlike the older R. Seymouri, the first known
hybrid of R. canadense.
In the following enumeration the different garden forms are placed
under their supposed parents, though in many cases it is not certain
whether the parentage given in the original description or the opinion
based on the evidence presented is correct. If an available binomial
exists, it follows the indication of the parentage and is printed in
HYBRIDS 175
heavy type. No attempt has been made to have binomial designa-
tions for all the different crosses; only when the plant is known to be
still in cultivation and had no available name under Rhododendron,
new combinations have been formed. The hybrids between Old
World species have been included, as far as they have not been men-
tioned in the preceding paper by my colleague, E. H. Wilson, to make
the enumeration of the Azalea hybrids as complete as possible.
SECT. PENTANTHERA
Rhododendron calendulaceum x nudiflorum (and partly x speci-
osum) = Rhododendron Mortieri Sweet, Hort. Brit. ed. 2, 343 (1830),
as R. Morterii, name only.
Rhododendron Morterii var. a. cornea Sweet, Hort. Brit. ed. 2, 343 (1830),
name only; Brit. Flow. Gard. ser. 2, I. t. 10 (1831).
Azalea calendulacea i. Morterii De Candolle, Prodr. VII. 718 (1839).
Azalea Mortieriana Spae in Ann. Soc. Agric. Bot. Gand, II. 325, t. 81 (1846),
in part.
"Azaleae Mortierianae" Morren in Ann. Soc. Agric. Bot. Gand, III. 9, t. 106
(1847), in part.
Azalea Mortieri K. Koch, Dendr. II. 190 (1872), as synonym.
Rhododendron calendulaceum var. Morteri Nicholson in Kew Hand-list Arb.
ed. 2, 497 (1902).
Rhododendron Mortieri Zabel in Mitteil. Deutsch. Dendr. Ges. XI. 30 (1902).
This is stated by Sweet to be a hybrid of and intermediate between R. calen-
dulaceum and R. nudiflorum and judging from the colored plate there is no reason
to doubt that statement. The pink flowers are large with spreading limb consist-
ing of broad lobes of which the upper is almost covered by an orange-yellow blotch.
From this form named a. cornea, which must be considered the type, the form praes-
tans differs in its pale copper-colored flowers tinged with blush and with the upper
lobe of the limb coppery yellow. Sweet states that this plant was received from
the Continent under the adopted specific name.
Of the same parentage and probably referable here as synonyms or varieties
are the following forms:
Azalea calendulacea a. flammea Sims in Bot. Mag. XL VII. t. 2143 (1820), not
Michaux.
The plant figured is apparently neither R. speciosum nor a true R. calendulaceum;
the pink corolla tube and the partly pink, partly orange-colored lobes, except the
upper one which is entirely orange, may be taken to indicate the influence of R.
nudiflorum, though there is a possibility that a variation of R. calendulaceum with
more or less pinkish flowers exists.
Azalea nudiflora TTTT. tricolor Sweet, Hort. Brit. 265 (1826), name only. —
Loddiges, Bot. Cab. XIV. t. 1382 (1828).
? Azalaea tricolor Carr, Cat. Trees & Shrubs Bartram's Bot. Gard. 10 (1814),
name only.
Rhododendron nudiflorum inr. tricolor Sweet, Hort. Brit. ed. 2, 344 (1830).
Rhododendron tricolor Sweet, Hort. Brit. ed. 2, 343 (1830), "Hybrid 1816." —
Millais, Rhodod. 255 (1917).
This form is stated to have been received from Philadelphia in 1821, but it
belongs apparently to this group of hybrids; the rather slender deep red tube and
176
HYBRIDS 177
the pale pink limb indicate a R. nudiflorum form, while the rather broad and large
limb with an orange-yellow lobe indicates the influence of R. calendulaceum.
Azalea calendulacea var. subcuprea Gowen apud Lindley in Bot. Reg. XVI. t.
1366 (1830).
Rhododendron calendulaceum i. subcupreum Sweet, Hort. Brit. ed. 3, 443 (1839).
This form, which has flowers very similar in shape to those of R. calendulaceum
and of a peculiar dull salmon-pink with an orange-colored upper lobe, is said to
have been raised at Highclere between A. nudiftora rubescens and A. calendulacea
triumphans, which is apparently correct.
Azalea calendulacea var. lepida Gowen apud Lindley in Bot. Reg. XVII. t.
1402 (1831).
Rhododendron calendulaceum K. lepidum Sweet, Hort. Brit. ed. 3, 443 (1839).
This form, which has flowers similar in shape to those of R. calendulaceum but
with bright pink tube, white lobes bordered with light pink and with a large
yellow blotch on the upper lobe, is stated to have been raised of the same parentage
aa var. subcuprea.
Azalea calendulacea var. Stapletoniana Lindley in Bot. Reg. XVII. t. 1407
(1831).
Rhododendron calendulaceum p. Stapletonianum Sweet, Hort. Brit. ed. 3, 443
(1839).
The flowers are similar to those of the preceding varieties, but of bright deep
rose color with a large yellow blotch on the upper lobe. This is also one of the
Highclere Azaleas, but its particular parentage is not stated.
Azalea pontica var. versicolor Lindley in Bot. Reg. XVIII. t. 1559 (1833).
Rhododendron flavum r. versicolor Sweet, Hort. Brit. ed. 3, 442 (1839).
Though this hybrid which was raised at Highclere was published without indi-
cation of its parentage as a variety of Azalea pontica, I cannot see any indication
of R. luteum in it. The flowers are rose-red in different shades with a deep orange
upper lobe and the tube is conspicuously pilose. A specimen before me collected
at Kew in 1880 and labeled Azalea versicolor grandiflora may be this form. It
resembles more a form of R. nudiflorum; the corolla is very pilose and only spar-
ingly glandular and the leaves do not show the slightest influence of R. luteum in
their pubescence and shape.
Rhododendron luteum x nudiflorum.
Rhododendron calendulaceum var. fulgidum Hooker in Bot. Mag. LXII. t.
3439 (1835).
Azalea calendulacea v&r.fulgina Mouillefert, Arb. Abriss. II. 1022 (1897).
Azalea calendulacea var. frigida Mouillefert, I. c.
Hooker states, this Azalea was received from the Glasgow Botanic Garden as
Azalea calendulacea v&r.fulgida, but that it has the appearance of a hybrid between
R. ponticum (probably a mistake for Azalea pontica) and R. nudiflorum var. cocci-
neum. It certainly does not belong to R. calendulaceum, and may be either a form
of R. nudiflorum or, as Hooker suggests, a hybrid of that species with R. luteum.
The flowers are bright pink with a whitish upper lobe and their shape is more like
that of R. nudiflorum. Mouillefert's two synonyms probably owe their origin to
some slip of the pen, for he cites for both "B. M. 3439."
I
178 THE AZALEAS OF NOKTH AMERICA
Rhododendron luteum x speciosum.
Azalea nudiflora var. scintillans » Lindley in Bot. Reg. XVII. t. 1461 (1831).
Rhododendron nudiflorum var. scintillans Hooker in Bot. Mag. LXV. t. 3667
(1839).
In the Botanical Register Mr. Gowensays: "This Azalea was raised at Highclere
in the same year with those already figured in previous parts of this work and is
a seedling from Azalea coccinea major impregnated by the pollen of Azalea pontica.
The flowers are bright pink with the narrow lobes of R. nudiflorum and with the
upper lobe of a pale buff color or nearly whitish."
The following are probably of the same parentage:
Rhododendron flavum var. ardens Sweet, Brit. Flow. Gard. ser. 2, IV. t. 306
(1835).
Azalea pontica * coronaria /3. ardens De Candolle, Prodr. VII. 718 (1839).
This form was introduced from Holland, according to Sweet, and he says that
it "is doubtless a production between R. flavum and one of the varieties of R. nudi-
florum." Judging from its bright scarlet flowers borne in a very large dense head
it is near R. speciosum and if not simply a form of that species it may very well be
a hybrid between it and R. luteum.
Rhododendron flavum var. coronarium Sweet, Brit. Flow. Gard. ser. 2, IV. t.
331 (1836).
Azalea pontica * coronaria a. flavum De Candolle, Prodr. VII. 718 (1839).
This is very similar to the preceding except that the flowers are orange-yellow
with a red tinge. It also was imported from Holland.
Rhododendron luteum x viscosum = Rhododendron ornatum Sweet
Brit. Flow. Gard. ser. 2, II. t. 137 (1832).
Azalea pontica-rubescens Gowen ex Sweet, I. c. (1832) as synonym.
Rhododendron viscosum ft. ornatum G. Don, Gen. Syst. III. 847 (1834).
Azalea viscosa * ornata De Candolle, Prodr. VII. 617 (1839).
Sweet states that he received the specimen figured the end of May, 1830, and
that "the seeds were raised by Lord Carnarvon's gardener from Azalea viscosa /5.
rubescens, fertilized by A. pontica under Mr. Gowen's own inspection."
Four varieties are distinguished and figured:
a. speciosum, with reddish orange flowers (fig. 1).
0. incarnatum, with pale pink flowers tipped with white, the upper lobe yellow
(fig. 3; in the text by mistake as var. and fig. 2).
7. luteum with pale yellow flowers slightly tinged with blush, the upper lobe
deep yellow (fig. 2; in the text by mistake as var. 3 and fig. 3).
1. roseum with pale rose flowers, the upper lobe with a large orange blotch
(fig. 4).
Rhododendron Mortieri x luteum (and partly viscosum or arbores-
cens) = Rhododendron gandavense Rehder, comb. nov.
1 This name should not be used for this plant as a binomial designation
under Rhododendron, as there is already a R. scintillans Bah", f. & W. W. Sm.
HYBRIDS 179
Azalea Mortieriana Spae in Ann. Soc. Agric. Bot. Gand, II. 325, t. 81 (1846),
in part (twelve named varieties are figured).
"Azaleae Mortierianae " Morren in Ann. Soc. Agric. Bot. Gand, 9, t. 106
(1847), in part.
Azalea pontica et var. Witte, Flora, 290, t. 73 (1868).
Azaleae Gandavenses K. Koch, Dendr. II. 185 (1872), as synons.
Azalea Gandavensis Hort. apud K. Koch, Dendr. II. 2, 367 (1873), in the
index. — Render in Bailey, Cycl. Am. Hort. I. 121 (1900), in part.
This collective group is intended to include all the hybrids between the different
species of American Azaleas (exclusive of R. occidentale) and R. luteum which can-
not be traced to any of the binary hybrids but are apparently of more mixed and
uncertain parentage. It comprises the garden forms known as Ghent Azaleas or
Azalea pontica varieties, also sometimes called Azalea Mortieriana, though Rhodo-
dendron Mortieri as first figured and described by Sweet is apparently a binary
hybrid between R. calendulaceum and R. nudiflorum. As it is desirable for prac-
tical reasons to have a definite name for this group of hybrids, I have adopted the
name gandavense, which has been used in some nursery catalogues in the combina-
tion "Azaleae gandavenses " for this group of hybrids. It is one of those cultigen
groups which as L. H. Bailey points out (in Science, XLVII. 306 [1918]) need
names in the taxonomic treatment of cultivated plants, though such groups can-
not be pinned down to a type and are more or less heterogenous and therefore not
exactly in accordance with present taxonomic usage.
The following forms seem also to belong here:
"Azaleas de Jardins " Lemaire in III. Hort. II. pi. 75 (1855).
Sixteen different named varieties are figured, a flower of each; most of them are
similar to the forms of R. Morteri, some suggest the influence of A. spedosum and
some of R. luteum.
"Azaleas rustiques de Gand " Van Houtte in Rev. Hort. Beige, III. 3 tab.
(1877).
Two named varieties of the R. Mortieri type.
"Hardy Azaleas " Osborn in Gard. XV. 318 t. 176 (1879).
Four varieties, probably all representing hybrids of R. Morteri.
Rhododendron gandavense var. plenum Rehder, nom. nov.
Under this name all the double-flowered forms of R. gandavense may be classed.
I refer here the following forms, of which the first may serve as a type of this group.
Azalea Van Houttei flore pleno Van Houtte in Fl. des Serres, XIII. t. 1298
(1858).
Raised from seed of a form of R. Mortieri. The flowers are semidouble with
5 to 10 stamens, and of pink color with the 3 or 4 upper lobes orange.
"Azaleas rustiques de Gand " Van Houtte in Fl. des Serres, XIX. t. 2019-
2024 (1873), excl. t. 2019, 2020.
The plants were bought by Van Houtte from the widow and sons of Louis
Hellebuyck, a contemporary of Mortier. Six forms are figured; four of them are
double-flowered, two of them (t. 2019 and 2020) are single.
"Hardy double Azaleas " Moore in Flor. & Pomol. 1880, 89. t. 516.
180 THE AZALEAS OF NORTH AMERICA
Three forme are figured: "Narcissiflora," "Graf von Meran" and "Sappho."
The two first named are in cultivation at the Arnold Arboretum. Of the form
"Narcissiflora " R. luteum seems to be the dominant parent, while Graf von Meran,
though similar, shows in its color and the less glandular pubescence the influence
of R. nudiflorum.
Rhododendron molle x occidentale = R. albicans Waterer apud
Zabel in Mitteil. Deutsch. Dendr. Ges. XI. 30 (1902). — For further
citations see page 97.
The following references may be added to those given on pages 97 and 98.
Azalea "Waterer's New Hardy " Moore in Flor. & Pomol. 1883, 177, t. in
part.
Three forms are figured, stated to have been raised by Anthony Waterer by
crossing A. occidentalis with various hybrids. Two of them, "C. S. Sargent" with
yellow flowers and "Henrietta Sargent" with bright rose-colored flowers, are
probably hybrids with R. Kosterianum forms and may be referred to R. albicans,
while "Rubra plena " is probably a hybrid of R. occidentale with one of the double-
flowered R. gandavense and does not belong here.
"New Hybrid Azaleas " W. G. in Gard. XXIX. 550, t. 548 (1886), in part.
Two unnamed varieties are figured of which the white-flowered one apparently
belongs here.
Azalea albicans [Waterer] apud Gard. XLV. 229, 322 (1894); apud Jour. Roy.
Hort. Soc. XVII. XLVI (1895).
Described as a hybrid between Azalea mollis and A. occidentalis with white
flowers just touched with yellow and with an orange suffusion on the upper lobes.
I am in favor of restricting the name R. albicans to the hybrid forms between
R. molle (including perhaps x R. Kosterianum) and R. occidentale, for which it was
originally intended, and to refer the last reference given on page 98 to R. mixtum.
Of the varieties cited by Wilson, "Graciosa" and "Exquisite" belong certainly
to R. albicans, of the other two I am not sure. The forms of R. albicans are char-
acterized by large light-colored flowers with rather short tube, puberulous and
scarcely glandular outside and with the orange blotch consisting of more or less
separate dots and with not or slightly exserted stamens; from R. molle and R. Kos-
terianum they differ chiefly in the longer, more cylindric tube and the generally
pinkish white color of the flowers.
Rhododendron gandavense x occidentale.
Azalea "Waterer's New Hardy " Moore in Flor. & Pomol. 1883, 177, t.; as to
var. "Rubra plena."
"New Hybrid Azaleas " W. G. in Gard. XXIX. 550, t. 548 (1886), as to the
red-flowered variety.
To this group I am inclined to refer such forms as "Emelie " and "Roi des
Beiges." They are rather difficult to distinguish from the forms of R. gandavense,
but may be recognized by the larger flowers with broad open limb, the compara-
tively short tube, the many-flowered dense inflorescence.
Rhododendron occidentale x (arborescens x japonicum).
Azalea occidentalis x arborescens x mollis Rehnelt in Gartenwelt, XX. 8, t.
(1916).
HYBRIDS 181
The two varieties figured, one with white flowers flushed pink (Verna Berger)
and one with deeper pink flowers (Schone von Giessen), were raised from seed of
R. occidentale, the other parent not being stated in the text, but on the plate the
hybrid is called Azalea occidentale x arborescens x mollis. I have not seen any of
these forms.
Rhododendron calendulaceum x occidentale.
A hybrid between these two species has been raised at the Arnold Arboretum
by W. H. Judd in 1915, and one plant flowered in 1920 for the first time, bearing
only a single inflorescence with white flowers suffused with pink and marked with a
large orange blotch on the upper lobe.
Rhododendron arborescens x calendulaceum = R. Anneliesae
Rehder, hybr. nov.
Rhododendron arborescens x calendulaceum Zabel in Beissner, Schelle & Zabel,
Handb. Laubholz-Ben. 380 (1903), name only.
This hybrid originated accidentally at the Arnold Arboretum and was raised
probably in 1896 from seed of R. calendulaceum or R. arborescens collected in the
Arboretum. It is exactly intermediate between R. calendulaceum and R. arbor-
escens and I have little doubt that it is a hybrid between these two species. The
first flowers of R. arborescens are usually just beginning to open about the middle
of June when late blooming forms of R. calendulaceum bear the last flowers; and
with dichogamous plants this is just a favorable condition for cross-fertilization.
From R. calendulaceum it differs chiefly in the glaucous and glabrous under side of
the leaves, only the midrib being furnished with strigose hairs and slightly pubes-
cent toward the base, in the very sparingly hairy branchlets and in the longer corolla-
tube of the pinkish white fragrant flowers marked with a large yellow blotch and
in the style puberulous only near the base. From R. arborescens it differs in the
slightly pilose and slightly puberulous branchlets, glabrescent toward the base,
in the pubescent and strigose midrib of the under side of the leaves, in the
large yellow blotch on the upper lobe of the pinkish white flowers, in the shorter
ovate calyx-lobes and in the style being puberulous near the base.
It is a shrub of vigorous habit, very handsome in flower with its large fragrant,
pinkish white flowers marked with a conspicuous yellow blotch; the pinkish corolla-
tube is rather densely furnished with short glandular hairs and the style is purple
toward the apex. The leaves are elliptic or broadly elliptic and somewhat bluish
green above.
This hybrid is named for my wife.
Rhododendron speciosum x molle.
Azalea marginata Paxton in Paxton's Mag. Bot. II. 121, t. (1835).
Azalea sinensis coccinea Cunningham Msc. ex Paxton, /. c. (1836), as synon.
The plant is stated to be "a hybrid produced from A. coccinea fertilized with the
pollen of A. sinensis. The size of the flowers and the foliage with the entire habit
of the plant is quite like that of the A. sinensis with the exception of the color
which differs only in the light orange-red margin of the corolla." The hybrid was
raised by Mr. Cunningham of Comely Bank near Edinburgh, in whose collection
it flowered February, 1835. The parentage given is probably correct as far as can
be judged from the colored plate.
182 THE AZALEAS OF NORTH AMERICA
Rhododendron calendulaceum x viscosum.
Such a cross is mentioned by Herbert (Amaryll. 360) in 1837: "I have raised
seedlings from Azalea Pontica-viscosa var. alba and Calendulacea-viscosa var.
rubescens." Nothing more, however, seems to have been published about the
latter cross; R. luteum x viscosum, see on page 178.
Rhododendron molle x viscosum = Rhododendron viscosepalum
Rehder, comb. nov.
Azalea viscosepala R. A. in Gard. Chron. II. 348 (1842).
Azalea viscocephala Arb. Kew. in Herb. Arnold Arb.
In Gardener's Chronicle (1. c.) this is stated to have been raised by Mr. Waterer
at Knap Hill and is described as "Azalea viscosepala, white with yellow throat.
This is a cross between viscosa and Indica alba which latter it very much resembles
in foliage."
I have before me specimens collected at Kew in 1880 as Azalea viscocephala
and specimens from plants growing at the Arnold Arboretum which probably
represent the same plant. They appear to be intermediate between R. viscosum
var. glaucum and R. molle. From R. viscosum they differ chiefly in the earlier
larger flowers with a yellow blotch, slightly yellowish in bud, with a stouter tube
more dilated above the middle, in the shorter stamens not or slightly exceeding
the lobes, in the more densely puberulous tube, in the tomentulose pedicels and
calyx and in the thinly pubescent under side of the leaves. From R. molle they
differ in the fragrant white flowers with a longer, more cylindric tube glandular-
pilose outside, in the glandular-pilose pedicels and in the smaller and broader
usually elliptic leaves glaucous beneath and only slightly pubescent. There is not
the slightest trace of Azalea indica alba, which is R. mucronatum, in the plant.
Rhododendron viscosepalum var. Daviesii Rehder, comb. nov.
Azalea Daviesii R. D. in Gard. Chron. ser. 2, XII. 200 (1879).1
Azalea hybrida Daviesii Hort. apud Brettschneider in Gartenfl. XLII. 65, t.
1387 (1893).
This form differs from R. viscosepalum chiefly in the larger flowers with a more
conspicuous yellow blotch and with a shorter, wider tube. The leaves are almost
identical in shape, color and pubescence.
This hybrid was raised by Isaac Davies of Brook Lane Nursery, Ormskirk,
and is stated to have been "produced from A. sinensis crossed with a hardy white
Azalea " and the flowers are described as pale sulphur yellow, changing to white
immediately they are fully expanded, and deliciously sweet-scented. A form
"Avalanche" is mentioned, produced from the same cross and similar but with
pure white smaller flowers. This must be very similar to A. viscosepala.
Very similar to var. Daviesii are the following forms:
Azalea altaclarensis Gowen apud Lindley in Bot. Reg. XXVIII. t. 27 (1842),
not Rhododendron altaclarense Lindl.
This handsome hybrid was raised at Highclere by J. R. Gowen, who states
that "it was produced by fertilizing the flowers of Azalea sinensis with the pollen
1 Not to be confused with R. Daviesii Dean, Floral Mag. n. ser. XX. t. 474
(1881), a hybrid of R. javanicum and R. retusum.
HYBRIDS 183
of the late flowering variety of Azalea viscosa, called by nurserymen A. rubescens
major." The flowers are large white, slightly bordered pink, with a faint yellow
tinge at the base of the lobes, and with the upper lobe distinctly dotted yellow
and the tube pinkish outside. The gradually dilated tube and the yellow tinge
and the spotted upper lobe indicate the influence of R. sinense and the white
color and hirsute tube of the corolla and the delicious fragrance the influence of
R. viscosum.
Azalea sinensis alba Van Houtte in Fl. des Serres, XX. 151. t. 2143-44 (1874).
Van Houtte gives no description and no hint of the origin of the plant save the
remark that it is far removed from the true A . sinensis. It is possibly the same form
of which a plant was received by the Arnold Arboretum from Koster and Son in
1904 under the name Azalea chinensis alba grandiflora.
Rhododendron ? gandavensis x molle.
Azalea sinensis var. Bylsiana Morren in Ann. Soc. Agric. Bot. Gand, I. 278,
t. 27 (1845).
This form was raised by the Ghent horticulturist Byls from seeds of A. sinensis.
It is apparently a hybrid and has large white flowers edged pink and the upper
lobe with a large yellow blotch. This is not to be confused with R. Bylsianum
Henderson, III. Bouquet, I. t. 18 (1857-59), a hybrid form of Eurhododendron.
Azalea sinensis var. macrantha Spae in Ann. Soc. Agric. Bot. Gand, III. 127,
t. 122 (1847).
This form is of the same origin as the preceding; its flowers are white tinged
with pale rose and marked with a large yellow blotch dotted orange. As a similar
form is mentioned A. sinensis var. versicolor raised by Buyck-Vander Meersch.
Rhododendron japonicum x nudiflorum.
Azalea nudiflora x sinensis Van Fleet in U. S. Dept. Agric. Bur. PL Indust.
CCXXIII. 17 (1911).
"Vigorous hybrids with profuse cream, rose and salmon colored blooms," raised
by Dr. W. Van Fleet at Little Silver, N. J., and presented to the Plant Introduc-
tion Garden in Chico, California, in 1910. The parent species called Azalea sinensis
is probably R. japonicum, for the former is not known to have been in cultivation
in this country before 1910 except young seedlings at the Arnold Arboretum,
raised in 1908.
Rhododendron japonicum x molle = Rhododendron Kosterianum
Schneid. See page 97.
Rhododendron gandavense x Kosterianum = Rhododendron mix-
turn Wilson. See page 98.
Azalea rustica flore-pleno Vandevoorde in Rev. Hort. Beige, XIX. 232 t. (1893).
Azalea mollis fl. pleno "Virgil" Reiter in Gartenwelt, XV. 493, fig. (1911),
habit figure.
Rhododendron occidentale x molle x "Ghent Azaleas" Millais, Rhodod. 220,
fig. (habit) (1917).
184 THE AZALEAS OF NORTH AMERICA
Three forms are represented in the colored plate with pink, yellow and orange
flowers. They are called double-flowered A. mollis, but are probably hybrids of
R. gandavense and R. Kosterianum. I have seen neither plants nor specimens of
these double-flowered forms.
Wilson has based the name R. mixtum on the double-flowered Azalea rustica
flore-pleno, but we may include under this name all the different forms probably
of the same parentage as given by Wilson.
SECT. PENTANTHERA x RHODORA
Rhododendron canadense x luteum = Rhododendron Seymouri
Herbert ex Lindley in Bot. Reg. XXIII. t. 1975 (1837), as synon. —
De Candolle, Prodr. VII. 728 (1839).
Azalea Seymouri Lindley in Bot. Reg. XXIII. t. 1975 (1837).
Rhododendron flavum i. Seymourii Sweet, Hort. Brit. ed. 3, 442 (1839).
This is a very interesting hybrid, being the first raised between species of the
sections Pentanthera and Rhodora. It is clearly intermediate between R. cana-
dense and R. luteum; the flowers are small, of a pale yellow color with a faint tinge
of pink and appear with the leaves; the stamens are shorter than the corolla-lobes
and 7 to 9 in number. According to Herbert "A great number of plants were
raised at Spofforth from Rhodora Canadensis impregnated with the pollen of Azalea
Pontica. Their constitution seemed ticklish or the peat in which they were grown
disagreed with them and only one plant was preserved, which formed a healthy
low bush, more spreading than Rhodora."
Rhododendron Seymouri is apparently no longer in cultivation. It was not a
showy plant with its small pale yellow flowers and thus the chief incentive to propa-
gate it was lacking. There is, however, no reason why among seedlings of this
cross should not appear plants with the color of R. canadense , and those certainly
would be much handsomer and more like the following hybrid.
Rhododendron canadense x japonicum = Rhododendron Fraseri
W. Watson in Gard. Chron. ser. 3, LXVII. 225 (1920). — See also page
103.
This interesting and handsome hybrid was raised by Mr. G. Fraser of Ucluelet,
Vancouver Island, B. C., by crossing R. canadense with R. japonicum in 1912.
The young plants flowered for the first time in 1919 and the same year Mr. Fraser
kindly sent a living plant to the Arnold Arboretum which flowered in the spring
of 1920. On account of the earliness of its profusely produced, rosy mauve flowers
much larger than those of Rhodora the new hybrid will have a decided ornamental
value and will also be useful for forcing. To supplement the short description in
the Gardeners' Chronicle (I. c.) a fuller description may be given here.
Low shrub of slender twiggy habit; young branchlets finely pubescent and
strigose, yellow-brown and glabrous the second year; winter-buds, consisting of
10 to 12, finely pubescent, ovate and mucronulate scales. Leaves elliptic-oblong to
oblong, acute and gland-tipped at apex, cuneate at base, 4 to 6 cm. long and about
2 cm. broad, ciliate, bright green, sparingly and finely villose and strigillose above,
lighter green or sometimes glaucescent beneath and short-villose, strigillose on the
midrib and veins, rather thin and often only slightly villose at maturity, with
10 to 12 pairs of veins prominent beneath and yellowish; pedicels slender, 5 to
8 mm. long, slightly villose and strigose while young. Flowers scentless, in dense
8- to 15-flowered clusters; pedicels 1 to 1.5 cm. long, finely pubescent and glandu-
lar-pilose; sepals unequal, ovate, 1 to 2 cm. long, ciliate with long setose eglandular
185
186 THE AZALEAS OF NORTH AMERICA
hairs; corolla deeply two-lipped, rosy-lilac, the upper lip spotted, slightly villose
and short-pilose and sparingly glandular outside, tube funnel-form, 6 to 8 mm.
long, sparingly pubescent inside, the two lower lobes separated nearly to the base
of the limb, oblong, 2 to 2.5 cm. long and 1 to 1.2 cm. broad, obtuse or obtusish,
upper lip as long and about 3 cm. broad, divided to about the middle into 3 ovate
lobes; stamens 10, unequal, the longer about two thirds as long as corolla; the fila-
ments pilose on the lower fourth; the anthers about 1 mm. long; style finely pilose
at base, with green stigma; ovary setosely pilose, eglandular.
SECT. TSUTSUTSI
Rhododendron ? indicum x linearifolium = Rhododendron Eeck-
hautei Rehder in Bailey, Stand. Cycl Hort. V. 2945 (1916).
Azalea Eeckhautei Pynaert in Rev. Hort. Beige, XXXVII. 117, t. (1911).
This very distinct hybrid was raised by Eeckhaute of St. Denis Westrem, Bel-
gium, from "Azalea linearifolia feconde" par VA. indica var. Souvenir du Recteur
Kickx." The shape of the corolla and of the leaves is similar to that of the mother
plant, but the flowers are larger and bright rose-colored.
Rhododendron Simsii x obtusum = Rhododendron Sanderi Wil-
son. See page 43.
There are probably other hybrids in this section as e. g. R. phoeniceum (see page
61) which according to Wilson is possibly a hybrid between R. mucronatum G. Don
and R. scabrum G. Don; and some of the varieties cultivated as Indian Azaleas are
in all probability hybrids between R. indicum and R. Simsii (see page 25). Rhodo-
dendron pulchrum Sweet, which is considered by Sweet a hybrid between R. indicum
and R. ledifolium ( = mucronatum), is according to Wilson probably a form of R.
phoeniceum (see page 62).
187
SUBGEN. ANTHODENDRON x EURHODODENDRON
SECT. PENTANTHERA x LEIORHODION
Rhododendro-Azalea Herbert, Amaryllid. 360 (1837).
Azaleodendron Rodigas in III. Hort. XXXIX. 53 (1892). — Masters in Gard.
Chron. ser. 3, XIII. 665 (1893). — Andre in Rev. Hort. 1893, 369.
Rhodazalea Croux & fils in Jour. Soc. Hort. France, se"r. 4, IX. 328 (1908). —
Genome in Jardin, XXIV. 279 (1910).
The first hybrid known to have been raised in the genus Rhododendron is one
between species of the two subgenera Anthodendron and Eurhododendron, which
originated before 1800 in Thompson's Nursery at Mile End near London. Later
other hybrids of similar origin were raised at Highclere in the gardens of the Earl of
Carnarvon, by William Herbert at Spofforth, by Wm. Smith at Norbiton, who is
particularly known for forms with yellow flowers produced by crossing R. molle
with various evergreen Rhododendrons, by Isaac Davies of Brook Lane Nursery,
Ormskirk, and others. Another race consisting of the hybrids between evergreen
Rhododendrons and R. japonicum was raised by Vander Meulen of Ghent about
1890 and more recently by Croux & fils, Val d'Aulnay, at Chateney (Seine).
By those who keep Azalea and Rhododendron distinct new generic names have
been coined. The oldest of them is Rhododendro-Azalea of Herbert, mentioned
only incidentally by the author and not formally proposed. The second was pro-
posed by Rodigas for the hybrids between R. japonicum and evergreen Rhodo-
dendrons. The third name was given for hybrids of similar origin, but Rhodazalea
Crouxii, the type of this group, has only five stamens and thus differs from Azaleo-
dendron which has ten stamens.
Rhododendron ? nudiflorum x ponticum = Rhododendron azale-
oides Hort. Lond. apud Dumont de Course!, Bot. Cult. III. 327 (1811);
VII. 165 (1814). — Desfontaines, Tabl. Jard. Paris, 272 (1815), as
R. azaloides, name only.
Rhododendron ponticum var. deciduum Andrews, Bot. Rep. VI. t. 379 (1801).
Rhododendron ponticum 0. subdeciduum "A. R." apud Sweet, Hort. Brit. 264
(1826).
Rhododendron ponticum b. azaleoides Loudon, Arb. Brit. II. 1131 (1838). —
De Candolle, Prodr. VII. 722 (1839).
Rhododendron azaleoides inodorum Andre", PL Terre Bruy. 162 (1864).
According to Andrews this hybrid originated in Thompson's Nursery at Mile
End near London and its supposed mother plant is Rhododendron ponticum fer-
tilized by some Azalea. The leaves are rather large, oblong and acuminate, and
the corolla is pale purple, not spotted or blotched, with the corolla-lobes very wavy
at the margin; the stamens have purple anthers. It is likely that a form of R. nudi-
florum is the male parent, as there is no indication of R. viscosum in the hybrid and
these two species are the only Azaleas well known before 1800. The plant described
by Dumont de Courset seems very similar, the flowers are about the same color
and nothing is said about fragrance, while the plants described and figured by later
authors as R. azaleoides differ in their usually white or nearly white very fragrant
flowers and are apparently of different origin. The R. azaleoides of Sprengel (Neu
188
HYBRIDS 189
Entdeck. II. 130 [1821]) is different from both, as he describes his plant as with
obtusish leaves pubescent on both sides, and it is doubtful if it belongs here at all.
Whether Hoffmannsegg's R. azaleoides (Verzeichn. 1826, 194) belongs here, I am
unable to say, as I have no access to that publication. Similar to R. azaleoides are
the following:
Rhododendron gemmiferum Hort. apud Zabel in Beissner, Schelle & Zabel, Handb.
Laubholz-Ben. 379 (1903), name only. — Bean, Trees & Shrubs Brit. Isl. II. 358
(1914). — Rehder in Bailey, Hand. Cycl Hort. V. 2946 (1916). — Millais, Rhodod.
172 (1917).
Bean does not say anything about its parentage, but according to a plant culti-
vated at the Arnold Arboretum it seems to be little different from Andrew's plant
except that it has broader obtusish or acutish leaves slightly pubescent beneath
and when very young also above; the flowers are nearly glabrous outside. A cross
between R. roseum and R. catawbiense might produce a similar offspring.
Rhododendron Gowenianum Sweet, Brit. Flow. Gard. III. t. 263 (1828). — De
Candolle, Prodr. VII. 728 (1839).— Bean, Trees & Shrubs Brit. Isl II. 344
(1914).
Rhododendron nudiflorum 6. Govenianum G. Don, Gen. Syst. III. 847 (1834).
Rhododendron nudiflorum x (catawbiense x ponticum) ex Sweet, I. c.
This hybrid was raised in the collection of the Earl of Carnarvon at Highclere
by J. R. Gowen from seed of "A. nudiflora or viscosa . . . fertilized with the pollen
of a hybrid Rhododendron between R. ponticum and R. catawbiense." The leaves
are evergreen or scarcely deciduous, elliptic-oblong to lanceolate-oblong, pubescent
on both sides when young, glabrous above and glossy when old. The flowers are
light purple, rather small, with a comparatively long and narrow tube. From the
illustration it is impossible to judge whether R. nudiflorum or R. viscosum is one of
the parents; G. Don calls it a hybrid of R. nudiflorum and makes it a variety of
that species, but Bean says that it is very near his R. azaleoides which is referred
here to R. hybridum.
Rhododendron Cartonianum De Candolle, Prodr. VII. 727 (1839).
"Carton's Rhododendron" Lindley in Bot. Reg. XVII. t. 1449 (1831).
Rhododendron nudiflorum W. Cartoni Sweet, Hort. Brit. ed. 3, 442 (1839).
Rhododendron Cartoni Bean, Trees & Shrubs Brit. Isl. II. 344 (1914).
Rhododendron nudiflorum x catawbiense ex Lindley, I. c.
According to Gowen "ninety-seven plants were raised in the Highclere Garden,
in the year 1825, from a specimen of Azalea nudiflora purposely touched with pollen
of Rhododendron Catawbiense. They vary in habit in the size of the umbel and in
the deeper or fainter purple tint of the corolla." Lindley named the plant figured
"the finest of the above set of hybrids in compliment to the Gardener of the Earl
of Caernarvon, Mr. James Carton."
The plant is very similar to that figured by Sweet as R. Gowenianum except that
the flowers are more white inside at the base of the limb.
Rhododendron viscosum x maximum = Rhododendron hybridum
Ker in Bot. Reg. III. t. 195 (1817). x
Rhododendron hybridum glaucum Herbert ex Sims in Bot. Mag. XLIX. sub t.
2308 (1822), incidental mention.
Rhododendron bigener Hort. ex Steudel, Nomencl. ed. 2, II. 450 (1841).
1 "Rhododendron hybridum Franch. — Yunnan" enumerated by Vilmorin &
Bois, Frut. Vilmor. 175 (1904), is probably a mistake. I have been unable to find
any reference to such a name elsewhere.
190 THE AZALEAS OF NORTH AMERICA
Rhododendron ponticum azaleoides 2. odoratum Loudon, Arb. Brit. II. 1131
(1838).
Rhododendron odoratum Loddiges apud Steudel, Nomencl. ed. 2, II. 450 (1841). l
Rhododendron azaleoides odoratum Andre", PL Terr. Bruy. 162 (1864).
Azalea odorata Hort. apud Goldring in Gard. Chron. ser. 3, VIII. 25 (1890). —
H. P. & W. G. in Gard. XL. 34 (1891).
Rhododendron fragrans in Jour. Hort. ser. 3, XLIX. 489, fig. (1904) ? not
Paxton.
Rhododendron azaleoides Bean, Trees & Shrubs Brit. Isl. II. 344 (1914), not
Dumont de Courset.
As stated by Ker this hybrid was "raised by Mr. Herbert at Spofforth near
Weatherby, from seed ripened on the common white glaucous-leaved Azalea in
the flower of which the pollen or dust from the anthers of Rhododendron maximum
had been purposely substituted for that of its own flower." The evergreen leaves
are oblong, acute at both ends and glaucous beneath; the flowers are rather small,
whitish, the lobes with a pinkish border and the upper lobe spotted yellow, the
tube cylindrical. I am referring to R. hybridum, though not without some doubt,
the R. azaleoides as described by Mr. Bean, which according to his opinion possibly
is a hybrid of R. viscosum and R. maximum and Mr. Bean's judgment can be de-
pended upon. Also a specimen I collected nearly twenty years ago at Kew as
R. odoratum agrees much better with Ker's figure than with that of R. fragrans
Paxton, though the corolla-tube is not so cylindrical as represented in that figure.
Rhododendron viscosum x ponticum = Rhododendron enneandrum
De Candolle, Prodr. VII. 728 (1839).
Azalea hybrida enneandra Sims in Bot. Mag. XLIX. t. 2308 (1822).
Rhododendron hybridum enneandrum Herbert in Trans. Hort. Soc. III. ex
Sims, 1. c.
Rhododendron azaleoides Reider in Ann. Blumist. V. 84 (1829); VII. 1. 11 (1831),
the plate bearing the name R. azaleoides alba odorata.
Sims states that this is a hybrid raised by Wm. Herbert from seed of a white-
flowered Azalea fertilized with the pollen of R. ponticum; the flowers are very fra-
grant, rather small, funnel-form, white, slightly tinged lilac, the upper lobe dotted
green. Reider's R. azaleoides may belong here though the upper lobe is not dotted
green.
Rhododendron viscosum x ? catawbiense = Rhododendron fra-
grans Paxton in Paxton' s Bot. Mag. X. 147, t. (1843) .2
1 A specimen collected by me at Kew Gardens in 1901 as R. odoratum apparently
belongs here and certainly is the hybrid described by Bean as R. azaleoides, while
another specimen in the herbarium of the Arnold Arboretum collected by H. Zabel
in the Botanic Garden at Muenden, Hanover, from a plant received in 1882 as
R. odoratum from T. Smith in Bergedorf near Hamburg, is not the same and similar
to R. azaleoides.
2 As R. fragrans Paxton must be considered a duly published name, it invali-
dates R. fragrans Maximowicz of 1870, for which I propose the following new name:
Rhododendron Adamsii Rehder, nom. nov.
Azalea fragrans Adams in Mem. Acad. Sci. St.-Petersb. II. 332, t. 14 (1808).
Azalea pallida Turczaninow in Bull. Soc. Nat. Mosc. 1838, 96 (1838), name
only.
HYBRIDS 191
Paxton observed this hybrid in the nursery of Chandler & Sons, Vauxhall, and
states that it was "raised accidentally from seed of a variety of R. catawbiense
twenty-five or thirty years ago." He describes it as "a very compact dwarf shrub,
decidedly evergreen with small and dense foliage and numerous clusters of pretty
pale pinkish lilac blossoms in which there is a variety of delicate tints approaching
to white in the center. It has quite the habit of a Rhododendron and looks like a
small close-growing, pale-flowered variety of R. ponticum" Herbert had appar-
ently this hybrid in mind when he says (Amaryll. 360) : "The fragrance of the Aza-
leas has been communicated to the Rhododendrons both by the Mitcham crosses
and that of Mr. Chandler." To the Mitcham crosses, however, I have found no
other references.
Here may belong:
Rhododendron elegantissimum Davies apud R. D. in Gard. Chron. ser. 2, XII.
200 (1879).
"Early White Azalea" x R. Hendersonii R. D., I. c.
This is said to have white flowers tipped with deep lilac and of agreeable fra-
grance. I assume that under Early White Azalea an early flowering form of R. vis-
cosum is understood, as the flowers are very fragrant and R. Hendersonii, a name
for which I can find no other reference except Millais, Rhodod. 38, and which is
possibly one of the R. catawbiense hybrids.
Rhododendron roseum odoratum Davies apud R. D. in Gard. Chron. ser. 2, XII.
200 (1879). — Vilmorin& Bois, Frut. Vilmor. 175 (1904).
"Early White Azalea" x R. Brayanum R. D., I. c.
This is described as similar to the preceding, but with rose-colored flowers.
Rhododendron Brayanum is mentioned by Millais, Rhodod. 35.
Rhododendron ? calendulaceum x ? catawbiense.
Rhododendron ponticum var. azaleoides Torloniana Morren in Ann. Soc. Agric.
Bot. Gand, I. 21, t. 4 (1845).
? Rhododendron Tolerianum hort. apud Zabel in Beissner, Schelle & Zabel,
Handb. Laubholz-Ben. 379 (1903), name only.
Nothing is said of the origin or parentage of this hybrid form. The flowers
much resemble in size, shape and color the plant figured by Guimpel as R. azaleoides
mentioned below, but the upper lobe shows a large orange blotch while GuimpePfl
figure does not show the slightest trace of orange or yellow; this and the shape
of the corolla seem to indicate the influence of R. calendulaceum.
I am not aware that this plant is at present in cultivation, though it is certainly
one of the handsomest of this group of hybrids.
Rhododendron azaleoides Guimpel, Otto & Hayne, Abb. Fremd. Holzgew. 15,
t. 15 (1825), not Dumont de Courset.
Osmothamnus fragrans De Candolle, Prodr. VII. 715 (1839).
Osmothamnus pallidus De Candolle, I. c. (1839).
Rhododendron fragrans Maximowicz in Mem. Acad. Sci. St.-Petersb. XVI.
No. 9, 16 (1870).
Rhododendron pallidum Diimmer in Gard. Chron. ser. 3, LIII. 264 (April 26,
1913), not R. pallidum W. Watson in Gard. Chron. I. c. 230 (April 12, 1913).
Diimmer seems to consider Azalea pallida Turcz. as specifically distinct, but
even if we unite it with Azalea fragrans the combination R. pallidum cannot be
used in place of R. fragrans, as it is antedated by W. Watson's name which, though
insufficiently described, should stand as the name of the hybrid for which he in-
tended it. (See also C. P. Raffil's remarks in Gard. Chron. I. c. 332.)
192 THE AZALEAS OF NORTH AMERICA
If the colored plate is a true representative of the plant it is certainly, with
the form just mentioned, one of the handsomest of this group of hybrids on account
of its large flowers and the pure pink color without any trace of the lilac or purple
found in most related forms. The leaves are almost acuminate, to 8 cm. long and
green on both sides; the flowers are broadly funnelform-campanulate, about 6 cm.
wide, with broad lobes wavy at the margin, white and more or less tinged and
striped pink. Nothing is said of the origin of the plant, but it was apparently
English.
The following is a hybrid probably of similar origin :
Azalea (var.) magnified (Rollisson's) Van Houtte in Fl. des Serr. XIII, 31, t.
1306-7 (1858). — Lemaire in III. Hart. VI. t. 209 (1859).
Nothing is said about the origin of this plant except that it was received from
W. Rollisson. According to the plate it is a very handsome plant with large white
flowers slightly tinged pink, the upper lobe with a large orange blotch and the other
lobes marked with pink veins near the margin; the number of stamens is 6 to 8.
Rhododendron gandavense x ? catawbiense.
Rhododendron "Deception" Standish and Noble in Jour. R. Hort. Soc. V. 274
(1850). — Burbidge, Cult. PI. 298 (1876).
Described as having pink spotted flowers and fine foliage and stated to be a
hybrid between a "large yellow Ghent Azalea and R. catawbiense."
Rhododendron discolor x occidentale Bean in Rhodod. Soc. Notes,
I. 191 (1919), name only.
Flowers not yet known.
Rhododendron luteum x ponticum = Rhododendron Laetitiae Her-
bert apud Lindley in Bot. Reg. XXXI. t. 51 (1845).
This hybrid was raised by W. Herbert of Spofforth from seed of Rhododendron
ponticum fertilized by Azalea pontica. The leaves are described as "rather more
durable, broader and blunter than the leaves of Azalea Pontica"; the flowers are
large, white and fragrant, the three upper lobes with large orange blotches and
smaller dots. The plant is named after Mrs. W. Herbert. This is apparently one
of the seedlings mentioned in 1837 by Herbert in his Amaryllidaceae, page 359:
"Four evergreen seedlings obtained from the seed of Rhododendron Ponticum which
I had fertilized with pollen of Azalea Pontica have flowered at Highclere."
Of similar origin ("Azalea pontica X evergreen Rhododendron") were the
hybrids raised by Adam of Altenburg, and offered to the trade by Rinz of
Frankfort, Germany, probably about 1850; eleven varieties are enumerated by
Andre" (PL Terre Bruy. 164 [1864]).
Rhododendron speciosum x arboreum.
Rhododendron nudiflorum var. eximium Sweet, Brit. Flow. Gard. ser. 2, III.
t. 291 (1835).
Rhododendron eximium D. Don apud Zabel in Beissner, Schelle & Zabel,
Handb. Laubholz-Ben. 379 (1903), not Nuttall.
HYBRIDS 193
This hybrid was raised by William Smith of Norbiton Common, near Kingston,
"in 1829 from seeds of the variety coccinea major of Rhododendron nudiflorum
that had been fertilized by arboreum." This handsome hybrid has evergreen,
thin, oblong-lanceolate leaves, pubescent beneath and crimson flowers with a
rather long tube finely pubescent outside and with the upper lobe dotted dark
purple. The varietal name cannot be used for a binomial combination on account
of R. eximium Nutt. of 1853.
Rhododendron molle x arboreum.
Rhododendron carneum elegantissimum Lemaire in Fl. des Serres, II. pt. 3, t. 3
(1846).
Lemaire states that this is one of the hybrids obtained by William Smith of
Norbiton and that it was raised from seed of R. arboreum fertilized by Azalea sinen-
sis. It has exactly the habit of R. Smithii aureum, but the flowers are pale pink
or lilac, whitish toward the center and the upper lip conspicuously dotted. The
name elegantissimum cannot be used for a binomial on account of R. elegan-
tissimum Davies (see page 191).
•
Rhododendron molle x (maximum x ponticum) = Rhododendron
norbitonense Smith apud Andr6, PL Terre Bruy. 166 (1864) ; in Rev.
Hort. 1893, 370.
"Norbiton hybrids" Hort. ex Masters in Gard. Chron. ser. 3, XIII. 665 (1893).
Rhododendron sinense x Eurhodendron spec. Zabel in Beissner, Schelle & Zabel,
Handb. Laubholz-Ben. 379 (1903).
This interesting and handsome race of hybrids was raised by Wm. Smith of
Norbiton near Kingston, England, about 1830. After they had been exhibited in
Ghent in 1839 and before the Horticultural Society in London in 1842, they at-
tracted much attention as yellow-flowered Rhododendrons and became widely
known. Of their parentage Lindley (in Bot. Reg. XXXI. sub t. 51 [1845]) says:
"The yellow and coppery mules of the late Mr. Smith of Norbiton were obtained
from that white Rhododendron ["the fine white cross between R. ponticum and
maximum"] by the pollen of sinense." Smith apparently raised a large number
of different forms; fifteen of them are enumerated by Henderson in his Illustrated
Bouquet, t. 46 (1859-61), and by Millais, Rhodod. 26 (1917), and others by Andre",
PI. Terre Bruy. 166 (1864), one of them being "Victoria regina" mentioned on
page 99 of this work. Of these many forms only the two following seem to be
well known to-day.
Rhododendron norbitonense var. aureum Rehder, comb. nov.
Rhododendron Smithii aureum Paxton, Mag. Bot. IX. 79, t. and fig. (1842). —
Lemaire in Fl. des Serres, I. 45, t. (1845). — For further literature and syn-
onyms, see page 98.
This variety differs from the typical form, which has orange-yellow flowers, in
its golden yellow flowers. It is still in cultivation and well known as R. Smithii
aureum, but as there is a R. Smithii Nutt. which is an entirely different Himalayan
species, and also a R. Smithii Sweet which is R. arboreum x ponticum, this name
194 THE AZALEAS OF NOKTH AMERICA
should be discarded, as it is not only against all rules of nomenclature but also
misleading and confusing.
Rhododendron norbitonense var. broughtonianum Rehder, comb,
nov.
Rhododendron broughtonianum Andre", PL Terr. Bruy. 166 (1864) ; in Rev. Hort.
1893, 370.
Rhododendron broughtonii aureum Hort. apud W. Watson, Rhodod. & Azaleas,
93 (1911). — For further literature and remarks, see page 99.
I have little doubt that R. broughtonianum and R. broughtonii aureum are iden-
tical, and though the plant is well known under the latter name, its use should be
discontinued, as it is, like R. Smithii aureum, both incorrect and misleading, since
there is already a R. broughtonii Hort. which is a hybrid between two species or
forms of Eurhododendron with rosy-red flowers; moreover, the name broughtonii
suggests the proper name of a person and not of a place. A good habit picture is
given by Millais in his Rhododendrons (pi. opposite page 184).
Other forms of similar parentage were raised by Standish and Noble and later
by Anthony Waterer and by Mr. White of Sunningdale. The following also belongs
here:
Rhododendron Williamsii Millais, Rhodod. 262 (1917).
A hybrid raised by Williams of Holloway about 1885 between a hardy Rhodo-
dendron and R. sinense.
Rhododendron japonicum x Eurhododendron " hybrids " = Rho-
dodendron azaleodendron Vilmorin & Bois, FruL Vilmor. 175 (1904).
Azaleodendron Rodigas in III Hort. XXXIX. 53 (1893).— (See also page 136).
Azaleodendron "Comte de Kerchove," De Bosschere in Rev. Hort. Beige, XIX.
177, t. (1893).
Here belong the hybrids raised by G. Vander Meulen between "Azalea mollis"
( = R. japonicum) and R. "Prince Camille de Rohan" and "Leopard." As the
type of this group of hybrids "Comte de Kerchove" may be taken; this form is
described in detail by Masters (in Gard. Chron. ser. 3, XIII. 667 [1893]) and figured
in Gard. Chron. 1. c. 663 and also in Rev. Hort. Beige, I. c. (colored pi.), and in Rev.
Hort. 1893, 369. Besides "Comte de Kerchove" five other varieties were exhibited
at Ghent in 1892 by Pynaert and Van Gaert who acquired the entire stock of Van-
der Meulen's hybrids; their color ranges between white and rosy-red or rose-lilac
with conspicuous dark spots on the upper lobes. According to Andre" (in Rev.
Hort. 1893, 371) similar hybrids between "Rhododendron and Azalea mollis" had
been shown in Ghent by Ad. Rosseel in 1888.
Rhododendron ? Kosterianum x Eurhododendron hybrids = Rhodo-
dendron Crouxii Rehder, comb. nov.
Rhodazalea Crouxii Croux & fils in Jour. Soc. Hort. France, s4r. 4, IX. 328, fig.
(1908). — G&ome in Jardin, XXIV. 279, fig. 157 (1910).
This hybrid was obtained by Croux & fils of Val d'Aulnay at Chatenay (Seine),
according to their statement, by crossing a Rhododendron with a variety of Azalea
mollis, the exact name of neither of the parents being given. The flowers are large,
HYBRIDS 195
their color is Naples yellow tinged with rose, the upper lobes conspicuously spotted.
The number of stamens is 5, which distinguishes this hybrid from the similar
R. azaleodendron.
Rhododendron Crouxii f . plenum Rehder, nom. nov.
Rhodazalea Crouxii flore pleno, Croux & fils in Jour. Soc. Hort. France, se*r. 4,
IX. 328 (1908). — G6r6me in Jardin, XXIV. 279, fig. 158, 159 (1910).
Azalea mollis x Rhododendron "Marie Van Houtte" Croux & fils, I. c.
This form has semi-double yellow flowers tinged with rose.
SECT. TSUTSUTSI x LEIORHODION
The following forms have been supposed to be hybrids between the sections
Tsutsutsi and Leiorhodion.
Rhododendron azaleoides var. crispiflorum Lemaire in III. Hort. V. 1. 181 (1858) .l
This handsome and interesting hybrid was raised, according to Lemaire, by a
Ghent horticulturist, Louis Demotte, by crossing a hybrid Rhododendron with an
Indian Azalea, probably the var. " Reyndersiana" Judging from the figure and
the characters given in the description this plant seems indeed to be a hybrid of a
species or form of the section Tsutsutsi and a form of Eurhododendron, the only
one known to me, for the two following forms which are supposed to be hybrids of
an Indian Azalea and an evergreen Rhododendron are apparently only forms of
R. phoeniceum.
Azalea Rawsonii Paxton in Paxton's Flow. Gard. III. 123 t. (1836).
This Azalea was raised by John Menzies, gardener to Christopher Rawson of
Hope House near Halifax. In a letter Mr. Menzies "states as his belief that it is
produced between A. phoenica and Rhododendron dauricum atrovirens." Judging
from the colored plate it is a simple form of R. phoeniceum. See also pages 61 and
62.
Rhododendron phoeniceum var. splendens Sweet, Brit. Flow. Gard. ser. 2, IV. t.
385 (1837).
This is said to have been "raised by Mr. Wood, gardener to Mrs. May at Syden-
ham, from a plant of Rhododendron phoeniceum that had been fecundated by
R. catawbiense." It appears to be only a form of R. phoeniceum; not the slightest
influence of R. catawbiense is noticeable in the plant figured. See also page 63.
1 Not R. indicum var. crispiflorum Schneid. — See page 27.
196
DOUBTFUL NAMES
AZALEA CALENDULACEA ALBA BICOLOR Hort. apud Kirchner in Petzold & Kirch-
ner, Arb. Muse. 479 (1864).
Described as having white flowers with rose-carmine tube. Probably a form of
R. nudiflorum.
AZALEA CALENDULACEA ASTREANS Hort. apud Kirchner, I. c. 479 (1864).
Described as having brick-red flowers.
AZALEA CALENDULACEA /3. CHRYSOLECTA Sweet, Hort. Brit. 265 (1826), name
only.
Rhododendron calendulaceum ft. chrysolectum Sweet, Hort. Brit. ed. 2, 343
(1830), "golden."
AZALEA CALENDULACEA COCCINEA FULQENS Hort. apud Kirchner, I. c. 479
(1864).
Flowers described as dark brick red.
AZALEA CALENDULACEA CRISTATA Hort. apud Kirchner, in Petzold & Kirschner,
Arb. Muse. 479 (1864).
Described with yellowish brick-red flowers.
AZALEA CALENDULACEA CUPREA ELEGANS Hort. apud Kirchner, I. c.
Flowers described as rose red, small and very crowded. Possibly a form or
hybrid of R. nudiflorum.
AZALEA CALENDULACEA FENESTRATA Hort. apud Kirchner in Petzold & Kirch-
ner, A rb. Muse. 479 (1864).
Flowers described as ponceau-rose, marked yellow and whitish, very handsome.
Probably a form of X R. Mortieri.
AZALEA CALENDULACEA FULGENS EXCELSA Hort. apud Kirchner, I. c. 479 (1869).
Flowers described as dark orange-red.
AZALEA CALENDULACEA 7. GRANDIFLORA Sweet, Hort. Brit. (1826), name.
Rhododendron calendulaceum y. grandiflorum, Sweet, I. c. ed. 2, 343 (1830),
"orange."
AZALEA CALENDULACEA 6. IGNESCENS Sweet, Hort. Brit. 265 (1826), name only.
Rhododendron calendulaceum 6. ignescens Sweet, 1. c. ed. 2, 343 (1830), "copper-
yellow."
AZALEA CALENDULACEA RECURVA Hort. apud Kirchner in Petzold & Kirchner,
Arb. Muse. 479 (1864).
Flowers described as fawn-colored, marked pale yellow, very flat, small and
crowded. Probably a form of x R. Morteri.
AZALEA CALENDULACEA SANGUINEA Hort. apud Kirchner, I. c. 479 (1864).
Flowers described as similar to var. coccinea fulgens, but darker and more scarlet.
AZALEA CALENDULACEA SATURNEA Hort. apud Kirchner, I. c. 479 (1864).
Flowers described as bright and deep rose-colored.
AZALEA CALENDULACEA e. SPLENDENS Sweet, Hort. Brit. 265 (1826).
Rhododendron calendulaceum e. splendens Sweet, I. c. ed. 2, 343 (1830), "copper-
yellow."
AZALEA CALENDULACEA STERNIANA Hort. apud Kirchner, in Petzold & Kirchner,
Arb. Muse. 479 (1864).
Flowers described as bright orange, very handsome and large.
197
198 THE AZALEAS OF NORTH AMERICA
AZALEA CALENDULACEA 17. TRIUMPHANS Sweet, I. c. 265 (1826), name.
Rhododendron calendulaceum 77. triumphans Sweet, I. c. 343 (1830), "copper-
yellow."
AZALEA FASCICULATA Dumont de Conrset, Bot. Cult. VII. 166 (1814).
Azalea fastigiata Dumont de Courset, I. c. (1814).
Described as having the flowers fascicled in a kind of an umbel. Probably the
same as Azalea nudiflora X. fastigiata Sweet (see below).
AZALEA LUCID A Meerburgh, PL Selec. Icon. t. 7 (1798).
This species is described as with "foliis lanceolatis, flore luteo piloso, staminibus
brevioribus. Cl. Linnaeus hanc descripsit pro Azalea nudiflora." The illustration
resembles in general appearance R. nudiflorum, but the leaves are narrow-lanceo-
late, and the flowers have more the shape of those of R. viscosum and are colored
light yellow. It possibly represents R. viscosum var. nitidum, and the yellowish
tinge of the flowers may be a mistake of the artist.
AZALEA NUDIFLORA AMOENA Loddiges Cat. 1836, apud Loudon, Arb. Brit. II.
1142 (1838), name only.
AZALEA NUDIFLORA y. BLANDA Sweet, Hort. Brit. 265 (1826), name. — Loddiges, /. c.
Rhododendron nudiflorum y. blandum Sweet, Hort. Brit. ed. 2, 343 (1830),
"blush."
AZALEA NUDIFLORA ft. CALYCOSA Wood, Classb. Bot. 490 (1870).
This is a form from Georgia described as having one calyx-lobe subulate and
three or four times longer than the others.
AZALEA NUDIFLORA e. CAROLINIANA Sweet, Hort. Brit. 265 (1826). — Loddiges
Cat. 1836 apud Loudon, Arb. Brit. II. 1142 (1838), name only.
? Azalea caroliniana in Cat. Am. Trees & Shrubs in John Bartram's Garden
(179?), name only.
Rhododendron nudiflorum e. carolinianum Sweet, Hort. Brit. ed. 2, 343
(1830).
In Bartram's Catalogue it is called "Sweet Honeysuckle," which would sug-
gest that it is one of the fragrant species.
AZALEA NUDIFLORA COBURGIA Loddiges, I. c. 1142 (1838).
AZALEA NUDIFLORA COLORATA Loddiges, I. c. 1142 (1838).
AZALEA NUDIFLORA CONSPICUA Loddiges, I. c. 1142 (1838), name.
AZALEA NUDIFLORA 77. CORTMBOSA Sweet, I. c. 265 (1826), name.
Rhododendron nudiflorum 77. corymbosum Sweet, I. c. 343 (1830), "white."
AZALEA NUDIFLORA 6. CRISPA Sweet, I. c. 265 (1826), name. — Loddiges, L c.
1142 (1838).
Rhododendron nudiflorum 6. crispum Sweet, I. c. 343 (1830), "blush."
AZALEA NUDIFLORA t. CUMULATA Sweet, 1. c. 265 (1826), name. — Loddiges, I. c.
1142 (1838), as var. cumula.
Rhododendron nudiflorum i. cumulatum Sweet, I. c. 344 (1830), "white."
AZALEA NUDIFLORA K. DISCOLOR Sweet, L c. 265 (1826), name. — Loddiges, /. c.
1142 (1838).
Rhododendron nudiflorum K. discolor Sweet, I. c. 344 (1830), "red, white."
AZALEA NUDIFLORA X. FASTIGIATA Sweet, I. c. 265 (1826), name. — Loddiges,
I.e. 1142 (1838).
Rhododendron nudiflorum X. fastigiatum Sweet, I. c. 344 (1830), "blush."
AZALEA NUDIFLORA /*. FLORIDA Sweet, 1. c. 265 (1826), name. — Loddiges, I. c.
1142 (1838).
Rhododendron nudiflorum n. floridum Sweet, I. c. 344 (1830), "blush."
DOUBTFUL NAMES 199
AZALEA NUDIFLORA v. GLOBOSA Sweet, I. c. 265 (1826), name. — Loddiges, L c.
1142 (1838).
Rhododendron nudiflorum v. globosum Sweet, L c. 344 (1830) "blush."
AZALEA NUDIFLORA £. GLOMERATA Sweet, L c. 265 (1826), name.
Rhododendron nudiflorum £. glomeratum Sweet, L c. 344 (1830) "blush."
AZALEA NUDIFLORA GRANDIFLORA Loddiges, L c. 1142 (1838).
AZALEA NUDIFLORA o. INCANA Sweet, L c. 265 (1826), name. — Loddiges, I.e.
(1838).
Rhododendron nudiflorum o. incanum Sweet, L c. 344 (1830) "white."
AZALEA NUDIFLORA v. INCARNATA Sweet, I. c. 265 (1826), name. — Loddiges,
I.e. 1142(1838).
Rhododendron nudiflorum IT. incarnatum Sweet, I. c. 344 (1830) "flesh-colored."
AZALEA NUDIFLORA p. MIRABILIS Sweet, I.e. 265 (1826), name. — Loddiges,
I c. 1142 (1838).
Rhododendron nudiflorum p. mirabile Sweet, L c. 344 (1830), "red."
AZALEA NUDIFLORA e. Mizr^A. De Candolle, Prodr. VII.? 717 (1839).
Described as having pale rose-colored flowers with the lower lobe inside yellow-
ish and with a small calyx.
AZALEA NUDIFLORA a. MONTANA Sweet, I. c. 265 (1826), name. — Loddiges, I. c.
1142 (1838).
Rhododendron nudiflorum a. montanum Sweet, I. c. 265 (1830), "flesh-colored."
AZALEA NUDIFLORA OCHROLEUCA Loddiges, I. c. 1142 (1838), name.
AZALEA NUDIFLORA T. PALLIDA Sweet, I. c. 265 (1826).
Rhododendron nudiflorum r. pallidum Sweet, I. c. 344 (1826), "lilac white."
AZALEA NUDIFLORA v. PALUDOSA Sweet, I. c. 265 (1826), "lilac white." — Lod-
diges, L c. 1142 (1838).
Rhododendron nudiflorum v. paludosum Sweet, 1. c. 344 (1830), as var. pallidosa.
AZALEA NUDIFLORA f. PAPILIONACEA Aiton, Hort. Kew. I. 203 (1789). — De
Candolle, Prodr. VII. 717 (1838).
Azalea papilionacea Dumont de Courset, Bot. Cult. ed. 2, III. 333 (1811), as
var. of A. nudiflora.
Azalea periclymenoides var. €. papilionacea Pursh, Fl. Am. Sept. 152 (1814).
Rhododendron nudiflorum <f>. papilionaceum Sweet, Hort. Brit. ed. 2, 344 (1830). —
G. Don, Gen. Syst. III. 847 (1834).
This form is described by Aiton as having pale reddish flowers with the lower
lobe white, and a foliaceous calyx.
AZALEA NUDIFLORA 77. PARTITA Aiton, Hort. Kew. I. 203 (1789). — De Candolle,
Prodr. VII. 717 (1838).
Azalea periclymenoides f. partita Pursh, FL Am. Sept. 152 (1814).
Rhododendron nudiflorum x- partitum Sweet, Hort. Brit. ed. 2, 344 (1830). —
G. Don, Gen. Syst. III. 847 (1834).
This form is described by Aiton as having pink flowers 5-parted to the base.
This is apparently an abnormal form corresponding to Kalmia latifolia f. mon-
strosa. It seems to have soon disappeared from cultivation.
AZALEA NUDIFLORA \l/. PARVIFLORA Sweet, I. c. 265 (1826), name.
Rhododendron nudiflorum j. parviflorum Sweet. L c. 344 (1830), "blush."
AZALEA NUDIFLORA PERICLYMENOIDES Loddiges, I. c. (1838), name.
AZALEA NUDIFLORA X. POLYANDRA De Candolle, Prodr. VII. 717 (1838). —
Wood, Classb. Bot. 490 (1870).
Azalea periclymenoides ij. polyandra Pursh, Fl. Am. Sept. 152 (1814).
200 THE AZALEAS OF NORTH AMERICA
Rhododendron nudiflorum 17. polyandrum G. Don, Gen. Syst. III. 847 (1834).
? Azalea octandra Michaux, Journal, ed. C. S. Sargent, 91 (in Proc. Am. Philos.
Soc. (1889)), name only.
This form is described by Pursh as having short rose-colored flowers with
10 to 20 stamens and is said to have been found near Philadelphia. Michaux
collected his Azalea octandra in or in the neighborhood of Perry County, Pennsyl-
vania.
AZALEA NTTDIFLORA w. PROLIFERA Sweet, I. c. 265 (1826), name.
Rhododendron nudiflorum «. proliferum Sweet, I. c. 344 (1830), "blush."
AZALEA NUDIPLORA aa. PUMILA Sweet, I. c. 265 (1826), name.
Rhododendron nudiflorum aa. pumilum Sweet, I. c. 344 (1830), "blush."
AZALEA NTJDIFLORA /3/3. PURPURASCENS Sweet, 1. c. 265 (1826), name. — Loddiges,
I.e. 1142(1838).
Rhododendron nudiflorum /3j8. purpurascens Sweet, I. c. 344 (1830), "flesh-
colored."
AZALEA NUDIPLORA 77. PURPUREA Sweet, I. c. 265 (1826), name. — Loddiges,
I. c. (1838).
Rhododendron nudiflorum 77. purpureum Sweet, I. c. 344 (1830), "purple."
AZALEA NUDIPLORA n\ RUBERRIMA Sweet, I. c. 265 (1826), name. — Loddiges,
I c. 1142 (1838).
Rhododendron nudiflorum ff . ruberrimum Sweet, L c. 344 (1830), "red."
AZALEA NUDIPLORA 1777. RUBESCENS, Sweet, L c. 265 (1826), name.
Rhododendron nudiflorum 1717. rubescens Sweet, L c. 344 (1830), "pink."
AZALEA NUDIPLORA XX. RUPA Sweet, L c. 265 (1826), name. — Loddiges L c.
1142 (1838).
Rhododendron nudiflorum XX. rufum Sweet, L c. 344 (1830), "red."
AZALEA NUDIPLORA w. SEMI-DUPLEX Sweet, L c. 265 (1826), name.
Rhododendron nudiflorum vv» semiduplex Sweet, L c. 344 (1830), "white."
AZALEA NUDIPLORA /3. RUTILANS Aiton, Hort. Kew. I. 203 (1789). — De Can-
dolle, Prodr. VII. 717 (1838).
Azalea rubicunda Dumont de Courset, Bot. Cult. ed. 2, III. 332 (1811), as var.
of A . nudiflora.
Azalea periclymenoides /3. rutilans Pursh, Fl. Am. Sept. 152 (1814).
Rhododendron nudiflorum »». rutilans Sweet, Hort. Brit. ed. 2, 343 (1830). — G.
Don, Gen. Syst. III. 847 (1834).
Azalea nudiflora rubicunda Loddiges Cat. 1836 apud Loudon, Arb. Brit. II.
1142 (1838).
Azalea nudiflora Be. rubicunda Sweet, Hort. Brit. 265 (1826).
Rhododendron nudiflorum 66. rubicundum Sweet, Hort. Brit. ed. 2, 343 (1830).
This form is described by Aiton as having deep red flowers with small calyx.
Dumont de Courset says that the young branchlets and the leaves are pubescent,
the calyx greenish brown and the winter-buds pale yellow in autumn.
AZALEA NUDIPLORA SEROTINA Loddiges, I. c. 1142 (1838), name.
AZALEA NUDIPLORA ££. STAMINEA Sweet, I. c. 265 (1826), name. — Loddiges,
I.e. 1142(1838).
Rhododendron nudiflorum St. stamineum Sweet, I. c. 344 (1830), "white."
AZALEA NUDIPLORA oo. STELLATA Sweet, I.e. 265 (1826), name. — Loddiges,
I. c. (1838).
Rhododendron nudiflorum oo. stellatum Sweet, I. c. 344 (1830), "white."
AZALEA NUDIPLORA VARIA Loddiges, I. c. 1142 (1838), name.
DOUBTFUL NAMES 201
AZALEA NUDIFLORA pp. VARIABILIS Sweet, 1. c. 266 (1826), name. — Lod-
diges, I.e. 1142 (1838).
Rhododendron nudiflorum pp. variabilis Sweet, I. c. 344 (1830), "red, white."
AZALEA NUDIFLORA <r<r. VARIEGATA Sweet, I. c. 266 (1826), name. — Loddiges,
I.e. (1838).
Rhododendron nudiflorum <?<?. variegatum Sweet, I. c. 344 (1830), "striped."
AZALEA NUDIFLORA TT. VERSICOLOR Sweet, 1. c. 266 (1826), name. — Loddi-
ges,/. c. 1142(1838).
Rhododendron nudiflorum TT.versicolor Sweet, I. c. 344 (1830), "red, white."
AZALEA NUDIFLORA w. VIOLACEA Sweet, 1. c. 266 (1826), name. — Loddiges,
I.e. (1838).
Rhododendron nudiflorum w. violaceum Sweet, I. c. 344 (1830), "violet."
AZALEA PULCHELLA CARMINEA Hort. apud Kirchner in Petzold & Kirchner, Arb.
Muse. 480 (1864).
Described as with deep carmine flowers in flattened umbels.
AZALEA PULCHELLA ROSEOLA Hort. apud Kirchner, I. c. 480 (1864).
Described as having crowded small rose-colored flowers.
AZALEA RUBRA Weston, Bot. Cult. I. 16 (1770). — Meerburgh, PI. Select. Icon.
(7) t. 8 (1798).
By Weston this species is characterized as a red-flowered Azalea nudiflora.
Also Meerburgh's plate represents apparently R. nudiflorum and judging from the
hirsute corolla-tube the typical form; it is therefore not identical with Azalea
nudiflora rubra of Loddiges (see page 138).
AZALEA SALICIFOLIA Dumont de Courset, Bot. Cult. VII. 166 (1814).
Described as having willow-like leaves.
AZALEA SPECIOSA t. ACUTIFOLIA Sweet, Hort. Brit. 265 (1826), name.
Rhododendron speciosum i. acutifolium Sweet, Hort. Brit. ed. 2, 343 (1830)
"red."
AZALEA SPECIOSA 8. CILIATA Sweet, I. c. 265 (1826), name.
Rhododendron speciosum B. ciliatum Sweet, I. c. 343 (1830) "red."
AZALEA SPECIOSA COCCINEA Kirchner in Petzold & Kirchner, Arb. Muse. 479
(1864).
Flowers described as bright scarlet or garnet-red. This is probably typical
R. speciosum.
AZALEA SPECIOSA /3. CRISPA Sweet, Hort. Brit. 265 (1826), name.
Rhododendron speciosum /3. crispum Sweet, Hort. Brit. ed. 2, 343 (1830),
"scarlet."
AZALEA SPECIOSA f . CUCULLATA Sweet, I. c. 265 (1826), name.
Rhododendron speciosum f. culcullatum Sweet, I. c. 343 (1830), "red."
AZALEA SPECIOSA 5. OBLIQUA Sweet, I. c. 265 (1826), name.
Rhododendron speciosum d. obliquum Sweet, I. c. 343 (1830), "red."
AZALEA SPECIOSA e. PRUNIFOLIA Sweet, I c. 265 (1826), name.
Rhododendron speciosum «. prunifolium Sweet, I. c. 343 (1830), "red."
AZALEA SPECIOSA PURPUREO-AURANTIACA Kirchner, I. c. 479 (1864), name.
AZALEA SPECIOSA 77. REVOLUTA Sweet, I. c. 265 (1826), name.
Rhododendron speciosum 77. revolutum Sweet, I. c. 343 (1830), "red."
AZALEA SPECIOSA X TORTULIFOLIA Sweet, I. c. 265 (1826), name.
Rhododendron speciosum X. tortulifolium Sweet, I. c. 343 (1830), "red."
Rhododendron speciosum X. tortuifolium Sweet, 1. c. ed. 3, 443 (1839).
202 THE AZALEAS OF NORTH AMERICA
AZALEA SPECIOSA «. UNDULATA Sweet, I. c. 265 (1826), name.
Rhododendron speciosum K. undulatum Sweet, I. c. 343 (1830), "red."
AZALEA VISCOSA 0. CRISPA Sweet, Hort. Brit. 266 (1826). — Loddiges, Cat.
apud Loudon, Arb. Brit. II. 1143 (1838).
Rhododendron viscosum ft. crispum Sweet, Hort. Brit. ed. 2,344 (1830), "white."
AZALEA VISCOSA 7. DEALBATA Sweet, I.e. 266 (1826). — Loddiges, I.e. 1143
(1838).
Rhododendron viscosum 7. dealbatum Sweet, I. c. 344 (1830), "white."
AZALEA VISCOSA e. PENICILLATA Sweet, I.e. 266 (1826). — Loddiges, I.e. 1143
(1838).
Rhododendron viscosum e. penicillatum Sweet, I. c. 344 (1830), "red, white."
AZALEA VISCOSA PRAECOX Loddiges, I. c. 1143 (1838), name.
AZALEA VISCOSA STRICTA Carriere in Rev. Hort. 1872, p. 299.
Described as a very dwarf compact plant, with oval leaves glaucous beneath
and small white slightly pinkish flowers appearing at the beginning of May. The
early flowering time makes it improbable that this form belongs to R. viscosum.
AZALEA VISCOSA f. VARIEGATA Sweet, I.e. 265 (1826). — Loddiges, I.e. 1143
(1838).
Rhododendron viscosum f . variegatum Sweet, I. c. 344 (1830), "red, white."
AZALEA VISCOSA VIOLAE ODORE Loddiges, I. c. 1143 (1838), name.
Besides the doubtful names enumerated above, a large number of names with-
out or with very inadequate description have appeared in horticultural publications
taken in about all cases from various nursery catalogues. The following are some
of the more important references to lists of garden forms of Azaleas (exclusive of
Indian Azaleas) :
Loudon, Arb. Brit. II. 1142-1144 (1838).
Bosse, Vollst. Handb. Blumengart. I. 337, 340-342 (1840).
Heynhold, Nomencl Bot. Hort. 108 (1840); II. 55-56 (1846).
Steudel, Nomencl. I. 175 (1841).
Henderson, Itt. Bouquet, text to t. 46 (1859-61), forms of R. norbitonense.
Andre, PL Terr. Bruy. 164, 166, 187-189 (1864).
Millais, Rhodod. 166-167, 212-214 (1917).
ILLUSTRATIONS
References to illustrations of garden forms (exclusive of Indian
Azaleas) not mentioned elsewhere in this publication. They are
mostly forms of R. gandavense or R. Mortieri if not stated otherwise.
ANTHONY KOSTER. Gard. Chron. ser. 3, XIII. 513, fig. 76 (1893). — Watson,
Rhodod. & Azaleas, frontisp. (1912) = R. Kosterianum.
ATRORUBENS NOVA. Lemaire in III. Hort. II. pi. 75, fig. 15 (1855).
BARON G. PYCKE. Lemaire, I c. fig. 16 (1855).
BEAUTE DE FLANDRE. Lemaire, I. c. fig. 9 (1855).
BIJOU DE GENDBRUGGE. Van Houtte in Fl des Serr. XIX. t. 2024 (928) (1873)
= R. gandavense plenum.
BONNEUR DE LA BELGiQUE. Lemaire in III. Hort. II. pi. 75, fig. 4 (1855).
BOUQUET DE FLORE. Ottolander, Nederl FL Pom. 53, t. 16 (1876).
CARDINAL. Spae in Ann. Soc. Agric. Bot. Gand, II. 326, t. 81, fig. 9 (1846).
COCCINEA SPECIOSA. Ottolander, Nederl. Fl. Pom. 5, t. 15, fig. 2 (1876).
COMTE DE GOMER. Rev. Hort. Beige, I. 97, t. 6 (1875). — Dean, Floral Mag.
n. ser. XVIII. t. 367 (1879) = R.japonicum var.
COMTESSE DE KERCHOVE. Andre in III. Hort. XXV. 59, t. 311 (1878) = R.
japonicum var.
CUPREA EXIMIA NOVA. Osborn in Gard. XV. 318, t. 176 (1879).
CZARINE. Pynaert & Van Geert in Rev. Hort. Belg. XX. 277, t. (1894) = R.
Kosterianum.
DELICATA NOVA. Lemaire in III. Hort. II. pi. 75, fig. 10 (1855).
Due D'URSEL. Lemaire, 1. c. fig. 1 (1855).
Morren in Ann. Soc. Agric. Bot. Gand, III. 9, t. 106, fig. 14 (1847).
EUGENIE. Lemaire in III. Hort. II. pi. 75, fig. 6 (1855).
EUGENIE. Ottolander, Nederl. Fl. Pom. 51, t. 15, fig. 3 (1876), not the same as
the preceding variety.
FLORENTINE. Spae in Ann. Soc. Agric. Bot. Gand, II. 326, t. 81, fig. 6 (1846).
FRANCOIS DE TAYE. Van Houtte in Fl. des Serr. XIX. t. 2023 (927) (1873) =
R. gandavense plenum.
GEANT DES BATAILLES. Ottolander, Nederl. Fl. Pom. 51, t. 15, fig. 1 (1876).
GLOIRE DE VERSCHAFFELT. Morren in Ann. Soc. Agric. Bot. Gand, III. 9,
t. 106, fig. 16 (1847).
GRAF VON MERAN. Rinz in Gartenfl. III. 171, t. 88 (1854). — Moore in FL
Pomol. 1880, 89, t. 516, fig. 2, = R. gandavense plenum.
GRAND-DUC. Spae in Ann. Soc. Agric. Bot. Gand, II. 326, t. 81, fig. 7 (1846).
IGNAEA NOVA. Ottolander, Nederl. Fl. Pom. 51, t. 15, fig. 5 (1876).
JAS. H. LAING. Pynaert & Van Geert, Rev. Hort. Belg. XVII. 121, t. (1891) =
R. Kosterianum.
203
204 THE AZALEAS OF NORTH AMERICA
Louis AIME VAN HOUTTE. Van Houtte in Fl. des Serr. XIX. t. 2022 (929)
(1873) = R. gandavense plenum.
Louis HELLEBUYCK. Van Houtte in Fl. des Serr. XIX. t. 2019 (931) (1873).
MADAME ALEX. HAEDY. Van Houtte in Fl. des Serr. XIX. t. 2020 (930) (1873).
MAGNIPICA ALBICANS. Lemaire in III. Hort. II. pi. 75, fig. 14 (1855).
MARIE-DOROTHEE. Spae in Ann. Soc. Agric. Bot. Gand, II. 326, t. 81, fig. 5
(1846).
MINA VAN HOUTTE. Van Houtte in FL des Serr. XIX. t. 2021 (926) (1873) =
R. gandavense plenum.
MINERVE. Spae in Ann. Soc. Agric. Bot. Gand, II. 326, t. 81, fig. 10 (1846).
MINIATA FLORIBUNDA. Lemaire in III. Hort. II. pi. 75, fig. 13 (1855).
MOLLIS VAR. ALBICANS. Andre" in III. Hort. XXV. 59, t. 311 (1878) = R. ja-
ponicum var.
MOLLIS VAR. AUREA FLORIBUNDA. Andre" in III. Hort.XXV. 91, t. 317 (1878) =
R. japonicum var.
MURILLO. Vandevoorde in Rev. Hort. Belg. XIX, 232, t. fig. 1 (1893) = R.
mixtum.
NARCISSIFLORA. Moore in Fl. Pomol. 1880, 89, t. 516, fig. 1 (1880) = R. ganda-
vense plenum.
NE PLUS ULTRA. Osborn in Gard. XV. 318, t. 176 (1879).
NERON. Lemaire in III. Hort. II. t. 75, fig. 7 (1855).
NICOLAS II. Pynaert & Van Geert in Rev. Hort. Beige, XX. 277, t. (1894) =
R. Kosterianum.
NOBILIS. Lemaire in III. Hort. II. pi. 75, fig. 12 (1855).
ORANGE PEINTE. Spae in Ann. Soc. Agric. Bot. Gand, II. 326, t. 81, fig. 2 (1846).
OSCAR PREMIER. Morren in Ann. Soc. Agric. Bot. Gand, III. 9, t. 106, fig. 13
(1847).
PERLE DU PRINTEMPS. Morren in Ann. Soc. Agric. Bot. Gand, II. 9, 1. 106, fig. 19
(1847).
PHEBE. Vandervoorde in Rev. Hort. Belg. XIX. 232, t. fig. 3 (1893) = R. mixtum.
PONTICA MACRANTHA. Osborn in Gard. XV. 318, t. 176 (1879).
PONTICA VERSICOLOR. Osborn in Gard. XV. 318, t. 176 (1879).
PRINCE HENRI DES PAYS-BAS. Spae in Ann. Soc. Agric. Bot. Gand, II. 326, t. 81,
fig. 1 (1846).
PRINCE TROUBETZKOY. Andre" in III. Hort. XXV. 91, t. 317 (1878) = R. ja~
ponicum var.
QUADRICOLORE. Spae in Ann. Soc. Agric. Bot. Gand, II. 326, t. 81, fig. 8 (1846).
QUEEN VICTORIA. Van Hulle in Rev. Hort. Beige, III. 4, t. fig. 1 (1877).
RAYON DU MATIN. Morren in Ann. Soc. Agric. Bot. Gand, II. 9, t. 106, fig. 18
(1847).
REINE D'ANGLETERRE. Spae in Ann. Soc. Agric. Bot. Gand, II. 326, t. 81, fig. 4
(1846).
RICHARDII. Lemaire in III. Hort. II. pi. 75, fig. 11 (1855).
ROSALIE. Morren in Ann. Soc. Agric. Bot. Gand, III. 9, t. 106, fig. 15 (1847).
ROSEA FORMOSISSIMA. Lemaire in III. Hort. II. pi. 75, fig. 3 (1855).
ROSEA LINEATA. Lemaire, 1. c. fig. 8 (1855). — Ottolander, Nederl. FL Pom. 51,
t. 15, fig. 4 (1876).
ROSEA ROTUNDIFLORA. Lemaire, L c. fig. 5 (1855).
RUBENS. Spae in Ann. Soc. Agric. Bot. Gand, II. 326, t. 81, fig. 12 (1846).
RUBRA SPLENDIDISSIMA. Lemaire in III. Hort. II. pi. 75, fig. 2 (1855).
ILLUSTRATIONS 205
SAPPHO. Moore in Fl. Pomol. 1880, 89, t. 516, fig. 3 = R. gandavense plenum.
SOUPIR DU CREPUSCULE. Morren in Ann. Soc. Agric. Bot. Gand, III. 9, t. 106,
fig. 20 (1847).
SOUVENIR DE MORTIER. Van Hulle in Rev. Hort. Beige, III. 4, t. fig. 2 (1877).
SOUVENIR DE ROYGHEM. Ottolander, Nederl. FL Pom. 51, t. 15, fig. 6 (1876).
SPIGELIUS. Morren in Ann. Soc. Agric. Bot. Gand, III. 9, t. 106, fig. 17 (1847).
TRIOMPHE DE ROYGHEM. Spae in Ann. Soc. Agric. Bot. Gand, II. 326, fig. 3
(1846).
TSARINE. See Czarine.
VAN DYCK. Spae in Ann. Soc. Agric. Bot. Gand, II. 326, t. 81, fig. 11 (1846).
VIRGILE. Vandevoorde in Rev. Hort. Belg. XIX, 232, t. fig. 2 (1893). — Reiter
in Gartenwelt, XV. 493, fig. (1911). = R. mixtum.
206 ADDITIONS
ADDITIONS
P. 29. Add to the synonyms of R. obtusum:
Rhododendron amoenum var. obtusum Zabel in Mitteil. Deutsch. Dendr.
Ges. XL 35 (1902).
P. 32. Add to the synonyms of R. obtusum f. amoenum:
Rhododendron amoenum var. euamoenum Zabel in Mitteil. Deutsch.
Dendr. Ges. XL 35 (1902).
Rhododendron amoenum subvar. normale Zabel, I. c. (1902).
Rhododendron amoenum subvar. genuinum Zabel, I. c. (1902).
Rhododendron amoenum subvar. Buergeri Zabel, I. c. (1902).
P. 33. Add to the synonyms of R. obtusum f. japonicum:
Rhododendron amoenum subvar. japonicum, Zabel in Mitteil. Deutsch.
Dendr. Ges. XI. 35 (1902).
P. 105. Add as a doubtful name:
Rhododendron boninense Nakai in Tokyo Bot. Mag. XXXIV. (324)
(1920), name only.
INDEX
INDEX
Synonyms are printed in Italics; new names and new combinations in bold-face type ; garden names
and doubtful names under Azalea in Roman.
Anthodendron, 115
— flavum, 103
— nudiflorum, 135
— ponticum, 103
— viscosum, 158
Azalea, 22, 115, 124
— subgen. Euazalea, 79, 124
— subgen. Pentanthera, 124
— subgen. Tsutsutsi, 22
— Agemaki, 38
— Aioi, 38
— Aka-yodogawa, 64
— alba, 68, 137
— Alba insignis, 48
— albicans, 180
— Albrechtii, 91
— Alice Sargent, 44
— altaclarensis, 182
— Alphonse Lavallee, 102
— America, 71
— amoena, 32
alba, 31
Caldwetti, 32
Hatsu-giri, 32
— Anthony Roster, 203
— arborea, 103, 167
— arbor escens, 166
— Asagasumi, 37
— atlantica, 148
luteo-alba, 150
— Atrorubens nova, 203
— aurantiaca, 128, 130
— austrina, 146
— Avalanche, 182
— Aya Kammuri, 37
— Azuma Kagami, 37
— balsaminaeflora, 26
— Baron Edmond de Rothschild, 102
— Baron G. Pycke, 203
— Baroness Rothschild, 97
— Bealii, 49
— Beaute de Flandre, 203
— Benifude, 37
— Beni-renge-tsutsiji, 101
— bicplor, 143
— Bijinsui, 37
— Bijou de Gandbrugge, 203
— Bonneur de la Belgique, 203
— Botan tsutsuji, 65
Azalea Bouquet de Flore, 203
— Breynii, 23
— Bride, 25
— Brookline, 44
— calendulacea, 126, 127, 132
alba bicolor, 197
astreans, 197
chrysolecta, 197
coccinea fulgens, 197
cristata, 197
crocea, 130
cupraea, 139
cuprea elegans, 197
fenestrata, 197
flammea, 131, 176
frigida, 177
fulgens excelsa, 197
fulgida, 177
fulgina, 177
grandiflora, 197
ignescens, 197
lepida, 177
Morterii, 176
recurya, 197
sanguinea, 197
Saturnea, 197
splendens, 197
Stapletoniana, 177
Sterniana, 198
subcuprea, 177
triumphans, 198
var. a, 131
a., 130
— calij 'ornica, 126
— canadensis, 121
— Candida, 146
— canescens, 139, 143
— Cardinal, 203
— carnea, 137
— caroliniana, 168, 198
— Centi Striatella, 97
— Charles Encke, 27
— Charles Kekule, 102
— Chevalier A. de Reali, 102
— coccinea, 131
aurantia, 131
major, 130, 131
— Coccinea speciosa, 203
— Comte de Gomer, 102, 203
209
210
INDEX
Azalea Comte Papadopoli, 102
— Comtesse de Kerchove, 203
— Consul Pecher, 102
— crispiflora, 27
— Cuprea eximia nova, 203
— Czarine, 203
— Damask Rose, 72
— Danielsiana, 23
— Daviesii, 182
— Decora, 44
— decumbens, 23
— Delicata nova, 203
— dianthiflora, 76
— dilatata, 84
— Director Rodigas, 99
— Double Blush, 138
— Dr. Masters, 99
— Due de Nassau, 44
— Due d'Ursel, 203
— Ebenezer Pyke, 97
— Edouard Andre", 99
— Eeckhautei, 187
— erecta foliis ovatis integris altemis flore
luteo piloso praecoci, 128
— fitendard, 203
— Eugenie, 203
— Exquisite, 98, 180
— fasciculata, 198
— fastigiata, 198
— Farrerae, 80
— fimbriata, 105
— Firefly, 33, 44
— flssa, 166
— Flambeau, 44
— flammea, 127
— flava, 103, 128
— Florentina, 203
— floribunda, 161
— fragrans, 167, 190
— Francois de Taye, 203
— Fudesute Yama, 37
— Fuji-manyo, 64
— fulva, 131
— Furstin Baro Trysky, 49
— Gandavensis, 179
— Garnet, 43, 44
— Ge*ant des batailles, 203
— glauca, 161
flore se?nipleno, 166
. hispida, 163
plena, 166
purpurascens, 161
rosea, 161
— Gledstanesii, 27
— Gloire de Verschaffelt, 203
— Goldlack, 103
— Gosho Zakura, 38
— Graciosa, 98, 180
— Graf von Meran, 98, 203
— Grand-Due, 203
Azalea Hachika Tsugi, 37
— Hana Asobi, 38
— Hana-guruma, 78
— Hatsu-giri, 33
— Havemeyer, 44
— Hebe, 44
— Helena, 44
— Hennione, 44
— Hexe, 33, 44
— Hilda Hedlund, 44
— Hinodegiri, 38
— Hinode No Taka, 38
— Hino-tsukasa, 30
— Hiryu, 30
— hispida, 163
— Hiwoge-yodogawa, 60
— Holm Lea, 44
— Hoo, 37
— hybrida Daviesii, 182
enneandra, 190
— Ignaea nova, 203
— indica, 22, 29, 38, 45
alba, 68
amoena, 32
angustifolia, 23
calycina, 63
crispiflora, 27
exquisita, 26
floribunda, 23
grandiflora, 27
Hexe, 44
hybrida, 62
ignescens, 45
Iveryana albo-cincta, 26
Kaempferi, 38
lateritia, 23
obtusa, 29
obtusa alba, 31
phoenicea, 61
plena, 73
punctulata, 25
punicea, 45
— • — purpurea, 73
purpurea plena, 73
Rawsonii, 61
roseum, 72
rosiflora, 26
Simsii, 45
spatulata, 23
var. 7., 61
variegata, 26
vittata, 48
vittata punctata, 49
— Ima Shojo, 37
— Irohayama, 37
— Iso-tsutsuji, 73
— Iveryana, 27
— japonica, 99
alba grandiflora Van Noordt, 71
grandiflora superba, 72
INDEX
211
Azalea Jas. H. Laing, 203
— Jedogawa-tsutsuji, 70
— J. T. Lovett, 25
— Jupiter, 44
— Kaempferi, 38
— Kasane Kagaribi, 37
— Kasumi Gaseki, 37
— Katsura No Hana, 37
— Kimigayo, 37
— Kin-np-zai, 27
— Kinshibe-tsutsuji, 42
— Ki-renge-tsutsuji, 102
— Kirin, 37
— Kirishima-tsutsuji, 30
— Kiritsubo, 37
— Ki-tsutsuji, 102
— Kochonomai, 33
— Kocho-zoroi, 77
— Komanyp-satsuki, 26
— Kumagai-yodogawa, 64
— Kumo No Uye, 37
— Kurai No Himo, 38
— Kureno Yuki, 37
— Kurofune-tsutsuji, 90
— lateritia, 23
— kdifolia, 68
alba pleno, 72
Noordtiana, 71
phoenicea, 62
— liliiflora, 68
— linearifolia, 74
— Louis Aime Van Houtte, 98, 204
— Louis Hellebuyck, 204
— lucida, 198
— lucida, 162
— lugens, 105
— lutea, 127, 134, 143
— macrantha, 23
— macrosepala, 75
— Madame Alex. Hardy, 204
— Madame Camille van Langenhone,
97
— Magnifica, 98
— magnifica, 72, 192
— Magnifica albicans, 204
— marginata, 181
— Marie-Dorothe'e, 204
— Mars, 44
— Mattapan, 71
— Maxwellii, 64
— Milton, 98
— Mina Van Houtte, 204
— Minerve, 204
— Miniata floribunda, 204
— Miss Louisa Hunnewell, 97
— Mochi-tsutsuji, 75
— mollis, 95, 100
— Mollis var. albicans, 204
— Mollis var. aurea floribunda, 204
— mollis flore-pleno, 183
Azalea mollis glabrior, 99
X sinensis, 97
— Momp-iro-yodogawa, 73
— Mortieri, 176
— Mortieriana, 176, 179
— Mrs. Carmichael, 33
— mucronata, 68
— Murasaki-botan-tsutsuji, 73
— Murasaki Yama-tsutsuji, 43
— Muriel, 44
— Murillo, 98, 204
— Nani Wagata, 37
— narcissiflora, 71, 98, 204
— Natalie, 44
— neglecta, 149
— Ne plus ultra, 204
— Neron, 204
— Nicolas II, 204
— nitida, 157, 162
— Nobilis, 204
— Nonpareil, 97
— nudiflora, 127, 131, 134, 139, 143, 147
alba, 137, 141
albo-plena, 138
amoena, 198
bicolor, 143
blanda, 198
calycosa, 198
canescens, 143
carnea, 137
caroliniana, 198
ciliata, 126
Coburgia, 198
coccinea, 131
colorata, 198
conspicua, 198
corymbosa, 198
crispa, 198
cumulata, 198
discolor, 198
fastigiata, 198
flore pleno, 138
florida, 198
glandifera, 138
globosa, 199
glomerata, 199
grandiflora, 199
incana, 199
incarnata, 199
lutea, 128
mirabilis, 199
mixta, 199
montana, 199
ochroleuca, 199
pallida, 199
paludosa, 199
papilionacea, 199
partita, 199
paryiflora, 199
periclymenoides, 199
212
INDEX
Azalea nudiflora periclymenoides, 135
polyandra, 199
prolifera, 200
pumila, 200
purpurascens, 200
purpurea, 200
purpureo-plena, 138
rosea, 139
ruberrima, 200
rubescens, 200
rubicunda, 200
rubra, 138
rubro-plena, 138
ruf a, 200
rutilans, 200
rutilans, 132
sdntillans, 178
semi-duplex, 200
semi-duplex, 138
serotina, 200
staminea, 200
stellata, 200
thyrsiflora, 132
tricolor, 176
varia, 200
variabilis, 201
variegata, 201
versicolor, 201
violacea, 201
X sinensis, 183
— oblongifolia, 150
— obtusa, 29
alba, 31
— occidentalis, 126
"Hybrids," 98
X arborescens X mollis, 180
— octandra, 200
— odorata, 190
— Oino Mezame, 37
— Oldhamii, 67
— Omoine, 37
— Omurasaki-tsutsuji, 62, 63
— Optima, 48
— Orange peinte, 204
— 0-riukiu-tsutsuji, 71
— Osaraku, 37
— Osaraku Seedling, 38
— Oscar premier, 204
— Otome, 37
— Oyeyama-tsutsuji, 78
— pallida, 190
— papilionacea, 199
— periclymena, 135
— periclymenoides, 135
alba pleno, 138
carnea, 137
coccinea, 131
papilionacea, 199
partita, 199
polyandra, 199
Azalea periclymenoides rubra pleno, 138
rutilans, 200
— Perle du printemps, 204
— Ph6b<§, 204
— phoenicea, 61
— pontica, 103
autumnalis, 103
calendulacea, 128
coronaria /3. ardens, 178
coronaria a. flavum, 178
flava, 103
Goldlack, 103
macrantha, 204
— — sinensis, 95
et var., 179
versicolor, 177, 204
X evergreen Rhododendron, 192
— pontica-rubescens, 178
— Prince Albert, 48
— Prince Henri des Pays-Bas, 204
— Prince Troubetzkoy, 204
— prinophylla, 139
— prolifera, 73
— prunifolia, 169
— pulchella canninea, 201
roseola, 201
— punctata, 105
— punctulata omnicolor, 25
variegata, 25
— punicea, 61
— purpurea pleno, 73
— Quadricolore, 204
— Queen Victoria, 204
— quinquefolia pink, 93
— Racine, 98
— ramentacea, 31
— ramis infra foliosis, 158
— Rasho Mon, 37
— Rawsonii, 61, 196
— Rayon du Matin, 204
— Reine d'Angleterre, 204
— Reine Louise, 27
— Renge-tsutsuji, 101
— reticulata, 84
— Reyndersiana, 196
— rhombica, 84
— Rice Azalea, 54
— Richardii, 204
— Rjuku Tsutsusi fl. igneo, 103
— Rollissoni, 26
— rosaeflora, 26
— Rosalie, 204
— rosea, 138
— Rosea formosissima, 204
lineata, 204
rotundiflora, 204
— Rose Queen, 44
— rosmarinifolia, 68
alba, 69
narcissiflora, 71
INDEX
213
Azalea rosmarinifolia purpurea, 63
— Rubens, 204
— rubicunda, 200
— nibra, 201
— Rubra splendidissima, 204
— Ruby, 44
— rustica flore-pleno, 98, 183
— Sakura Tsukasa, 38
— salicifolia, 201
— Saotome, 37
— Sappho, 205
— Satsuki, 25
— Satsuki-tsutsuji, 24
— scabra, 161, 163
— scapo nudo floribus confertis termina-
tricibus staminibus declinatis, 135
— Schlippenbachii, 89
— Schone von Giessen, 181
— Seikai, 37
— Seikan-tsutsuji, 77
— serotina, 166
— serpyllifolia, 53
— serrulata, 153
— Seymouri, 185
— Shide-satsuki, 27
— Shiki-takane-satsuki, 26
— Shin Seikai, 37
— Shintoki No Hagasane, 26
— Shin Utena, 37
— Shirobana-unzen-tsutsuji, 54
— Shiro-manyo-tsutsuji, 72
— Shiro-yodogawa, 70
— sinensis, 95
alba, 183
Bylsiana, 183
coccinea, 181
genuina, 95
glabrior, 99
macrantha, 183
— Soupir du Cre"puscule, 205
— Souvenir de Mortier, 205
— Souvenir de Royghem, 205
— spathulata, 162
— speciosa, 131
acutifolia, 201
aurantia, 131
aurantiaca, 131
ciliata, 201
coccinea, 201
coccinea, 132
crispa, 201
cucullata, 201
major, 131
obliqua, 201
prunifolia, 201
purpureo-aurantiaca, 201
revoluta, 201
tortulifolia, 201
undulata, 202
— Spigelius, 205
Azalea squamata, 80
— squamosa, 80
— sublanceolata, 59
— Suetsumu. 37
— Suga No Ito, 37
— Suiyohi, 37
— Superba, 98
— Tado Guno, 64
— Takasago, 37
— Tamafuyo, 37
— Tama No Utena, 38
— Tancho, 37
— Tasso, 98
— The Bride, 25
— Thunbergii, 29
— Token, 25
— tomentosa, 162
— tricolor, 176
— Triomphe de Royghem, 205
— Tsarine, 205
— Tschonoskii, 55
— Tsuta Momiji, 37
— Ukamuse, 38
— Uncas, 44
— Van Dyck, 205
— Van Houttei flare pleno, 179
— Vaseyi, 122
— Venus, 44
— Verna Berger, 181
— versicolor grandiflora, 177
— verticillata, 167
— Vervaeniana, 48
alba, 48
— Victoria regina, 99, 193
— virens, 157
— Virgil, 183
— Virgile, 98, 205
— viscosa, 153, 157, 166
crispa, 202
dealbata, 202
flssa, 166
flore pleno, 166
floribunda, 161
glauca, 161
glauca flore pleno, 166
hispida, 163
nitida, 162
ornata, 178
palustris, 157
penicillata, 202
praecox, 202
pubescens, 161
rubescens, 161
stricta, 202
tomentosa, 162
variegata, 202
violae odore, 202
— viscocephala, 182
— viscosepala, 182
— vittata, 48, 105
214
INDEX
Azalea vittata Bealii, 49
— vittato-punctata, 49
— Vivid, 44
— Vulcan, 44
— Vuylestekeana, 44
— Waka Kayede, 37
— Weyrichii, 82
— Yama tsutsuji, 40
— Yayegiri, 30
— Yayehiryu, 37
— Yedogawa Satsuke, 70
— Yin-shan-hung, 47
— Yodogava, 64
— Yorozuyo, 37
Azaleae Gandavenses, 179
— Mortierianae, 176, 179
Azaleodendron, 188, 194
— " Comte de Kerchove," 194
Beverinckia, 22
Biltia, 119
— Vaseyi, 122
Chamaerhodendron exoticum amplissi-
mis floribus liliaceis, 24
Chamaerhododendros, 121
— Pontica maxima Mespili folio flore
luteo, 104
— Virginiana Periclymeni flore am-
pliori minus odorato, 135
Cistus Indicus Ledi Alpinifoliis & flori-
bus amplis, 25
— Virginiana flore et odore Periclymeni,
143
flore et odore Periclymeni, 158
Periclymeni flore ampliori et minus
odorato, 135
Hochenwartia, 119
— canadensis, 120
Loiseleria, 22
Osmothamnus fragrans, 191
— pallidus, 191
Rhodazalea, 188
— Crouxii, 194
flore pleno, 195
Rhododendro-Azalea, 188
Rhododendron a. Anthodendron, 115, 124
— sect. Azalea, 79, 119, 124
— sect. Euazalea, 124
— sect. Pentanthera, 95, 124
— sect. Pentanthera, 115
— sect. Pentanthera X Leiorhodion, 188
— sect. Pentanthera X Rhodora, 185
— sect. Rhodora, 91, 119
— sect. Rhodora, 79
Rhododendron sect. Sciadorhodion, 79
— sect. Toutousi, 22
— sect. Tsusia, 22
— sect. Tsutsugi, 22
— sect. Tsutsutsi, 22, 79, 187
— subgen. Anthodendron, 115
— subgen. Anthodendron X Eurhoden-
dron, 188
— subgen. Azalea, 115
— subgen. Tsutsia, 22, 79
— Adamsii, 190
— alabamense, 141
— albicans, 97, 180
— Albrechtii, 91
— amoenum, 32
Buergeri, 206
euamoenum, 206
genuinum, 206
japonicum, 33, 206
normale, 206
obtusum, 206
— Anneliesae, 181
— arborescens, 166
— — Richardsonii, 168
X calendulaceum, 181
X Mortieri, 178
— atlanticum, 147
luteo-album, 150
neglectum, 149
— atrovirens, 50
— austrinum, 146
— azaleodendron, 194
— azaleoides, 188
— azaleoides, 190, 191
alba odorata, 190
crispiflorium, 196
inodorum, 188
odoratum, 190
— bicolor, 143
— bigener, 189
— boninense, 206
— breviperulatum, 28
— Breynii, 23
— broughtonianum, 194
— brougtonii aureum, 99
— broughtonii aureum, 194
— Buergeri, 32
— Burmanni, 68
— calendulaceum, 127
— calendulaceum, 132
aurantiacum, 131
aurantium, 130
chrysolectum, 197
croceum, 130
cupreum, 139
flammeum, 131
fulgidum, 177
grandiflorum, 197
ignescens, 197
Upidum, 177
INDEX
215
Ehododendroncalendulaceum M orteri, 1 76
speciosum, 132
splendens, 197
Stapletonianum, 177
subcupreum, 177
triumphans, 198
X ? catawbiense, 191
X nudiflorum, 176
X occidentale, 181
X speciosum, 176
X viscosum, 182
— Calleryi, 45
— calycinum, 63
— canadense, 120
albiflorum, 122
album, 122
viridifolium, 122
X japonicum, 103, 185
X luteum, 185
— candidum, 146
— canescens, 143
— canescens, 139
candidum, 146
subglabrum, 145
— carneum elegantissimum, 193
— Cartoni, 189
— Cartonianum, 189
— caryophyllum, 52
— Comte de Kerchove, 194
— coreanum, 65
— crispiflorum, 27
— Crouxii, 194
plenum, 195
— Danielsianum, 23
— decandrum, 84
— Deception, 192
— decumbens, 23
— dianthiflorum, 76
— dilatatum, 83, 86
decandrum, 84
typicum, 87
— discolor X occidentale, 192
— Eeckhoutei, 187
— elegantissimum, 191
— enneandrum, 190
— eximium, 192
— Farrerae, 79
— Farrerae, 81
leucotrichum, 81
mediocre, 81
typicum, 80
Weyrichii, 81
— flammeum, 132
— flavum, 103
ardens, 178
coronarium, 103, 178
macranthum, 105
Seymourii, 185
versicolor, 177
— fragrans, 190
Rhododendron fragrans, 190, 191
— Fraseri, 103, 185
— gandavense, 178
plenum, 179
X ? catawbiense, 192
X Kosterianum, 183
X molle, 183
X occidentale, 180
— gemmiferum, 189
— glaucum, 161
— gnaphalocarpum, 81
— Gowenianum, 189
— hallaisanense, 65
— hangnoense, 23
— hispidum, 163
— hybridum, 189
— hybridum enneandrum, 190
glaucum, 189
— indicum, 22
— indicum, 45, 59
amoenum Buergeri, 32
amoenum genuinum, 32
amoenum japonicum, 33
amoenum normale, 32
balsaminaeflorum, 26
brachytrichum, 23
Buergeri, 32
crispiflorum, 27
eriocarpum, 49
exquisitum, 26
formosanum, 45
Hakatajiro, 26
hakatashiro, 25
H exe, 44 .
incarnatum, 73
ignescens, 45
japonicum, 33
Kaempferi, 38
Kaempferi subalpina, 32
kinnozai, 26
Kirishima, 29
laciniatum, 27
laciniatum, 27
lateritium, 23
macranthum, 23
macranthum genuinum, 23
macrostemon, 31
Matsushima, 26
mikawanum, 43
obtusum, 29
obtusum album, 31
phoeniceum, 61
polypetalum, 27, 105
polypetalum, 27
pulchrum, 62
puniceum, 45
purpureum, 61
Rollisoni, 26
rosiflorum, 26
Simsii, 45, 65
216
INDEX
Rhododendron indicum sinensis, 59
Smithii, 62
spedosum, 61
subalpina, 32
sublanceolatum, 59
Tamurai, 45
tanimanoyuki, 26
var. 45
variegatum, 26, 105
X Kaempferi, 72
X linearifolium, 187
X mucronatum, 187
X Simsii, 187
— japonicum, 99
aureum, 102
X Eurhodendron " hybrids,"
194
X molle, 183
X midiflorum, 83
— Jodogawa, 59
— Kaempferi, 38
album, 41
amoenum, 32
japonicum, 33
Kinshibe, 42
Komatsui, 42
macrostemon, 31
mikawanum, 43
plenum, 41
X rosmarinifolium, 64
— Kanehirai, 28
— kiusianum, 33
— Kosterianum, 97, 183
X Eurhodendron hybrids, 194
— Laetitiae, 192
— lasiostylum, 50
— lateritium, 23
brachytrichum, 23
— ledifolium, 68
album, 69
cryptopetalum, 42
Hanaguruma, 77
Kochozoroi, 77
leucanthum, 69
narcissiflorum, 71, 73
Noordtianum, 71
phoeniceum, 61, 62
plena purpurea, 73
purpureum, 59, 63
— leucanthum, 68
— liliiflorum grandiflorum souchetianum,
69
— linearifolium, 74, 105
decandrum, 77
dianthiflorum, 76
hanaguruma, 77
linearifolium, 74
macrosepalum, 74
macrosepalum genuinum, 75
polypetalum, 77
Rhododendron linearifolium rhodoroide s ,
77
— liukinense, 59
— longiperulatum, 67
— Loureiriana, 105
— luteum, 103
— luteum, 128
flammeum, 131
macranthum, 105
X nudiflorum, 177
X ponticum, 192
X speciosum, 178
X viscosum, 178
— macranthum, 23
albiflorum Souchetianum, 68
polypetalum, 105
semper flor ens, 105
— macrosepalum, 74
Amaga-shita, 78
Hanaguruma, 77
linearifolium, 74
— — Osuyo, 78
rhodoroides, 77
Suruga-momyo, 78
— macrostemon, 31
— Mariae, 58
— Mariesii, 80
— Matsumurai, 64
— Maxwellii, 64
— microphyton, 57
— mixtum, 98, 183
— molle, 95
— molle, 97, 99
glabrior, 99
X arboreum, 193
X (maximum X ponticum), 193
X occidental*, 98, 180
X sinense, 97
X speciosum, 181
X viscosum, 182
— Morterii, 176
cornea, 176
— Mortieri, 176
X luteum, 178
X viscosum, 178
— mucronatum, 68
amethystinum, 73
Mattapan, 71
narcissiflorum, 71
Noordtianum, 71
plenum, 73
ripense, 72
sekidera, 72
X scabrum, 187
— Nakaharai, 54
linearifolium, 105
— narcissiflorum, 71
— nipponicum, 93, 119
— nitidum, 162
— Norbiton hybrids, 98, 193
INDEX
217
Rhododendron norbitonense, 193
aureum, 193
broughtonianum, 194
— nudiflorum, 134
— nudiflorum, 139, 143
aWo-plenum, 138
album, 137
blandum, 198
carneum, 137
carolinianum, 198
Cartpni, 189
coccineum, 132
corymbosum, 198
crispum, 198
cumulatum, 198
discolor, 198
eximium, 192
fastigiatum, 198
floridum, 198
glandif erum, 138
globosum, 199
glomeratum, 199
Govenianum, 189
incanum, 199
incarnatum, 199
luteum, 146
mirabile, 199
montanum, 199
pallidum, 199
paludosum, 199
papilionaceum, 199
partitum, 199
parviflorum, 199
polyandrum, 200
proliferum, 200
pumilum, 200
purpurascens, 200
purpureo-plenum, 138
purpureum, 200
roseum, 139
ruberrimum, 200
rubescens, 200
rubicundum, 200
rubro-plenum, 138
rubrum, 138
rw/wra, 200
rutilans, 200
sdntillans, 178
semiduplex, 138, 200
stamineum, 200
stellatum, 200
tricolor, 176
varidbilis, 201
variegatum, 201
versicolor, 201
violaceum, 201
X catawbiense, 189
X (catawbiense X ponticum), 189
X ponticum, 188
— obtusum, 29
Rhododendron obtusum, 33
albiflorum, 41
album, 31
amoenum, 32
amoenum, 32
cryptopetalum, 42
Honkirishima, 29
japonicum, 33
Kaempf eri, 38
Komatsui, 42
mikawanum, 43
monstrosum, 42
multicolor, 41
macro stemon, 31
plenum, 41
— oblongifolium, 150
— occidentale, 125
sonomense, 127
X (arborescens X japonicum), 180
X discolor, 192
X moWe X " Ghent Azaleas," 98,
183
X sinense, 98
— odoratum, 190
— Oldhamii, 66
glandulosum, 67
— Oomurasaki, 63
— ornatum, 178
incarnatum, 178
luteum, 178
roseum, 178
speciosum, 178
— Osakazuki, 63
— pallidum, 191
— pentaphyllum, 92
nikoense, 92
— phoeniceum, 61
— phoeniceum, 64
calycinum, 63
./tore pZeno, 73
Maxweffii, 64
semiduplex, 62
Smithii, 62
splendens, 63
splendens, 63, 196
tebotan, 64
— ponticum, 103
azaleoides, 188
deciduum, 188
odoratum, 190
subdeciduum, 188
Torloniana, 191
— poukhanense, 43, 65
acutifolium, 43
obtusifolium, 43
plenum, 64
yodogawa, 64
— prinophyllum, 139
— prunifolium, 169
— pulchrum, 62
218
INDEX
Rhododendron puniceum, 61
— purpureum, 43
— quinquefolium, 87
roseum, 92
— ramentaceum, 31
— reticulatum, 83
albiflorum, 86
pentandrum, 86
— Rhodora, 120
albiflora, 122
— rhombicum, 81, 83
albiflorum, 86
— ripense, 72
— roseum, 138
— roseum odoratum, 191
— rosmarinifolium, 69
album, 69
Fujimanyo, 73
narcissiflorum, 72
Oriukiu, 71
purpureum, 63
Sekidera, 72
Shiromanyo, 72
speciosum, 63
— rubropilosum, 52
— Sanderi, 43, 187
— scabrum, 59
— scabrum, 43
angustifolium, 38
coccineum, 61
Kaempferi, 38
latifolium, 38
purpureum, 43
tubiflorum, 38
— Schlippenbachii, 88
— Seniavinii, 57
— Sekidera, 72
— serpyllifolium, 53
— serpyllifolium, 54
albiflorum, 54
— serrulatum, 153
georgianum, 156
molliculum, 155
— Seymouri, 185
— shikokianum, 82
— shojoense, 81
— Sieboldii, 38
• ellipticum, 60
minor, 29
serrulatum, 23
— Simsii, 45
Bealii, 49
eriocarpum, 49
vittatum, 48
X R. obtusum, 43, 187
— sinense, 95, 97, 99, 102
flammeum, 95
flavescens, 95, 102
X Eurhodendron, 98, 193
X molle, 97
Rhododendron Smithii aureum, 98
— Smithii aureum, 193
— sonomense, 127
— speciosum, 131
— speciosum, 131
acutifolium, 201
aurantium, 131
ciliatum, 201
crispum, 201
cucullatum, 201
major, 132
obliquum, 201
prunifolium, 201
revolutum, 201
tortuifolium, 201
tortulifolium, 201
undulatum, 202
X arboreum, 192
X molle, 181
— sublanceplatum, 59
— sublateritium, 59
— subsessile, 51
— Tebotan, 64
— Thunbergii, 29
— Tolerianum, 191
— tosaense, 52
— tricolor, 176
— trinerve, 55
— Tschonoskii, 55
pentanerum, 55
tetramerum, 55
trinerve, 55
typicum, 55
— Vaseyi, 122
album, 123
— venustum, 135, 157
— viscosepalum, 182
Daviesii, 182
— viscosum, 157
— viscosum, 153
aemulans, 165
coerulescens, 165
crispum, 202
dealbatum, 202
fissum, 166
glaucum, 160
hispidum, 163
montanum, 164
nitidum, 162
ornatum, 178
penicillatum, 202
pubescens, 161
rhodanthum, 160
roseum, 161
rubescens, 161
rubescens, 161
tomentosum, 162
variegatum, 202
X ? catawbiense, 190
X maximum, 189
INDEX
219
Rhododendron viscosumX ponticum, 190
— vittatwn, 49
Bealii, 49
punctata, 49
— Wadanum, 84
— Weyrichii, 82
— Weyrichii, 81, 89
— Williamsii, 194
Rhododendron yedoense, 64
poukhanense, 65
— Yodogawa, 64
Rhodora, L., 119
— canadensis, 120
Theis, 124
Tsutsutsi, 22
14 DAY USE
RETURN TO DESK FROM WHICH BORROWED
LANDSCAPE Aivs^TIZCTURE LIBRARY
This book is due on the last date stamped below, or
on the date to which renewed.
Renewed books are subject to immediate recall.
General Library
University of California
Berkeley
LD 21-50m-8,'57
(C8481slO)476
U.C. BERKELEY LIBRARIES
SANTA BARBARA
BINDERY