Bulletin of the Natural History Museum

Bulletin of
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"STORY MUSEUf

26 NOV 1997

Botany Series

THE

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HISTORY
MUSEUM

VOLUME 27 NUMBER 2 27 NOVEMBER 1 997

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© The Natural History Museum, 1997

Botany Series
ISSN 0968-0446 Vol. 27, No. 2, pp. 77-147

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London SW7 5BD Issued 27 November 1997

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Bull. not. Hist. Mus. Loncl. (Bot.) 27(2): 77-147

Issued 27 November 1997

Systematics of Pogostemon (Labiatae)

THE NATURAL
HISTORY MUSEUM

G. RAZA BHATTI* and MARTIN INGROUILLE

Biology Department, BTrkbeck College, University of London, Malet Street, London WC1E 7HX
^Present address: Botany Department, Shah Abdul Latif University, Khairpur, Sindh, Pakistan

t NOV I99/

PRESENTED
GENERAL LIBRARY

CONTENTS

Introduction 77

History of the classification of Pogostemon 78

Materials and methods 79

Results 79

Summary of infrageneric classification 79

Character variation 80

Indumentum and glands 80

Stem 80

Leaves 83

Inflorescence 83

Bracts and bracteoles 83

Calyx 83

Corolla 85

Gynoecium 86

Nutlets 86

Systematic account 86

Key to subgenera, section, and subsections 86

Key to species 86

References 1 18

Index ... ... 147

SYNOPSIS. A taxonomic review of the genus Pogostemon Desf. and related genera has been undertaken. About 80-90 species
of Pogostemon sensu lato are currently recognized, 79 of which have been examined for this review. A new infrageneric
classification is presented. The character variation in the genus is described in full with the inclusion of many characters not used
before and a reassessment of previously used characters. Nutlet shape and surface morphology and calyx shape and the
distribution of hairs on the calyx is described systematically for the first time. Taxonomically important characters come from all
parts of the plant but inflorescence type and calyx morphology and hairiness have proved most useful in establishing a clearly
defined infrageneric classification. Keys to infrageneric taxa and species are provided and a systematic account is given of 79
species. Three new species and one new variety are described, P. barbatus, P. ciliatus, P. elatispicatus, and P. erectus var.
diplolobatus .

INTRODUCTION

Pogostemon Desf. is a well defined genus of moderate size. The
presence of exserted stamens bearing moniliform hairs marks it out
from other Labiatae. It is variable with much variation concentrated
in small flowered aquatic and marshland plants and larger flowered
terrestrial herbs or subshrubs. These two kinds of variants have been
recognized as separate genera, subgenera or sections, for example
Dysophylla Blume for the former and Pogostemon sensu stricto for
the latter, but they are linked by species intermediate in various
characters.

Pogostemon sensu stricto includes the most important species
used as a source of patchouli oil. Patchouli oil, a strong scented
essential volatile oil, is extracted from the dried tops. It is used in
incense, perfumes, and cosmetics. Almost all of the patchouli spe-
cies have a well-branched inflorescence. Cultivated species are
marked by their lack of both floral and vegetative diversity. However
several species, somewhat obscurely delimited, have been described.

The recognition of species is made difficult by the introduction of
patchouli plants to new areas and by the development of new
cultivars in different areas. Cultivated species have become natural-
ized so that some are very widespread in nature. Pogostemon
plectranthoides Desf. is widespread throughout India but especially
in the north. Pogostemon heyneanus Benth. is found from Sri Lanka
and southern India through mainland Malaysia and Sumatra to Java.
Pogostemon cablin (Blanco) Benth. is the most scattered, with
populations on Fiji, in the Philippines, Mauritius, as well as Sum-
atra and Thailand. There are a number of geographically restricted
similar taxa. Pogostemon benghalensis (Burm.f.) Kuntze which is
very like P. plectranthoides but has smaller flowers, is concentrated
in the more temperate conditions of northern India, Nepal, China,
and northern Thailand, and P. glaber Benth., which is distinct in leaf
shape and pattern of hairiness, is found over a similar geographical
range. A more in depth examination of the population and geo-
graphical variation of these species may result in the amalgamation
of several species. Without a population study and without cultiva-
tion experiments the currently recognized species have been

© The Natural History Museum. 1997

78

maintained as operational taxonomic units as a first step in a revision
of the infrageneric classification.

Non-patchouli species of Pogostemon sensu stricto are more
diverse and better delineated. For example there is P. litigiosus Doan
with a two-lipped calyx. Species are generally narrowly endemic to
areas such as Sri Lanka or southern India, the eastern Himalayas,
Yunnan, Java, Borneo or southern Africa.

Dysophylla includes all the small flowered species which tend to
have flowers crowded into dense verticillasters. Many species have
a weak stem, probably because they are aquatic or marshland
inhabitants. The calyx is small, translucent, and infundibular with a
wide diameter. Most species have verticillate, linear to linear-
lanceolate leaves. However, there are a number of species which
combine the character states of Pogostemon sensu stricto and
Dysophylla, so that the boundary between these taxa has not always
been stable, with different workers putting the same species into one
or other group or not recognising the groups at all. This is described
in greater detail below.

The study reported here is a re-examination of the variation of
Pogostemon sensu lato leading to the erection of a new infrageneric
classification which is more natural and which may be used as the
basis for future studies at lower taxonomic rank. A cladistic and
phenetic analysis of characters has aided the resolution of new
infrageneric taxa but this has not been used directly because certain
characters, thought to be more constant and reliable, have been
weighted as more important in the classification, but all characters
were weighted equally in the cladistic and phenetic analysis. The
cladistic and phenetic analysis will be reported elsewhere.

History of the classification of Pogostemon

Pogostemon was described by Desfontaines (1815) as a distinct
genus of Labiatae because of its hairy stamens: pogon is Greek for
beard and pogonostemon means 'with bearded stamen' (Steam,
1992). The type species for the genus is P. plectranthoides Desf.
Desfontaines placed his new genus near Hyssopus L. Dysophylla
Blume was described as a distinct genus, related to Pogostemon by
having bearded stamens (Blume, 1 826). Dysophylla had been previ-
ously recognized as distinct by some authors under different names.
Hermann (1717) gave the polynomial Veronica hirsuta latifolia
Zeylanica aquatlca to a species of Dysophylla. Linnaeus (1747)
listed a genus Alopecuro-veronica, a name he later cited as a
synonym of Mentha auricularia (Linnaeus, 1767). The name
Majorana foetida was given as another synonym, a species de-
scribed by Rumphius (1750) as Majana foetida. He described it as
having no close affinity to other species of Mentha. Blume ( 1 826)
cited Rumphius' illustration when he recognized Dysophylla as a
distinct genus based on Dysophylla auricularia (L.) Blume (=
Mentha auricularia L.). Although he placed Dysophylla next to
Mentha L. he considered it different from Mentha by having closure
of the fruiting calyx, fleshy swelling of the disc, and bearded
stamens. At about the same time Blume (1826) published a species
from Java he called P. menthoides Blume. Later, however, Bentham
(1829) questioned the placing of P. menthoides in the genus
Pogostemon because it had naked filaments.

Bentham (1829, 1830, 1832-1836) also widened the concept of
Dysophylla by including species described as Mentha by Loureiro
(1790) and Roxburgh (1814, 1832). Bentham (1830) divided
Dysophylla into two groups on the basis of phyllotaxy, one group
with opposite leaves and the other verticillate leaves. In Labiatarum
genera et species Bentham ( 1 832) formally recognized these groups
as section Oppositifoliae and section Verticillatae. Section
Oppositifoliae, which agreed with Blume's original description of

G.R. BHATTI AND M. INGROUILLE

Dysophylla included three species: D. auricularia, D. myosuroides
Benth., and D. strigosa Benth. In the same work Bentham (1832-
1836) divided the genus Pogostemon into two sections, the
Paniculatae and the Racemosae on the basis of the type of inflores-
cence.

Bentham's splitting of Dysophylla and Pogostemon was taken
further, first by Rafinesque-Schmaltz (1847) and later by Briquet
(1897). Rafinesque-Schmaltz (1847) effectively raised Dysophylla
section Verticillatae to generic rank by publishing a new genus
Eusteralis Raf, which included Mentha pumila Graham and M.
verticillata Roxb. Briquet (1897) subdivided Dysophylla and
Pogostemon into sections and subsections, as follows:

Genus Dysophylla

Sect. l.Rhabdocalicinae Briq. (Calyx tube cylindrical and rounded

or very indistinct, pentagonal)
§1. Oppositifoliae Benth.

A. Perennial species

B. Annual species
§2. Verticillatae Benth.

Sect. II. Goniocalicinae Briq. (Calyx tube prominently five-
angled)

Genus Pogostemon
§1. Section Racemosa Benth.

A. Glabriuscula Briq. (Naked filaments)

B. Barbata Briq. (Hairy filaments)
§2. Section Paniculata Benth.

A. Interrupted verticils

B. Continuous verticils

Kudo (1927) treated Dysophylla and Pogostemon as distinct
genera under subtribe Pogostemoninae. He divided Dysophylla into
two sections:

Section Eudysophylla - stem indumentum tomentose to hirsute and
leaves opposite, broad, ovate-lanceolate, margin serrulate (in-
cludes only D. auricularia).

Section Chotekia - stem glabrous to pubescent and leaves verticil-
late, narrow, linear to linear-lanceolate with an entire margin.

Four species which belong to Bentham's Dysophylla section
Oppositifoliae (D. auricularia, D. myosuroides, D. rugosa Hook.f.
andD. salicifolia Dalzell ex Hook.f.) were transferred toPogostemon
on the basis of having opposite, broad and petiolate leaves, presence
of crystals in the calyx, and absence of an aerenchyma tissue in the
stem (El-Gazzar & Watson, 1967). Wu & Li (1975) also transferred
D. auricularia and D. falcata C.Y. Wu to Pogostemon but without
mentioning any reason for doing so. The removal of D. auricularia,
in particular, posed a nomenclatural problem because it is the type
species of Dysophylla. A solution to this problem was put forward by
Panigrahi (1976) and Bakhuizen van den Brink & van Steenis
(1963), who suggested the generic name Eusteralis Raf. for the
remaining species of Dysophylla, those in section Verticillatae.
Keng (1978) also placed Dysophylla section Verticillatae in
Pogostemon section Eusteralis Raf. However, Panigrahi (1984)
referring to Article 22.4 (I.C.B.N. 78) mentioned that Pogostemon
section Verticillatae Benth. has priority over Pogostemon section
Eusteralis (Raf.) H. Keng.

Several authors found it difficult to distinguish Dysophylla from
Pogostemon (Hasskarl, 1842; Miquel, 1859; Kuntze, 1891; Keng,
1978). Press (1982) criticized Briquet's division of Pogostemon and
Dysophylla because of the obscurity of the characters used. Press'
( 1 982) phenetic analysis of characters found no evidence for the
grouping of taxa as proposed in Briquet's classification.

SYSTEMATICS OF POGOSTEMON

79

MATERIALS AND METHODS

All the specimens listed in the systematic account were examined
and used for data analysis. Some other specimens were rejected
because they were incomplete at the correct state of development or
had no information about their geographical origin. As a result the
following possibly distinct species were not available: Pogostemon
brevicorollus Y.Z. Sun, P. reticulatus Merr., P. falcatus (C.Y. Wu)
C.Y. Wu & H.W. Li, P. szemacensis (C.Y. Wu & S.J. Hsuan) Press,
and P. tsiangii (Y.Z. Sun) Press. Herbarium material of Pogostemon
and other genera has been obtained from the herbaria of The
Natural History Museum (BM), the Royal Botanic Gardens, Kew
(K), and the Royal Botanical Garden Edinburgh (E). More than half
of the total number of species under investigation have been re-
ported from India. A field excursion to this country was undertaken
in 1991. The following herbaria of the Botanical Survey of India
were visited: Poona (BSI), Calcutta (CAL), Coimbatore (MH),
Dhera Dune (BSD), and Rabinath Herbarium, St. Joseph College
(RHT).

Wherever doubt existed regarding identification, type material
and the type description have been examined. In eighty-five per cent
of species it was possible to study at least one type specimen. A few
species have been observed in their natural habitat in India. These
include: Pogostemon paniculatus (Willd.) Benth. (not flowering), P.
purpurascens Dalzell (not flowering), P. quadrifolius (Benth.)
Kuntze, P. heyneanus Benth. (cultivated), P. auricularius (L.) Hassk.,
and P. plectranthoid.es Desf. (not flowering). Cultivated material of
P. plectranthoides and P. quadrifolius was available and used to
check that dried material accurately represented the living state.

Descriptions of species in the various Floras of the different
regions were also examined. However, it has been found that many
floristic accounts simply repeat descriptions of earlier workers, even
where these are erroneous. Some specimens have been regularly
misidentified because of the close similarity of a number of species.
For example, the names Pogostemon brachystachyus Benth., P.
fraternus Miq., and P. macgregorii W.W. Sm. have often been
wrongly applied by earlier workers.

Mature plant specimens were selected for examination. The
maximum size of each part of the plant were recorded. However, for
many tall plants, the herbarium sheets have been prepared from only
the upper parts of the plant with the inflorescence. Much longer
leaves are present at the basal part of the plant. For example, in
Pogostemon plectranthoides older leaves towards the basal part of
the stem of about 23 cm long have been observed in living material,
whereas the maximum size in herbarium specimens is about 14 cm.

The small size of the flowers posed many difficulties in carrying
out a detailed study of the calyx and corolla directly from herbarium
material. Flowers ranged from 1.5-4 mm. Permanent slides of the
corollas and calyces, and where possible bracts, were made in order
to record some of the unique characters which have never previously
been fully described. Dried flowers, obtained from herbarium speci-
mens, were boiled in water. Then the soaked corollas and calyces
were dissected to expose their inner sides and mounted on slides
with DPX mountant without any other treatment.

Normally 5-10 calyces and corollas were examined from each
specimen, but, if there was any doubt or complication in scoring the
required information, then the number of samples were increased.
Nutlets were obtained from fruiting calyces. A scanning electron
microscope (JEOL JSM 35CF) study was carried out on nutlet
morphology and hairs at the middle and towards the lower part of the
filaments. Samples were collected from herbarium sheets, mounted
on stubs, and coated with gold by a sputter coater (EMITECH K550)

for 8-12 minutes. Almost all of the samples examined were air dried,
but a comparison was made with fresh material, dried using a critical
point drier (POLARON) to confirm characterization.

Data were subjected to cladistic analysis and phenetic analysis
(Bhatti, 1995). Details and a comparison of the results of different
cladistic and phenetic analysis will be reported elsewhere.

RESULTS

For this study most species currently recognized in floristic works
were maintained. Three new species are described below.

Geographical coverage was patchy. In particular there were few
specimens from China and parts of southeastern Asia. Even in the
Indian sub-continent, from where the majority of samples origi-
nated, it was clear that some geographical areas were much better
represented than others. This may reflect in part the greater floristic
diversity of parts of Assam and Keralia, but also probably reflects the
historical incidence of sampling by individual collectors. The lack of
a good sample of the variation of many species made it impossible at
this stage to consider redefining the limits of most species. Instead
we have concentrated on describing reliable characters for identifi-
cation in the systematic account below. Nonetheless it was clear that
some species are more distinct than others.

An infrageneric classification is proposed which resurrects, at
least in part, that of previous workers. However, the inclusion of new
characters, especially those from a detailed study of floral morphol-
ogy, has allowed subgenera, sections, and subsections to be defined
more clearly. The order of taxa in the systematic treatment is similar
to that in a computed consensus tree obtained by cladistic analysis
but the arrangement is not identical because in the classsification the
characters have been weighted by their ease of use and reliability.
Complex character states and combinations of unitary character
states which may be less likely to exhibit parallel or convergent
evolution have been used to define groups at the higher ranks in the
hierarchy and more simple unitary characters at lower ranks. There
is a shortage of 'good' characters and in some cases a polythetic
approach has been adopted as a more reliable guide to forming a
natural group. In these cases rank has been established with refer-
ence to the magnitude of the taxonomic discontinuity between the
groups and the size of the group, validated where possible with
reference to geographical and ecological data. Some groups are
linked by intermediate species but these have been allocated to the
group which contains their closest relative.

Summary of infrageneric classification

Genus Pogostemon Desf.

I. Subgenus Pogostemon sensu Bhatti & Ingr.

II. Subgenus Allopogostemon Bhatti & Ingr., subgen. nov.

a. Section Racemosus (Benth.) Bhatti & Ingr., stat. nov.

i. Subsection Racemosus

ii. Subsection Glabriusculus (Briq.) Bhatti & Ingr., stat. nov.

b. Section Zygocalyx Bhatti & Ingr., sect. nov.

III. Subgenus Dysophyllus (Blume) Bhatti & Ingr., comb, et stat.
nov.

a. Section Dysophyllus

b. Section Verticillatus (Benth.) Bhatti & Ingr., comb. nov.

Names of infrageneric taxa used in the text below are sensu Bhatti &
Ingr., except where stated otherwise.

The shrubby patchouli species which have been placed here in
subgenus Pogostemon include several rather poorly defined taxa

80

around Pogostemon benghalensis, P. plectranthoides, P. cablin, and
P. heyneanus. Patterns of variation are complicated by the cultiva-
tion of variants which are maintained vegetatively and rarely flower
and their introduction into areas outside the native distribution of the
species. New data are required before they may be considered as
variants of one or more polymorphic species. We have hesitated to
submerge all species of subgenus Pogostemon into a single polymor-
phic species P. plectranthoides sensu lato.

In subgenus Dysophylla a similar population based study is
needed to evaluate the relationship of narrowly restricted endemics
like Pogostemon erectus Kuntze, P. koehneanus (Muschl.) Press,
and P. andersonii (Prain) Press to geographically widespread taxa
like P. stellatus (Lour.) Kuntze, P. crassicaulis (Benth.) Press, and P.
cruciatus (Benth.) Kuntze.

A newly defined group is Pogostemon subgenus Allopogostemon
which consists of most non-patchouli species of Pogostemon sensu
stricto. It is a diverse group with well marked species. Section
Racemosus has eleven species in southern India, five species from
the Philippines, and one from southern Africa. Species of section
Zygocalyx show a trend towards having a two-lipped calyx, with P.
litigiosus the most extreme. This section is centred on an area from
the eastern Himalayas to Yunnan and Thailand but includes three
species endemic to Java, Borneo, and Sri Lanka respectively. Sec-
iionZygocalyx shares some characters with subsectionGlabriusculus
of section Racemosus. Pogostemon wightii Benth. of section
Zygocalyx has a similar shaped corolla to that of species of subsec-
tion Glabriusculus. The calyx of P. reflexus Benth. and P. speciosus
Benth. of subsection Glabriusculus has some teeth rather subulate
and fringed by bristles like section Zygocalyx. The pattern of hairs
on the interior of the calyx of these two groups is homologous.
Pogostemon paludosus Benth. of subsection Racemosus shares char-
acters with subsection Glabriusculus, by having stalked glands on
the nutlets, and section Zygocalyx, by having a somewhat asym-
metrical calyx, but it has moniliform hairs on the stamens and lacks
subulate teeth, the key characteristics of these taxa.

Most species of subgenus Dysophylla have a corolla in which the
separate lobes of the upper lip and the single lobe of the lower lip are
approximately equal, and are shaped so that the corolla has a
symmetry which is nearly radial. Many have linear to linear-lanceo-
late leaves. These are useful key characters but there are a number of
different species in section Verticillatus: Pogostemon andersonii
(Prain) Press, which has two opposite leaves at each node and P.
trinervis Chermsir. ex Press, which has orbicular leaves.

Section Dysophyllus is a poorly delimited group. It includes
species intermediate between section Verticillatus and subgenera
PogostemonandAllopogostemon. The boundary belweenDysophylla
and Pogostemon sensu stricto has taxed previous workers. It has only
been resolved here by recognizing section Dysophyllus for a group
of heterogeneous species which do not fit easily into either subgenus.
Emphasis has been placed here on calyx characters so that species in
section Dysophyllus may have varied characters of Pogostemon
sensu stricto, but have the broadly conical and translucent calyx of
Dysophylla; so, for example, P. amaranthoides Benth. which has
normally been placed within Pogostemon sensu stricto is here placed
in subgenus Dysophyllus.

Pogostemon mutamba (Hiern) G. Taylor and P. micangensis G.
Taylor, the African species, have also traditionally been placed in
Pogostemon sensu stricto. They have the normal zygomorphic co-
rolla of other Pogostemon species from subgenera Pogostemon and
Allopogostemon, but although they also have a calyx with intercostal
veins it is very strongly conical/campanulate like species of subgenus
Dysophylla.

Section Dysophylla is clearly not a natural group and in the future

G.R. BHATTI AND M. INGROUILLE

will be subdivided into several smaller taxa. Data to enable stable
groups to be erected are not yet available.

CHARACTER VARIATION

Indumentum and glands

A significant feature of the genus is the nature and distribution of the
hairs. Most important are the moniliform hairs found on the fila-
ments of almost all species (Fig. 1). Hairs of various other kinds,
simple, stellate, fruticose, and dendromorphic, have been found
elsewhere on plants (Fig. 1). In most species similar kinds of hairs
can be found on all parts of the plant but rarely different parts of the
plant have different hairs. Hairs may be simple or branched. Many
have a swollen basal cell which has different cell contents from the
distal part. These may be glandular trichomes. Hairless glands may
be found intermixed with hairs (Fig. 1 ).

Simple trichomes are either unicellular or uniseriate multicellular.
They are elongated, broader at the base, and gradually tapering
towards the apex. In multicellular types they are generally slightly
swollen at the septa, forming a node. All taxa have multicellular,
simple trichomes except Pogostemon koehneanus and P. peguanus
(Prain) Press which have unicellular hairs on stems, leaves, and
inflorescence. Stellate trichomes have been found only in P.
tuberculosus Benth. On most of the plant the hair branch which
occupies the central position is 2-celled and longer than the others.
The remaining lateral branches, which are unicellular, radiate from
the central one, at 30-40° to the surface. Stellate hairs on the calyx
have 2-3-celled central branches. Fruticose trichomes are composed
of a bunch of branches, attached only at the base. The central branch
is longer than the lateral branches and together they look like a bush.
This type of trichome is found in P. velatus Benth. and P. williamsii
Elmer. Press (1982) reported these trichomes as sessile branched
hairs in comparison to dendromorphic trichomes because they are
without a central boss and have long flexuous branches with each
branch uniseriate and multicellular. However, the use of the term
sessile is unfortunate because this is impossible to determine with-
out branching. Dendromorphic trichomes are branched hairs in
which the basal part is like the main trunk of a tree. This basal part
gives rise to lateral branches of considerable length. The lateral
branches are arranged either in opposite or alternate fashion. Fruticose
and dendromorphic trichome types occur in combination in P.
velatus and P. williamsii, although the leaves and calyces of P.
williamsii have only dendromorphic trichomes. The abaxial leaf
surface of P. elatispicatus Bhatti & Ingr., has both simple and
dendromorphic hairs, whereas other parts of the plant have only
simple hairs.

Stem

Collectors' remarks on herbarium sheets sometimes provide helpful
notes about the form and habit of the plant. The stem is erect in most
species. The exceptions are taxa like Pogostemon auricularius,
which has an aquatic habit. In nature the stems of this species are
prostrate and root at the nodes; it is a straggling plant and spreads
over an area of 1-2 m in marshy places with the erect flowering
branches arising from the main stem in water. The part of the plant
which is used to prepare a herbarium sheet is an erect branch but here
it has been considered as an erect stem. P. rupestris Benth. roots at
the nodes. Many species of subgenus Dysophyllus, especially those
of section Verticillatus, have a weak stem, sometimes contracted at
the internodes and obviously procumbent. In contrast, species of

SYSTEMATICS OF POGOSTEMON
b

81

Fig. 1 Indumentum types observed in Pogostemon: (a) gland without a hair; (b-d) unicellular trichomes, (c, d) with basal glandular cell; (f-j) uniseriate
multicellular trichomes, (e) with basal glandular cell; (k) fruticose trichomes; (l-o) stellate trichomes, (1, n) with unicellular arms, (m, o) with some
multicellular arms, (1, m) sessile, (n, o) stalked; (p, q) dendromorphic, (p) branches opposite, (q) branches alternate; (r, s) moniliform filament hairs.

82

G.R. BHATTI AND M. INGROUILLE

Fig. 2 Leaf forms found in Pogostemon: (a) whorl of five leaves at a node; (b) whorl of three leaves at a node; (c) two leaves opposite at a node; (a, e, f)
linear to linear-lanceolate; (b, c, g-1) ovate to lanceolate; (d) pinnatifid; (1) base cordate; (b-k) base attenuate to truncate; (a, b, e-h) sessile to subsessile;
(c, h-1) petiolate.

SYSTEM ATICS OF POGOSTEMON

subgenus Pogostemon are large semi-woody shrubs or subshrubs.
Most other species are herbs.

Normally the upper part of the stem towards the inflorescence
region is more hairy than lower parts. A study of hairs on the stem
showed a glabrous stem in Pogostemon glaber Benth., P.fraternus
Miq., P. nelsonii Doan, P. travancoricus Beddome, P. pumilus
(Graham) Press, P. lythroides (Diels) Press, P. helferi (Hook.f.)
Press, P. yatabeanus (Makino) Press, P. sampsonii (Hance) Press, P.
stocksii (Hook, f.) Press, P. linearis (Benth.) Kuntze, P. pressii
Panigrahi, and P. faurei (Leveille) Press. Stellate trichomes have
been found on P. tuberculosus. Fruticose and dendromorphic
trichomes are found on P. velatus and P. williamsii. The remaining
taxa have simple hairs. Unicellular hairs have been found on the
stems of P. peguanus and P. koehneanus.

Leaves

Most species have a pair of opposite leaves at each node but among
the species of section Verticillatus the number of leaves at each node
ranges from three to more than ten, with four as the most common
number. The number of leaves is normally constant within species
but variation has been noticed in Pogostemon quadrifolius which has
most nodes with whorls of four leaves, but two leaves at some nodes.
Pogostemon yatabeanus, P. sampsonii, P. crassicaulis, P. koehneanus,
and P. trinervis have three leaves in a whorl. Pogostemon cruciatus
and P. stocksii have five leaves in a whorl. Eight or more leaves are
present in P. erectus, P. deccanensis (Panigrahi) Press, and P.
stellatus.

All species have simple leaves, except Pogostemon tisserantii
(Pellegr.) Bhatti & Ingr., which has pinnatifid leaves. Leaves may be
ovate, lanceolate, orbicular, cordate, elliptic, ovate-lanceolate, or
linear (Fig. 2). The majority of the members of subgenera Pogostemon
and Allopogostemon have an ovate to lanceolate leaf shape, although
P. rotundatus Benth. has orbicular leaves and P. speciosus has
cordate leaves. Species belonging to subgenus Dysophyllus usually
have linear to linear-lanceolate leaves. Most exceptions are found in
sectionDysophyllus: P. auricularius, P. myosuroides (Benth.) Kuntze,
and P. salicifolius Dalzell ex Hook.f.) El Gazzar & L. Watson have
a lanceolate to linear-lanceolate leaf shape while an elliptic leaf
shape has been recorded from P. mutamba and/3. glabratusChermsir.
ex Press. Pogostemon trinervis is unusual in section Verticillatus
because its leaves are more or less orbicular. Most species have a
cuneate leaf base but P. speciosus has leaves which are cordate at the
base. Leaves with a rounded base have been found inP atropurpureus
Benth., P. brachystachyus, P. macgregorii, P. mollis Benth., P.
philippinensis S. Moore, P. pressii, and P. trinervis.

The leaf apex is commonly acute or acuminate, but an obtuse apex
has been recorded from Pogostemon brachystachyus, P. cablin, P.
glaber, P. mollis, P. nepetoides Stapf., P. nigrescens Dunn, P.
rotundatus, P. speciosus, P. velatus, P. peguanus, P. pentagonus
(C.B. Clarke ex Hook.f.) Kuntze, P. quadrifolius, P. sampsonii, P.
trinervis, and P. cruciatus.

Dentate, double dentate, crenate, double crenate, inciso-crenate,
and serrate margins have been recorded. An entire/revolute margin is
found in some species of subgenus Dysophyllus, but not elsewhere.
The leaf margin in Pogostemon cristatus Hassk., P. formosanus
Oliver, and P. gardneri Hook.f. has a deep incision, and is described
as inciso-crenate.

Petiolate, subsessile (petiole < 5 mm), and sessile leaves have
been observed. Most of the members of subgenus Dysophyllus have
a sessile leaf, a character state not found outside this subgenus,
although Pogostemon auricularius, P. glabratus, P. mutamba, P.
myosuroides, P. micangensis, P. quadrifolius, and P. salicifolius

83

have a subsessile leaf and P. barbatus Bhatti & Ingr. and P.
amaranthoides are petiolate. Petiolate leaves are normal in other
subgenera with only P. nigrescens, P. strigosus (Benth.) Benth., and
P. velatus having a subsessile leaf.

The leaves of Pogostemon nelsonii are glabrous but all other
species of subgenus Pogostemon are hairy. Most species of subgenus
Allopogostemon are hairy but P. travancoricus has glabrous leaves.
Several species of subgenus Dysophyllus have glabrous leaves,
including P. pressii, P. helferi, P. pentagonus, P. sampsonii, and P.
Verticillatus.

The abaxial leaf surface of many species is densely hairy when
compared to the adaxial surface. The veins are more hairy than the
lamina on both the adaxial and abaxial surfaces.

Inflorescence

The inflorescence in Pogostemon, like most Labiatae, is a terminal,
verticillate thyrse. This has a spike-like appearance. Inflorescences
have been categorized into three kinds: a single terminal spike, a
terminal spike with two lateral spikes, and a terminal spike with
more than two lateral spikes (Fig. 3).

In subgenus Pogostemon the inflorescence is branched; the termi-
nal verticillaster is usually accompanied by more than two lateral
verticillasters, less frequently by just two laterals, but in P.
purpurascens it is simple. Branched inflorescences are found in a
few species in other subgenera, but most have a single verticillaster.

The verticillaster is commonly very dense but in some species the
lowest verticils are arranged laxly and the upper part densely. A few
species, especially in subgenus Allopogostemon, have a lax
verticillaster throughout.

Bracts and bracteoles

The arrangement, shape, and persistence of the bracts and bracteoles
is very variable, even on a single plant. In some species bracts are large
and there is a continuum in size and shape between lower vegetative
leaves on an inflorescence and the bracts associated with the verticils.
This pattern is common in subgenus Pogostemon. More frequently
bracts are distinctly different from vegetative leaves: smaller, nar-
rower, and less petiolate. Sometimes they are indistinctly toothed. In
P. purpurascens, P. cablin, P. nepetoides, and P. nelsonii they are
distinctly toothed. Deeply cleft, two-lobed bracts can be found in P.
villosus Benth. andP.paniculatus. In subgenus Pogostemon the bracts
and bracteoles are smallest and narrowest in P. tuberculosus, P.
formosanus, P. elsholtzioides Benth., and P. dielsianus Dunn. Bracts
in the other subgenera are normally narrow, linear-lanceolate to linear,
and filiform bracteoles are found. In section Verticillatus several
species, including P. helferi, P. pumilus, P. stocksii, P. erectus, P.
stellatus, and P. deccanensis the bracts/bracteoles are spathulate.
Bracts and bracteoles are normally densely hairy.

Calyx

The calyx is either infundibular, tubular or campanulate. In subgenus
Dysophyllus the calyx is infundibular with a wide diameter, greater
than the length of the tube. In subgenus Allopogostemon the calyx is
normally tubular or infundibular, and then two-lipped and with a
circumference less than or equal to the length of the calyx tube. In
subgenus Pogostemon the calyx is normally infundibular and has a
diameter narrower than the tube length.

Pogostemon normally has a calyx with five teeth. Some speci-
mens of P. atropurpureus, P. brachystachyus, P. micangensis, and P.
philippinensis have 5-7 toothed calyces. Extra teeth are particularly
common in P micangensis so that the calyx toothing is rather

84

G.R. BHATTI AND M. INGROUILLE

Fig. 3 Inflorescence types observed in Pogostemon; (a, d, g) single spike; (b, e) with two lateral spikes; (c, 0 with branched lateral spikes; (b, c, f, g)
spikes dense; (a) spike lax below, dense above; (d, e) lax.

SYSTEMATICS OF POGOSTEMON

irregular. InP.faurei some of the calyces have four teeth. Calyx teeth
are normally either broadly or narrowly triangular.

Species of section Zygocalyx have the most distinct calyx. The
calyx is asymmetrical and two-lipped, with the two lower teeth
narrower than the upper three, and the teeth tips drawn out into a
narrow point (subulate). This condition is most pronounced in
Pogostemon litigiosus but is seen to a lesser extent in P.fraternus, P.
brachystachyus, P. wightii, P. nigrescens, P. strigosus, P. menthoides,
P. hirsutus Benth., and P. macgregorii.

Calyx venation is a very important character for delimiting
subgeneric groups. All species have five prominent veins along the
ribs of the calyx. In subgenus Dysophylla the only veins which are
obvious are those at the ribs of the calyx and the intercostal region is
thin and translucent. Pogostemon micangensis has the same pattern
but with irregular toothing so that there may be an intervening rib
which does not end in a tooth. In subgenus Pogostemon, as well as
the five main rib veins, there are numerous secondary veins or lines
of elongated cells in the intercostal region, running in parallel to the
ribs, and converging at the teeth sinuses. In the distal part of the tube
and in the teeth secondary branches arise from the rib vein and run
to the thickened margin of the calyx. The calyx tube is incrassate and
opaque with the exterior often densely covered with hairs. In subgenus
Allopogostemon two patterns may be observed: either the calyx has
five midrib veins plus five other strong intercostal veins, terminating
at each sinus; or there is a more reticulate pattern of venation with
five rib veins plus some other intercostal veins. In the intercostal
region the number of veins is variable and the veins interconnect in
a reticulate fashion with the rib veins. The intercostal region is
thinner than in subgenus Pogostemon, but papery rather than trans-
lucent as in subgenus Dysophyllus.

Calyx hairiness is an important character. Pogostemon
elsholtzioides, P. nelsonii, P. nepetoides, and P. travancoricus have
a glabrous margin to the teeth. The presence of a row of hairs on the
inner side of the margin has been recorded in P. dielsianus and P.
formosanus. Hairs originating slightly inside and outside the margin
of the teeth have been recorded inf. philippinensis, P. strigosus, and
P. tuberculosus. Hairs on the margin are either similar to those on the
exterior of the calyx and ciliate, or they are stiff and bristle-like. The
latter are found in section Zygocalyx.

The exterior of the calyx is normally hairy to very hairy. In most
species it is the distal part of the exterior calyx tube which is hairy.
Pogostemon auricularius, P. barbatus, P. glabratus, and P. ciliatus
Bhatti & Ingr. have just the teeth hairy andPogostemon travancoricus
is glabrous.

The majority of the hairy species have simple, uniseriate, multi-
cellular hairs in which the basal cells are broad and apical cells
sharply pointed. Both fruticose and dendromorphic trichomes have
been found in Pogostemon velatus, while in P. williamsii, which is
considered by various authors as synonymous with P. velatus, only
fruticose trichomes like those on its leaves are found. Pogostemon
tuberculosus possesses stellate trichomes. These trichomes differ
from those on other parts of the plant, having a central 3-celled,
rather than 2-celled, branch. In subgenus Dysophyllus most of the
taxa have simple, multicellular hairs except P.faurei, P. koehneanus,
and P. peguanus, which have unicellular hairs on the outer surface of
the calyx. In subgenus Dysophyllus hairless glands are obvious as
little patches of circular cells with yellowish cell contents. These are
probably present on all species but are not so obvious on the thicker
and opaque calyces of subgenera Pogostemon and Allopogostemon.

Observation of hairs within the calyx is difficult because they can
be very fine and sparsely distributed here. Where visible, the distri-
bution of hairs in the distal part provides an important character. The
hairs may be spread over the teeth and down the tube or confined

85

more or less distally, in some species, just to the tip of the teeth, as
in Pogostemon membranaceus Merr. and P. petiolaris Benth.

An alternate pattern of hair distribution, which can be confused
with the last condition, is where the hairs form a wavy annulus around
the top of the calyx tube. In these species the most dense hairs are often
found at the teeth sinuses.The annulus varies from being very strongly
developed mPogostemon speciosus, so that tufts of hairs seem to spill
out at the teeth sinuses, to poorly developed in P. strigosus, which has
only a few hairs present, mainly at the sinuses of the teeth. In section
Zygocalyx an annulus of hairs has been observed in the throat of the
calyx in P. wightii, P. brachystachyus, P.fraternus, P. litigiosus, P.
macgregorii, P. menthoides, and P. nigrescens. This character state
may be homologous to that seen in section Racemosus subsection
Glabriusculus, in P. atropurpureus, P. reflexus, and P. speciosus
which have tufts of hairs at the tips of the teeth and a line of hairs
running down the edge of the teeth to the sinus.

The patterns described above are clearly different from that seen
in subgenus Pogostemon, where hairs are more evenly distributed
within the calyx, over the teeth, and sometimes down into the tube
including the region of the ribs. Normally the upper part of the calyx
tube and teeth are hairy or only the teeth are hairy. Pogostemon
paniculatus, P. pubescens Benth., P. purpurascens, and P. wattii
C.B. Clarke have the entire calyx tube and teeth hairy. Pogostemon
gardneri has the tube but not the teeth hairy.

In subgenus Dysophyllus the interior of the calyx is glabrous
except for a few species which have the inner teeth hairy.

Corolla

The corolla consists of two parts, the tube and the two-lipped limb.
The upper lip is three lobed. The outer surface of the upper lip, and
sometimes also the lower lip, is normally hairy. Pogostemon
tuberculosus, P. auricularius, P. rogersii N.E. Br., P. mutamba, and
P. paludosus have hairs only on the central lobe of the upper lip.

The corolla tube varies in length from shorter to longer than the
limb. The tube may have a narrow diameter relative to its length and
be uniformly tubular or become wider in its distal part. The relative
size of the lower and upper lips and the size and shape of the upper
lobes provide useful characters for distinguishing species. The
dissected corolla reveals that there are several prominent veins ( 1 2 to
16) in the tube. Four of these give rise to staminal filaments. The
remaining veins continue as midribs or lateral veins of the lobes in
the upper and lower lip of the corolla.

The site of filament attachment in the corolla tube is closely
correlated to the total length of the corolla. For example, the total
length of the corolla in Pogostemon amaranthoides is about 2.6 mm
and the tube length up to the site of filament attachment is about 1.0
mm. In P. velatus corolla length is about 8.0 mm and the site of
filament attachment is 3.5 mm up the tube. The length of the exserted
part of the filament is more or less constant within species but varies
between species, ranging from hardly exserted up to 5.0 mm.

The presence of hairy filaments gave Pogostemon its name.
Moniliform hairs are found on all four filaments. The hairs are
unilaterally distributed. Moniliform hairs are only absent from
section Glabriusculus, namely P. atropurpureus, P. speciosus, P.
travancoricus, and P. reflexus, but these have a few simple hairs
scattered over the filaments. Simple hairs are found mixed with
moniliform hairs in P. hirsutus. Pogostemon menthoides has only a
few moniliform hairs present.

In subgenera Dysophyllus and Pogostemon filaments are nor-
mally glabrous in the lower part and at the base but a few simple hairs
may be found here. Most species in subgenus Allopogostemon have
the filament base villous with short sharp hairs. The central/upper
two filaments are generally more hairy than the outer/lower two.

86

Gynoecium

The style in all taxa under examination is terminated by a bifid
stigma with equal or unequal lobes. Simple, uniseriate 2-3-celled
hairs have been observed on the stigma lobes of Pogostemon ciliatus.
The maximum length of lobes is 1 .9-2. 1 mm, recorded from P.
nepetoides. On one specimen of P. elsholtzioides flowers with both
bifid and three-lobed stigmas have been observed. The flowers with
three-lobed stigmas have six nutlets.

Some glands have been found on the ovary in Pogostemon
atrvpurpureus, P. reflexus, P. speciosus, and P. tmvancoricus.

The disc is four-chambered where each of the ovary segments fit.
These chambers are normally equal and regular in shape in all taxa.
An asymmetrical disc, with one arm of the disc elongated, has been
found in Pogostemon erectus, P. deccanensis, and P. stellatus of
subgenus Dysophylla.

Table 1 Nutlet surface morphology in Pogostemon.

Nutlet surface morphology

Species

smooth

puncticulate

(smooth surface with tiny
scattered dots)

smooth-lineate

(thin lines running in parallel on
the smooth surface)

smooth-reticulate
(smooth surface is covered by a
thin lined network)

undulate
foveate (pitted)

smooth with thinly scattered

small pits

reticulate with punctate walls
reticulate-punctate

granulate

(evenly covered with closely
spaced grains but without
reticulate appearance)

reticulate (unornamented)

reticulate with secondary
reticulations

reticulate-foveate with warty
patches

rugose

zig-zag channels

ruminate, penetrated by irregular
channels running in different
directions, showing eroded
features

smooth, covered by more or less
circular scales

small tubercles

stalked, cup-like glands

P. helferi, P. erectum, P. salicifolius, P.

stellatus, P. pressii, P. peguanus, P.

trinervis, P. stocksii
P. amaranthoides, P. benghalensis, P.

gardneri, P. glaber, P. hispidus, P.

paniculatus, P. plectranthoides, P.

pubescens, P. villosus

P. koehneanus

P. deccanensis

P. crassicaulis
P. hispidus
P. nelsonii

P. purpurascens

P. pumilus, P.faurei

P. tuberculosus, P. verticillatus

P. auricularius, P. brachystachyus, P.
membranaceus, P. nigrescens, P.
philippinensis, P. hirsutus

P. nilagiricus, P. petiolaris, P. strigosus,
P. wightii

P. cristatus

P. aquaticus
P. ciliatus

P. delsianus, P. elsholtzioides, P.
griffithii

P. rotundatus

P. myosuroides, P. elatispicatus,
P. strigosus, P. velatus, P. williamsii,
P. quadrifolius

P. speciosus, P. reflexus,P.
travancoricus, P. atropurpureus, P.
paludosus

G.R. BHATTI AND M. INGROUILLE

Nutlets

Only minor variations were observed in nutlet surface characteris-
tics within species (Figs 14-40). The majority of nutlets from
species belonging to subgenus Dysophyllus are oblong. Ellipsoid to
ellipsoid-oblong nutlets have been found \nPogostemon linearis and
P. verticillatus. Orbicular and ovoid nutlets have been found in P.
deccanensis and/5, tisserantii respectively. In subgenera Pogostemon
and Allopogostemon a wide range of shapes has been observed:
ovoid, orbicular, oblong, obovoid, lanceolate to linear-lanceolate,
ellipsoid to ellipsoid-oblong, ellipsoid-fusiform, and 'D'-shaped.

A scanning electron microscope study of the nutlet surface re-
vealed several different types of nutlet epidermal structure (Table 1).
Few patterns correlate closely with groups. A smooth surface is
common in species of subgenus Dysophyllus. Subsection
Glabriusculus is characterized by having glands on the nutlets, a
character also found in Pogostemon paludosus.

Nutlet colour could not always be ascertained because very
mature specimens are required and of course mature nutlets fall out
of the flowers.

SYSTEMATIC ACCOUNT

POGOSTEMON Desf . in Mem. Mus. Hist. nat. Paris
2: 154(1815).

Inflorescence a single, spike-like verticillaster or with two or more
lateral verticillasters. Leaves sessile or petiolate. Bracts and bracteoles
not membranous, persistent. Calyx 5-toothed; veined within, glabrous
or hairy within, densely or sparsely hairy outside. Corolla 4-lobed,
three lobes forming upper lip, lower lip single-lobed; exterior of upper
lip densely or sparsely hairy, lower lip glabrous or sparsely hairy.
Filaments in two pairs, inserted at the same height or at different
heights in the tube, mostly unequal in length, exserted; anthers
unilocular ; moniliform hairs present towards the middle (most species)
or with a few fine simple hairs, basal part glabrous or with a few simple
hairs, or densely villous, and then all bases equally hairy or only two
hairy. Style exserted; stigma with two equal or unequal lobes. Disc
symmetrical or asymmetrical. Nutlets 4, rarely one.

Key to subgenera, sections, and subsections

1 . Calyx broadly conical, diameter greater than length, length < 4 mm, five
veins only, thinand translucent (except/? micangensis and/? mutamba);
calyx teeth normally < 1 mm; leaves normally sessile or subsessile
(petiole < 5 mm) (III. subgenus Dysophyllus) 2

Calyx tubular, diameter narrower than length, length > 4 mm, five main
veins but with intercostal veins, thick or papery; calyx teeth normally
> 1 mm; leaves normally petiolate 3

2. Leaves linear or linear-lanceolate, sessile, base truncate, rounded or
cuneate, verticillate, > 2 per node (rarely 2 opposite leaves at each node)

Illb. section Verticillatus

Leaves lanceolate, elliptic, ovate, or clavate, petiolate, base usually
cuneate, rarely rounded, 2 opposite leaves at each node (rarely some
nodes with 4) Ilia, section Dysophyllus

3. Calyx with 5 main rib- veins and multiple parallel intercostal secondary
veins meeting at the sinuses; calyx tube often with scattered hairs within;
bracts and bracteoles large, equalling or exceeding calyx, frequently
broadly lanceolate or bifid and toothed or lobed, less frequently nar-
rowly lanceolate; lateral verticillasters 2 or more, or rarely anunbranched
verticillaster but then filament bases normally glabrous or with long
simple hairs I. subgenus Pogostemon

SYSTEMATICS OF POGOSTEMON

87

Calyx with 5 main rib veins plus isolated, more or less branched
intercostal veins from sinuses of teeth; annulus of hairs present around
top of calyx tube and teeth; bracts and bracteoles linear to linear-
lanceolate, large or small; inflorescence an unbranched verticillaster, or
if branched then filament bases glabrous or densely villous(II. subgenus
Allopogostemon) 4

4. Calyx more or less 2-lipped; at least 2 calyx teeth awl-shaped, the
margins fringed by stiff bristle-like hairs lib. section Zygocalyx

Calyx symmetrical; calyx teeth triangular with a fringe of fine hairs (Ha.
section Racemosus) 5

5. Moniliform staminal hairs present Ilai. subsection Racemosus

Moniliform staminal hairs absent Haii. subsection Glabriusculus

Key to species

1. Leaves in opposite pairs 2

Leaves in whorls of three or more, at least at some nodes 59

2. Inflorescence an unbranched verticillaster 3

Inflorescence branched, with two or more lateral verticillasters 32

3. Stamens lacking moniliform hairs; ovary/nutlets with cup-shaped glands

4

Stamens with moniliform hairs; ovary and nutlets usually without cup-
shaped glands 7

4. Inflorescence lax; calyx exterior glabrous 36. P. travancoricus

Inflorescence dense; calyx exterior hairy 5

5. Petiole > 4 cm long; hairs on stem and inflorescence 8-9 celled

35. P. speciosus

Petiole < 4 cm long; hairs on stem and inflorescence 5-6 celled 6

6. An annulus of hairs in the calyx throat, calyx teeth conspicuously hairy;
filaments inserted at the same height 37. P. reflexus

An annulus of hairs around the calyx throat, conspicuously tufted at

teeth sinuses; filaments inserted at different heights

38. P. atropurpureus

7. Calyx tubular-inflated, asymmetrical, with 5 main veins and a variable
number of intermediate, reticulately-branched sinus veins; teeth un-
equal, lanceolate-subulate, with a margin of stiff bristles 8

Calyx infundibular, tubular or tubular-inflated but symmetrical, with 5
main rib veins, with or without sinus veins; teeth equal, with or without
a margin of fine white hairs 14

8. Inflorescence dense, continuous 9

Inflorescence with at least the lower verticil separate from the others
11

9. Leaf margin dentate; calyx < 4 mm long; corolla < 5 mm long;
moniliform hairs few on filaments 40. P. menthoides

Leaf margin serrate; calyx > 4 mm; corolla > 5 mm long; moniliform
hairs dense on filaments 10

10. Leaves subsessile, lanceolate; petiole < 5 mm long; inflorescence > 50
mm long 47. P. strigosus

Leaves petiolate, ovate; petiole > 5 mm long; inflorescence < 50 mm
long 43. P. hirsutus

11. Inflorescence > 100 mm long 45. P. brachstachyus

Inflorescence< 100 mm long 12

12. Verticils arranged densely in upper part 42. P. macgregorii

Verticils arranged laxly throughout 13

13. Calyx strongly asymmetrical and 2-lipped; filament bases glabrous ...

41.P.litigiosus

Calyx weakly asymmetrical and 2-lipped; filament bases villous

44. P.wightii

14. Calyx infundibular, with 5 main veins only, translucent 15

Calyx with 5 main veins and intermediate veins running to the sinuses,
texture thick 20

15. Corolla lower lip shorter than upper; filaments arising at two levels ...

55. P. micangensis

Corolla lips equal in length; filaments arising at the same level 16

16. Petiole > 5 mm long 50. P. barbatus

Petiole < 5 mm long 17

17. Margin of calyx teeth glabrous 49. P. glabratus

Margin of calyx teeth fringed with white hairs 18

18. Inflorescence < 30 mm long 62. P. andersonii

Inflorescence > 30 mm long 19

1 9. Exterior of calyx very hairy with dense long hairs at base, teeth hairy
within 53. P. salicifolius

Exterior of calyx with few hairs but many glands, teeth glabrous within
48. P. auricularius

20. Calyx < 4 mm long; length of corolla tube less than or equal to
circumference 21

Calyx > 4 mm long; length of corolla tube greater than circumference

23

21. Inflorescence > 50 mm long 34. P. paludosus

Inflorescence < 50 mm long 22

22. Stem hairy; inflorescence lax below, dense above 23. P. mollis

Stem glabrous except at the nodes; inflorescence lax throughout

26. P. rupestris

23. Calyx with 5 rib veins and minor parallel secondary veins

8. P. purpurascens

Calyx with 5 rib veins and 5 sinus veins 24

24. Calyx teeth shallowly triangular 25

Calyx teeth deeply triangular 29

25. Indumentum of dendromorphic and fruticose hairs; nutlet surface
spinulose 26

Indumentum of simple, multicellular hairs; nutlet surface reticulate to
reticulate-foveate 28

26. Petiole c. 5 mm long 30. P. velatus

Petiole > 10 mm long 27

27. Inflorescence > 150 mm long, verticils arranged evenly and relatively
laxly throughout spike 33. P. elatispicatus

Inflorescence < 150 mm long, lax below or dense throughout

31.P.williamsii

28. Inflorescence > 100 mm long, lax below, dense above

29. P. philippinensis

Inflorescence < 100 mm long, dense throughout 24. P. vestitus

29. Leaves orbicular 28. P. rotundatus

Leaves ovate 30

30. Corolla > 7.5 mm long; tube long and narrow, c. 2 x limb

88

32. P. membranaceus

Corolla < 7 mm long; tube relatively short and broad, < 2 x limb .. 3 1

31. Calyx c. 4.5 x 3.5 mm, with 10 main veins 22. P. nilagiricus

Calyx c. 5.0 x 5.2 mm, with 5 main veins, subsidiary veins indistinct
25. P. petiolaris

32. Leaves subsessile, petiole < 5 mm long 33

Leaves petiolate, petiole > 5 mm long 36

33. Verticillasters lax below, dense above 46. P. nigrescens

Verticillasters dense throughout 34

34. Verticillasters > 70 mm long 54. P. quadrifolius

Verticillasters < 70 mm long 35

35. Calyx < 2 mm long; corolla < 3 mm long 52. P. myosuroides

Calyx > 2 mm long; corolla > 3 mm long 56. P. mutamba

36. Inflorescence lax, at least below 37

Inflorescence dense 48

37. Inflorescence with two lateral Verticillasters only

51. P. amaranthoides

Inflorescence with more than two lateral Verticillasters 38

38. Calyx 10-veined, lobes unequal 39

Calyx with 5 main veins and numerous parallel veins or lines of cells in
intercostal region, lobes equal 40

39. Plant upright, up to 1 m tall; calyx with an annulus of hairs in the throat

39. P. fraternus

Plant procumbent, rooting at nodes; calyx lacking an annulus of hairs in
the throat 27. P. rogersii

40. Indumentum on stem and leaves with 2-3-celled hairs

17. P. formosanus

Indumentum on stem and leaves with more than 3 cells 41

41. Petiole c. 6 mm long 18. P. elsholtzioides

Petiole > 10 mm long 42

42. Inflorescence normally < 50 mm long 43

Inflorescence normally > 50 mm long 44

43. Lateral Verticillasters with a single verticil 16. P. champion!!

Lateral Verticillasters with several verticils 45

44. Stem weak, contracted at internodes; corolla up to 1 mm long

5. P. cristatus

Stem strong and even; corolla < 10 mm long 46

45. Verticils surrounded by broad ovoid bracts, some deeply cleft

7. P. paniculatus

Verticils surrounded by elliptic-oblong bracts, sometimes toothed but
never deeply cleft 9. P. cablin

46. Corolla < 5 mm long; nutlet surface foveate 14. P. hispidus

Corolla > 5 mm long; nutlet surface puncticulate 47

47. Corolla 8-9 mm long; leaves with margin double dentate, apex acumi-
nate, base cuneate; hairs on all parts of plant < 500 um long

1. P. benghalensis

Corolla 6-7 mm long; leaves with margin inciso-serrate, apex obtuse,

base truncate;hairs on all parts of plant > 500 um long

10. P. nepetoides

G.R. BHATTI AND M. INGROUILLE

48. Lateral Verticillasters two 49

Lateral Verticillasters three or more 52

49. Stem and leaf hairs 3-celled, < 500 um long 50

Stem and leaf hairs 5-6 celled, > 500 um long 5 1

50. Stem dark reddish purple; petiole up to 40 mm long; calyx exterior
sparsely hairy 13. P. glaber

Stem green; petiole up to 10 mm long; calyx exterior strongly

hairy 20. P. griffithii

51. Stem reddish; stem and leaf hairs > 1000 \im long 6. P. gardneri

Stem green; stem and leaf hairs < 1000 pm long 14. P. hispidus

52. Calyx glabrous within 53

Calyx teeth hairy within 54

53. Stem and leaves glabrous 1 2. P. nelsonii

Stem and leaves with stellate hairs 19. P. tuberculosus

54. Calyx teeth shallow; lower lip of corolla relatively narrow, < the upper
lip 55

Calyx teeth deep; lower lip of corolla relatively wide, > the upper lip
56

55. Corolla up to 8 mm long, lower lip > 2 mm long

. 3. P. plectranthoides

Corolla up to 6.5 mm long, lower lip < 2 mm long .... 4. P. pubescens

56. Filaments arising at two heights 57

Filaments arising at the same height 58

57. Calyx tube sparsely hairy within 1 1 . P. heyneanus

Calyx tube glabrous within 21. P. dielsianus

58. Calyx c. 3 mm long; corolla < 4 mm long 15. P. wattii

Calyx c. 4 mm long; corolla > 5 mm long 2. P. villosus

59. Leaves linear to linear-lanceolate 60

Leaves lanceolate 68. P. koehneanus

Leaves pinnatifid 57. P. tisserantii

Leaves orbicular 72. P. trinervis

60. Leaves > 6 at each node 61

Leaves < 6 at each node 64

61. Disc regular 75. P. stocksii

Disc irregular, with one arm elongated 62

62. Calyx teeth hairy within 76. P. erectus

Calyx glabrous within 63

63. Corolla very short, < 2 mm long, exserted portion of filament exceeding
it in length 77. P. stellatus

Corolla > 2 mm long, exserted part of filament equalling it in length .
78. P. deccanensis

64. Corolla with middle lobe of upper lip narrower than lateral lobes .. 65
Corolla with middle lobe of upper lip wider than lateral lobes 66

65. Inflorescence < 40 mm long 61. P. pentagonus

Inflorescence > 40 mm long 67. P. peguanus

66. Stigma hairy 59. P. ciliatus

Stigma glabrous 67

SYSTEMATICS OF POGOSTEMON 39

67. Inflorescence with more than two lateral verticillasters 68 more than two lateral spikes; hairs 5-celled, 1 100 um long; bracts

Inflorescence unbranched or with 2 lateral verticillasters only 69 ovate' 6~7 x 2~3 mm' hairv- Calyx tubular-inflated, 4.3 x 4.0 mm, 5-

veined; teeth and upper part of tube hairy outside, ± glabrous within;
olla < 2 mm long 70. P. verticillatus teeth dliate; longest tooth c j 2-l .3 mm long, 0.8-0.9 mm wide at

Corolla > 2 mm long 79. P. aquaticus base; outer hairs 2-celled, c. 200 um long. Corolla up to 8.7 mm

, „ long; lower lip c. 2.2 x 2 mm; upper lip c. 2 mm across; central lobe

69. Inflorescence with two lateral verticillasters only ... 69. P. crassicaulis ,£ m

c. 1 .6 x 0.7 mm; lobes hairy outside and scattered down the tube.

Inflorescence simple, unbranched 70 Filaments inserted at different heights, the lowest at a height of 4 mm

70. Leaves in whorls of 3 71 *n the tube; fi'aments c- 5.1-7.0 mm long, exserted portion c. 2.3

mm; two filaments glabrous towards the base. Style c. 9.5 mm long;
Leaves in whorls of 4-5 stigma lobes c. 1.2mm.Discc. 1 mm long. Nutlets 4, c. 1200x700

7 1 . Stem sparsely hairy; inflorescence < 35 mm long .... 64. P. sampsonii Mm> obovoid, puncticulate.

Stem glabrous; inflorescence > 35 mm long 65. P. yatabeanus DISTRIBUTION. Pogostemon benghalensis grows in open Bombax-

Trewia riverine forest on the bare flood plain in Nepal and is also

72. Calyx asymmetrical; lower corolla lips larger than upper 73 f , • , •• D , , , D T« ., . 0 • i

found in India, Bangladesh, Burma, Thailand, Sri Lanka, and China.

Calyx symmetrical; lower corolla lips equal to or less than upper .. 74

ETHNOBOTANY. One of the patchouli species. Pogostemon

73. Corolla < 1 mm long 71.P.pumilus benghalensis contains an astringent resin, an alkaloid, a yellow

Corolla > 1 mm long 73 P. helferi varnish of a slightly bitter taste and mouse-like odour of trimethyl-

amine, and a volatile oil with an odour like that of cedar wood.

74. Leaf base rounded or truncate 75 Extracts are a stimulant and styptic. Fresh leaves are used to clean

Leaf base cuneate 76 wounds and provide healthy granulation. P. benghalensis is a good

source of pollen or nectar for bees, thereby providing panagol honey.

75. Inflorescence < 20 mm long 58. P. lythroides

SPECIMENS EXAMINED. Kerr 10333 (BM), Kerr 17496 (BM),
Inflorescence > 20 mm long 74. P. press,, Kingdon.Ward 20299 (BM K)> Tmfh 67? (BM)> ^ 75Q (BMX

76. Leaf margin entire, revolute 63. P. cruciatus Wang 30222 (BM).

Leaf margin dentate 77 Pogostemon benghalensis has previously been recorded as a syno-

77. Stem rooting at nodes, reddish brown; leaves sparsely hairy nym of R plectranthoides, but they are distinct. However, it is

60. P. linearis possible that many records of this species from southern India and

Sri Lanka are referable to P. plectranthoides. Pogostemon

Stem not rooting at nodes, not reddish brown; leaves glabrous , , , . , ,, •,, ,. , .

benghalensis has a corolla with a narrower cylindrical tube and a

66. P. taure, . ... ....

verticillaster which is generally less crowded than in P.

I. Subgenus POGOSTEMON sensu Bhatti & Ingr. plectranthoides It is a variable species with smaller flowered vari-

ants (= P. parviflorus Benth.) with verticillasters less than 10 mm in
Pogostemon subgenus Paniculatae Benth., pro parte. diameter and purple-stemmed plants (= P. purpuricaulis Dalzell).

Stem strong; leaves in opposite pairs at each node, distinctly peti-
olate (P. griffithii sessile), ovate, rarely lanceolate; inflorescence a
verticillaster with two or more lateral verticillasters (P. purpurascens
a single verticillaster), normally dense or with lower verticils laxly
arranged, rarely lax throughout, with large, ovate, rarely lanceolate
bracts, commonly lobed, deeply cleft and two-lobed, or toothed,
equaling or exceeding the calyx. Calyx tubular-inflated to
campanulate, with 5 rib veins, pinnately-branched in region of teeth,
incrassate with lines of elongated cells parallel to ribs and coming
together at sinuses of teeth; teeth triangular, hairy outside, coarsely
hairy or glabrous within except at tips. Corolla tube usually equal to
limb.

1 . Pogostemon benghalensis (Burm.f.) Kuntze, Rev. gen. pi. 2: 529

(1891).
Figs 4a, 14a.

Origanum benghalense Burm.f., Fl indica: 128, t. 38 f. 3 (1768).
Pogostemon parviflorus Benth. in Wall., PI. asiat. rar. 1: 31 (1830).
P. intermedius Benth. in Wall., Numer. List: 2327 (1830).
P.frutescens Graham, Cat. pi Bombay: 149 (1839), pro parte.
P. purpuricaulis Dalzell in Hooker's J. Bot. 2: 336 ( 1 850), pro parte.
P. plectranthoides auct. pro maj., non Desf.

Stem solid, angular; hairs 5-celled, c. 460 urn long. Leaves ovate,
130 x 60 mm, base cuneate, apex acuminate, margin double dentate;
hairs 4-celled, c. 330 urn long. Petiole 25 mm long; hairs 4-celled, c.
360 urn long. Inflorescence a terminal spike, c. 70 mm long, with

2. Pogostemon villosus Benth., Labiat. gen. spec.: 153 (1833).
Figs4b, 14b.

Stem solid, terete; hairs 7-celled, c. 600 jam long. Leaves ovate, 65 x
30 mm, base cuneate, apex acute, margin crenate; hairs 4-celled, c.
400 urn long. Petiole 15 mm long; hairs 4-celled, c. 270 urn long.
Inflorescence a terminal spike, c. 50 mm long, dense, with more than
two lateral spikes; hairs 3-celled, c. 500 um long; bracts lanceolate
to ovate, c. 6-7 mm long, some deeply cleft, two-lobed, c. 6 x 2-3
mm, hairy. Calyx tubular-inflated, 4.0 x 3.7 mm, 5-veined; teeth and
upper part of tube tomentose with long hairs outside, hairy within,
more densely above to sparsely below; teeth ciliate, c. 1.0-1.5 mm
long, 0.7-0.8 mm wide at base; outer hairs 7-celled, c. 1 600 um long.
Corolla up to 6.2 mm long; lower lip c. 1 .8 x 1 .2 mm; upper lip c. 1
mm across; central lobe 1.1 x 0.5 mm; lobes hairy outside. Filaments
inserted more or less equally, at a height of c. 2.7 mm in the tube;
filaments c. 5.6-6 mm long, exserted portion c. 2.5 mm; many long
simple hairs at middle and base of filaments, some with a few
moniliform hairs. Style c. 1 mm long; stigma lobes c. 1 mm. Disc c.
0.8 mm long. Nutlets 4, c. 900 x 650 um, oblong, puncticulate.

DISTRIBUTION. India (Bengal) and Bangladesh.

SPECIMENS EXAMINED. Hooker s.n. (K), Roxburgh s.n. (BM-
syntype), Wallich 153 (K-syntype).

This species is similar to Pogostemon benghalensis but has smaller
flowers and a calyx tube which is hairy within.

90

G.R. BHATTI AND M. INGROUILLE

Fig. 4 Dissected corollas, calyces, and bracts, showing inner surface. Pogostemon subgenus Pogostemon: (a) P. benghalensis, (b) P. villosus, (c) P.
plectranthoides, (d) P. pubescens, (e) P. gardneri, (f) P- cristutus, (g) P. paniculatus. Scale bar 5 mm.

SYSTEMATICS OF POGOSTEMON

91

3. Pogostemon plectranthoides Desf. in Mem. Mus. Hist. nat.
Paris 2: 155, pi. 6 (1815).

Figs4c, 14c.

Mentha secunda Roxb., Hort. bengai: 44 (1814).

Shrubby plant up to 3 m high; stem solid, angular; hairs 4-celled, c.
560 um long. Leaves ovate, 152 x 70 mm, base rounded, apex acute,
margin double dentate; hairs 4-celled, c. 500 urn long. Petiole 32 mm
long; hairs 5-celled, c. 500 urn long. Inflorescence a terminal spike,
c. 60 mm long, dense, with more than two lateral spikes; hairs 5-
celled, c. 780 urn long; bracts broadly ovate, c. 6 x 2-4 mm, hairy.
Calyx tubular-inflated, 4.8 x 4.4 mm, 5-veined; with short hairs
outside, only teeth hairy within; teeth ciliate, c. 1.1-1.3 mm long,
0.9-1.0 mm wide at base; outer hairs 4-celled, c. 650 um long.
Corolla up to 8 mm long, purple; lower lip c. 2.2 x 1.1 mm; upper lip
c. 2.3 mm across; central lobe 1 .5 mm long, 0.6 mm wide at base.
Filaments purple, inserted at different heights, the lowest at a height
of 3.5 mm in the tube; longest filament c. 8.0-8.6 mm long, exserted
portion c. 4. 1 mm; filaments more or less glabrous towards the base.
Style c. 10 mm long, purple; stigma lobes c. 1.2 mm. Nutlets 4, c.
600 x 450 um, obovoid, puncticulate.

DISTRIBUTION. Throughout the Indian subcontinent from Tamil
Nadu to Nepal and Bangladesh; absent from Sri Lanka. A very
common constituent of the ground flora of Terminalia woodland or
open bush.

ETHNOBOTAN Y. Pogostemon plectranthoides is one of the patchouli
species, called 'Rudilo' in Nepal, 'Thekkali' in India, and used
medicinally.

SPECIMENS EXAMINED. Barber 1353 (K), Bista 2591 (BM),
Chatterjeo (K), Codrington 380 (BM), Cooper 4991 (K), Dobremez
2149 (BM), Drummond 20646 (K), Drummond 26164 (K),
Drummond 26165 (K), Drummond 26166 (K), Duthie 10531 (K),
Duthie 22399 (K), Falconer (K), Gamble 9007 (K), Gamble 9173
(K), Gamble 10212 (K), Gamble 13941 (K), Gamble 15843 (K),
Gamble 24539 (K), Gardner 230 (BM), Lai s.n. (K), Lambert 1030
(K), Meebold 4699 (K), Mooney 673 (K), Mooney 2 1 7 1 (K), Mooney
2635 (K), Nanak 20248 (K), Nanak 202647 (K), Polunin, Sykes &
Williams 3784 (BM), Rich 508 (K), Ritchie 543 (K), Roxburgh s.n.
(BM), Stainton 13 (BM), Stainton 5220 (BM), Stewart 1000 (K),
Strachey & Winterbottom 1 (BM), Talbot 1839 (K), Thomson 527
(K), Verma 6891 (K), Wallich 1530 (K), Wood s.n. (K).

This species is similar to Pogostemon benghalensis. Differences are
listed under that species.

4. Pogostemon pubescens Benth. inA. DC., Prodr. 12: 152 (1848).
Figs4d, 15a.

Stem solid, terete; hairs 3-5 celled, c. 375-1300 um long. Leaves
ovate, 70-90 x 31-67 mm, base truncate or cuneate, apex acute,
margin serrate or double crenate; hairs 3-4-celled, c. 850 jam long.
Petiole 20 mm long; hairs 3-5-celled, 475-850 um long. Inflores-
cence a terminal spike, c. 45-58 mm long, dense, with more than two
lateral spikes; hairs 3-4-celled, c. 350-480 (am long; bracts ovate-
lanceolate, 3-4 x 1-2 mm, hairy. Calyx tubular-inflated, 4.2^.5 x
3.5^.5 mm, 5-veined; hairy outside, teeth and upper part of tube with
short fine hairs within; teeth ciliate, shortest tooth c. 1.3 x 0.9 mm,
longest tooth c. 1 .4-1 .6 x 1 .0 mm; outer hairs 3-celled, 560-670 urn
long. Corolla up to 5.8-6.5 mm long; lower lip c. 1 .2-1 .4 x 0.5-1 . 1
mm; upper lip c. 1 .4-2.3 mm across; central lobe c. 1 mm long, 0.5-
0.6 mm wide at base, hairy. Filaments inserted more or less equally at
a height of 2.5 mm in the tube; longest filamentc. 7 mm long, shortest

filament c. 6.5 mm long, exserted portion c. 3.2-4.4 mm; filaments
glabrous towards the base. Style 7.0-9.7 mm long; stigma lobes c.
0.6-0.8 mm. Disc c. 0.6-0.9 mm long. Nutlets 4, c. 400-500 x 400-
437 um, obovoid, puncticulate to reticulate-foveate.

DISTRIBUTION. Southeast Asia (Thailand and Vietnam).

SPECIMENS EXAMINED. Kerr 2384 (BM), Kerr 3113 (BM), Petelot
5297 (BM).

This species is like Pogostemon plectranthoides but has smaller
flowers.

5. Pogostemon cristatus Hassk. in Hoeven & de Vriese, Tijdschr.
Natuurl. Gesch. Physiol. 10: 127 (1843).

Figs 4f, 15c.

Stem weak, contracted at the base of the internodes, angular, sparsely
hairy; hairs 4-celled, c. 370 u,m long. Leaves ovate, 120 x 80 mm,
base cuneate, apex acute, margin inciso-crenate; hairs 4-celled, c.
562 |im long, some covered with a crystalline powder. Petiole c. 60
mm long; hairs 4-celled, c. 370 um long. Inflorescence a terminal
spike, c. 100 mm long, lax below and dense above, with more than
two lateral spikes; hairs 3-celled, c. 430 (am long; bracts ovate, up to
6x3 mm, hairy. Calyx tubular, 6x5 mm, 5-veined; hairy outside
with long hairs and shorter hairs on veins and margin, teeth and
upper part of tube hairy within; teeth ciliate, 1.7-1.9 mm long, 0.9-
1 .0 mm wide at base; outer hairs 4-celled, c. 750 urn long. Corolla up
to 1 1 mm long; lower lip 2.2 x 1.5 mm; upper lip c. 2 mm across,
hairy outside; central lobe c. 1.7 x 0.7 mm. Filaments attached at a
height of 4 mm in the tube, c. 10-1 1 mm long, exserted portion c. 4
mm; filaments glabrous towards the base. Style c. 12 mm long;
stigma lobes 1 .3 x 1 .6 mm. Disc c. 0.5 mm long. Nutlets 4, c. 900 x
700 um, oblong, tan, with rounded patches on the surface.

DISTRIBUTION. Scattered throughout the East Indies including the
Lesser Sunda Islands and Timor.

SPECIMENS EXAMINED. Kostermans & Wirawam 55 1 (K).

Keng ( 1 978: 356) quoted Backer & Bakhuizen van den Brink Jr. who
had noted that Pogostemon cristatus is closely related tof! heyneanus,
but may be distinguished by its larger flowers.

6. Pogostemon gardneri Hook.f., Fl. Brit. India 4: 632 (1885).
Figs4e, 15b.

Stem erect, bluntly 4-angled, reddish brown, villous; hairs 5-celled,
c. 1500 (am long. Leaves ovate, 80 x 50 mm, base cuneate, apex
acuminate, margin inciso-crenate or sharply double crenate; hairs 5-
celled, c. 1300 (am long. Petiole c. 30 mm long; hairs 6-celled, c.
1300 (am long. Inflorescence a terminal spike, c. 80 mm long, dense,
with two lateral spikes, flowers in whorls; hairs on stalk 5-celled, c.
1250 um long; bracts ovate, up to 6 x 1.5 mm, hairy. Calyx tubular-
inflated, 4 x 4.5 mm, 5-veined; outside with relatively few, stout
hairs, upper half of tube hairy within with long fine hairs, the teeth
glabrous within; teethe. 0.9 x 0.9 mm; outer hairs 10-celled,c. 1750
urn long. Corolla up to 5.5 mm long; lower lip 1 .5 x 1 mm; upper lip
c. 1.7 mm across; central lobe c. 1 x 0.5 mm. Filaments all inserted
at a height of 2 mm in the tube, c. 4.3^.7 mm long; exserted portion
c. 1.2 mm; filaments glabrous at base. Style c. 5.5 mm long; stigma
lobes 0.5 mm. Disc c. 0.8 mm long. Nutlets 4; c. 1000 x 900 um,
ellipsoid to ellipsoid-oblong, dark brown, puncticulate.

DISTRIBUTION. Western India in the vicinity of Travancore.

SPECIMENS EXAMINED. Gardner 1 847 (K-syntype), Gardner 2 1 22
(CAL-syntype), Venkabo 3229 (K), Wight 1913 (K).

92

G.R. BHATTI AND M. INGROUILLE

7. Pogostemon paniculatus (Willd.) Benth. in Wall., PI. asiat. rar.
1:30(1830).

Figs4g, 16a.

Hyssopus cristatus Lam., Encycl. 3: 187 (1789), non Elsholtzia
cristatus (Willd. )Willd. ( 1 800), non Pogostemon cristatus Hassk.
(1843).

Elsholtzia paniculata Willd., Sp. pi 3: 59 (1800).

Stem solid, angular; hairs 4-celled, c. 750 (am long. Leaves ovate,
106 x 57 mm, base cuneate, apex acute, margin double dentate; hairs
3-celled, c. 600 u,m long. Petiole c. 1 8 mm long; hairs 5-celled, c,
800 u.m long. Inflorescence a terminal spike, c. 40 mm long, secund,
lax below and dense above, with more than two lateral spikes; hairs
c. 4-celled, c. 750 jam long; bracts broad, toothed or entire, up to 7 x
3.5 mm. Calyx infundibular, 4.0 x 3.2 mm, 5-veined; hairy outside
especially on the teeth, teeth and upper tube hairy within; teeth
ciliate, c. 0.9-1.0 mm long, c. 0.4-0.7 mm wide at base; outer hairs
5-celled, c. 1 100 urn long. Corolla up to 5.9 mm long; lower lip c. 1
x 1 mm; upper lip c. 1.5 mm across, hairy; central lobe c. 0.9 x 0.5
mm. Filaments inserted at different heights, the lowest at a height of
2.5 mm in the tube; filaments c. 4.5-5.2 mm long, exserted portion
c. 1.8 mm; filaments glabrous towards the base. Style c. 6.3 mm
long; stigma lobes c. 0.7-0.8 mm. Disc c. 0.8 mm long. Nutlets 4, c.
500 x 400 um, ellipsoid to ellipsoid-oblong, puncticulate.

DISTRIBUTION. India (Madras, Bombay, Nilgiri, Kannoth, Kunda
Hills, Travancore, Mysore, Malabar, Carnatic, Salem, Namakkal
Dist.) and Thailand.

SPECIMENS EXAMINED. Beddome s.n. (BM), Fernandes 1786 (K),
Gamble 9576 (K), Gamble 1 1987 (K), Gamble 15566 (K), Hooker
& Thomson s.n. (K), Kerr 17609 (BM), Miguel 249 (K), Perumal
21757 (K), Rungachari s.n. (K), Saldanha 15771 (K), Wallich 1561
(K-neotype), Wight 21 19 (K), Wight 2126 (BM, K), Wight 2529 (K).

8. Pogostemon purpurascens Dalzell in Hooker's J. Bot. 2: 337
(1850).

Figs 5a, 16b.

Stem solid, terete; hairs 1 3-celled, c. 1500 jam long. Leaves ovate, 100
x 68 mm, base cuneate, apex acute, margin double dentate; hairs 8-
celled, c. 1700 u,m long. Petiole 25 mm long; hairs 7-celled, 1600 um
long. Inflorescence a single terminal spike, 80 mm long, dense; hairs 4-
celled, c. 860 um long; bracts ovate to palmate, obscurely or markedly
toothed, up to 5-6 x 1 .5-5 mm, hairy. Calyx tubular, 6.0 x 4.5 mm, 5-
veined; hairy outside with long hairs, teeth and tube less densely hairy
within; teeth ciliate, c. 1 .3-2.2 mm long, c. 0.7-1 . 1 mm wide at base;
outer hairs 4-celled, c. 930 um long. Corolla up to 5.5 mm long; lower
lipc. l.lxl mm; upper lip c. 1 mm across; central lobe c. 1 x 0.4 mm,
sparsely hairy. Filaments all inserted at a height of 2.4 mm in the tube,
c. 5.7-7.0 mm long, exserted portion c. 3.9 mm; filaments glabrous
towards the base. Style c. 7.2 mm long; stigma lobes c. 2.0-2.5 mm.
Disc c. 0.5 mm long. Nutlets 4, c. 500 x 400 jam, ellipsoid to ellipsoid-
oblong, reticulate with punctate walls.

DISTRIBUTION. Throughout India (Assam, Himalaya (West),
Concan, Manipur, Bombay).

ETHNOBOTANY. Pogostemon purpurascens contains an astringent
resin, an alkaloid, a yellow varnish of a slightly bitter taste and
mouse-like odour of trimethylamine, and a volatile oil with an odour
similar to cedar wood. The stem and leaves are a stimulant and
styptic. Fresh leaves are used to clean wounds and provide healthy
granulation. In parts of India the roots are reputed to be a remedy for
snake bite.

SPECIMENS EXAMINED. Dalzell 5747 (K-syntype), Duthie 10537
(K), Hooker 2337 (K-syntype), Stocks s.n. (BM), Watt 5078 (K),
Wight s.n. (K).

9. Pogostemon cablin (Blanco) Benth. in A. DC., Prodr. 12: 156
(1848).

Figs 5b, 16c.

Mentha cablin Blanco, Fl. Filip.: 473 (1837).

M. auricularia Blanco, Fl Filip. ed. 2: 473 (1845), non L. (1767).

Pogostemon patchouly Pellet, in Mem. Soc. Sci. phys. Orleans 5:

277, t. 7(1845).
P. suavis Ten. in Parl., G. Bot. ital 2: 56 (1847), pro parte.

Stem solid, angular; hairs 4-celled, 680 um long. Leaves ovate, c. 80
x 60 mm, base cuneate, apex obtuse, margin dentate; hairs 5-celled,
c. 1250 um long. Petiole c. 26 mm long; hairs 5-celled, c. 900 um
long. Inflorescence a terminal spike, c. 45 mm long, lax below and
dense above, with more than two lateral spikes; hairs 3-celled, c. 150
um long; bracts ovate to lanceolate, entire or toothed, 4-9 x 0.7-4.0
mm. Calyx tubular-inflated, c. 4.5 x 2.8 mm, 5-veined; densely hairy
outside, teeth and upper part of tube more or less glabrous within,
with only a few scattered hairs; teeth ciliate, c. 1.8-1.9 mm long, c.
0.6 mm wide at base; outer hairs 3-celled, c. 400 um long. Corolla up
to 6.2 mm long, mauve; lower lip c. 1.4 x 0.9 mm; upper lip c. 1.1
mm across, slightly hairy; central lobe 1.3 x 0.4 mm. Filaments all
inserted at a height of 2 mm in the tube, c. 5.8-6.0 mm long, exserted
portion c. 1.8 mm; filaments glabrous towards the base. Style c. 5.8
mm long; stigma lobes 1 .4-1 .9 mm. Disc 0.8 mm long. Nutlets 4, c.
800 x 600 um, ellipsoid to ellipsoid-oblong, reticulate-foveate.

DISTRIBUTION. Widespread in the tropics including Thailand, Fiji,
Philippines (Luzon), Sumatera, India, Mauritius, and introduced to
Florida. This is one of the species which yields patchouli oil and it
has evidently been introduced into many places. According to
Merrill ( 1 944) it is commonly found in cultivation in the Philippines,
although not on a commercial scale. It flowers in the Philippines but
rarely elsewhere. This fact does not support the suggestion by
Merrill (1912) that it is not truly native in the Philippines.

ETHNOBOTANY. The leaves and stems of Pogostemon cablin are
employed as an insecticide against cockroaches, moths, and other
insects and also as a repellent for leeches. In the Philippines the
crushed leaves are sometimes used for washing. Leaves are also
added to baths for their antirheumatic property and an infusion of
fresh leaves is taken internally to allay painful menstruation. The
inflorescence of P. cablin is sold in Goa to dress the hair of women.

SPECIMENS EXAMINED. Alston 14403 (K), Clemens s.n. (BM),
Degener & Ordonez 14018 (K), Dupont 1769/23 (K-cult.), Kerr
17069 (K), Merrill 112 (BM, K), Plowman 13285 (K-cult.), Reillo
19292 (BM).

10. Pogostemon nepetoides Stapf in Bull misc. Inf. R. hot. Gdns,
Kew [1908]: 116(1908).

Figs 5c, 17a.

Stem solid, angular; hairs 4-celled, c. 980 um long. Leaves ovate, 91
x 64 um, base truncate, apex obtuse, margin inciso-serrate; hairs 4-
celled, c. 1200 um long. Petiole 34 mm long; hairs 4-celled, c. 1 100
um long. Inflorescence a terminal spike, c. 105 mm long, lax below
and dense above, with more than two lateral spikes; hairs 3-celled, c.
360 um long; bracts ovate to deeply cleft, three-lobed or toothed, 4-
8 mm long, hairy. Calyx tubular, 4.6 x 3.6 mm, 5-veined; teeth and
upper part of tube with long hairs outside, within the teeth hairy, the
tube more or less glabrous; teeth ciliate, 1 .8-2.0 mm long,c. 0.7 mm

SYSTEMATICS OF POGOSTEMON

93

Fig. 5 Dissected corollas, calyces and bracts, showing inner surface. Pogostemon subgenus Pogostemon: (a) P. purpurascens, (b) P. cablin, (c) P.
nepetoides, (d) P. heyneanus, (e) P. nelsonii, (f) P. glaber. Scale bar 5 mm.

94

wide at base; outer hairs 2-celled, c. 560 |jm long. Corolla up to 6.2
mm long; lower lip c. 1.6 x 1 mm; upper lip c. 1.6 mm across; central
lobe 1 .2 x 0.5 mm, with a few hairs. Filaments inserted at slightly
different heights, the lowest at a height of 2.6 mm in the tube;
filaments c. 5.3-6.8 mm long, exserted portion c. 3.2 mm; filaments
glabrous towards the base. Style c. 7.2 mm long; stigma lobes 1 .9-
2. 1 mm. Disc c. 0.9 mm long. Nutlets 4, c. 600 x 400 urn, ellipsoid
to ellipsoid-oblong, puncticulate.

DISTRIBUTION. The Philippines (Luzon).

SPECIMENS EXAMINED. Micholitz s.n. (K-holotype), Ramos 22432
(BM).

1 1. Pogostemon heyneanus Benth. in Wall., PL asiat. rar. 1: 31
(1830).

FigsSd, 17b.

Origanum indicum Roth, Nov. pi. sp.: 265 (1821).

Pogostemon patchouly sensu Hook.f., Fl. Brit. India 4: 633 (1885),

nonPelletier(1845).
P. suavis Ten. in Par!., G. Bot. /to/. 2: 56 (1847), pro parte.

Stem solid, angular; hairs 4-celled, c. 500 urn long. Leaves ovate, 85
x 45 mm, base cuneate, apex acuminate, margin double dentate;
hairs 4-celled, c. 460 u.m long. Petiole 32 mm long; hairs 4-celled, c.
350 urn long. Inflorescence a terminal spike, c. 70 mm long, lax
below, dense above, with more than two lateral spikes; hairs 4-
celled, 350 urn long; bracts ovate to lanceolate, entire or indistinctly
toothed, 3.0-5.0 x 0.8-3.0 mm. Calyx tubular, 4.3 x 3.1 mm, 5-
veined; teeth and upper part of tube hairy within, hairy throughout
outside; teeth ciliate, c. 1.2-1.4 mm long, 0.4-0.6 mm wide at base;
outer hairs 3-celled, c. 312 urn long. Corolla up to 4.8 mm long;
lower lipc. 1.6x0.9mm;upperlipc. 1.5 mm across; central lobe 0.9
x 0.3 mm, hairy. Filaments inserted more or less equally, at a height
of 1.7 mm in the tube, c. 3.7^.3 mm long, exserted portion c. 1.2
mm; filaments glabrous towards the base. Style c. 5.6 mm long;
stigma lobes c. 0.6-0.7 mm. Disc c. 0.7 mm long. Nutlets 4, c. 500
x 400 urn, orbicular, reticulate and punctate.

DISTRIBUTION. Widespread in southern Asia from Sri Lanka, In-
dia (Bombay, Mysore, Tinnually Ghats) to Indonesia (Java,
Sumatera). Perhaps introduced into some areas like the Seychelles,
although also found beside pathways through the jungle.

ETHNOBOTANY. One of the most important sources of patchouli oil
which is extracted from the dried tops. It is very rich in volatile
terpenoids.The dried leaves and tops of plants are sold in the markets
of India and the Seychelles. The leaves of Pogostemon heyneanus
(var. 'Patch-Pat') are used medicinally for stomach and skin diseases
and in Malaysia to treat coughs and asthma. A decoction made from
the roots is sometimes administered for dropsy. Hartwell (1982)
listed P. heyneanus as a possible anti-cancer medicine. In different
parts of India the leaves are used as a diuretic and carminative agent
and they are generally given with the seeds of Ocimum tenuiflorum
(vernacular name 'Tulsi') in cases of scanty urine and biliousness.

SPECIMENS EXAMINED. Barber 2218 (K), Beddome s.n. (BM),
Farnandas 1886 (K), Gardner 660 (BM, K), Johnson 130 (K),
Kuntze 5258 (K), Macrae 254 (BM, K), Macrae 1532 (K-type),
Macrae 1733 (K), Ridley 14300a (BM), Robinson & Kloss 88 (BM),
Simpson 9513 (BM), Wallich 231 (K), Wallich 1830 (K), Wallich
1891 (BM), Wallich 2131 (BM), Wight 2120 (K).

12. Pogostemon nelsonii Doan in Humbert, Fl. gen. Indo-Chine 4:
975(1936).

Figs 5e, 17c.

G.R. BHATTI AND M. INGROUILLE

Stem solid, terete, glabrous. Leaves ovate, 104 x 68 mm, base
cuneate, apex acute, margin double dentate, lamina glabrous. Petiole
14 mm long, glabrous. Inflorescence a terminal spike, c. 43 mm
long, with two lateral spikes, all spikes dense, glabrous; bracts ovate,
entire or toothed, up to 8-9 x 2-6 mm, glabrous. Calyx tubular, 5.0
x 3.8 mm, 5-veined; with very short hairs outside, glabrous within;
teeth ciliate, 1 .2-1 .4 mm long, 0.7-0.8 mm wide at base. Corolla up
to 8.2 mm long; lower lip c. 2.3 x 1 mm; upper lip c. 2 mm across;
central lobe 1 .5 x 0.7 mm, with a few hairs. Filaments inserted at
different heights, the lowest at a height of 3.5 mm in the tube;
filaments c. 6.5-7.5 mm long, exserted portion c. 2.8 mm; monili-
form hairs poorly developed, filaments glabrous towards the base.
Style c. 10.2 mm long; stigma lobes c. 1.1-1.3 mm. Disc c. 0.6 mm
long. Nutlets 4, c. 600 x 300 urn, oblong, foveolate.

DISTRIBUTION. Southern India (Kerala).
SPECIMENS EXAMINED. Nelson s.n. (BM).

13. Pogostemon glaber Benth. in Wall., PI. asiat. rar. 1: 31 (1830).
FigsSf, 18a.

Perilla polystachya D. Don, Prodr.fl. nepal: 115 (1825).

Bush up to 2 m high; stem dark red-purple; hairs 3-celled, c. 250 urn
long. Leaves ovate, 150 x 97 mm, base cuneate, apex acuminate,
margin double dentate; hairs 3-celled, c. 300 urn long. Petiole 40 mm
long, glabrous. Inflorescence a terminal spike, c. 55 mm long, dense,
with two lateral spikes; hairs 3-celled, c. 230 urn long; bracts
lanceolate, 3.0-7.0 x 0.8-1.3 mm, hairy. Calyx tubular-inflated, c.
3.3 x 3.5 mm, 5-veined; outside the tube sparsely hairy and the teeth
glabrous, the teeth hairy within; teeth ciliate, c. 0.9-1 . 1 mm long, c.
0.6-0.8 mm wide at base. Corolla up to 4.7 mm long, pale whitish
pink or light mauve; lower lip c. 1 .2 x 1 mm; upper lip c. 1 .6 mm
across, hairy; central lobe 0.9 x 0.6 mm. Filaments inserted at
different heights, the lowest at a height of 2 mm in the tube; filaments
c. 4.7-5.8 mm long, exserted portion c. 3.1 mm; filaments glabrous
towards the base. Style 6.5 mm long; stigma lobes 0.9-1 mm. Disc
c. 0.7 mm long. Nutlets 4, c. 700 x 600 urn, orbicular, puncticulate.

DISTRIBUTION. Widespread from northwestern India and Nepal to
Yunnan and Thailand. In Thailand it is found in mixed-oak forest, in
shade, above 1000 m, and in Nepal it is a common weed on cut-over
slopes.

ETHNOBOTANY. The leaves ground in water are used to relieve the
pain and itching of mosquito bites.

SPECIMENS EXAMINED. Dawson 262 (BM), Dobremez 739 (BM),
Flatt 161 (BM), Forrest 16161 (BM, K), Gamble 3846 (K), Henry
10418 (K), Henry 11487 (K), Henry 12832 (K), H.I. 1533 (K-
syntypes), Kerr 1 684 (BM), Kerr 2907 (BM), Kerr 3922 (BM), Kerr
4737 (BM), McClure 8454 (K), Nicolson 2941 (BM), Schilling 749
(K).

14. Pogostemon hispidusPrain in Bull. misc. Inf. R. hot. Gdns, Kew
[1908]:254(1908).

Figs6a, 18b.

Stem solid, angular; hairs 6-celled, c. 720 jam long. Leaves ovate, c.
1 18 x 87 mm, base cuneate, apex acute, margin double dentate; hairs
4-celled, c. 770 urn long. Petiole 46 mm long; hairs 5-celled, 870 jam
long. Inflorescence a terminal spike, c. 70 mm long, dense, with two
lateral spikes; hairs 5-celled, c. 780 urn long; bracts ovate or
lanceolate, indistinctly toothed, 5.0-7.0 x 1.0-1.8 mm, hairy. Calyx
tubular-inflated, 4.0 x 3.5 mm, 5-veined; tube more or less glabrous
within, the teeth very hairy inside at tip, more sparsely below, the

SYSTEMATICS OF POGOSTEMON

95

Fig. 6 Dissected corollas, calyces and bracts, showing inner surface. Pogostemon subgenus Pogostemon: (a) P. hispidus, (b) P. wattii, (c) P. championii,
(d) P.formosanus, (e) P. elsholtzioides, (f) P. tuberculosus, (g) P. griffithii, (h) P. dielsianus. Scale bar 5 mm.

96

outside with relatively few long hairs throughout; teeth ciliate, c.
0.8-1.0 mm long, 0.5-0.9 mm wide at base; outer hairs 3-celled, c.
680 urn long. Corolla up to 4.5 mm long; lower lip c. 1 .2 x 1 .2 mm;
upper lip c. 1 .9 mm across; central lobe c. 0.9 x 0.8 mm, with a few
hairs. Filaments inserted at different heights, the lowest at a height of
2 mm in the tube; filaments c. 3.7-4 mm long, exserted portion c. 1 .5
mm; filaments glabrous towards the base. Style c. 8.5 mm long;
stigma lobes c. 0.6 mm. Disc c. 0.4 mm long. Nutlets 4, c. 700 x 600
urn, orbicular, foveate.

DISTRIBUTION. Thailand to Bangladesh. In forest areas.

SPECIMENS EXAMINED. Jenkins in Herb. Hooker (K-paratype),
terr 6631 (BM).

15. Pogostemon wattii C.B. Clarke in J. Linn. Soc. 25: 59 (1889).
Figs6b, 18c.

Pogostemon battakianus Ridl. in J. Asiat. Soc. Mai. 1: 85 (1923).

Stem solid, terete; hairs 5-celled, c. 800 urn. Leaves ovate, c. 75 x 45
mm, base truncate, apex acute, margin double dentate; hairs 5-
celled, c. 1000 (am long. Petiole c. 20 mm long; hairs 5-celled, c. 0.8
mm long. Inflorescence a terminal spike, c. 1 cm long, dense, with
two or more lateral spikes; hairs 8-celled, c. 1000 (am long. Calyx
tubular-inflated, c. 3 x 3.5 mm, 5-veined; sparsely hairy or glabrous
outside, teeth and upper part of tube hairy within; teeth ciliate, c.
0.8-1 mm long, c. 0.5-0.7 mm wide at base; outer hairs 3-celled, c.
350 urn long. Corolla up to 4 mm long; lower lip c. 1 x 1 mm; upper
lip c. 1.8 mm across; central lobe c. 0.8 mm long, 0.6 mm wide at
base. Filaments all inserted at a height of 1.7 mm in the tube, c. 3.5-
4 mm long, exserted portion c. 0.5 mm; filaments all glabrous at the
base. Style 5.5 mm long; stigma lobes c. 0.5 mm. Disc c. 0.4 mm
long. Nutlets 4; c. 430 x 360 urn, ovoid, reticulate-foveate.

DISTRIBUTION. India (western Assam).
SPECIMENS EXAMINED. Clarke 41719 (K-holotype).

The name Pogostemon wattii C.B. Clarke has been a source of
confusion. Prain (1891) included P. wattii in 'Some additional
species of Labiatae', remarking that it was very distinct. Later he
described Eurysolen gracilis, citing the same specimens he had
previously listed under Pogostemon wattii. It is doubtful if he saw
the holotype of P. wattii which is very different. Use of Prain's
account has resulted in the misidentification of many specimens of
Eurysolen gracilis as Pogostemon wattii.

16. Pogostemon championii Prain in Bull. misc. Inf. R. hot. Gdns,
Kew [1908]: 254 (1908).

Figs 6c, 19a.

Stem erect, solid, 4-angled, glabrous below, hairy towards upper
parts; hairs 5-celled, c. 500 jam long. Leaves ovate, up to 1 10 x 60
mm, base cuneate, apex acuminate, margin double crenate; hairs 4-
celled, c. 550 urn long. Petiole up to 40 mm long; hairs 5-celled, c.
500 urn long. Inflorescence a terminal terminal spike, c. 40 mm
long, first whorl of flowers separated from the rest, lateral spikes
with single whorl of flowers; hairs on stalk 4-celled, c. 400 urn
long. Calyx tubular-inflated, c. 4.2 x 3.2 mm, 5-veined; hairy
outside especially on veins, glabrous within; teeth ciliate, 1.1-1.3
mm long; outer hairs 4-celled, c. 550 urn long. Corolla up to 5.5
mm long; lower lip 1.5 x 1 mm; upper lip 1.2 mm across, hairy;
central lobe c. 1 x 0.5 mm. Filaments inserted at different heights,
the lowest two at a height of 2.5 mm in the tube; filaments c. 5-6
mm long, exserted portion c. 2.5 mm; filaments glabrous at the
base. Style c. 7.5 mm long; stigma lobes c. 0.7 mm. Disc c. 0.8 mm

G.R. BHATTI AND M. INGROUILLE

long. Nutlets 4, c. 780 x 650 um, orbicular, black, shiny, reticulate-
foveate.

DISTRIBUTION. Hong Kong.

SPECIMENS EXAMINED. Champion 339 ( K-holotype), Hu 12421 (K).

17. Pogostemon formosanus Oliver in Hooker's Icon. PI. 25: pi.
2440(1896).

Figs6d, 19b.

Stem solid, terete, sparsely hairy; hairs 3-celled with longer apical
cell, c. 250 um long. Leaves ovate, 1 1 x 6.5 mm, base cuneate, apex
acuminate, margin inciso-serrate, abaxial surface of lamina gla-
brous, adaxial surface sparsely hairy; hairs 2-celled, c. 250 um long.
Petiole 45 mm long, weak; hairs 2-celled, c. 160 um long. Inflores-
cence a terminal spike, c. 45 mm long, lax, with three or more lateral
spikes; hairs 2-celled, c. 300 um long; bracts small, lanceolate, c. 3.5
x 0.7 mm, hairy. Calyx campanulate, angular, c. 4 x 3.6 mm, 5-
veined; puberulent outside, mostly on the veins, teeth hairy within
near tip with a row of hairs slightly inside the margin, otherwise
glabrous; teeth c. 1 .3-1 .5 x c. 0.6-0.8 mm; hairs 2-celled, c. 250 um
long. Corolla c. 4.5 mm long; lower lip c. 1 .2 x 0.9 mm, few hairs at
tip; upper lip c. 1 .5 mm across, hairy outside; central lobe c. 1 .2 x 9
mm. Filaments all inserted a height of 2.4 mm in the tube, c. 2.5-2.8
mm long, exserted portion c. 0.7 mm; filaments hairy towards the
base, two upper stamens more so than lower two. Style c. 6 mm long;
stigma lobes c. 0.5 mm. Disc c. 0.5 mm long. Nutlets 4, c. 700 x 600
um, obovoid, dark brown, reticulate-foveate.

DISTRIBUTION. Taiwan.

SPECIMENS EXAMINED. Henry 1 178 (CAL, K).

18. Pogostemon elsholtzioides Benth. in A. DC., Prodr. 12: 153
(1848).

Figs 6e, 19c.

Bushy shrub up to 2 m high; stem solid, angular; hairs 4-celled, c.
220 um long. Leaves lanceolate, 120 x 28 mm, base cuneate, apex
acuminate, margin serrate; hairs 4-celled, 225 um long. Petiole 0.6
mm long; hairs 4-celled, c. 225 um long. Inflorescence a terminal
spike, c. 50 mm long, dense, with more than two lateral spikes; hairs
3-celled, c. 170 um long; bracts ovate or lanceolate, 1.5-5.0 x 0.6-
1.4 mm. Calyx tubular, 4.2 x 3.0 mm, 5-veined; teeth hairy within,
hairy outside with many white hairs and with small tufts of hair at
sinuses of teeth; teeth not ciliate, c. 1.0-1.1 mm long, c. 0.5-0.7 mm
wide at base; outer hairs 3-celled, c. 160 um long. Corolla up to 4.5
mm long, purple; lower lip c. 1 x 0.7 mm; upper lip c. 1.7 mm across,
glabrous; central lobe 0.7 x 0.9 mm. Filaments pink, inserted at
different heights, the lowest at a height of 2 mm in the tube; filaments
c. 4.5-5 mm long, exserted portion c. 2.5 mm; filaments with a few
hairs, more or less equally hairy towards the base. Style 5.8 mm
long; stigma lobes c. 0.7 mm long. Disc c. 0.5 mm long. Nutlets 4,
c. 1700 x 600 um, lanceolate, ruminate.

DISTRIBUTION. Widespread in the Himalayas: Bhutan, India
(Khasia, Naga Hills). Common in secondary growth, waste places,
along roadsides, at the edge of forests, on cultivated land, and around
villages.

SPECIMENS EXAMINED. Bar 24 (K), Bar 6649 (K), Clarke 4 1 505
(K), Clarke 42819 (BM), Griffith 202 (BM, K-syntypes), Griffith
3962 (K-syntype), Kingdon-Ward 6346 (K), Kingdon-Ward 6449
(K), Kingdon-Ward 7841 (K), Kingdon-Ward 11293 (BM, K),
Kingdon-Ward 14234 (BM), Kingdon-Ward 18372 (BM), Kingdon-
Ward 18894 (BM), Kingdon-Ward 20274 (BM), Ludlow, She r riff &

SYSTEMATICS OF POGOSTEMON

Elliot 12255 (BM), Meebold 17.021 (K), Simon s.n. (K), Watt 6656
(K),

19. Pogostemon tuberculosus Benth. in Wall., PL asiat. rar. 1: 31

(1830).
Figs 6f, 20a.

Shrub 2-3 m high; stem solid, terete; hairs stellate, central hair 2-
celled, c. 1 10 |am long, radiating hairs 1 -celled. Leaves ovate, 1 10 x
65 mm, base cuneate, apex acute, margin crenate; hairs similar to
those of stem. Petiole 30 mm long; hairs similar to those of stem.
Inflorescence with more than two laterals verticillasters; verticillasters
c. 200-300 mm long; verticils many flowered, very dense, widely
spaced in inflorescence; bracts small, ovate, 2.5 x 1.0 mm, hairy.
Calyx tubular-inflated, 3.0 x 3.0 mm, 5-veined; with many stellate
hairs outside, teeth hairy within; teeth ciliate, c. 0.9-1 .0 mm long, c.
0.4-0.6 mm wide at base; outer hairs with central hair 3-celled, c.
370 urn long, lateral hairs 1 -celled. Corolla up to 7.2 mm long, pale
mauve; lower lip c. 1 .5 x 1 mm; upper lip c. 2 mm across, glabrous;
central lobe c. 1 .3 x 0.8 mm. Filaments all inserted at a height of 2.4
mm in the tube, deep purplish, c. 7.4-8.9 mm long, exserted portion
c. 4. 1 mm; filaments glabrous at the base, anthers fawn. Style deep
purplish, 11.5mmlong;stigmalobesc. 12mm. Disc c. 0.7 mm long.
Nutlets 4, c. 800 x 600 um, oblong, granulose.

DISTRIBUTION. Eastern Himalayas (Bhutan, Nepal, Kaluimphoong,
Assam, Darjiling). Among thick undergrowth in broad-leaved forest.

SPECIMENS EXAMINED. Clarke 26368B (K), Gamble 3843A (K),
Gamble 3847 A (K), Gamble 7515 (K), Haines 1041 (K), Hooker
s.n. (K), Ludlow, Sherriff& Taylor 61 '59 (BM, E), Treutler 1 194 (K),
Wallich s.n. (K-type).

20. Pogostemon griffithii Prain in Bull. misc. Inf. R. hot. Gdns, Kew
[1908]: 181 (1908).

Figs 6g, 20b.

Pogostemon griffithii var. latifolius C.Y. Wu & Y.C. Huang, Fl.
Yunnanical: 744(1977).

Stem solid, terete; hairs 3-celled, 250 um long. Leaves 2, lanceolate,
95 x 25 mm, base cuneate, apex acute, margin dentate; hairs 3-
celled, c. 250 um long. Petiole c. 10 mm long; hairs 3-celled, c. 250
um long. Inflorescence a terminal spike, c. 50 mm long, dense, with
two lateral spikes; hairs 3-celled, c. 250 um long; bracts ovate or
lanceolate, 2.0-3.0 x 0.5-1.0 mm, hairy. Calyx campanulate, 3.3 x
3.5 mm, 5-veined; upper part of tube and teeth hairy within, hairy
throughout outside; teeth ciliate, c. 1.1-1.4 mm long, 0.5-0.7 mm
wide at base, incurved in fruit; outer hairs 3-celled, c. 375 um long.
Corolla up to 5 mm long; lower lipc. 1 .5 x 1 mm; upper lipc. 1 .2 mm
across; central lobec. 1 .3 x 0.7 mm. Filaments all inserted at a height
of 2 mm in the tube, c. 4.7-5.2 mm long, exserted portion c. 2.2 mm;
filaments more or less glabrous towards the base. Style c. 5.5 mm
long; stigma lobes c. 1.2 mm. Disc c. 0.4 mm long. Nutlets 4, c. 800
x 600 um, oblong, ruminate.

DISTRIBUTION. Burma.

SPECIMENS EXAMINED. Griffith 3962 (K-holotype).

The type specimen of Pogostemon elsholtzioides is also Griffith
3962, although the collection is of a different plant from a different
locality.

21 . Pogostemon dielsianus Dunn in Notes R. hot. Gdn Edinb. 8: 159
(1913).

Figs 6h, 20c.

97

Spreading shrub up to 3 m; stem solid, angular; hairs 3-celled, c. 100
um long. Leaves linear-lanceolate, 120 x 32 mm, base cuneate, apex
acuminate, margin dentate, lamina more or less glabrous above, with
reddish 3-celled hairs below, c. 150 um long. Petiole c. 1 mm long;
hairs 3-celled, c. 125 um long. Inflorescence a terminal spike, c. 45
mm long, dense, with more than two lateral spikes; hairs 3-celled, c.
1 80 um long; bracts lanceolate, c. 4.5 x 0.8 mm, hairy. Calyx tubular,
c. 4.4 x 3.0 mm, 5-veined; teeth hairy within with long fine hairs, a
row of hairs slightly inside the margin, outside with glands and a
dense felt of short hairs; teeth c. 1 .2 x 0.7 mm; outer hairs 3-celled,
c. 1 25 um long. Corolla up to 7.5 mm long, rose-red; lower lip 1 .4 x
1 mm; upper lip c. 1.8 mm across; central lobe c. 1.2 x 1 mm.
Filaments inserted at different heights, the lowest at a height of 3 mm
in the tube; filaments c. 6.2-7 mm long, exserted portion c. 3.5 mm;
two filaments villous towards the base. Style c. 6.4 mm long; stigma
lobes c. 1 .2 mm. Disc c. 0.7 mm long. Nutlets 4, c. 1500 x 800 um,
lanceolate, ruminate.

DISTRIBUTION. Western China (Yunnan, Salween Irrawaddy di-
vide, and valley of the Salween). Amongst rocky scrub on dry rocky
hillsides.

SPECIMENS EXAMINED. Forrest 875 (E, K-isotypes), Henry 9082
(K), Henry 1 1 174 (K), Henry 12563 (K).

II. Subgenus ALLOPOGOSTEMON Bhatti & Ingr.,
subgen. nov.

Pogostemon section Racemosa Benth., pro parte.

Inflorescentia plerumque simplex. Bracteae lanceolatae, lineares
vel filiformis. Calyx tubulosus, actinomorphus, 5 nervi medii plus
usque ad 5 nervos secundarios marginem attingentes, introrsum
annulo hirsute. Filamentis a basi villosis vel glabratis, a medium
pilibus moniliformibus vel glabratis.

Inflorescence normally an unbranched verticillaster, bracts lanceo-
late, linear or filiform, equalling or much smaller than calyx; calyx
with 5 main rib veins plus isolated ± branched secondaries reaching
sinuses of teeth, calyx interior glabrous or with a continuous or
broken annulus of hairs around top of tube and teeth; filament bases
densely villous or glabrous, with or without moniliform hairs.

Ha. Section RACEMOSUS (Benth.) Bhatti & Ingr., stat.
nov.

Pogostemon section Racemosa Benth., Pogostemon section Barbata
Briq., pro parte.

Inflorescence, bracts and bracteoles linear to linear-lanceolate, large
or small, verticillaster unbranched, or if branched then calyx with 5
main rib veins plus isolated ± branched secondaries from sinuses of
teeth, with an annulus of hairs around top of tube and teeth, or
filament bases densely villous.

Ha i. Subsection RACEMOSUS
With moniliform hairs on the filaments.

22. Pogostemon nilagiricus Gamble, Fl. Madras: 1 134 (1924).
Figs 7a, 2 la.

Stem solid, bluntly terete; hairs whitish, 12-celled, c. 2500 um long.
Leaves ovate, c. 45 x 33 mm, base rounded, apex bluntly acute,
margin crenate, with shiny hairs on both sides of lamina; hairs 10-
celled, c. 2500 um long. Petiole c. 10 mm long; hairs similar to those
of leaves. Inflorescence a single terminal spike up to 80 mm long,
dense; glandular and eglandular hairs on stalk, eglandular hairs 10-

98

G.R. BHATTI AND M. INGROUILLE

Fig. 7 Dissected corollas, calyces and bracts, showing inner surface. Pogostemon subgenus Allopogostemon section Racemosus subsection Racemosus:
(a) P. nilagaricus, (b) P. vestitus, (c) P. mollis, (d) P. rotundatus, (e) P. rupestris, (f) P. rogersii, (g) P. petiolaris. Scale bar 5 mm.

SYSTEMATICS OF POGOSTEMON

99

celled, c. 2500 jam long; bracts lanceolate or linear, 4-6 x 0.3-1.3
mm, hairy. Calyx tubular, c. 4.3 x 3.5 mm, 10- veined; the tube
glabrous within, the teeth sparsely hairy, outside hairy; teeth ciliate,
c. 1 .5-1 .7 mm long,c. 0.6-0.8 mm wide at base; outer hairs 6-celled,
c. 870 urn long. Corolla up to 6 mm long; lower lip c. 2.3 x 1.1 mm;
upper lip c. 1 .5 mm across; central lobe c. 1 .6 x 0.8 mm; upper and
lower lip hairy outside. Filaments inserted at different heights, the
lowest at a height of 3 mm in the tube; filaments c. 5.0-5.5 mm long,
exserted portion c. 2.5 mm; filaments thickened towards the base,
the two filaments under upper lip more hairy at the base. Style c. 8
mm long; stigma lobes c. 0.5 mm. Disc c. 0.4 mm long Nutlets 4, c.
500 urn, orbicular, dark brown to black, reticulate-foveate with
secondary reticulation.

DISTRIBUTION. Southern India, Nilagiri (Kunda Hills near
Ootacamund).

SPECIMENS EXAMINED. Bourne s.n. (K-isotypes), Hooker s.n. (K),
Rao 46997 (CAL).

23. Pogostemon mollis Benth., Labial, gen. spec.: 155 (1833).
Figs 7c, 21c.

Stem solid, terete; hairs 6-celled, c. 1750 urn long. Leaves ovate,
soft, c. 32 x 24 mm, base rounded, apex obtuse, margin double
dentate; hairs 4-celled, c. 1500 urn long. Petiole c. 8 mm long; hairs
7-celled, c. 2000 urn long. Inflorescence a single terminal spike, c.
55 mm long, lax below and dense above; hairs 6-celled, c. 1000 urn
long; bracts linear or filiform, 1.5-7.5 x 0.2-0.9 mm. Calyx in-
fundibular, c. 3.8 x 4.0 mm, 10-veined; very hairy outside, glabrous
within; teeth ciliate, c. 1.3-1.5 mm long,c. 0.7-0.8 mm wide at base;
outer hairs 5-celled, c. 410 urn long. Corolla up to 5.5 mm long;
lower lip c. 2. 1 x 1.1 mm; upper lip c. 1 .5 mm across, hairy; central
lobe 1.3 x 0.6 mm. Filaments inserted at more or less the same
height, the lowest at a height of 1 .8 mm in the tube; filaments c. 4.5-
5.5 mm long, exserted portion c. 1.3 mm; filaments equally strigose
at the base. Style c. 6.2 mm long; stigma 1.0-1.2 mm. Disc c. 0.4 mm
long. Nutlets 4, c. 700 x 550 jam, orbicular, reticulate-foveate.

DISTRIBUTION. India (Bombay, Concan, Western Ghats,
Ootacamund, Nilgiri, Kunda Hills, Pulney Hills).

SPECIMENS EXAMINED. Anglade 893 (K), Barber 37 '62 (K), Bourne
5355 (K), Clarke 10673 (BM), Dalzell s.n. (K), Hooker s.n. (K),
Vine 216 (BM), Wight 2124 (K-isotype), Wight 2525 (K).

24. Pogostemon vestitus Benth. in Wall.,/1/, asiat. rar. 1: 31 (1830).
Figs7b, 21b.

Stem solid, terete, very hairy especially at the base; hairs 7-celled, c.
1500 urn long. Leaves ovate, soft felted, 40 x 30 mm, base rounded,
apex acute, margin dentate; hairs c. 5-celled, c. 1100 urn long.
Petiole c. 25 mm long; hairs 5-celled, c. 1200 urn long. Inflorescence
a single terminal spike, c. 30 mm long, dense; hairs 5-celled, c. 1500
urn long. Calyx tubular, 5.8 x 4.8 mm, 10-veined; densely hairy
outside, teeth hairy within; teeth ciliate, c. 0.6-0.8 mm long, c. 0.7-
0.9 mm wide at base; outer hairs 3-celled, c. 3200 urn long. Corolla
c. 8.6 mm long; lower lip c. 3 x 2 mm; upper lip c. 2.5 mm across;
central lobe c. 1.4 x 1.1 mm wide at base. Filaments inserted at
different heights in the tube, the lowest at a height of 4.5 mm in the
tube; filaments c. 7.0-8.5 mm long, exserted portion c. 1.5 mm, two
filaments tomentose at the base. Style c. 12 mm long; stigmas c. 1.2
mm. Disc c. 0.4 mm long. Nutlets 4, c. 600 x 500 urn, oblong,
reticulate-foveate.

DISTRIBUTION. Southern India (western Tamil Nadu).

SPECIMENS EXAMINED. Heyne 1534 (BM, K-syntypes), Heyne
1561 (BM-syntype), Wight 2126 (K), Wight 2527 (E, K-syntypes).

25. Pogostemon petiolaris Benth. in A. DC., Prodr. 12: 154 (1848).
Figs 7g, 23a.

Stem solid, angular; hairs 7-celled, c. 1 100 urn long. Leaves ovate,
c. 55 x 41 mm, base truncate, apex acute, margin double dentate;
hairs 6-celled, c. 900 (am long. Petiole 32 mm long; hairs 7-celled, c.
1000 urn long. Inflorescence a single terminal spike, c. 75 mm long;
hairs 6-celled, c. 1200 urn long; bracts filiform, 2-3 x 0.1-0.3 mm,
hairy. Calyx tubular, 5.0 x 5.2 mm, 5- veined; with a few long hairs
outside, glabrous within, except at the tip of the teeth; teeth ciliate,
c. 1 .2-1 .5 mm long,c. 0.9-1 .2 mm wide at base; outer hairs 6-celled,
c. 1000 um long. Corolla up to 6.5 mm long; lower lip c. 2.5 x 1.2
mm; upper lip c. 1.6 mm across; central lobe c. 1.7 x 0.7 mm.
Filaments inserted at different heights, the lowest at a height of 2 mm
in the tube; filaments c. 6.2-7.5 mm long, exserted portion c. 3 mm;
filaments strigose towards the base, the two upper more densely.
Style c. 8.2 mm long; stigma lobes c. 0.7-0.8 mm. Disc c. 1 mm
long. Nutlets 4, c. 600 x 500 um, orbicular, reticulate-foveate with
secondary reticulation.

DISTRIBUTION. Southern India (Western Ghats).
SPECIMENS EXAMINED. Hohenacker 1224 (BM, K).

26. Pogostemon rupestris Benth., Labial, gen. spec.: 156 (1833),
non Dysophylla rupestris Dalzell (1851).

Figs 7e, 22b.

Annual herb with straggling branches; stem angular, swollen and
rooting at the nodes, glabrous except for a ring of hairs at the nodes.
Leaves ovate to ovate-lanceolate, up to 25 x 15 mm, base cuneate to
truncate, apex acute, margin dentate towards the apex, lamina
sparsely hairy and glandular-punctate; hairs 4-celled, c. 400 um
long. Petiole up to 15 mm long; hairs similar to those of lamina.
Inflorescence a single terminal spike, c. 40 mm long, lax; hairs on
the stalk 4-celled, c. 400 um long; bracts lanceolate to spathulate, c.
4.0 x 0.9 mm, hairy. Calyx tubular to urceolate, c. 3.5 x 3.8 mm, 10-
veined; glabrous within, outside with sparse hairs above; teeth
unequal, triangular, apex blunt, margins ciliate, c. 0.9-1 . 1 x 0.7 mm;
outer hairs c. 4-celled, 400 aem long. Corolla c. 4.6 mm long, rose or
pinkish; lower lip c. 2 x 1 .3 mm; upper lip c. 2.8 mm across, central
lobe c. 1 . 1 x 0.9 mm. Filaments all inserted at a height of c. 2 mm in
the tube, c. 4.0-5.2 mm long, exserted portion c. 2.6 mm; two
filaments under central lobe slightly hairy at the base, staminal hairs
towards the middle blue. Style c. 6.2 mm long; stigma lobes c. 0.6
mm long. Disc c. 0.3 mm long. Mature nutlets 2 or 4, c. 570 x 500
um, orbicular, light brown, shiny, reticulate-foveate.

DISTRIBUTION. Sri Lanka (Adam's Peak, Kandy Distr., Nuwara-
Eliya). Growing in shade on the damp floor of secondary montane
forest.

SPECIMENS EXAMINED. Cramer 3800 (K), Cramer 3807 (E),
Cramer 4277 (K), Cramer 4390 (E, K), Cramer & Jayasuriya 3725
(E), Macrae 396 (K-holotype), Thwaites 343 (BM).

27. Pogostemon rogersii N.E. Br. in Bull. misc. Inf. R. hot. Gdns,
Kew[ 1909]: 379 (1909).

Figs 7f, 22c.

Stem procumbent, rooting at the nodes, solid, angular; hairs 5-
celled, c. 430 um long. Leaves elliptic to elliptic-oblong, soft-flaccid,
62 x 24 mm, base cuneate, apex acute, margin serrate; hairs 4-celled,

100

G.R. BHATTI AND M. INGROUILLE

c. 450 jam long. Petiole c. 20 mm long; hairs 4-celled, 480 jam long.
Inflorescence a terminal spike, c. 30 mm long, dense, with more than
two lateral spikes; hairs 5-celled, c. 720 um long. Calyx infundibu-
lar, 2.1 x 2.2 mm, 10-veined; hairy outside, glabrous within; teeth
ciliate, c. 0.7-0.9 mm long, c. 0.4-0.5 mm wide at base; outer hairs
up to 6-celled, c. 950 urn long. Corolla 6.4 mm long, whitish violet;
lower lipc. 1.9x 1.4 mm; upper lip c. 1.7 mm across; central lobe 1.4
x 0.5 mm. Filaments inserted at different heights, the lowest at a
height of 3.4 mm in the tube; longest filament c. 5.5-5.7 mm long,
exserted portion c. 2.7 mm; filaments equally villous at base. Style
c. 7.7 mm long; stigmas c. 1.1 x 1.4 mm, violet-purple. Disc c. 0.5
mm long. Nutlets 4, c. 400 x 300 urn, orbicular, reticulate-foveate.

DISTRIBUTION. Southern Africa (Zimbabwe, Zambia, Angola,
South Africa, Mozambique). In marshy ground.

ETHNOBOTANY. Produces edible 'tubers'.

SPECIMENS EXAMINED. Fanshawe 3435 (K), Fanshawe 9336 (K),
Gossweiler 14137 (K), Henriques & B rites 1132 (K), Hundt 149
(BM), Johnston 983 (K), Multimushii 1023 (K), Rogers 8314 (K-
holotype), Silva 3801 (K), Stohm 123 (K).

According to Brown (1909) this was the first species of Pogostemon
to be reported from Africa and it is quite distinct from Asiatic
species.

28. Pogostemon rotundatus Benth. in Wall., PL asiat. rar. 1: 31
(1830).

Figs 7d, 22a.

Stem solid, terete; hairs 7-celled, c. 2300 urn long. Leaves orbicular,
c. 50 x 25 mm, base truncate to cordate, apex obtuse, margin double
crenate; hairs shiny, whitish, 7-celled, c. 1300 urn long. Petiole up to
20 mm long; hairs 7-celled, c. 2000 urn long. Inflorescence a single
terminal spike up to 1 10 mm long, flowers in whorls, arranged side-
by-side; hairs 7-celled, c. 2000 urn long; bracts lanceolate to filiform,
3.5-5.5 x 0.2-1.2 mm. Calyx tubular, c. 6 x 5.5 mm long, 10-veined;
very hairy outside, especially the teeth, more or less glabrous within;
teeth ciliate, c. 1.6-1.9 mm long; outer hairs up to 4-celled, c. 900
urn long. Corolla c. 9 mm long; lower lip 3 x 1 .8 mm; upper lip c. 3
mm across, villous outside; central lobe c. 2.4 x 1.5 mm. Filaments
inserted at different heights, the lowest at a height of 3.7 mm in the
tube; filaments c. 8-9 mm long, exserted portion c. 3.7 mm; fila-
ments widening towards the base, the two upper densely strigose
towards the base. Style c. 13 mm long; stigma lobes c. 0.5-1 mm.
Disc c. 0.5 mm long. Nutlets 4, c. 400 x 300 um, oblong, black,
covered by more or less circular scales.

DISTRIBUTION. Southern India (Madras).

SPECIMENS EXAMINED. Heyne s.n. (K-syntype), Wallich 1535 (K-
syntype).

29. Pogostemon philippinensis S. Moore in J. Bot., Land. 43: 146
(1905).

Figs 8a, 23b.

Stem solid, angular; hairs 4-celled, c. 280 um long. Leaves ovate, 68
x 34 mm, base rounded, apex acute, margin dentate; hairs 5-celled,
c. 500 um long. Petiole 20 mm long; hairs 4-celled, c. 440 jam long.
Inflorescence a single terminal spike, c. 125 mm long, lax below,
dense above; hairs 5-celled, 600 jam long; bracts lanceolate to
filiform, 1.3-4.5 x 0.2-1.5 mm, hairy. Calyx tubular, 5.6 x 5.0 mm,
10-veined; hairy outside especially on veins, only teeth hairy within,
with a few hairs; teeth ciliate, c. 0.9-1 .0 mm long, 0.9-1 .0 mm wide
at base; outer hairs 3-celled, c. 370 um long. Corolla up to 9 mm

long; lower lip c. 2.5 x 1.9 mm; upper lip c. 2.3 mm across, hairy;
central lobe c. 1.5 mm long, c. 1 mm wide at base. Filaments inserted
at different heights, the lowest at a height of 4.5 mm in the tube;
filaments c. 8.4-9.0 mm long, exserted portion c. 4.5 mm; two
filaments villous towards the base. Sty lee. 12 mm long; stigma lobes
1.1-1.2 mm. Disc c. 0.5 mm long. Nutlets 4, c. 400 x 200 um,
oblong, reticulate.

DISTRIBUTION. East Indies, Philippines (Panay, Luzon), and
Mariana Islands.

SPECIMENS EXAMINED. Ramos 33320 (BM, K), Ramos & Edano
45012 (BM), Santos 31792 (BM), Vidal 1659 (K), Vidal 3421 (K-
syntype), Whitehead s.n. (BM-syntype),

30. Pogostemon velatus Benth. in A. DC., Prodr. 12: 155 (1848).
Figs 8b, 23c.

Stem solid, angular; hairs dendromorphic and fruticose, 6-celled, c.
1250 um long. Leaves ovate, 33 x 19 mm, base rounded, apex
obtuse, margin dentate, hairs dendromorphic and fruticose, 4-celled,
c. 1100 um long. Petiole c. 5 mm long; hairs dendromorphic and
fruticose, 9-celled, c. 1750 um long. Inflorescence a single terminal
spike, c. 165 mm long, dense; hairs dendromorphic; bracts linear or
filiform, 2.5-7.0 x 0.3-0.5 mm, hairy. Calyx tubular, 5.4 x 4.1 mm,
10-veined; densely hairy outside, margin of teeth hairy within,
otherwise glabrous; teeth ciliate, c. 1 .0-1 .2 mm long, c. 0.8-1 .0 mm
wide at base; outer hairs dendromorphic, 4-celled, c. 465 um long.
Corolla up to 8 mm long; lower lip c. 2.5 x 1 .4 mm; upper lip c. 2.5
mm across, hairy outside; central lobe c. 1.2 x 0.9 mm. Filaments
inserted at different heights, the lowest filaments at a height of 3.8
mm in the tube; filaments c. 8.0-8.8 mm long, exserted portion c. 4.6
mm; two filaments strigose towards the base. Style c. 10 mm long;
stigma lobes 1.1-1.2 mm. Disc c. 0.5 mm long. Nutlets 4, c. 500 x
300 um, oblong, spinulose.

DISTRIBUTION. Philippines (Luzon).

SPECIMENS EXAMINED. Cuming 1097 (BM, K-isotypes), Elmer
s.n. (BM), Loher 4209 (K), McGregor 1 1339 (BM), Mendoza 40923
(BM), Merrill s.n. (BM).

31. Pogostemon williamsii Elmer in Leafl. Philipp. Bot. 9: 3197
(1934).

Figs 8c, 24a.

Stem solid, terete; hairs dendromorphic and fruticose, 5-celled, c.
600 um long. Leaves lanceolate, c. 105 x 35 mm, base cuneate, apex
acuminate, margin crenate; hairs fruticose, 5-celled, c. 800 um long.
Petiole 26 mm long; hairs fruticose, 5-celled, c. 800 um long.
Inflorescence a single terminal spike, c. 95 mm long, dense; hairs
fruticose, 5-celled, c. 8 1 5 um long; bracts lanceolate to filiform, 4.0-
6.0 x 0.2-1.5 mm, hairy. Calyx tubular, 5.0 x 4.3 mm, 10-veined;
sparsely hairy outside, margin of teeth hairy within; teeth ciliate, c.
0.6-0.8 mm long, c. 0.7-0.9 mm wide; outer hairs fruticose, 4-
celled, c. 650 um long. Corolla up to 8 mm long; lower lip c. 2.5 x
1.5 mm; upper lipc. 2.7 mm across, hairy outside; central lobe 1.5 x
0.8 mm wide at base. Filaments inserted at different heights, the
lowest at a height of 3.5 mm in the tube; filaments c. 10-11 mm long,
exserted portion c. 6.5 mm; two filaments strigose towards the base.
Style c. 12 mm long; stigma lobes c. 1.1-1.2 mm. Disc c. 0.6 mm
long. Nutlets 4, c. 900 x 600 um, ellipsoid to ellipsoid-oblong,
spinulose.

DISTRIBUTION. Phillippines (Luzon, Mt. Pinatubo, Mt.
Semenublam, Baguio, Benguet).

SYSTEMATICS OF POGOSTEMON

101

Fig. 8 Dissected corollas, calyces and bracts, showing inner surface. Pogostemon subgenus Allopogostemon section Racemosus subsection Racemosus:
(a) P. philippinensis, (b) P. velatus, (c) P. williamsii, (d) P. membranaceus, (e) P. elatispicatus. Scale bar 5 mm.

102

SPECIMENS EXAMINED. Elmer 22225 (BM, K-isotypes), Iwatsuki,
Murata & Gutierrez 318 (K), Merrill 1 1673 (BM, K).

Keng (1978) and Press (1982) treated Pogostemon williamsii as
conspecific with P. velatus but it differs in its trichomes, nutlets, and
leaf shape.

32. Pogostemon membranaceus Merr. in Philipp. J. Sci. (Bot.) 7:
347(1912).

Figs 8d, 24b.

Stem solid, terete; hairs 4-celled, c. 370 um long. Leaves ovate, c. 70
x 34 mm, base cuneate, apex acute, margin crenate; hairs 3-celled, c.
250 |um long. Petiole c. 14 mm long; hairs 4-celled, c. 400 um long.
Inflorescence a single terminal spike c. 140 mm long, lax below,
dense above; hairs 5-celled, c. 600 jam long; bracts early deciduous.
Calyx tubular, 7.0 x 4.0 mm, 10- veined; hairy outside, glabrous
within except at the tip of the teeth; teeth ciliate, c. 1 .2-1 .4 mm long,
c. 0.7-0.9 mm wide at base; outer hairs 3-celled, c. 376 (jm long.
Corolla up to 8.5 mm long; lower lipc. 2 x 1 . 1 mm; upper lipc. 2 mm
across; central lobe 1.3 x 0.6 mm. Filaments inserted at different
heights, the lowest at a height of 4.3 mm in the tube; filaments c. 7.5-
8.8 mm long, exserted portionc. 4.6 mm; filaments equally tomentose
towards the base. Style c. 12.5 mm long; stigma lobes c. 0.5 mm.
Disc c. 1 mm long. Nutlets 4, c. 800 x 300 (am, 'D' -shaped,
reticulate.

DISTRIBUTION. Philippines (Luzon, Laguna, San Antonio).

SPECIMENS EXAMINED. Ramos 16419 (BM-holotype), Ramos
14419 (K), Ramos 16596 (K).

33. Pogostemon elatispicatus Bhatti & Ingr., sp. nov.
Figs 8e, 24c.

Herbae hirsutae. Caules subquadrangulati. Folia opposita, lamina
25-75 x 20-35 mm, ovata, crenata, petioli 10-25 mm, abaxialis
hirsuta, dendropilis et simplipilis, adaxialis glabrata. Inflorescentia
terminalis ad 230 mm, laxa vel densa ordinate verticillastris numerosis
multifloribus; bracteae c. 4.0-5.0 x 1.0 mm, lanceolatae, hirsutae.
Calyx tubulatus, tubo 5.0 mm longo, dentibus quinque 0.9-1.3 mm
longis, triangularibus, sub fructu incurvatis. Corolla bilabiata
purpurea, tubo ad 8.4 mm longo exserto, labio superiori lobus
centralis 1.3 x 0.8 mm, labio inferiori 2.3 x 1.5 mm longo integro.
Stamina quator filamentis exsertis, pari inferiori longiori, prope
medianum pilis longis barbati, prope inferior villosus; antherae
uniloculares. Discus non lobatus. Nuculae maturae quatuor, semi-
quaternari-spheroideus, spinifer.

TYPE. Philippines, Luzon, Ilocos, Norte Prov., Mt. Darna, Febru-
ary-March 1953, Edano 18046 (BM!-holotype).

Stem solid, terete; hairs 6-celled, c. 780 urn long. Leaves ovate, 25-
65 x 20-35 mm, base cuneate, apex acuminate, margin crenate;
hairs simple-uniseriate on the adaxial surface, 6-celled, c. 870 urn
long; dendromorphic hairs and simple hairs on the abaxial surface.
Petiole 10-25 mm long; hairs 6-celled, 870 urn long. Inflorescence
a single terminal spike c. 230 mm long, verticils arranged regularly
and relatively laxly; hairs 7-celled, c. 1400 urn long; bracts lanceo-
late, c. 4.0-5.0 x 1.0 mm, hairy. Calyx tubular, 5.0 x 4.4 mm,
10-veined; sparsely hairy outside, teeth and tube glabrous within;
teeth ciliate, c. 0.9-1.3 mm long, c. 0.8-0.9 mm wide at base; outer
hairs 6-celled, c. 1000 urn long. Corolla up to 8.4 mm long; lower lip
c. 2.3 x 1.5 mm; upper lip c. 3 mm across; central lobe c. 1 .3 x 0.8
mm. Filaments inserted at different heights, the lowest at a height of
3.7 mm in the tube; filaments c. 8.9-9.3 mm long, exserted portion

G.R. BHATTI AND M. INGROUILLE

c. 4.6 mm; two filaments setose towards the base. Style 13.3 mm
long; stigma lobes c. 0.6 mm. Disc 0.7 mm long. Nutlets 4, c. 330 x
200 urn, semi-circular or 'D' -shaped, spinulose.

DISTRIBUTION. Philippines.

This taxon has affinities with Pogostemon philippinensis, P.
membranaceus, P. williamsii, and P. velatus but it differs by having
dendromorphic hairs only on the abaxial surface, setose hairs at the
basal part of the filaments, and semi-circular or 'D' -shaped nutlets.
The verticillaster is very long with a very regular arrangement of
verticils.

34. Pogostemon paludosusBenth.inA. DC., Prodr. 12: 154(1848).
Figs 9a, 25a.

Stem solid, angular; hairs 5-celled, c. 600 urn long. Leaves ovate, c.
70 x 35 mm, base somewhat truncate, apex obtuse, margin double
crenate; hairs 5-celled, c. 700 um long. Petiole c. 45 mm long; hairs
5-celled, c. 700 um long. Inflorescence a single terminal spike, c. 90
mm long, lax; hairs 5-celled, c. 1000 um long. Calyx tubular, 3.5 x
2.8 mm, 10 veins obscure, 5 veins distinct; annulus of hairs in the
calyx throat, outside with long and short hairs; teeth ciliatec. 0.5-0.8
mm long, c. 0.4-0.6 mm wide at base; outer long hairs 5-celled, 750
um long. Corolla up to 5. Omm long; lower lipc. 1.9x 1.5 mm; upper
lip c. 2.0 mm across; central lobe 0.9 x 0.4 mm. Filaments inserted
at different heights, the lowest at a height of 2 mm in the tube;
filaments c. 4.0-4.5 mm long, exserted portion c. 1.5 mm; two
filaments tomentose towards the base. Style c. 6 mm; stigma lobes
0.8 mm long. Ovary glandular. Discc. 0.5 mm long. Nutlets 4, c. 650
x 600 um, orbicular, with cup-like glands.

DISTRIBUTION. India (Nilgiri, Kunda Hills, Tamil Nadu).
SPECIMEN EXAMINED. Klackenberg & Lundin 116 (K).

Ha ii. Subsection GLABRIUSCULUS (Briq.) Bhatti &
Ingr., stat. nov.

Pogostemon section Racemosa subsection Glabriuscula Briq.

Filaments lacking moniliform hairs. A few simple hairs may be
present.

35. Pogostemon speciosus Benth. in Wall., PL asiat. rar. 1: 31

(1830).
Figs 9b, 25b.

Stem solid, terete; hairs 8-celled, c. 1750 um long. Leaves ovate, 65
x 62 mm, base cordate, apex acute, margin double crenate; hairs 6-
celled, c. 1000 um long. Petiole 60 mm long; hairs 8-celled, c. 1600
(am long. Inflorescence a single terminal spike, c. 100 mm long,
dense; hairs 9-celled, c. 1700 um long; bracts small, filiform, c. 1.0
x 0.2 mm, hairy. Calyx tubular, somewhat 2-lipped, 6.4 x 4.5 mm, 5
main veins plus a variable number of parallel minor veins reaching
teeth sinuses; outside with a few scattered hairs, tufts of hairs within
at the junction of the teeth; teeth ciliate, c. 2.3-2.6 mm long, c. 0.9
mm wide at base, sometimes two narrower than others; outer hairs 5-
celled, c. 470 um long. Corolla up to 7 mm long; lower lip c. 2.8 x
1.5 mm; upper lip c. 2.5 mm across; central lobe 1.6 x 0.8 mm.
Filaments inserted at different heights, the lowest at a height of 2.7
mm in the tube; filaments c. 1 1 . 1-1 1 .6 mm long, exserted portion c.
7.3 mm; filaments lacking moniliform hairs in the middle, two
tomentose at the base. Style c. 14 mm long; stigma lobes c. 0.8 mm
long; ovary glandular. Disc c. 0.8 mm long. Nutlets 4, c. 800 x 700
um, ovoid, with cup-like glands.

SYSTEMATICS OF POGOSTEMON

103

Fig. 9 Dissected corollas, calyces and bracts, showing inner surface. Pogostemon subgenus Allopogostemon section Racemosus: subsection Racemosus
(a) P. paludosus; subsection Glabrimculus: (b) P. speciosus, (c) P. atropurpureus, (d) P. travancoricus, (e) P. reflexus; section Zygocalyx: (f) P. wightii.
Scale bar 5 mm.

104

G.R. BHATTI AND M. INGROUILLE

DISTRIBUTION. India (Nilgiri (Kunda Hills), Ootacamund, on the
border of Kerala with Tamil Nadu).

SPECIMENS EXAMINED. Bourne 5314 (K), Callaro s.n. (K), Clarke
10651 (K), Gamble 11611 (K), Gamble 1 1630 (K), Gamble 18389
(K), Hohenacker 1225 (BM, K), Townsend & Ramamoorthy 47 (K),
Schmidt s.n. (BM), Vine 215 (BM), Wight 2028 (K).

The calyx of Pogostemon paludosus approaches that found in spe-
cies of section Zygocalyx.

36. Pogostemon travancoricus Bedd., Icon. pi. Ind. or. 1: 34
(1868-1874).

Figs 9d, 26a.

Stem solid, angular, glabrous. Leaves ovate, 50 x 38 mm, base
cuneate, apex acuminate, margin crenate, lamina glabrous. Petiole c.
38 mm long, glabrous. Inflorescence a single terminal spike, c. 45
mm long, lax, glabrous. Calyx tubular, 6.3 x 5.0 mm, 10- veined;
glabrous within and outside; teeth not ciliate, c. 1.3-1.8 mm long, c.
0.9-1.1 mm wide at base. Corolla up to 9 mm long; lower lip c. 2.1
x 2 mm; upper lip c. 3.8 mm across; central lobe 1.6 x 1.2 mm.
Filaments inserted at different heights, the lowest at a height of 3.5
mm in the tube; filaments c. 12.8-13.9 mm long, exserted portion c.
8.4 mm; filaments glabrous towards the middle, equally villous at
the base. Style c. 14.1 mm long; stigma lobes c. 1.0-1.1 mm. Ovary
glandular. Disc c. 1 . 1 mm long. Nutlets 4, c. 1 000 x 800 jam, oblong,
with cup-like glands.

DISTRIBUTION. Southern India (Travancore).

SPECIMENS EXAMINED. Beddome 109 (BM, K-isotypes),/tao 3223
(K).

37. Pogostemon reflexus Benth. in A. DC., Prodr. 12: 155 (1848).
Figs 9e, 26b.

Stem solid, terete; hairs 6-celled, c. 610 urn long. Leaves ovate, 63 x
40 mm, base truncate, apex acute, margin double crenate; hairs 5-
celled, c. 500 urn long. Petiole 2 1 mm long; hairs 5-celled, c. 670 urn
long. Inflorescence a single terminal spike, c. 1 1 5 mm long, dense;
hairs 6-celled, c. 760 urn long. Calyx tubular, 6.8 x 6.0 mm, 10-
veined; hairy outside, an annulus of hairs in the throat; teeth ciliate,
c. 1.9-2.1 mm long, c. 1.0- 1.3 mm wide at base; outer hairs 5-celled,
c. 560 u,m long. Corolla up to 7.7 mm long; lower lipc. 2.3 x 1 .2 mm;
upper lip c. 2.6 mm across; central lobe 1.5 x 1 mm. Filaments all
inserted at a height of 2.8 mm in the tube, c. 8-10 mm long, exserted
portion c. 2 mm; filaments glabrous towards the middle, two villous
towards the base. Style c. 12 mm long; stigma lobes c. 1.1 mm.
Ovary glandular. Disc c. 0.6 mm long. Nutlets 4, c. 1 100 x 800 um,
oblong, with cup-like glands.

DISTRIBUTION. Sri Lanka (Kandy, Adam's Peak, Nuwara-Eliya).

SPECIMENS EXAMINED. Cramer 3483 (K), Cramer 3488 (K),
Cramer 4028 (K), Cramer 4448 (K), Davidse & Sumithraarachchi
8653 (K), Moon 199 (BM), Thwaites 154 (BM), Walker s.n. (K-
syntype).

38. Pogostemon atropurpureus Benth. in A. DC., Prodr. 12: 154
(1848).

Figs 9c, 25c.

Pogostemon imberbe C.H. Wright ex Hook.f., Fl. Brit. India 4: 637
(1885).

Stem solid, terete; hairs 5-celled, 750 um long. Leaves elliptic to
elliptic-oblong, 70 x 37 mm, base rounded, apex acute, margin

crenate to double crenate; hairs 7-celled, 600 um long. Petiole c. 30
mm long; hairs 5-celled, c. 650 um long. Inflorescence a single
terminal spike, c. 80 mm long, dense; hairs 6-celled, c. 750 um long.
Calyx campanulate, 5.0 x 4.0 mm, 10- veined; a broken annulus of
hairs in the throat, a tuft of hairs at the sinuses; teeth ciliate, c. 1 .5-
1.7 mm long, 0.6-0.9 mm wide at base; outer hairs 7-celled, c. 750
um long. Corolla up to 9.4 mm long; lower lipc. 2.3 x 1 .5 mm; upper
lip c. 3 mm across; central lobe 1.1 x 1.1 mm. Filaments inserted at
different heights, the lowest at a height of 3.2 mm in the tube;
filaments c. 12-13 mm long, exserted portion c. 6.8 mm; filaments
glabrous towards the middle, two villous towards the base. Style c.
15.5 mm long; stigma lobes 0.8 mm. Ovary glandular. Disc c. 1 mm
long. Nutlets 4, c. 1200 x 1 100 um, oblong, with cup-like glands.

DISTRIBUTION. India (Kerala, Nilgiri, Kunda Hills, Anaimalai
Hills).

SPECIMENS EXAMINED. Beddome s.n. (BM, K), Hb. Miers s.n.
(BM), Wight 2127 (K-holotype).

lib. Section ZYGOCALYX Bhatti & Ingr., sect. nov.

Calyx plusminusve bilabiatus, dentibus subulatibus, fimbriatus
setaceus, fauci annularis pilibus.

Calyx irregular, somewhat or markedly two-lipped, teeth awl-shaped
and fringed with bristles, throat ringed by hairs, either densely or
sparsely.

39. Pogostemon fraternus Miq., Fl. Ned. Ind., Eerste bijv. 2: 635

(1859).
Figs lOa, 26c.

Herb up to 1 m tall; stem solid, terete, glabrous. Leaves ovate, 89 x
51 mm, base cuneate, apex acute, margin double dentate; hairs 5-
celled; c. 1000 um long. Petiole c. 45 mm long, glabrous.
Inflorescence a terminal spike, c. 80 mm long, dense, with more than
two lateral spikes; hairs 4-celled, c. 750 um long. Calyx infundibu-
lar, c. 6.5 x 3.5 mm, 10- veined; sparsely hairy outside and with
spherical glandular trichomes equally or more common, an annulus
of hairs in the throat; teeth margin, c. 2.2-3.3 mm long, c. 0.8-1.1
mm wide at base; outer hairs 3-celled, c. 660 |im long. Corolla up to
7.5 mm long, purple- to pinkish white; lower lipc. 2.7 x 1 mm; upper
lip c. 1.5 mm across; central lobe c. 1.5 x 0.6 mm. Stamens violet;
filaments inserted at different heights, the lowest at a height of 3.5
mm in the tube; filaments c. 8.0-8.8 mm long, exserted portion c. 4.8
mm; filaments more or less glabrous towards the base. Style c. 1 1
mm long, violet; stigma lobes 0.6-0.9 mm. Disc c. 0.8 mm long.
Nutlets 4, c. 1 100 x 900 um, orbicular, reticulate-foveate.

DISTRIBUTION. Widespread from northern India (Sikkim, Gangtok,
Darjiling, Naga Hills, gorge of the Trin river, south of Saramati) to
China (Yunnan, Szemao Forest) and Thailand (Chiang Mai, Kao
Lwta Kao Kem, Korat, Kao Soi Dao-Chantatum, Doi Sutip, Kao
Sunj, Tranj), Burma (Kachin, Keenam, Tennaserium, Chin Hills),
and Java. In dry forests, on precipitous cliffs and open ground.

SPECIMENS EXAMINED. Bular s.n. (K), Clarke 21239 A (K), Henry
1 1699 (K), Hooker 25 (K), Horsfield 28 (K), Hosseus 198 (BM, K),
Kerr 1646 (BM, K), Kerr 3554 (BM), Kerr 4685 (BM), Kerr 9658
(BM), Kerr 15252 (BM), Kerr 16762 (BM), Kingdon-Ward 21740
(BM), Lister 20 (K), Meebold 7378 (K), Moorely s.n. (K), Tun Aung
& Tha Hla 3626 (K).

Called 'Prao Lam' in Thailand. Miquel (1859) described the fila-
ments as glabrous. Hooker (1885) clearly mentioned that Miquel
found glabrous filaments in Javan plants, but noted that they were

SYSTEMATICS OF POGOSTEMON

105

Fig. 10 Dissected corollas, calyces and bracts, showing inner surface. Pogostemon subgenus Allopogostemon section Zygocalyx: (a) P.fraternus, (b) P.
menthoides, (c) P. macgregorii, (d) P. litigiosus, (e) P. hirsutus, (f) P. brachystachyus, (g) P. nigrescens, (h) P. strigosus. Scale bar 5 mm.

106

hairy towards the base in the Indian plants he examined. Mukerjee
(1940) also reported stamens were only hairy towards the base, but
Press (1982) scored the filaments as hairy towards the middle.

Keng (1969) regarded Pogostemon fraternus as a synonym of P.
menthoides. He commented that the description of P. fraternus made
on Horsfield's collection from G. Praoe, Java, is identical with the
type specimen off! menthoides at K. Hooker ( 1 885) treated Horsfield
28 as P. fraternus in the Flora of British India. In fact, there is
another specimen, Horsfield 29, which has been considered as the
type of P. menthoides.

40. Pogostemon menthoides Blume, Bijdr. fl. Ned. Ind. 3: 825
(1826).

Figs lOb, 27a.

Stem solid, angular; hairs 5-celled, c. 600 urn long. Leaves ovate, 45
x 23 mm, base cuneate, apex acute, margin dentate; hairs 6-celled, c.
625 urn long. Petiole 6 mm long; hairs 5-celled, c. 670 urn long.
Inflorescence a single terminal spike, c. 40 mm long, dense through-
out; hairs 5-celled, c. 500 urn long. Calyx tubular, 3.5 x 3.3 mm,
10- veined; hairy outside, an annulus of hairs in the throat; teeth
ciliate, c. 1 .2-1 .4 mm long, c. 0.5-0.8 mm wide at base; outer hairs
6-celled, c. 700 urn long. Corolla up to 4.6 mm long; lower lip c. 2.0
x 0.9 mm; upper lip c. 1 .7 mm across; central lobe c. 1 . 1 x 0.6 mm.
Filaments inserted at different heights, the lowest at a height of 2 mm
in the tube; filaments c. 3.5^.3 mm long, exserted portion c. 1.7
mm; filaments more or less glabrous at the base. Style c. 4.5 mm
long; stigma lobes c. 0.5 mm. Disc c. 0.5 mm long. Nutlets 4, c. 1 000
x 800 jam, orbicular, reticulate-foveate.

DISTRIBUTION. Widely distributed from India (Manipur, Ukhrul)
to Indonesia andVietnam (Khu-Tu-Tri-Tay-Bac, near Chapa). Grow-
ing in patches at roadsides in the shade of the climax forest.

ETHNOBOTANY. In Java the fragrant leaves of Pogostemon
menthoides are kept among clothes as an insect repellent.

SPECIMENS EXAMINED. Horsfield 29 (K-isotypes), Kingdon-Ward
18036 (BM), Kingdon-Ward 20423 (BM), Petelot 51 10 (BM).

The filaments have been described as glabrous in various floras, but
a few moniliform hairs have been observed. This is a strongly
scented plant with branches rooting so that it forms a carpet.

41. Pogostemon litigiosus Doan in Humbert, Fl. gen. Indo-China
4:972(1936).

Figs lOd, 27c.

Stem solid, terete, rooting at the nodes; hairs 8-celled, c. 1600 urn
long. Leaves ovate, 54 x 34 urn, base truncate, apex acute, margin
double dentate; hairs 7-celled, c. 1 1 00 urn long. Petiole 25 mm long;
hairs 7-celled, 1400 urn long. Inflorescence a single terminal spike,
c. 60 mm long, lax throughout; hairs 7-celled, c. 1300 urn long.
Calyx bilabiate, 5.5 x 5.5 mm, 10-veined; with scattered long hairs
outside, an annulus of hairs in the throat; teeth unequal, ciliate, c.
0.8-2.3 mm long, c. 1.1-1.5 mm wide at base; outer hairs 5-celled,
c. 680 (am long. Corolla up to 6.5 mm long, white; lower lip c. 1.8 x
1.5 mm; upper lip c. 1.5 mm across; central lobe 0.6-1.5 mm.
Filaments inserted at different heights, the lowest at a height of 2.5
mm in the tube; filaments c. 5.2-5.4 mm long, exserted portion c. 1.4
mm; filaments glabrous towards the base. Style c. 7.7 mm long;
stigma lobes c. 0.7-0.8 mm. Disc c. 0.5 mm long. Nutlets 4, c. 1200
x 1000 um, orbicular, reticulate-foveate.

DISTRIBUTION. Only found in Sabah on the slopes of Mt Kinabalu
above 1000 m. Along wet forest trails and in other wet places.

G.R. BHATTI AND M. INGROUILLE

SPECIMENS EXAMINED. J. & M.S. Clemens 29042 (BM), J. & M.S.
Clemens 29727 (BM), J. & M.S. Clemens 32575 (BM), J. & M.S.
Clemens 40267 (BM).

This is a very distinct species, although specimens have sometimes
been incorrectly identified as Pogostemon menthoides.

42. Pogostemon macgregorii W.W. Sm. in Rec. hot. Surv. India 6:
39(1914).

Figs lOc, 27b.

Stem solid, erect; hairs 6-celled, c. 720 um long. Leaves ovate, 80 x
25 mm, base rounded, apex acute, margin serrate; hairs 5-celled, c.
520 um long. Petiole 10 mm long; hairs 5-celled, c. 560 um long.
Inflorescence a single terminal spike, c. 60 mm long, with 1 2 closely
arranged verticils, the lowermost whorl of flowers separated from
the rest; hairs 7-celled, c. 550 (am long. Calyx tubular-inflated, 4.0 x
3.6 mm, 10-veined; an annulus of hairs inside the tube, outside a few
glandular tipped hairs present; teeth ciliate, c. 1-2 mm long, widest
tooth c. 1.0-1.3 mm wide at base; outer hairs 4-celled, c. 340 um
long. Corolla up to 6.0 mm long; lower lip 1.8 x 1.3 mm; upper lip
c. 2.6 mm across; central lobe c. 1.1x0.6 mm. Filaments all inserted
at a height of 2.6 mm in the tube, c. 3.8-4.5 mm long, exserted
portion c. 1 . 1 mm; filaments equally hairy towards the base. Style c.
5.4 mm long; stigma lobes c. 0.7 mm long. Disc c. 0.9 mm long.
Nutlets 4, c. 1 . 1 x 1 . 1 mm, orbicular, dark brown, reticulate-foveate.

DISTRIBUTION. Northern Thailand (Pa-Ngem Chiang Mai,
Doichong).

SPECIMENS EXAMINED. Gam>«438 (BM, K), Hansen & Smitinand
12661 (K), Iwatsuki, Funkuoka & Chintayungkum 9659 (K), Murata
15941 (K).

43. Pogostemon hirsutus Benth., Labial, gen. spec.: 155 (1833).
Figs lOe, 28a.

Stem erect, solid, angular; hairs 4-celled, c. 500 um long. Leaves
ovate, c. 26 x 15 mm, base cuneate, apex acute, margin serrate; hairs
4-celled, c. 620 um long. Petiole c. 7 mm long; hairs 4-celled, c. 500
um long. Inflorescence a single terminal spike, up to 32 mm long,
dense; hairs 6-celled, c. 1000 um long. Calyx tubular, c. 5 x 4 mm,
10-veined; with scattered very long hairs outside, glabrous within;
teeth unequal, ciliate, longest tooth c. 1 .5 mm long, shortest c. 0.7
mm long, c. 0.5-0.7 mm wide at base; outer hairs 5-celled, c. 820 um
long. Corolla up to 6.3 mm long; lower lip c. 2. 1 x 1 .2 mm; upper lip
c. 2.5 mm across, hairy outside; central lobe c. 1.5 x 0.8 mm.
Filaments inserted at different heights, the lowest at a height of 2.5
mm in the tube; filaments c. 3.2-6.3 mm, exserted portion c. 2.5 mm;
filaments all more or less equally villous at the base. Style c. 7.0 mm
long; stigma lobes c. 0.6 mm. Disc c. 0.5 mm long. Nutlets 4, c. 450
x 300 um, oblong, reticulate-foveate.

DISTRIBUTION. Sri Lanka (Hakgala, Nuwara-Eliya, Matale).

SPECIMENS EXAMINED. Cramer 4872 (K), Macrae 446 (K-
holotype), Simpson 9049 (BM), Thwaites 283 (BM), Townsend 73/
155 (K).

44. Pogostemon wightii Benth., Labial, gen. spec.: 156 (1833).
Figs 9f, 28b.

Stem solid, angular; hairs 9-celled, c. 1700 um long. Leaves ovate,
50 x 43 mm, base truncate, apex acute, margin double crenate; hairs
7-celled, c. 1500 um long. Petiole 26 mm long; hairs 9-celled, 1400
um long. Inflorescence a single terminal spike, c. 70 mm long, lax;
hairs 8-celled, c. 1700 um long. Calyx tubular, 5.7 x 5.7 mm, 10-

SYSTEMATICS OF POGOSTEMON

107

veined; sparsely hairy outside, an annulus of hairs in the throat; teeth
ciliate, c. 1.3-1.5 mm long, c. 0.8-1.1 mm wide at base; outer hairs
7-celled, c. 1500 jam long. Corolla up to 6 mm long; lower lip c. 2.2
x 1.5 mm; upper lip c. 2.5 mm across; central lobe 1.1 x 0.7 mm.
Filaments inserted at different heights, the lowest at a height of 2.4
mm in the tube; filaments c. 6.0-6.5 mm long, exserted portion c. 5.0
mm; two filaments villous at the base. Style c. 7.0 mm long; stigma
lobes c. 0.4-0.5 mm. Disc c. 0.8 mm long. Nutlets 4, c. 600 x 500
urn, orbicular, reticulate-foveate with secondary reticulation.

DISTRIBUTION. Southern India (Nilaghiri, Kunda Hills, Malabar,
Concan).

SPECIMENS EXAMINED. Gamble 16929 (K), Gamble 17853 (BM,
K), Klackenberg & Lundin 116 (K), Stocks & Law s.n. (BM),
Schmidt 74 (BM), Wight s.n. (K).

45. Pogostemon brachystachyus Benth. in A. DC., Prodr. 12: 156
(1848).

Figs lOf, 28c.

Stem solid, rooting at nodes, angular; hairs up to 6-celled, c. 900 (am
long. Leaves ovate, 33 x 20 mm, base cuneate, apex acuminate,
margin dentate; hairs 7-celled, c. 550 (am long. Petiole c. 6 mm long;
hairs 5-celled, c. 400 urn long. Inflorescence a single terminal spike,
c. 140 mm long; hairs 6-celled, c. 630 urn long. Calyx tubular, c. 4 x
3.8 mm, 10-veined; outside with a few hairs, some glandular, an
annulus of hairs in the throat; teeth ciliate, c. 1.3-1.6 mm long, 0.4-
0.6 mm wide at base; outer hairs 4-celled, c. 470 urn long. Corolla up
to 4 mm long, bright purple; lower lip c. 1 .5 x 1 mm; upper lip c. 1 .3
mm across; central lobe 1 . 1 x 0.5 mm. Filaments inserted at different
heights, the lowest at a height of 1 .6 mm in the tube; filaments c. 3.5-
4.0 mm long, exserted portion c. 1 .6 mm; filaments glabrous towards
the base. Style c. 5.2 mm long; stigma lobes c. 0.9 mm. Disc c. 0.5
mm long. Nutlets 4, c. 800 x 700 urn, orbicular, reticulate.

DISTRIBUTION. Northern India (Khasia, Shillong) to Burma
(Sumpra Prum). A weed of open roadsides, forming mat-like colo-
nies with ascending verticillasters.

SPECIMENS EXAMINED. Clarke 15559A (BM, K), Clarke 40303
(BM), Griffith 3967 (K-isotypes), Kingdon-Ward 20519 (BM, K).

In Kew herbarium there are two specimens of Griffith 3967 from
East Bengal, dated 14 November 1834, and a third specimen dated
24 September 1850.

Bentham (1832-1836) described the filaments of Pogostemon
brachystachyus as glabrous or nearly so (filamentis nudis vel leviter
barbatis). Hooker (1885), Mukerjee (1940), and all other workers
reported this character in the same fashion. Nevertheless, the fila-
ments of P. brachystachyus are clearly densely hairy towards the
middle.

46. Pogostemon nigrescens Dunn in Notes R. hot. Gdn Edinb. 8:
159(1913).

Figs lOg, 29a.

Stem solid, angular; hairs 4-celled, c. 370 um long. Leaves ovate, 30
x 20 mm, base cuneate, apex obtuse, margin crenate; hairs 4-celled,
c. 275 um long. Petiole 4 mm long; hairs 5-celled, c. 250 um long.
Inflorescence a terminal spike, c. 170 mm long, lax below, dense
above, with two lateral spikes; hairs 5-celled, c. 350 um long. Calyx
campanulate, 4.0 x 4.1 mm, 10-veined; hairy outside, an annulus of
hairs in the throat; teeth ciliate, c. 0.9-1.2 mm long, 0.8-0.9 mm
wide at base; outer hairs 4-celled, 270 (am long. Corolla up to 3.9 mm
long; lower lip c. 1.3 x 0.7 mm; upper lip c. 1.5 mm across; central

lobe 0.5-0.9 mm wide at base. Filaments inserted at different
heights, the lowest at a height of 1 .7 mm in the tube; filamentsc. 3.2-
3.5 mm long, exserted portion c. 1.3 mm; filaments equally villous
towards the base. Style c. 3.9 mm long; stigma lobes c. 0.6 mm. Disc
c. 0.5 mm long. Nutlets 4, c. 800 x 600 um, obovoid, reticulate.

DISTRIBUTION. Western China (Yunnan).

SPECIMENS EXAMINED. Forrest 18590 (BM, K), Henry 9082 &
9082T (K), Henry 1 1 174 (K-holotype), Henry 12563 (K).

47. Pogostemon strigosus (Benth.) Benth. in A. DC., Prodr. 12:

155(1848).
Figs lOh, 29b.

Dysophylla strigosa Benth. in Wall., PL asiat. rar. 1: 30 (1830).

Stem solid, angular; hairs 4-celled, c. 875-960 um long. Leaves
lanceolate, 41-51 x 12-20 mm, base truncate to rounded, apex
acute, margin serrate; hairs 5-celled, c. 1200 um long. Petiole c. 4
mm long; hairs 5-celled, c. 800-1000 um long. Inflorescence a
single terminal spike, c. 70-108 mm long; hairs 4-5 celled, c. 1000
um long. Calyx tubular, 4.3-5.0 x 3.2^4.2 mm, 10-veined; with
scattered hairs outside, a tuft of hairs at the sinuses within; teeth
ciliate slightly inside the margin, c. 0.9-1.7 mm long, 0.5-0.9 mm
wide at base; outer hairs 3-celled, 620-750 um long. Corolla up to

5.8 mm long; lower lip c. 2.0 x 1 . 1 mm; upper lip c. 2. 1 mm across;
central lobe 1.1 x 0.7 mm. Filaments all inserted at a height of 2.4-

2.9 mm in the tube, c. 5.0-6.6 mm long, exserted portion c. 2.3-3.5
mm; filaments all equally villous at base. Style c. 7.0-7.8 mm long;
stigma lobes c. 0.9 mm. Disc c. 0.5-0.6 mm long. Nutlets 4, c. 800-
900 x 700-800 jam, obovoid, reticulate-foveate with secondary
reticulation or spinulose.

DISTRIBUTION. India (Khasia Hills, Assam) and northeastern Bang-
ladesh. Found in roadside woods and pastures at an elevation of
1500-1800 m.

SPECIMENS EXAMINED. Clarke 550 1 (BM), Clarke 45456B (BM),
Griffith 209 (BM), Hooker s.n. (K), Kingdon-Ward 18763 (BM),
Lemann 209 (K), Wallich 1549 (BM, K-isotypes).

III. Subgenus DYSOPHYLLUS (Blume) Bhatti & Ingr.,
comb, et stat. nov.

Dysophylla Blume ( 1 826), pro parte.

Stems often weak. Leaves sessile to subsessile, rarely petiolate, in
whorls of more than two, rarely two opposite at each node, linear to
linear-lanceolate or elliptic to elliptic-oblong, rarely ovate or orbicu-
lar. Inflorescence dense. Calyx small, infundibular, usually < 3 mm
in length, 5-veined, thin and translucent, exterior usually hairy with
glands obvious, circumference of the flowering calyces greater than
the total length. Width of lower corolla lip usually > upper, length of
lower lip equal to its width at the base. Nutlets mostly oblong, rarely
ellipsoid to ellipsoid-oblong or ovoid.

Ilia. Section DYSOPHYLLUS

Dysophylla section Oppositifoliae Benth. (1832), pro parte,
Dysophylla section Eudysophylla Kudo (1927), pro parte.

Leaves two, opposite at each node, shape various but commonly
broadly elliptic, ovate or lanceolate, or deeply pinnatifid.

48. Pogostemon auricularius (L.) Hassk. in Hoeven & de Vriese,
Tijdschr. Natuurl. Gesch. Physiol. 10: 127 (1843).

Figs 11 a, 29c.

108

G.R. BHATTI AND M. 1NGROUILLE

m

Fig. 11 Dissected corollas, calyces and bracts, showing inner surface. Pogostemon subgenus Dysophyllus section Dysophyllus: (a) P. auricularius, (b) P.
glabratus, (c) P. barbatus, (d) P. amaranthoides, (e) P. myosuroides, (f) P. salicifolius, (g) P. quadrifolius, (h) P. tisserantii, (i) P. mutamba, (j) P.
micangensis. Scale bar 5 mm.

SYSTEMATICS OF POGOSTEMON

109

Mentha auricularia L., Mant. pi: 81 (1767).

Dysophylla auricularia (L.) Blume, Bijdr. fl. Ned. Ind. 3: 825

(1826).

Stem procumbent and rooting at the nodes, solid, angular, contracted
at the base of the internodes, pinkish; hairs up to 8-celled,c. 1200 urn
long. Leaves in opposite pairs, ovate to ovate-lanceolate, up to c. 50
x 30 mm, base cuneate, apex acute, margin serrate to double serrate,
lamina glandular-punctate on both surfaces; hairs 6-celled, c. 2000
urn long. Petiole up to 5 mm long, densely hairy; hairs 8-celled, c.
2000 urn long. Inflorescence a single terminal spike, c. 80 mm long,
dense, the flowers fragrant; hairs on stalk 7-celled, c. 1 600 urn long.
Floral leaves narrowly elliptic. Calyx campanulate-infundibuliform,
c. 2.5 x 3.5 mm, 5-veined; glabrous within, glandular and with a few
hairs outside; teeth ciliate, 0.5-0.7 mm long, c. 0.8-1.0 mm wide at
the base, incurved in fruit; outer hairs 4-celled, c. 500 urn long.
Corolla c. 3.5 mm long, purplish; lower lip c. 1 x 0.8 mm; upper lip
c. 2.8 mm across, central lobec. 0.8 x 0.6 mm. Filaments all inserted
at a height of 1.6 mm in the tube, c. 4.3-4.1 mm long, exserted
portion c. 2.8 mm; filaments glabrous towards the base. Style c. 5
mm long; stigma lobes c. 0.8 mm. Disc c. 0.3 mm long. Nutlets 4, c.
700 x 380 um, ellipsoid-fusiform, brown, reticulate.

DISTRIBUTION. Throughout south Asia from Sri Lanka (Kandy
Dist., Pussellawa, Uva Prov., Sabaragamuwa Prov.), India (Madras,
Assam, Sambalpur), Malaysia, Burma (Maymo Plateau), through
China (Hainan, Yunnan, Canton, Hong Kong), and south to New
Guinea. Common on marshy ground and in paddy fields.

ETHNOBOTANY. The leaves of Pogostemon auricularius are crushed
with lime and applied as a poultice on the abdomen for various
ailments, such as diarrhoea, colic, worms, and a sore throat. Its use
for disturbances of the stomach in children is very common in
Malaya.

SPECIMENS EXAMINED. Balcher 72 1 (K), Bourne 663 (K), Cramer
4056 (K), Cramer 5178 (K), Ford 3 (K), Henry 1231 1 (K), Henry
s.n. (K), Hepper, Maxwell & Fernando 4556 (K), Hooker 344 (K),
Jayasuriya 1454 (K), Lace 4246 (K), Lei 886 (K), McClure 9279
(K), Mooney 1827 (K), Parry 267 (K), Peng 6250 (K), Playfair 124
(K), Wiakabu et al. 73782 (K).

49. Pogostemon glabratus Chermsir. ex Press in Bull. Br. Mus. nat.

Hist. (Hot.) 10: 71 (1982).
Figs lib, 30a.

Stem erect, 4-angled, contracted at base of internodes; hairs few, 3-
celled, c. 250 um long, golden glands present. Leaves in opposite
pairs, elliptic to ovate-elliptic, c. 70 x 30 mm, base cuneate, apex
acute, margin dentate, lamina punctate; hairs few, white, c. 3-celled,
c. 300 urn long. Petiole c. 0.5 mm long. Inflorescence a single
terminal spike, c. 90 mm long, whorls densely arranged. Calyx
campanulate, c. 2 x 2.5 mm, 5-veined; glabrous within, glandular
outside; teeth not ciliate, c. 0.5-0.7 mm long, c. 0.4-0.7 mm wide at
base. Corolla c. 2.5 mm long; lower lip c. 0.6 x 0.6 mm, obtuse at
apex; upper lip c. 2 mm across, with a few hairs outside; central lobe
c. 0.5 x 0.6 mm. Filaments all inserted at a height of c. 1 mm in the
tube, c. 2.5-3 mm long, exserted portion c. 1.5 mm, glabrous
towards the base. Style c. 4 mm long; stigma lobes c. 0.3 mm. Disc
c. 0.3 mm long. Nutlets 4, c. 700 x 500 um, ellipsoid-fusiform with
small attachment point, light brown, reticulate-foveate.

DISTRIBUTION. Thailand (Hi Dat and Rachaburi, Kanburi area).
SPECIMENS EXAMINED. Kerr 10274 (BM), Put 1 32 (BM-holotype).

50. Pogostemon barbatus Bhatti & Ingr., sp. nov.
Figs 1 Ic, 30b.

Herbae hirsutae. Caules ad nodo contractes, fumosi. Foliae oppositae,
lamina ad 80 x 19 mm, oblonga, crenata, cuneata, hirsuta in
superficiebus ambabus folii, pilibus c. 1.25 mm, auricoloribus
glandulibus depressibus in lamina, petioli c. 20 mm. Inflorescentia
ad 90 mm, gracilis, dens, ad 30 verticillastros; bracteae c. 2.5 x 0.5
mm, oblanceolatae, hirsutae ad marginem. Calyx campanulatus,
tubo 15 x 22 mm, dentibus quinque 0.4-0.5 mm longis, ciliatus, sub
fructu incurvatis. Corolla bilabiata purpurea, tubo ad 3.1 mm, labio
superiori lobus centralis 1 .3 x 0.8 mm, labio inferiori 1 .0 x 1 .0 mm.
Stamina quator filamentis exserti, pari superiori affixus ad 2 mm
corollae tubo, pari inferiori ad 1 .5 mm, prope medianum pilis longis
barbati, prope inferior glabratus; antherae uniloculares. Discus non
lobatus. Nuculae 400 x 300 um maturae quatuor, oblongae,
reticulatae-foveatae.

TYPE. Hong Kong, Fau Tan Valley, 12 October 1972, Hu 12319
(K!-holotype).

Stem procumbent, solid, 4-angled, contracted at base of internodes,
greyish brown; hairs 8-celled, c. 1250 um long. Leaves in opposite
pairs, c. 80 x 19 mm, oblong-clavate, base cuneate, apex bluntly
acute, margin crenate to double crenate, lamina hirsute, glandular,
the glands golden, sunken; hairs c. 5-celled, c. 750 um long. Petiole
c. 20 mm long; hairs c. 8-celled, c. 1210 um long. Inflorescence a
single terminal spike, up to 90 mm long, slender, with c. 30 confluent
whorls; hairs 8-celled, c. 1150 um long. Floral leaves clavate-
oblanceolate, c. 2.5 x 0.5 mm; hairs only on margin, up to 5-celled,
c. 750 um long. Calyx campanulate, c. 15 x 22 mm, 5-veined inside;
glabrous within, with ball-like glands outside; teeth ciliate, c. 0.4-
0.5 mm long, c. 0.3-0.5 mm wide at base, incurved in fruit. Corolla
c. 3. 1 mm long; lower lip 1 x 1 mm; upper lipc. 2 mm across; central
lobe c. 0.6 x 0.6 mm, sparsely hairy outside. Two filaments under
central lobe inserted higher (c. 0.4 mm) than other two; filaments
equal in length, c. 3.5 mm long, exserted portion c. 1.8 mm;
filaments glabrous at the base, hairs towards the middle of filament
on one side, c. 750 um long. Style c. 4 mm long; stigma lobes c. 0.5
mm. Nutlets 4, c. 400 x 300 jam, oblong, brown, reticulate-foveate.

DISTRIBUTION. Hong Kong.
SPECIMENS EXAMINED. Hu 5652 (K).

This species is closely allied to Pogostemon auricularius and P.
glabratus but differs in having more dense and much longer hairs,
longer petioles, a crenate margin to the leaf, filaments attached at
different heights in the corolla tube, and oblong nutlets.

51. Pogostemon amaranthoides Benth. in A. DC., Prodr. 12: 153

(1848).
Figs 1 Id, 30c.

Herb up to 1 m high; stem solid, angular; hairs 4-celled, c. 310 um
long. Leaves in opposite pairs, ovate, 1 15 x 55 mm, base cuneate,
apex acuminate, margin dentate; hairs 4-celled, c. 325 urn long.
Petiole c. 30 mm long, glabrous. Inflorescence a terminal spike, c.
65 mm long, lax below, dense above, with two lateral spikes; hairs 4-
celled, c. 320 um long. Calyx campanulate, 2.8 x 3.6 mm, 5-veined;
hairy on ribs outside, teeth hairy on margin and just within margin;
teeth c. 0.5-0.7 mm long, 0.5-0.7 mm wide at base; outer hairs 3-
celled, c. 250 um long. Corolla up to 2.6 mm long, pinkish white;
lower lipc. 0.8 x 0.7 mm; upper lipc. 1 .4 mm across; central lobe 0.6
x 0.5 mm; lobes with a few hairs. Filaments inserted at different
heights, the lowest at a height of 1 mm in the tube; filaments c. 1.5-

110

1 .9 mm long, exserted portion c. 3 mm. Style c. 3 mm long, with a
few hairs; stigma lobes c. 0.7 mm. Disc c. 0.5 mm long. Nutlets 4, c.
600 x 500 jam, oblong, puncticulate.

DISTRIBUTION. Eastern Himalayas (Tibet (Ham Tawai valley),
Sikkim, Khasia, Darjiling, Bhutan, Chukka Dist. Chukka Dzong
Nepal).

SPECIMENS EXAMINED. Clarke 9520A (K), Clarke 24838B (K),
Dawson 257 (BM), Gamble Till (K), Gamble 3850A (K), Gamble
488388 (K), Grierson & Long 3227 (K), Griffith 2 1 2 (K), Hara et al.
06306529 (BM, K), Hooker s.n. (BM), Hooker s.n. (K-syntype),
Hooker s.n. (K), Kingdon-Ward 7410 (K), Manandhar 8348 (BM),
Stainton, Sykes & Williams 9276 (BM).

52. Pogostemon myosuroides (Benth.) Kuntze, Rev. gen. pi. 2: 530
(1891).

Figs lie, 3 la.

Dysophylla myosuroides Benth. in Wall., PI. asiat. rar. 1: 30 (1830).
D. rugosa Hook.f., Fl. Brit. India 4: 638 (1885).
Pogostemon rugosus (Hook.f.) El Gazzar & L.Watson in Taxon 16:
187(1967).

Stem erect, solid, terete, greyish because of hairs; hairs 4-celled, c.
550 um long. Leaves in opposite pairs, lanceolate, c. 40 x 7 mm, base
cuneate, apex bluntly acute, margin sharply dentate, lamina thick,
densely hairy on both sides, veins strongly developed; hairs 3-
celled, c. 500 um long. Petiole c. 3 mm long; hairs 4-celled, c. 560
um long. Inflorescence a terminal spike, c. 50 mm long, dense, with
lateral spikes, c. 30 mm long, dense; hairs 4-celled, c. 550 um long.
Floral leaves linear-oblong. Calyx campanulate, c. 1 .3 x 1 .7 mm, 5-
veined; hairy outside, glabrous within; teeth more or less equal,
ciliate, longest tooth c. 0.3 mm long, shortest 0.2 mm long, widest
tooth c. 0.3 mm wide, narrowest tooth c. 0.2 mm wide; outer hairs 4-
celled, c. 430 um long. Corolla 1 .5 mm long; lower lip 0.5 x 0.5 mm;
upper lipc. 1 mm across; central lobe c. 0.4 x 0.3 mm; a few hairs on
the lobes. Filaments all inserted at a height of 0.5 mm in the tube, c.
1-1.3 mm long, exserted portion c. 0.3 mm. Style 2.2 mm long,
stigma lobes c. 0.7 mm. Discc. 0.2 mm long. Nutlets 4,c. 1000 x 700
um, ellipsoid to ellipsoid-oblong, dark brown, spinulose.

DISTRIBUTION. Eastern India (Madras, Kaumbollan Hill).

SPECIMENS EXAMINED. Feicher 4724 (K), Gamble 20353 (K),
Wallich 1547 (BM, K-syntypes), Wight 2130 (K), Wight 2533 (K),
Wight 2534 (K).

53. Pogostemon salicifolius (Dalzell ex Hook.f.) El Gazzar & L.
Watson in Taxon 16: 187 (1967).

Figs llf, 31b.

Dysophylla salicifolia Dalzell ex Hook.f., Fl. Brit. India 4: 638
(1885).

Stem erect, solid, terete; hairs appressed, 2-celled, the cells more or
less equal, c. 425 um long. Leaves in opposite pairs, linear to linear-
lanceolate, c. 35 x 16 mm, base cuneate, apex cuneate, margin
shallowly dentate; hairs 2-celled, c. 560 um long, basal cell slightly
longer than upper cell. Petiole c. 0.5 mm long; hairs 3-celled, c. 440
um long. Inflorescence a single terminal spike, c. 60 mm long,
dense; hairs 2-celled, c. 680 um long. Calyx campanulate, c. 2.5 x
2.7 mm, 5-veined; hairy outside, especially near the base, teeth hairy
within; teeth ciliate, c. 0.4-0.5 mm long; outer hairs 3-celled, c. 500
um long. Corolla c. 3 mm long; lower lipc. 1 x 1 mm; upper lipc. 1.8
mm across; central lobe c. 0.8 x 0.4 mm. Filaments all inserted at a
height of 1.2 mm in the tube, c. 3.9-4.2 mm long, exserted portion

G.R. BHATTI AND M. INGROUILLE

c. 2 mm; filaments all sparingly hairy towards the base. Style c. 5.2
mm long; stigma lobes c. 0.5 mm. Disc c. 3 mm long. Nutlets 4, c.
700 x 200 um, oblong, very shiny dark brown, smooth.

DISTRIBUTION. Western India (Bombay, Maharashtra,
Mahabaleshwar, Concan, Mahabaleh Hills).

SPECIMENS EXAMINED. Dalzell s.n. (K-holotype), Hooker s.n.
(K), Liam s.n. in Herb. Hooker (K), Townsend 73/25 (K).

54. Pogostemon quadrifolius (Benth.) Kuntze, Rev. gen. pi. 2: 530
(1891).

Figs llg, 31c.

Mentha stellata Roxb., Hon. bengal: 44 (1814), nom. illegit.
Dysophylla quadrifolia Benth. in Wall., PI. asiat. rar. 1: 30 (1830).
D. velutina Benth. in Wall., PI. asiat. rar. 1: 30 (1830).

D. rupestris Dalzell in Hooker's J. Bot. 3: 120 (1851).
Eusteralis quadrifolia (Benth.) Panigrahi in Phytologia 32: 478

(1976).

E. quadrifolia (Benth.) Majumdar in J. Bombay nat. Hist. Soc. 74:
385(1978, '1977').

Stem erect, solid, terete; hairs 3-celled, c. 437 um long. Leaves
mostly in whorls of 4, sometimes in opposite pairs, lanceolate, c. 70
x 12 mm, base cuneate, apex acute, margin serrate; hairs 4-celled, c.
750 um long. Petiole c. 4 mm long; hairs similar to those of stem.
Inflorescence much branched, each branch terminated by a terminal
spike, spike on main axis c. 120 mm long, dense; hairs 4-celled, c.
750 um long. Calyx campanulate, c. 2 x 2.7 mm, 5-veined; hairy
outside, glabrous within; teeth ciliate, c. 0.4-0.5 mm long, 0.4-0.6
mm wide at base; outer hairs 3-celled, c. 3 10 um long. Corolla up to
3.3 mm long; lower lip c. 0.9 x 0.9 mm; upper lip c. 2 mm across;
central lobe 0.8 x 0.6 mm; lobes hairy. Filaments all inserted at a
height of 1 .4 mm in the tube, c. 4.2^.5 mm long, exserted portion
c. 2.6 mm; filaments equally hairy at the base. Style 4.5 mm long;
stigma lobes unequal, c. 0.9-1 mm. Disc c. 0.3 mm long. Nutlets 3,
c. 500 x 400 jam, ellipsoid-oblong, dark brown, spinulose.

DISTRIBUTION. Northern India (Khasia, Assam, Sambalpur) and
Bangladesh (Chittagong), and also from Kerala (Malabar, Godavari
Distr., Garo Hills) in southern India. In eastern Bangladesh it grows
on sandy soils.

SPECIMENS EXAMINED. Barber 7 1 1 5 (K), Bourne 3396 (K), Clarke
19782 (K), Gamble 6739 A (K), Gamble 15964 (K), Gamble 15965
(K), Griffiths 205 (K), Hooker 1538 (K), Hooker 1539 (K), Hooker
1540 (K), Monney 2557 (K), Parry 937 (K), Parry 1040 (K), Raza
786 (K), Roxburgh s.n. (K-syntype).

Tahir et al. (1995) report a reticulate nutlet surface and a calyx only
hairy on the teeth in material from Bangladesh.

55. Pogostemon micangensis G. Taylor in/ Bot., Lond. 69 (Suppl.
2): 166(1931).

Figs llj, 32c.

Aquatic herb with spreading caespitose rhizome; stem weak, terete,
red-purple; hairs 4-celled, c. 325 um long. Leaves in opposite pairs,
ovate, 22 x 9 mm, base cuneate, apex acute, margin serrate; hairs 3-
celled, c. 200 um long. Petiole 1 mm long; hairs 3-celled, c. 200 um
long. Inflorescence a single terminal spike, c. 44 mm long, dense;
hairs 2-celled, c. 430 um long. Calyx campanulate, 3.8 x 5.5 mm,
10- veined; glabrous or with a few hairs outside, teeth and upper part
of tube hairy within; teeth ciliate, c. 0.4-1.2 mm long, 0.8-1.4 mm
wide at base; outer hairs 5-celled, c. 580 um long. Corolla up to 4.9
mm long, whitish violet; lower lip c. 1.1 x 1 .4 mm; upper lip c. 1 .7

SYSTEMATICS OF POGOSTEMON

111

mm across; central lobe 0.8 x 0.5 mm, hairy. Filaments inserted at
different heights, the lowest at a height of 2.3 mm in the tube;
filaments c. 5.7-6.0 mm long, exserted portion c. 3.4 mm; filaments
glabrous towards the base. Stylec. 5.8 mm long; stigma lobesc. 0.7-
1 mm. Disc c. 0.5 mm long. Nutlets 4, c. 400 x 300 jam, ellipsoid to
ellipsoid-oblong, reticulate-foveate.

DISTRIBUTION. Angola (River Micango) and Cameroon. Found in
the marshes of the river Micango.

SPECIMENS EXAMINED. Gossweiller 2545 (BM-isotype), J. & A.
Raynal 12161 (BM).

Gossweiller 2545 has calyces which are 5, 6 & 7 toothed.

56. Pogostemon mutamba (Hiern) G. Taylor in J. Bot., Land. 69
(Suppl. 2): 166 (1930).

Figs Hi, 32b.

Geniosporum mutamba Hiern, Cat. afr. pi.: 854 (1900).

Amphibious perennial with a polycephalic rootstock; stem weak,
angular; hairs 4-celled, c. 275 jam long. Leaves in opposite pairs,
elliptic to elliptic-oblong, soft-flaccid, 90 x 35 mm, base rounded,
apex acute, margin dentate; hairs 6-celled, c. 600 |am long. Petiole 5
mm long; hairs 4-celled, 300 urn long. Inflorescence a procumbent
to ascending terminal spike, c. 60 mm long, with more than two
lateral spikes, all spikes dense; hairs 4-celled, c. 680 urn long. Calyx
campanulate, 2.5 x 3.0 mm, 5-veined; densely hairy outside, teeth
hairy within; teeth ciliate, c. 0.5-0.7 mm long, c. 0.5-0.6 mm wide
at base; outer hairs 5-celled, c. 430 urn long. Corolla up to 5.6 mm
long, whitish violet; lower lip c. 1.9 x 1.6 mm; upper lip c. 2 mm
across, hairy; central lobe c. 1.1 x 0.5 mm. Filaments all inserted at
a height of 2.8 mm in the tube, c. 5.0-5.7 mm, exserted portion c. 2.9
mm; filaments glabrous towards the base. Stylec. 7 mm long; stigma
lobesc. 0.7 mm, violet-purple. Discc. 0.5 mm long. Nutlets 4,c. 400
x 300 urn, oblong, reticulate-foveate.

DISTRIBUTION. Angola (between Ganda and Caconda, Planalto,
Benguela).

ETHNOBOTANY. Pogostemon mutamba is a source of starchy ed-
ible tubers.

SPECIMENS EXAMINED. Gossweiler 9668 (BM), Welwitsch 5496
(BM-syntype), Welwitsch 5590 (BM, K-syntypes).

57. Pogostemon tisserantii (Pellegr.) Bhatti & Ingr., comb. nov.
Figs llh, 32a.

Dysophylla tisserantii Pellegr. in C. r. Ass. fr. Avanc. Sci. 49: 387
(1926).

Stem weak; hairs thin, whitish, 2-celled, c. 200 urn long. Leaves in
whorls of 4, deeply pinnatifid, c. 30 mm long; hairs sparse, 1 -celled,
c. 75 um long. Inflorescence spikes c. 70 urn long, flowers in
interrupted whorls. Calyx campanulate, 2 x 2.5 mm; hairy outside
and distinctly glandular, teeth hairy within; teeth ciliate, c. 0.6-0.7
mm long, c. 0.4-0.5 mm wide at base; outer hairs 4-celled, c. 250 urn
long. Corolla c. 2.2 mm long; lower lip c. 0.8 x 0.8 mm; upper lip c.
1.7 mm across, hairy outside; central lobec. 0.5 x 0.5 mm. Filaments
all inserted at a height of 0.6 mm in the tube, c. 3. 1 mm long, exserted
portion c. 1.5 mm; filaments glabrous at the base. Style c. 3.3 mm
long; stigma lobes c. 0.7 mm. Disc c. 0.3 mm long. Nutlets 4, c. 570
x 400 um, ovoid, somewhat cuneate at the base, reticulate-foveate.

DISTRIBUTION. Chad.

SPECIMENS EXAMINED. Jacques 1807 (K).

This is the only species of Pogostemon which has compound leaves.

Illb. Section VERTICILLATUS (Benth.) Bhatti & Ingr.,
comb. nov.

Dysophylla Blume, pro parte ( 1 826), Dysophylla section Verticillatae
Benth. (1832), Eusteralis Raf. (1847), Dysophylla subgenus
Chotekia Keng, pro parte (1927).

Leaves usually linear to linear-lanceolate (P. trinervis orbicular),
sessile, truncate, rounded or cuneate), more than two leaves at each
node (P. andersonii two leaves).

58. Pogostemon lythroides (Diels) Press in Bull. Br. Mus. not. Hist.
(Bot.) 10: 74 (1982).

Figs 12a, 33a.

Dysophylla lythroides Diels mNotizbl. Bot. Gart. Mus. Berl. 9: 1031
(1926).

Stem terete, weak, glabrous. Leaves in whorls of 4, linear, violet
above, c. 88 x 10 mm, base truncate, apex acute, margin distantly
serrate, revolute, lamina with midvein sparsely hairy abaxially,
lateral veins obscure on adaxial surface but distinct on abaxial
surface; hairs 2-celled, c. 180 um long. Inflorescence a single
terminal spike c. 16 mm long, glabrous. Floral leaves claviform,
linear to linear-lanceolate. Calyx campanulate, c. 28 x 35 mm;
outside densely hairy throughout, teeth hairy within; teeth ciliate, c.
0.9-1.1 mm long, c. 0.5-0.7 mm wide at base; outer hairs 3-celled,
c. 560 um long. Corolla c. 4 mm long; lower lip c. 1 .4 x 1 .4 mm;
upper lip c. 2.8 mm across; central lobe c. 0.7 x 0.5 mm; upper and
lower lip hairy outside. Filaments all inserted at a height of 1 .5 mm
in the tube, c. 4.0-4.5 mm long, exserted portion c. 2.2 mm;
filaments glabrous at the base. Style c. 5.5 mm long; stigma lobes
0.6-0.8 mm long. Disc c. 0.4 mm long. Nutlets 4, c. 400 x 300 um,
oblong, reticulate-foveate.

DISTRIBUTION. Widespread throughout south Asia: India
(Sambalpur, Khasia), Sri Lanka, Malaysia, Sulawesi, Papua New
Guinea, China (Yunnan).

SPECIMENS EXAMINED. Cramer 3996 (K), Cramer 4902 (K),
Cramer 5084 (K), Duthie 9698 (K), Fan & Li 563 (BM), Flenley
2104 (K), Griffith 1544 (K), Hartley 9689 (K), Mooney 2139 (K),
Mooney 3226 (K), Steenis 1260 (K).

59. Pogostemon ciliatus Bhatti & Ingr., sp. nov.
Figs 12b, 33b.

Herba villosa. Caules solides quadrangulati, pilibus bicellularibus c.
750 um: in quoque nodus 4 folia lineares, verticillatae, ad 40 x 3
mm; cuneati et acutifolia, margine integre, pilibus bicellularibus, c.
560 um long. Inflorescentia terminalis ad c. 70 mm longa, pilibus
bicellularibus c. 750 um long. Calyx campanulatus, c. 1 .8 x 2.5 mm;
dentibusc. 0.4-0.5 mm, partibus interioribus pilibus, margine ciliato;
in partibus exterioribus villosibus, bicellularibus, c. 750 um. Corolla
c. 2.5 mm; labio inferiori 1 x 1 mm; labio superiori 1 .5 mm lato;
lobis superiori 0.6 x 0.6 mm; labio superiori et inferiori ciliati.
Stamina quator filamentis affixus ad 0.9 mm in tubo; filaments 3.0-
3.3 mm; partibus exsertibus c. 1.7 mm. Styli c. 3.4 mm; stigmatibus
lobibus c. 0.6 mm, hirsutibus. Disc non lobatus, 0.4 mm. Nuculae 4,
c. 600 x 400 um, oblongae, granulatae, valde flexuosa.

TYPE. New Guinea (expeditie 1954-55), Netherland, New Guinea
and Kebar valley, c. 100 km west of Manokwari, 2 November 1954,
Royen 3967 (K!-holotype).

112

G.R. BHATTI AND M. INGROUILLE

Fig. 12 Dissected corollas, calyces and bracts, showing inner surface. Pogostemon subgenus Dysophyllus section Dysophyllus: (a) P. lythroides, (b) P.
ciliatus, (c) P. linearis, (d) P. pentagonus, (e) P. andersonii, (f) P. cruciatus, (g) P. sampsonii, (h) P. yatabeanus, (i) P.faurei, (j) P. peguanus, (k) P.
koehneanus, (1) P. crassicaulis. Scale bar 5 mm.

SYSTEMATICS OF POGOSTEMON

Stem solid, angular, villous; hairs 2-celled, c. 750 jam long. Leaves
in whorls of 4, linear, 40 x 3 mm, base cuneate, apex acute, margin
entire; hairs 2-celled, c. 560 urn long. Inflorescence a single terminal
spike, c. 70 mm long; hairs 2-celled. c. 750 (am long. Calyx
campanulate, c. 1 .8 x 2.5 mm; hairy outside, teeth hairy within; teeth
ciliate, c. 0.4-0.5 mm long, 0.4-0.5 mm wide at the base; outer hairs
villous, 2-celled, c. 750 jam long. Corolla c. 2.5 mm long; lower lip
1 x 1 mm; upper lip 1 .5 mm across; central lobe 0.6 x 0.6 mm; upper
and lower lip ciliate. Filaments all inserted at a height of 0.9 mm in
the tube, 3.0-3.3 mm long, exserted portion c. 1.7 mm; filaments
equally hairy towards the base. Style c. 3.4 mm long; stigma lobes c.
0.6 mm, hairy. Disc 0.4 mm long. Nutlets 4, c. 600 x 400 um, oblong,
brown, granulate with 'zig-zag' channels.

DISTRIBUTION. New Guinea. Growing in meadows among tall
grasses; fairly common.

Pogostemon ciliatus is distinct in having hairy/ciliate stigma lobes,
the upper and lower lips of the corolla ciliate, and a nutlet surface
with zigzag channels (not spinulose).

60. Pogostemon linearis (Benth.) Kuntze, Rev. gen. pi. 2: 529
(1891).

Figs 12c, 33c.

Dysophylla linearis Benth. in A. DC., Prodr. 12: 157 (1848).
Eusteralis linearis (Benth.) Panigrahi in Phytologia 32: 476 (1976).
E. linearis (Benth.) Majumdar in /. Bombay nat. Hist. Soc. 74: 385
(1978,' 1977').

Stem erect or procumbent and rooting at the nodes, weak, reddish
brown, glabrous or with a few hairs towards the inflorescence.
Leaves in whorls of 4, linear to linear-lanceolate, c. 50 x 5 mm, base
acute, apex bluntly acute, margin distantly dentate, lamina sparsely
hairy, the abaxial surface with sunken glands; hairs 2-celled, c. 120
um long. Inflorescence a single terminal spike, c. 60 mm long; hairs
2-celled, c. 250 um long. Floral bracts oblong, brownish towards the
tip. Calyx infundibular, c. 2 x 2.8 mm; densely hairy outside,
especially at the teeth tips, with conspicuous brown glands, glabrous
within; teeth ciliate, c. 0.5-0.9 mm long, c. 0.4-0.6 mm wide at base;
outer hairs 4-celled, c. 430 um long. Corolla c. 4.2 mm long; lower
lip c. 1 .3 x 1.3 mm; upper lip c. 2.5 mm across; central lobe c. 1 . 1 x
0.7 mm; upper and lower lip hairy outside. Filaments all inserted at
a height of 1 .5 mm in the tube, c. 3^ mm long, exserted portion c.
1.3 mm; two filaments hairy. Style c. 5.5 mm long; stigma lobes c.
0.8-1.0 mm. Discc. 0.6 mm long, shallowly lobed. Mature nutlets 1,
c. 1000 x 800 um, ellipsoid to ellipsoid-oblong, tan, reticulate-
foveate.

DISTRIBUTION. Western China (Dirang-Dzong, Yunnan), Bhutan.

SPECIMENS EXAMINED. Bodinier s.n. (K), Clarke 45731 (BM),
Forrest 11747 (BM, K), Forrest 16059 (K), Forrest 25146 (K),
Henry 12628 (K), Kingdon-Ward 14260 (BM).

61 . Pogostemon pentagonus (C.B. Clarke ex Hook.f.) Kuntze, Rev.
gen.pl. 2:529(1891).

Figs 12d, 34a.

Dysophylla pentagona C.B. Clarke ex Hook.f., Fl. Brit. India 4: 641

'(1885).
Eusteralis pentagona (C.B. Clarke ex Hook.f.) Panigrahi in

Phytologia 32: 477 (1976).
E. pentagona (C.B. Clarke ex Hook.f.) Majumdar in J. Bombay nat.

Hist. Soc. 74: 386 (1978, '1977').

Stem procumbent, solid, terete, glabrous. Leaves in whorls of 4,

113

linear, c. 20 x 2 mm, base truncate, apex bluntly acute to obtuse,
margin entire, revolute, lamina glabrous. Inflorescence a single
terminal spike, c. 30 mm long, with glandular and eglandular hairs;
hairs 3-celled, c. 250 um long. Calyx campanulate, c. 1 .2 x 2 mm;
sparsely hairy outside, glabrous within; teeth ciliate, c. 0.3-0.5 mm
long, c. 0.4—0.5 mm wide at base, incurved in fruit, closing the
mouth of the tube; outer hairs 3-celled, c. 250 um long, basal cell
with dark contents, glands conspicuous. Corolla c. 2.5 mm long;
upper lip c. 1.5 mm across, lower lip c. 0.7 x 1 mm; central lobe c.
0.7 x 0.9 mm wide at base; upper and lower lip with a ring of hairs
outside. Filaments all inserted at a height of 0.8 mm height in the
tube, c. 3.5-4 mm long, exserted portion c. 2.2 mm; filaments
glabrous at the base. Style 3.5 mm long, bulbous at base; stigma
lobes unequal, c. 0.7 and 1 mm. Nutlets 4, c. 700 x 400 um, oblong,
4-angled, light brown.

DISTRIBUTION. India (Chota Nagar, Sambalpur, Bihar, and Orissa)
and Thailand (Dai Thai).

SPECIMENS EXAMINED. Clarke 20438 (BM, K-isotypes), Garrett
56 (BM, K), Kerr 1465 (BM, K), Mooney 1854 (K).

62. Pogostemon andersonii (Prain) Press in Bull. Br. Mus. nat.
Hist. (Bot.)10:71 (1982).

Figs 12e, 34b.

Dysophylla andersonii Prain in J. Asiat. Soc. Beng. 59: 298 (1891).
Eusteralis andersonii (Prain) Majumdar in/ Bombay nat. Hist. Soc.
74:386(1978, '1977').

Stem erect, terete, villous; hairs 3-celled with longer apical cell, c.
350 um long. Leaves in opposite pairs or in whorls of 3 or more,
sessile, lanceolate, c. 35 x 8 mm, base cuneate to truncate, apex
acute, margin distantly dentate, lamina villous; hairs up to 3-celled
with long apical cell, swollen at junction between cells, c. 440 um
long. Inflorescence a single terminal spike c. 15 mm long, dense;
hairs 3-celled, c. 350 um long. Floral leaves linear to linear-lanceo-
late. Calyx campanulate, c. 1.8 x 2.5 mm; 5-veined; villous outside,
teeth with a few hairs within; teeth more or less oblong with bluntly
acute apex, ciliate, c. 0.6-0.8 mm long, 0.4-0.6 mm wide at base;
outer hairs villous, 4-celled, c. 370 um long. Corolla c. 2.4 mm long;
lower lip 0.5 x 0.5 mm; upper lip c. 1.1 mm across; central lobe c. 0.5
x 0.4 mm; upper and lower lip hairy outside. Filaments all inserted
at a height of 1.2 mm in the tube, c. 1.5-1.8 mm long, exserted
portion c. 0.8 mm; filaments glabrous at the base. Style c. 2.5 mm
long; stigma lobes c. 0.3 mm. Disc c. 0.2 mm long. Nutlets 4, c. 360
x 230 um, oblong, dark brown, reticulate-foveate.

DISTRIBUTION. Northeastern India (Sikkim).
SPECIMENS EXAMINED. Anderson s.n. (K-holotype).

63. Pogostemon cruciatus (Benth.) Kuntze, Rev. gen. pi. 2: 529
(1891).

Figs 12f, 34c.

Dysophylla cruciata Benth. in Wall., PI. asiat. rar. 1: 30 (1830).
Eusteralis cruciata (Benth.) Panigrahi in Phytologia 32: 478 (1976),

non Dvsophvlla cruciata sensu Hemsl. ex F.B. Forbes & Hemsl.

(1890), non D. cruciata sensu Dunn (1915).
E. cruciata (Benth.) Majumdar in J. Bombay nat. Hist. Soc. 74: 385

(1978/1977').

Stem erect, solid, terete, hirsute; hairs 5-celled, c. 1200 um long.
Leaves in whorls of 4-5, linear, c. 30 x 4 mm, base cuneate, apex
obtuse to bluntly acute, margin entire, revolute; hairs 4-celled, c.
1000 um long. Inflorescence a single terminal spike, c. 100 mm

114

G.R. BHATTI AND M. INGROUILLE

long; hairs stalked, 5-celled, c. 1200 mm long. Calyx campanulate,
c. 1.8x2.7 mm; tube and teeth very hairy outside, teeth hairy within;
teeth ciliate, c. 0.5-0.7 mm long, c. 0.4-0.6 mm wide at base; outer
hairs 5-celled, c. 750 mm long. Corolla up to c. 2.7 mm long; lower
lip c. 1 x 1 mm; upper lip c. 1.8 mm across; central lobe c. 0.8 x 0.5
mm; upper and lower lip hairy outside. Filaments all inserted at a
height of c. 1 . 1 mm in the tube, c. 3.6-4.6 mm long, exserted portion
c. 3 mm; filaments hairy towards the base. Style c. 4 mm long;
stigma lobes c. 0.7 mm. Disc c. 0.2 mm long. Nutlets 4, c. 600 x 400
urn, oblong, basal part protuberant, light brown, smooth.

DISTRIBUTION. Widespread from eastern India and the Himalayas
(Orissa, Sambalpur, Nepal, Assam, Chota Nagpur, Nagaland,
Manipur), China (Yunnan) to Thailand.

SPECIMENS EXAMINED. Clarke 1 8059 (BM), Clarke 343 1 2A (K),
Forrest 25140 (K), Hensen, Seidenfaden & Smitinand 10824 (K),
Hensen, Seidenfaden & Smitinand 1 1008 (K), Meebold 6002 (K),
Meeboldl6l2(K), Mooney 1855 (K), Mooney 4234 (K), Strachey &
Winterbottom 1541 (K-isotypes).

64. Pogostemon sampsonii (Hance) Press in Bull. Br. Mus. nat.
Hist. (Hot.) 10:74(1982).

Figs 12g, 35a.

Dysophylla sampsonii Hance in Annls Sci. nat. 5: 284 (1866).
Eusteralis sampsonii (Hance) Panigrahi mPhytologia 32: 478 ( 1 976).

Stem solid, terete, sparsely hairy; hairs 3-celled, c. 250 um long,
violet. Leaves in whorls of 3, linear-lanceolate, c. 20 x 5 mm, base
truncate, apex obtuse to bluntly acute, margin serrate, lamina gla-
brous. Inflorescence a single terminal spike, c. 20 mm long, dense,
stalk glabrous. Floral leaves elliptic-ovate. Calyx campanulate, c.

1 .5 x 2.4 mm; tube and teeth hairy outside; teeth ciliate, c. 0.4-0.5
mm long, c. 0.5-0.6 mm wide at base; outer hairs 2-celled, c. 1 80 jam
long. Corolla c. 1 .7 mm long; lower lip c. 0.6 x 0.6 mm; upper lip c.

1 .6 mm across; central lobe 0.5 x 0.5 mm; upper and lower lip hairy
outside. Filaments all inserted at a height of 0.8 mm in the tube, inner
pair c. 3.3 mm long, outer pair 2.8 mm long, exserted portion c. 2.4
mm; filaments glabrous at the base. Style c. 3.5 mm long; stigma
lobes c. 0.4-0.5 mm. Disc 0.2 mm long. Nutlets 4, c. 640 x 450 um,
oblong, attachment point protruded, reticulate-foveate.

DISTRIBUTION China.

ETHNOBOTANY. Pogostemon sampsonii has been used to poison
flies in China (Von Reis, 1973).

SPECIMENS EXAMINED. Hance 10946 (BM, K-isotypes).

65. Pogostemon yatabeanus (Makino) Press in Bull. Br. Mus. nat.
Hist. (Bot.)10:74(1982).

Figs 12h, 35b.

Dysophylla yatabeana Makino in Bot. Mag., Tokyo 1: 55 (1898).
Eusteralis yatabeana (Makino) Panigrahi in Phytologia 32: 478

(1976).
E. yatabeana (Makino) Murata in Acta phytotax. geobot. Kyoto 33:

370(1982).

Stem solid, terete, glabrous. Leaves in whorls of 3, linear, c. 80 x 5
mm, base truncate, apex acute, margin distantly serrate, lamina
sparsely hairy and with golden glands; hairs 2-celled, c. 150 um
long. Inflorescence a single terminal spike, c. 50 mm long, stalk
glabrous. Floral leaves linear. Calyx campanulate, c. 2.5 mm long;
outside with many hairs and glands, teeth hairy within; teeth ciliate,
c. 0.5-0.7 mm long; outer hairs 3-celled, c. 370 um long. Corolla c.

4 mm long; lower lip c. 1.2 x 1.2 mm; upper lip c. 2 mm across;
central lobe c. 0.9 x 0.7 mm; upper and lower lip hairy outside.
Filaments all inserted at a height of 1.5 mm in the tube, c. 4.4-5.0
mm long, exserted portion c. 2.5 mm; filaments all glabrous at the
base. Style c. 5.5 mm long; stigma lobes 0.8-1 mm long. Disc c. 0.4
mm long. Nutlets 4, c. 900 x 600 um, oblong, light brown, reticulate-
foveate with small depression at the base.

DISTRIBUTION. Japan (Honshu, Shikoku, Kyushu) and Korea.
SPECIMEN EXAMINED. Midutoranowo s.n. (K-isotype).

66. Pogostemon faurei (H. Lev.) Press in Bull. Br. Mus. nat. Hist.

(Bot.) 10: 73 (1982).
Figs 12i, 35c.

Dysophylla faurei H. Lev. in Reprium Spec. nov. Regni veg. 9: 248
(1911).

Stem weak, glabrous. Leaves in whorls of 4, linear, c. 24 x 3 mm,
base cuneate, apex acute, margin dentate, lamina glabrous. Inflores-
cence a single terminal spike, c. 25 mm long; hairs 3-celled, c. 250
|im long. Calyx campanulate, 2 x 2.5 mm; glabrous or sparsely hairy
outside with very fine hairs, teeth hairy within; teeth ciliate, c. 0.5
mm long, widest tooth c. 0.8 mm wide at base, narrowest tooth c. 0.4
mm wide at base; outer hairs 1-celled, c. 100 um long. Corolla up to
3.3 mm long; lower lip 1 x 1 mm; upper lip c. 2 mm across; central
lobe c. 0.6 x 0.5 mm. Filaments all inserted at a height of c. 1.4 mm
in the tube, c. 3.5-3.8 mm long, exserted portion c. 1.9 mm;
filaments glabrous at the base. Style c. 4.5 mm long; stigma lobes c.
1 mm long. Disc c. 0.3 mm long. Nutlets 4, c. 410 x 305 um, oblong,
reticulate-punctate.

DISTRIBUTION. Korea. In rice paddies.

SPECIMENS EXAMINED. Esquiz 199 (E), Faurie 760 (E-holotype),
Taquet l\n (E).

67. Pogostemon peguanus (Prain) Press in Bull. Br. Mus. nat. Hist.

(Bot.) 10: 74 (1982).
Figs 12j, 36a.

Dysophylla peguana Prain in J. Asiat. Soc. Beng. 59: 298 (1891).

Stem erect, 4-angled, weak; hairs appressed, 1-celled, c. 370 um
long. Leaves in whorls of 4, linear, c. 60 x 3 mm, base truncate, apex
bluntly acute to obtuse, margin entire, revolute, lamina with appressed
hairs; hairs 1-celled, c. 400 um long. Inflorescence a single terminal
spike, c. 80 mm long; stalk with glandular and eglandular hairs;
eglandular hairs 1 -celled, c. 400 um long, glandular hairs 3-celled, c.
250 um long. Calyx campanulate, c. 1.8 x 2.4 mm; hairy outside
with glandular and eglandular hairs, teeth hairy within, the hairs
unicellular; teeth ciliate, c. 0.4-0.6 mm long, 0.4-0.6 mm wide at
base; outer eglandular hairs 1-celled, c. 400 um long, glandular hairs
3-celled, c. 250 jam long. Corolla c. 2.5 mm long; lower lip 1 x 0.8
mm; upper lip c. 1.5 mm across; central lobe 0.7 x 0.5 mm; upper
and lower lip hairy outside. Flaments all inserted at a height of 1 mm
in the tube, c. 3.5-3.8 mm long, exserted portion c. 2.3 mm; filament
glabrous at the base. Style 4.5 mm long; stigma lobes c. 0.8-0.9 mm.
Disc c. 1 mm long. Nutlets 4, c. 500 x 300 um, oblong with
protuberant base, light brown, smooth.

DISTRIBUTION. Southeastern Asia in Burma (Pegu, Lahamauge)
and Thailand (Pak Zong Chai).

SPECIMENS EXAMINED. Kunz 2401 (K-syntype), Kunz 2405 (K-
syntype), Lace 2899 (K), Collector unknown 8123 (K).

SYSTEMATICS OF POGOSTEMON

68. Pogostemon koehneanus (Muschl.) Press in Bull. Br. Mus. not.

Hist. (Bot.)10:74(1982).
Figs 12k, 36b.

Dysophylla koehneana Muschl. in Reprium nov. Spec. Regni veg. 4:
269(1907).

Stem weak; hairs 1 -celled, c. 430 um long. Leaves in whorls of 3,
lanceolate, c. 22 x 4 mm, base cuneate, apex acute, margin serrate;
hairs 1 -celled, c. 310 |am long. Inflorescence a single terminal spike,
c. 50 mm long; hairs 1 -celled, c. 430 urn long. Calyx campanulate,
c. 1 .5 x 2.3 mm; hairy outside, teeth hairy within; teeth ciliate, c. 0.5
x 0.5 mm, incurved in fruit; outer hairs 2-celled, c. 370 urn long,
basal cell swollen, glands obvious. Corolla c. 1 .7 mm long; lower lip
0.7 x 0.7 mm; upper lip c. 1 .3 mm across; central lobe 0.5 x 0.4 mm;
lips sparsely hairy. Filaments all inserted at a height of 0.7 mm in the
tube, c. 2.4-2.7 mm long, exserted portion c. 1.4 mm; filaments
glabrous towards the base. Style c. 2.4 mm long; stigma lobes c. 0.5
mm. Disc c. 0.2 mm long. Nutlets 4, c. 500 x 300 urn, oblong with
pointed base, brown, shiny, smooth-lineate.

DISTRIBUTION. Thailand.

SPECIMENS EXAMINED. Clarke 25 (K), Hosseus 704 (BM-isotype).

69. Pogostemon crassicaulis (Benth.) Press in Bull. Br. Mus. nat.
Hist. (Bot.) 10:73(1982).

Figs 121, 36c.

Dysophylla crassicaulis Benth. in Wall., PL asiat. rar. 1: 30 (1830).
Eusteralis crassicaulis (Benth.) Panigrahi in Phytologia 32: 476
(1976).

Annual herb; stem up to 40 cm, erect, solid, terete, rooting at the
nodes, glabrous. Leaves in whorls of 3-5, linear, c. 30 x 6 mm, base
cuneate, apex acute, margin dentate, lamina brick red, sparsely
hairy; hairs 2-celled, c. 250 urn long. Inflorescence branches termi-
nating in a single spike, spike on main axis c. 80 mm long, lateral
spikes up to 40 mm long, stalk with glandular and eglandular hairs;
hairs up to 3-celled, c. 300 urn long. Calyx campanulate, c. 1.5x2
mm; hairy outside with glandular and eglandular hairs, teeth hairy
within; teeth ciliate, c. 0.5-0.7 mm long, c. 0.4-0.6 mm wide; outer
eglandular hairs 2-4 celled, c. 250 jam long, basal cell of glandular
hairs swollen. Corollac. 2.2 mm long, violet; lower lip 0.5 x 0.5 mm;
upper lip c. 1.2 mm across; central lobe c. 0.5 x 0.3 mm; upper lip
hairy outside. Filaments all inserted at a height of c. 1 mm in the
tube, c. 2.0-2.4 mm long, exserted portion c. 1.2 mm; filaments
glabrous at base. Style c. 3 mm long; stigma lobes c. 0.4 mm. Disc
c. 0.2 mm long. Nutlets 4, c. 800 x 300 jam, oblong, basal part
protuberant, brown, shiny, the surface more or less undulate.

DISTRIBUTION. Bangladesh (Sylhet), India (Allahabad, Baharaich,
Motipur), and southeastern Asia to Vietnam. Rooting in the black
mud of swamps in roadside ditches.

SPECIMENS EXAMINED. Couder s.n. (K), Panigrahi 6588 (E),
Squires 249 (K), Wallich 1545 (BM, K-isotypes).

70. Pogostemon verticillatus (Roxb.) Bhatti & Ingr., comb. nov.
Figs 13a, 37a.

Mentha verticillata Roxb., Hort. Bengal: 44 (1814).

Dysophylla verticillata (Roxb.) Benth. in Wall., PI. asiat. rar. 1: 30

(1830), pro parte.

D. ramosissima Benth. in Wall., PL asiat. rar. 1: 30 (1830).
D. benthamiana Hance in Ann. Sc. Nat. V, 5: 234 (1866), pro parte.

115

Pogostemon benthamianum (Hance) Kuntze, Rev. gen. pi. 2: 530
(1891).

Aquatic herb; stem angular, weak, few hairs at nodes and towards the
inflorescence; hairs 3-celled, c. 280 um long. Leaves in whorls of up
to 6, linear, 50 x 2 mm, base truncate, apex acute, margin dentate,
lamina glabrous, with golden glands sunken in the abaxial surface,
adaxial surface covered with a white crystalline powder. Inflores-
cence a terminal spike, 60-160 mm long, the main axis sometimes
shorter than the branches, with more than two lateral spikes; hairs on
stalk few, 3-celled, c. 287 um long. Calyx infundibular, c. 1 .2 x 1 .7
mm; densely hairy throughout outside with relatively stout hairs and
round glands also present, glabrous within; teeth ciliate, c. 0.4 x 0.4
mm, spreading; outer hairs 2-celled, c. 200 um long, basal cell
glandular. Corolla up to 1.5 mm long; lower lip 0.5 x 0.6 mm, few
hairs outside; upper lipc. 1 mm across, ciliate at margin, few hairs on
outer surface; central lobe 0.5 x 0.5 mm. Filaments all inserted at a
height of 0.6 mm in the tube, c. 1 .5 mm long, exserted portion c. 0.6
mm; filaments equally hairy towards the base. Style c. 2 mm long;
stigma lobes 0.4-0.5 mm. Disc c. 0.2 mm long. Nutlets 4, c. 548 x
419 um, ellipsoid to ellipsoid-oblong, light brown, granular.

DISTRIBUTION. Bangladesh (Sylhet, Chutia Nagpur), India, and
China (Canton). In pools. According to Bentham (1848: 157) it is
also found in southeast Asia, the Philippines, and Australia.

ETHNOBOTANY. Vernacular name 'Pansinga baha'. The roots are
used for the female complaint 'Sitka'. Grows on the edges of
terraces.

SPECIMENS EXAMINED. Sampson 443 (E), Sampson s.n. (K),
Sinclair 3831 (E), Watt9S6\ (E), 24-8-1887. s.n. (K), Wallich 1543
(K-syntype), Wallich 1544 (BM, K-syntypes).

7 1 . Pogostemon pumilus (Graham) Press in Bull. Br. Mus. nat. Hist.

(Bot.) 10: 74 (1982).
Figs 13b, 37b.

Mentha pumila Graham in Edinb. New phil. J. 4: 393 (1828).
Dysophylla pumila (Graham) Benth. in Wall., PL asiat. rar. 1: 30

(1830).

Eusteralis pumila (Graham) Panigrahi in Phytologia 32: 477 (1976).
E. pumila (Graham) Majumdar in J. Bombay nat. Hist. Soc. 74: 385

(1978, '1977').

Stem erect, terete, weak, glabrous. Leaves in whorls of 4, linear to
linear-lanceolate, c. 20 x 3 mm, base truncate, apex acute, margin
serrate, lamina glabrous. Inflorescence a single terminal spike up to
15 mm long, glabrous; floral leaves clavate, c. 1.7 x 0.7 mm; bracts
spathulate, up to 1 mm long, hairy at margin. Calyx campanulate, c.
1.6 x 2.5 mm; glabrous within, hairy outside, mainly on the teeth;
teeth ciliate, c. 0.4-0.5 mm long, c. 0.4-0.5 mm wide at base; outer
hairs 2-3-celled, c. 200 ^im long, some glandular with dark basal
cell. Corolla c. 0.8 mm long; lower lip c. 0.5 x 0.5 mm; upper lip c.
1 .2 mm across; central lobe c. 0.4 x 0.5 mm; upper lip hairy outside.
Filaments all inserted at a height of 0.9 mm in the tube, c. 1 .7-2 mm
long, exserted portion c. 1.1 mm; filaments glabrous towards the
base. Style c. 2.5 mm long; stigma lobes c. 0.2-0.4 mm. Disc c. 0.2
mm long. Nutlets 4, c. 500 x 400 um; oblong with protuberant base,
brown, reticulate-punctate.

DISTRIBUTION. Nepal to Bangladesh.

SPECIMENS EXAMINED. Stone s.n. (E-isotypes), Wallich 1546 (E,
K).

116

G.R. BHATTI AND M. INGROUILLE

Fig. 13 Dissected corollas, calyces and bracts, showing inner surface. Pogostemon subgenus Dysophyllus section Verticillatus: (a) P. verticillatus, (b) P.
pumilus, (c) P. trinervis, (d) P. helferi, (e) P. pressii, (f) P. stocksii, (g) P. erectus, (h) P. stellatus, (i) P. deccanensis, (j) P. aquaticus. Scale bar 5 mm.

72. Pogostemon trinervis Chermsir. ex Press in Bull. Br. Mus. nat.

Hist. (Bot.) 10: 74 (1982).
Figs 13c, 37c.

Stem erect, thin; hairs 2-celled, c. 180 jam long, apical cell some-
times hook-shaped. Leaves in whorls of 3, more or less orbicular, c.
7x5 mm, base rounded, apex obtuse, margin dentate, lamina with
short stiff hairs on both sides; hairs 2-celled, c. 180 jam long.
Inflorescence branches terminated by a single spike, spike on main
axis c. 20 mm long, stalk with glandular and eglandular hairs; hairs
2-celled, c. 250 urn long. Calyx campanulate, 1.5 x 2 mm, very hairy
outside, teeth hairy within; teeth ciliate, c. 0.5 mm long, 0.4-0.5 mm

wide at base; outer hairs 2-celled, c. 500 |im long, glandular or
eglandular. Corolla c. 1 .5 mm long; lower lip c. 0.5 x 0.5 mm; upper
lip c. 1.1 mm across; central lobe 0.4 x 0.4 mm. Filaments all
inserted at a height of 0.7 mm in the tube, three filaments c. 1 .5-1 .7
mm long, exserted portion c. 1 . 1 mm; filaments glabrous at the base.
Style c. 1.7 mm long; stigma lobes c. 0.4 mm. Disc 0.3 mm long.
Nutlets 4, c. 600 x 400 urn, oblong with protuberant base, tan, shiny,
smooth.

DISTRIBUTION. Thailand (Hui-Taleng, Korat, Pak-tang-chai).
SPECIMENS EXAMINED. Alam 8115 (K), Put 2223 (BM-holotype).

SYSTEMATICS OF POGOSTEMON

73. Pogostemon helferi (Hook.f.) Press in Bull. Br. Mus. nat. Hist.
(Bot.) 10: 73 (1982).

Figs 13d, 38a.

Dysophylla helferi Hook.f., Fl. Brit. India 4: 640 (1885).
Eusteralis helferi (Hook.f.) Panigrahi in Phytologia 32: 477 (1976).
E. helferi (Hook.f.) Majumdar in J. Bombay nat. Hist. Soc. 74: 385
(1978, '1977').

Stem solid, 4-angled, more or less glabrous, a few hairs towards the
inflorescence; hairs 2-celled, c. 160 jam long. Leaves in whorls of 4,
linear, c. 30 x 5 mm, base truncate, apex acute, margin dentate,
lamina glabrous, punctate. Inflorescence a terminal spike, c. 20 mm
long, with 4-5 lateral spikes; floral leaves wide, triangular-ovate to
rhombic; bracts broadly or narrowly spathulate, c. 1 mm long. Calyx
campanulate, c. 1.6x2 mm, hairy outside and with white, globose
glands, glabrous within; teeth ciliate and hairy at the tips, c. 0.5 mm
long, c. 0.3-0.4 mm wide at base; outer hairs 2-celled, c. 160 um
long. Corolla c. 2.5 mm long; lower lip c. 0.7 x 0.7 mm; upper lip c.
1 .5 mm across; central lobe c. 0.5 x 0.5 mm; lobes with a few hairs
outside. Filaments all inserted at a height of 1 mm in the tube, c. 2.5
mm long, exserted portion c. 1 mm; filaments glabrous towards the
base. Style 2.8 mm long; stigma lobes c. 0.6-0.7 mm. Discc. 0.3 mm
long. Nutlets 4, c. 300 x 250 um, oblong, brown, shiny, smooth.

DISTRIBUTION. India (Bengal) and Burma (Tenasserim).

SPECIMENS EXAMINED. Heifer 194 (BM, E), Heifer 3968 (K-
holotype).

74. Pogostemon pressii Panigrahi in Taxon 33:
Figs 13e, 38b.

(1989).

Dysophylla griffithii Hook.f., Fl. Brit. India 4: 641 (1885).
Eusteralis griffithii (Hook.f.) Panigrahi inPhytologia 32: 477 ( 1 976).
E. griffithii (Hook.f.) Majumdar in 7. Bombay nat. Hist. Soc. 74: 386

(1978, '1977').
Pogostemon griffithii (Hook.f.) Press in Bull. Br. Mus. nat. Hist.

(Bot.) 10: 73 (1982).

Stem erect, slender, glabrous. Leaves in whorls of 4, linear, 40 x 5
mm, base rounded, apex acute, margin distantly serrate, lamina
glabrous, glandular. Inflorescence a single terminal spike, c. 60 mm
long; hairs 2-celled, c. 250 urn long. Calyx obconic, c. 1 .2 x 2.5 mm;
outside the teeth with whitish hairs above, the tube glabrous, gla-
brous within; teeth ciliate, c. 0.4 x 0.5 mm, incurved in fruit; hairs 3
celled, c. 370 jam long. Corolla up toe. 1.7 mm long; lower lipc. 0.5
x 0.7 mm; upper lip c. 1 .7 mm across; central lobe c. 0.5 x 0.4 mm.
Filaments all inserted at a height of c. 0.7 mm in the tube, c. 2 mm
long, exserted portion c. 1 mm; filaments glabrous at the base. Style
c. 2.2 mm long; stigma lobes c. 0.3 mm. Discc. 0.2 mm long. Nutlets
4, c. 500 x 400 um, oblong with attachment point at base, dark
brown, smooth.

DISTRIBUTION. India (Madras) and China.

SPECIMENS EXAMINED. Chattaya 5224 (K), Gamble 13748 (K),
Griffiths 3968 (K-holotype).

75. Pogostemon stocks!! (Hook.f.) Press in Bull. Br. Mus. nat. Hist.

(Bot.) 10: 74 (1982).
Figs 13f, 38c.

Dysophylla stocksii Hook.f., Fl. Brit. India 4: 642 (1885).
Eusteralis stocksii (Hook.f.) Panigrahi inPhytologia 32: 478 (1976).
E. stocksii (Hook.f.) Majumdar in J. Bombay nat. Hist. Soc. 74: 386
(1978, '1977').

117

Stem solid, terete, glabrous. Leaves in whorls of 10 or more, linear,
c. 16x2 mm, base truncate, apex acuminate, margin entire, lamina
glabrous. Inflorescence a single terminal spike, c. 45 mm long;
bracts cup-shaped, with fine hairs at the tip and margin. Calyx
campanulate, pentagonous, c. 1 x 2 mm; sparsely hairy outside,
glabrous within, the teeth glandular; teeth ciliate, c. 0.4 x 0.4 mm,
incurved in fruit; outer hairs 2-celled, c. 200 um long. Corolla c. 1 .4
mm long; lower lip 0.5 x 0.5 mm; upper lip 1.4 mm across; central
lobe 0.5 x 0.5 mm, with a few hairs and many glands. Filaments all
inserted at a height of 0.5 mm in the tube, c. 2.5-2.8 mm long,
exserted portion c. 1.9 mm; filaments glabrous towards the base.
Sty lee. 2.4 mm long; stigma lobes c. 0.4 mm. Discc. 0.2 mm. Nutlet
1, c. 600 x 200 um, narrowly oblong, light brown, smooth.

DISTRIBUTION. Southwestern India (Bombay, Concan).
SPECIMENS EXAMINED. Stocks s.n. in Herb. Hooker (K-holotype).

76. Pogostemon erectus (Dalzell) Kuntze, Rev. gen. pi. 2: 530

(1891).
Figs 13g, 39a.

Dysophylla gracilis Dalzell in Hooker's J. Bot. 2: 337 (1850), non

Pogostemon gracilis Hassk. (1843).

Eusteralis gracilis (Dalzell) Panigrahi in Phytologia 32: 476 (1976).
E. erecta (Kuntze) Panigrahi in Phytologia 32: 477 (1976).
E. erecta (Kuntze) Majumdar in J. Bombay nat. Hist. Soc. 74: 386

(1978, '1977').
E. gracilis (Dalzell) Majumdar in J. Bombay nat. Hist. Soc. 74: 386

(1978, '1977').
E. tomentosa var. gracilis Bennet & Raizada in Indian Forester 108:

303(1982).

Stem erect, terete, brown to purplish, sparsely hairy; hairs 3-celled,
c. 375 um long. Leaves in whorls of 10 or more, linear, c. 2.5 x 1 mm,
base truncate, apex acute, margin entire, revolute; hairs few, up to 3-
celled, c. 250 um long. Inflorescence a single terminal spike, c. 70
mm long; hairs 3-celled, c. 370 um long; floral leaves claviform, two
hairs at apex giving appearance of a cobra head with exserted
tongue; bracts filiform-spathulate, c. 1-2 mm long. Calyx
campanulate, c. 1 .7 x 2. 1 mm; very hairy outside, especially in upper
half, teeth hairy within; teeth ciliate, c. 0.5-0.6 mm long; outer hairs
white, up to 3-celled, c. 430 pm long. Corolla up to 2.4 mm long;
lower lip c. 0.6 x 0.6 mm; upper lip c. 1 .4 mm across; central lobe c.
0.5 x 0.4 mm; lobes hairy. Filaments all inserted at a height of c. 1
mm in the tube, c. 2.5-2.7 mm long, exserted portion c. 1 mm;
filaments hairy from middle to connective of anthers, all equally
hairy at the base. Style c. 3.5 mm long; stigma lobes c. 0.7 mm. Disc
c. 3 mm long, unequal with one arm elongated. Nutlets 4, c. 400 x
200 um, oblong, tan, smooth.

DISTRIBUTION. India (Bombay).

SPECIMENS EXAMINED. Dalzell s.n. (K-holotype), Hooker s.n.
(K).

var. diplolobatus Bhatti & Ingr., var nov.
a var. erecto, tow bilobo dignoscenda.

TYPE. India: Kerala; Karimbam, 23 December 1 980, Ansari 69986
(K!-holotype).

Differs from var. erectus in having a 2 armed disc.

77. Pogostemon stellatus (Lour.) Kuntze, Rev. gen. pi. 2: 429
(1891).

118

Figs 13h, 39b.

Mentha stellata Lour, in Flora cochinch. 2: 361 (1790).
Dysophylla stellata (Lour.) Benth. in Wall., PL asiat. rar. 1: 30

(1830), non Mentha stellata Roxb. (1814).
D. benthamiana Hance in Ann. Sc. Nat. V, 5: 234 (1866), pro parte.

D. peguana auct., non Prain (1891).

Eusteralis stellata (Lour.) Panigrahi in Phytologia 32: 477 (1976).

E. malabarica (Lour.) Majumdar in J. Bombay nat. Hist. Soc. 74:
385 (1978, '1977'), nom. inval.

Stem solid, terete, with short internodes, puberulent; hairs 3-celled,
c. 3 10 um long. Leaves in whorls of up to 10, linear, 9x2 mm, base
truncate, apex acuminate, margin entire, revolute; hairs 2-celled, c.
125 um long. Inflorescence a single terminal spike, c. 55 mm long;
bracts linear-clavate or spathulate, c. 1 mm long. Calyx campanulate,
c. 1 .5 x 2.2 mm, tube and teeth hairy within and with white hairs
outside; teeth ciliate, c. 0.4-0.5 mm long, 0.4-0.5 mm wide at base,
incurved in fruit; outer hairs 2-celled, c. 190 um long. Corolla c. 1 .7
mm long; lower lip c. 0.6 x 0.6 mm; upper lip 1 .5 mm across; central
lobe c. 0.5 x 0.5 mm; upper and lower lip hairy outside. Filaments all
inserted at a height of 0.8 mm in the tube, two under central lobe
(inner) c. 3.3 mm long, two on lower side c. 3 mm long, exserted
portion c. 2.4 mm; filaments puberulent at the base and with
moniliform hairs from middle to connective of anthers. Style c. 3.4
mm long; stigma lobes c. 0.9 mm. Disc c. 0.2 mm long, unequal.
Nutlets 4, c. 600 x 350 um, oblong, tan, smooth.

DISTRIBUTION. India (Bombay, Calicut, Karnataka, Mysore, Ma-
dras), Bangladesh, and Hong Kong. In rice paddies.

SPECIMENS EXAMINED. Dalz s.n. (K), Gibbs 7725 (K), Heynes
1542(K),Lo«re/ros.n.(BM-holotype),/?a026(K), Wight 2\3\ (K),
Wight 2136 (K).

Tahir et al. (1995) report orbicular nutlets with protruberances in
material from Bangladesh.

78. Pogostemon deccanensis (Panigrahi) Press in Bull. Br. Mus.

nat. Hist. (Bot.) 10: 73 (1982).
Figs 13i, 39c.

Dysophylla tomentosa Dalzell \nHooker's J. Bot. 2: 337 (1850), non

Pogostemon tomentosa Hassk. (1844).

Eusteralis deccanensis Panigrahi in Phytologia 32: 475 (1976).
E. tomentosa (Dalzell) Panigrahi in Phytologia 32: 477 (1976).
E. tomentosa (Dalzell) Majumdar in J. Bombay nat. Hist. Soc. 74:

385(1978/1977').

Stem terete, with short internodes, brownish violet; hairs 3-celled, c.
250 |im long. Leaves in whorls of 6-8 or more, linear, c. 8 x 2 mm,
base truncate, apex acute, margin more or less entire, revolute; hairs
3-celled, c. 437 um long. Inflorescence a single terminal spike, c. 50
mm long, tapering towards apex; hairs 5-celled, c. 1000 um long;
bracts filiform-spathulate, c. 1-2 mm long. Calyx campanulate, c.
1 .7 x 3 mm; teeth and tube hairy within, hairy and glandular outside;
teeth ciliate, the longest c. 0.6-0.7 mm long, 0.4-0.6 mm wide at
base; outer hairs 4-celled, c. 500 |im long. Corolla c. 2.3 mm long;
lower lip 0.9 x 0.9 mm; upper lipc. 1 .7 mm across; central lobec. 0.5
x 0.5 mm; upper and lower lip hairy outside. Filaments all inserted
at a height of c. 1 mm in tube, c. 3.2-3.5 mm long, exserted portion
c. 2.2 mm; two filaments with long moniliform hairs from the
middle to connective of anthers, two filaments only hairy at middle,
all glabrous at the base. Style c. 3.8 mm long; stigma lobes c. 0.5
mm. Discc. 0.2 mm long, uneven, with one lobe elongated c. 0.3 mm
in notch between nutlets. Nutlets 4, c. 500 x 450 um, orbicular, tan
with whitish notch at the base, smooth to reticulate.

G.R. BHATTI AND M. INGROUILLE
DISTRIBUTION. India (Bombay, Mysore, Madras).

SPECIMENS EXAMINED. Dalz s.n. (K-holotype), Madras Herb.
1 1982 (K), Ramamoorthy 1407 (K).

79. Pogostemon aquaticus (C.H. Wright) Press in Bull. Br. Mus.

nat. Hist. (Bot.) 10: 73 (1982).
Figs 13j, 40.

Elsholtzia aquatica C.H.Wright in Dyer, Fl. Trop. Afr. 5: 45 1 ( 1900).

Stem terete, hollow, glabrous except at the nodes; hairs 4-celled; c.
430 um long. Leaves in whorls of 4, linear, c. 18x6 mm, base
cuneate, apex acute, margin entire, glandular, lamina more or less
glabrous, a few hairs on the midrib on abaxial surface. Inflorescence
a terminal spike with six lateral spikes, all in a single whorl; terminal
spike with long peduncle c. 70 mm long and a dense spike of more
or less the same length, first whorl separated, lateral spikes c. 30 mm
long, equalling peduncles. Floral leaves linear, c. 2 mm long. Calyx
campanulate, c. 2 x 3 mm; glabrous but glandular within, hairy
outside, more densely above to sparsely at the base; teeth ciliate, c.
0.7 mm long, 0.5-0.7 mm wide at base; outer hairs 2-celled, c. 310
um long. Corolla c. 3 mm long; lower lip 1 .2 x 1 .2 mm, strigose
within; upper lip c. 2 mm across; central lobe c. 1 x 0.7 mm; lobes
ciliate at margin. Filaments all attached at a height of 1 .2 mm in the
tube, c. 2.5-3.2 mm long, exserted portion c. 2.2 mm; filaments
glabrous at the base. Style c. 4 mm long; stigma lobes c. 0.7 mm.
Disc 0.4 mm long. Nutlets 4, c. 900 x 600 um, oblong, dark brown
to black, smooth.

DISTRIBUTION. East Africa, Zimbabwe, Mozambique (Unangu to
Lake Shireva), and Malawi (Dedza, Chongoni forest).

SPECIMENS EXAMINED. Fanshawe F8512 (K), Johnson 15 (K-
type), Salubeni 1780 (K), Salubeni 1888 (K), Wight 8530 (K).

ACKNOWLEDGEMENTS. Dr G.R. Bhatti was supported by a studentship
from Shah Abdul Latif University, Khaipur, Pakistan. We would like to thank
J.R. Press, R. Harley, A. Paton, I. Hedge, and staff at The Natural History
Museum and the Royal Botanic Gardens, Kew and Edinburgh.

REFERENCES

Bakhuizen van den Brink, R. C. & van Steenis, C.G.G.J. 1 963. A note onPogostemon

Desf. and Dysophylla Blume. Taxon 17: 235-236.
Bentham, G. 1829. Bot. Reg. 15: t. 1282 & t. 1300.
1 830. Synopsis of the genera and species of Indian Labiatae enumerated in the

catalogue of the collections in DrWallich's charge. In N. Wallich, Plantae Asiaticae

Rariores 1: 28-31. London.

1832-1836. Labiatarum genera et species. London.

1848. Labiatae. In A.P. de Candolle, Prodromus systematis naturalis regni

vegetabilis 12: 27-603.
Bhatti, G.R. 1995. Systematic! o/Pogostemon Desf. and related genera. Ph.D. thesis.

London.

Blume, C.L. 1826. Bijdragen tot de Flora van Nederlandsch Indie 3. Batavia.
Briquet, J. 1 897. Labiatae. In A. Engler & K. Prantl, Die Natiirlichen Pflanzenfamilien

4(3a): 183-374. Leipzig.
Brown, N.E. 1909. Pogostemon rogersii in Diagnoses africanae: XXXII. Bull. misc.

Inf. R. hot. Gdns. Kew [1909]: 376-380.
Desfontaines, R.L. 1815. Description d'un nouveau genre de Labiee. Mem. Mus. Hist.

nat. Paris!: 154-156.
El-Gazzar,A. & Watson, L. 1967. Consequences of an escape from floral minutiae and

floristics in certain Labiatae. Taxon 16: 186-189.

Hartwell, J.L. 1982. Plants used against cancer. A survey. Lawrence, Mass.
Hasskarl, J.K. 1 842. Plantarum genera et species novae aut reformatae javanenses.

Flora, Jena 25, Beib. 2(1-2): 1-32.

Hermann, P. 1717. Musaeum Zeylanicum 3. Lugduni Batavorum.
Hooker, J.D. 1885. Flora of British India 4. London.

SYSTEMATICS OF POGOSTEMON

119

Keng, H. 1 969. Flora Malesianae precursores 48. A revision of Malesian Labiatae.

Gdns' Bull., Singapore 24: 13-180.

1978. Labiatae. In C.G.G.J. Steenis (Ed.) Flora Malesiana I, 8(3): 301-394.

Kudo, Y. 1927. Labiatarum sino-japonicarum prodromus. Mem. Fac. Sci. Agric.

Taihoku imp. Univ. 2(2): 37-332.

Kuntze, O. 1891. Revisio generum plantarum 2. Leipzig.
Linnaeus, C. 1747. Flora Zeylanica. Holmiae.

1767. Mantissa plantarum 1. Holmiae.

Loureiro, J. 1790. Flora Cochinensis 2. Ulyssipone

Merrill, E.D. 1912. Phil. Journ. Sc. Bot. 7: 347.

Miquel, F.A.W. 1 859. Flora Indiae Batavae 2. Amsterdam.

Mukerjee, S.K. 1940. A revision of the Labiatae of the Indian empire. Rec. hot. surv.

Ind. 14(1): 1-228.
Panigrahi, G. 1 976.Taxonomic notes on certain taxa ofAsiatic angiosperms. Phytologia

32: 473-479.

1984. Nomenclatural notes on Pogostemon Desf. Taxon 33: 102.

Prain, D. 1891. Noviciae Indicae. III. Some additional species of Labiatae. J. Asiat.

Soc. Beng.59: 294-318.
Press, J.R. 1982. Taxonomic studies in the Labiatae tribe Pogostemoneae. Bull. Br.

MU.I. not. Hist (Bot.) 10: 1-89.

Rafinesque-Schmaltz , C.S. 1837. Flora Telluriana 2. Philadelphia.
Roxburgh, W. 1814. Hortus Bengalensis. Serampore.

1 832. Flora Indica 3. Serampore.

Ku in phi us, G.E. 1750. Herbarium Amboinense 6. Amsterdam.

Steam, W.T. 1992. Botanical Latin, 2nd ed. London.

Tahir, S.S., Khanam, M. & Husain, S.Z. 1995. A micromorphological study of

Pogostemon Desf. species (Lamiaceae) from Bangladesh. Pakist. J. Bot. 27: 73-82.
Von Reis, S.A. 1973. Drugs and food from little known plants. Cambridge, Mass.
Wu, C.Y. & Li, H.W. 1975. Some changes of botanical names in Chinese Labiatae.

Ada phytotax. sin. 13: 72-95.

120

G.R. BHATTI AND M. INGROUILLE

Fig. 14 Nutlet and nutlet surface, (a) P. benghalensis, (b) P. villosus, (c) P. plectranthoides.

SYSTEMATICS OF POGOSTEMON

121

'

Fig. 15 Nutlet and nutlet surface, (a) P. pubescens, (b) P. gardneri, (c) P. cristatus.

122

G.R. BHATTI AND M. INGROUILLE

Fig. 16 Nutlet and nutlet surface, (a) P. paniculatus, (b) P. purpurascens, (c) P. cablln.

SYSTEMATICS OF POGOSTEMON

123

Fig. 17 Nutlet and nutlet surface, (a) P. nepetoides, (b) P. heyneanus, (c) P. nelsonii.

124

G.R. BHATTI AND M. INGROUILLE

Fig. 18 Nutlet and nutlet surface, (a) P. glaber, (b) P. hispidus, (c) P. wattll.

SYSTEMATICS OF POGOSTEMON

125

Fig. 19 Nutlet and nutlet surface, (a) P. championii, (b) P. formosanus, (c) P. elsholtzioides.

126

G.R. BHATTI AND M. INGROUILLE

Fig. 20 Nutlet and nutlet surface, (a) P. tuberculosus, (b) P. griffithii, (c) P. dielsianus.

SYSTEMATICS OF POGOSTEMON

127

Fig. 21 Nutlet and nutlet surface, (a) P. nilagaricus, (b) P. vestitus, (c) P. mollis.

128

G.R. BHATTI AND M. INGROUILLE

Fig. 22 Nutlet and nutlet surface, (a) P. mtundatus, (b) P. rupestris, (c) P. rogersii.

SYSTEMATICS OF POGOSTEMON

129

Fig. 23 Nutlet and nutlet surface, (a) P. petiolaris, (b) P. philippinensis, (c) P. velatus.

130

G.R. BHATTI AND M. INGROUILLE

Fig. 24 Nutlet and nutlet surface, (a) P. williamsii, (b) P. membranaceus, (c) P. elatispicatus.

SYSTEMATICS OF POGOSTEMON

131

Fig. 25 Nutlet and nutlet surface, (a) P. paludosus, (b) P. speciosus, (c) P. atropurpureus.

132

G.R. BHATTI AND M. INGROUILLE

Fig. 26 Nutlet and nutlet surface, (a) P. travancoricus, (b) P. reflexus, (c) P.fraternm.

SYSTEMATICS OF POGOSTEMON

133

Fig. 27 Nutlet and nutlet surface, (a) P. menthoides, (b) P. macgregorii, (c) P. litigiosus.

134

G.R. BHATT1 AND M. INGROUILLE

Fig. 28 Nutlet and nutlet surface, (a) P. hirsutus, (b) P. wightii, (c) P. brachystachyus.

SYSTEMATICS OF POGOSTEMON

135

^ '
•« - •-

>* ' ^.

Fig. 29 Nutlet and nutlet surface, (a) P. nigrescens, (b) £ strigosus, (c) £ auricularius.

136

G.R. BHATTI AND M. 1NGROUILLE

Fig. 30 Nutlet and nutlet surface, (a) P. glabratus, (b) P. barhatus, (c) P. amamnlhoides.

SYSTEMATICS OF POGOSTEMON

137

Fig. 31 Nutlet and nutlet surface, (a) P. myosumides, (b) P. salicifolius, (c) P. quadrifolius.

138

G.R. BHATTI AND M. INGROUILLE

Fig. 32 Nutlet and nutlet surface, (a) P. tisserantii, (b) P. mutamba, (c) P. micangensis.

SYSTEMATICS OF POGOSTEMON

139

Fig. 33 Nutlet and nutlet surface, (a) P. lythroides, (b) P. ciliatus, (c) P. linearis.

140

G.R. BHATTI AND M. INGROUILLE

Fig. 34 Nutlet and nutlet surface, (a) P. pentagonus, (b) P. andersonii, (c) P. cruciatus.

SYSTEMATICS OF POGOSTEMON

141

Fig. 35 Nutlet and nutlet surface, (a) P. sampsonii, (b) P. yatabeanus, (c) P. faurei.

142

G.R. BHATTI AND M. INGROUILLE

Fig. 36 Nutlet and nutlet surface, (a) P. peguanus, (b) P. koehneanus, (c) P. crassicaulis.

SYSTEM ATICS OF POGOSTEMON

143

Fig. 37 Nutlet and nutlet surface, (a) P. verticillatus, (b) P. pumilus, (c) P. trinervis.

144

G.R. BHATTI AND M. INGROUILLE

Fig. 38 Nutlet and nutlet surface, (a) P. helferi, (b) P. pressii, (c) P. stocksii.

SYSTEMATICS OF POGOSTEMON

145

Fig. 39 Nutlet and nutlet surface, (a) P. erectus, (b) P. stellatus. (c) P. deccanensis.

146

G.R. BHATTI AND M. INGROUILLE

Fig. 40 Nutlet and nutlet surface of Pogostemon aquaticus.

SYSTEMATICS OF POGOSTEMON

147

SYSTEMATIC INDEX

Accepted names are in roman and synonyms in italic; new names and principal references are in bold.

Dysophylla Blume 78, 107

section Eudysophylla Kudo 78, 107

section Oppositifoliae Benth. 78, 107

section Verticillatae Benth. 78, 111

subgenus Chotekia Keng 78, 1 1 1

andersonii Prain 1 1 3

auricularia (L.) Blume 109

benthamiana Hance 115, 118

crassicaulis Benth. 112, 115

cruciata Benth. 113

cruciata sensu Dunn 113

cruciata sensu Hemsl. ex F.B. Forbes & Hemsl. 1 13

faureiU. LeY 114

gracilis Dalzell 1 17

griffithii Hook.f. 117

helferi Hook.f. 117

koehneana Muschl. 1 15

linearis Benth. 113

lythroides Diels 1 1 1

myosuroides Benth. 78, 110

peguana auct. 118

peguana Prain 1 14

pentagona C.B. Clarke ex Hook.f. 1 13

pumila (Graham) Benth. 115

quadrifolia Benth. 110

ramosissima Benth. 1 1 5

rugosa Hook.f. 78, 110

rupestris Dalzell 110

salicifolia Dalzell ex Hook.f. 1 10

sampsonii Hance 114

stellata (Lour.) Benth. 118

stocksii Hook.f. 117

strigosa Benth. 107

tisserantii Pellegr. 1 1 1

tomentosa Dalzell 1 1 8

velutina Benth. 1 10

verticillata (Roxb.) Benth. 1 15

yatabeana Makino 1 14
Elsholtzia aquatica C.H.Wright 118

cristatus (Willd.) Willd. 92

paniculata Willd. 92
Eusteralis Raf. 78

andersonii (Prain) Majumdar 1 1 3

crassicaulis (Benth.) Panigrahi 1 15

cruciata (Benth.) Majumdar 113

cruciata (Benth.) Panigrahi 113

deccanensis Panigrahi 1 1 8

erecta (Kuntze) Majumdar 1 17

erecta (Kuntze) Panigrahi 1 17

gracilis (Dalzell) Majumdar 1 17

gracilis (Dalzell) Panigrahi 1 17

griffithii (Hook.f.) Majumdar 117

griffithii (Hook.f.) Panigrahi 117

helferi (Hook.f.) Majumdar 1 17

helferi (Hook.f.) Panigrahi 1 17

linearis (Benth.) Majumdar 113

linearis (Benth.) Panigrahi 113

malabarica (Lour.) Majumdar 1 18

pentagona (C.B. Clarke ex Hook.f.) Majumdar 1 13

pentagona (C.B. Clarke ex Hook.f.) Panigrahi 1 13

pumila (Graham) Majumdar 1 1 5

pumila (Graham) Panigrahi 115

quadrifolia (Benth.) Majumdar 1 10

quadrifolia (Benth.) Panigrahi 1 10

sampsonii (Hance) Panigrahi 1 14

stellata (Lour.) Panigrahi 118

stocksii (Hook.f.) Majumdar 117

stocksii (Hook.f.) Panigrahi 1 17

tomentosa (Dalzell) Majumdar 1 18

tomentosa (Dalzell) Panigrahi 1 18
yatabeana (Makino) Murata 1 14
yatabeana (Makino) Panigrahi 1 14
Geniosporum mutamba Hiern 1 1 1
Hyssopus cristatus Lam. 78, 92
Mentha auricularia Blanco 92
auricularia L. 78, 109
cablin Blanco 92
pumila Graham 1 1 5
secunda Roxb. 91
stellata Lour. 1 1 8
stellata Roxb. 110
verticillata Roxb. 1 1 5
Origanum benghalense Burm.f. 89

indicum Roth 94
Perilla polystachya D. Don 94
Pogostemon Desf. 77, 86

section Barbata Briq. 78

section Racemosa Benth. 78, 97

subsection Glabriuscula Briq. 102
subgenus Allopogostemon Bhatti & Ingr. 97

section Racemosus (Benth.) Bhatti & Ingr. 97
subsection Racemosus 97, 98, 101, 103
subsection Glabriusculus (Briq.) Bhatti &
Ingr. 102, 103

section Zygocalyx Bhatti & Ingr. 103, 104, 105
subgenus Dysophyllus (Blume) Bhatti & Ingr. 107,

108

section Dysophyllus 107, 1 1 2

section Verticillatus (Benth.) Bhatti & Ingr. 79,

111, 116
subgenus Pogostemon sensu Bhatti & Ingr. 89, 90,

93,95

subgenus Paniculatae Benth. 78
amaranthoides Benth. 108, 109, 136
andersonii (Prain) Press 1 12, 113, 140
aquaticus (C.H. Wright) Press 1 16, 118, 146
atropurpureus Benth. 103, 104, 131
auricularius (L.) Hassk. 107, 108, 135
barbatus Bhatti & Ingr. 108, 109, 136
battakianus Ridl. 96

benghalensis (Burm.f.) Kuntze 89, 90, 1 20
benthamianum (Hance) Kuntze 1 15
brachystachyus Benth. 105, 107, 134
brevicorollus Y.Z. Sun 79
cablin (Blanco) Benth. 92, 93, 122
championii Prain 95, 96, 125
ciliatus Bhatti & Ingr.lll, 1 12, 139
crassicaulis (Benth.) Press 115, 142
cristatus Hassk. 90, 91, 121
cruciatus (Benth.) Kuntze 112, 113, 140
deccanensis (Panigrahi) Press 1 16, 118, 145
dielsianus Dunn 95, 97, 126
elatispicatus Bhatti & Ingr. 101, 102, 130
elsholtzioides Benth. 95, 96, 125
erectus (Dalzell) Kuntze 1 16, 117, 145

var. diplolobatus Bhatti & Ingr. 117
falcatus (C.Y. Wu) C.Y. Wu & H.W. Li 79
faurei (H. Lev.) Press 112, 114, 141
formosanus Oliver 95, 96, 125
fraternus Miq. 104, 105, 132
frutescens Graham 89
gardneri Hook.f. 90, 91, 121
glaber Benth. 93, 94, 124
glabratus Chermsir. ex Press 108, 109, 136
gracilis Hassk. 1 17
griffithii (Hook.f.) Press 1 17
griffithii Prain 95,97, 126

var. latifolius C.Y. Wu & Y.C. Huang 97

helferi (Hook.f.) Press 1 16, 117, 144

heyneanus Benth. 93, 94, 123

hirsutus Benth. 105, 106, 134

hispidus Prain 94,95, 124

imberbe C.H. Wright ex Hook.f. 104

intermedius Benth. 89

koehneanus (Muschl.) Press 112, 115, 142

linearis (Benth.) Kuntze 112, 113, 139

litigiosus Doan 105, 106, 133

lythroides (Diels) Press 111, 112, 139

macgregorii W.W. Sm. 105, 106, 133

membranaceus Merr. 101, 102, 130

menthoides Blume 105, 106, 133

micangensis G. Taylor 108, 110, 138

mollis Benth. 98, 99, 127

mutamba (Hiern) G. Taylor 108, 111, 138

myosuroides (Benth.) Kuntze 108, 110, 137

nelsonii Doan 93, 94, 123

nepetoides Stapf. 92, 93, 123

nigrescens Dunn 105, 107, 135

nilagiricus Gamble 97, 98, 127

paludosus Benth. 102, 103, 131

paniculatus (Willd.) Benth. 90, 92, 122

parviflorus Benth. 89

patchouly Pellet. 92

patchouly sensu Hook.f. 94

peguanus (Prain) Press 1 12, 114, 142

pentagonus (C.B. Clarke ex Hook.f) Kuntze 112,

113, 140

petiolaris Benth. 98, 99, 129
philippinensis S. Moore 100, 101, 129
plectranthoides auct. pro maj., non Desf. 89
plectranthoides Desf. 90, 91, 120
pressii Panigrahi 116, 117, 144
pubescens Benth. 90, 91, 121
pumilus (Graham) Press 115, 1 16, 143
purpurascens Dalzell 92, 93, 122
purpuricaulis Dalzell 89
quadrifolius (Benth.) Kuntze 108, 110, 137
reflexus Benth. 103, 104, 132
reticulatus Merr. 79
rogersii N.E. Br. 98, 99, 128
rotundatus Benth. 98, 100, 128
rugosus (Hook.f.) El Gazzar & L. Watson 1 10
rupestris Benth. 98, 99, 128
salicifolius (Dalzell ex Hook.f.) El Gazzar & L.

Watson 108, 110, 137
sampsonii (Hance) Press 112, 114, 141
speciosus Benth. 102, 103, 131
stellatus (Lour.) Kuntze 1 16, 117, 145
stocksii (Hook.f.) Press 1 16, 117, 144
strigosus (Benth.) Benth. 105, 107, 135
suavis Ten. 92, 94

szemacensis (C.Y. Wu & S.J. Hsuan) Press 79
tisserantii (Pellegr.) Bhatti & Ingr. 108, 111,

138

tomentosa Hassk. 1 18
travancoricus Bedd. 103, 104, 132
trinervis Chermsir. ex Press 116, 143
tsiangii (Y.Z. Sun) Press 79
tuberculosus Benth. 95, 97, 126
velatus Benth. 100, 101, 129
verticillatus (Roxb.) Bhatti & Ingr. 115, 1 16, 143
vestitus Benth. 98, 99, 127
villosus Benth. 89. 90, 120
wattii C.B. Clarke 95, 96, 124
wightii Benth. 103, 106, 134
williamsii Elmer 100, 101, 130
yatabeanus (Makino) Press 112, 114, 141

Bulletin of The Natural History Museum
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CONTENTS

77 Systematics of Pogostemon (Labiatae)
G.R. Bhatti and M. Ingrouille

jlletin of The Natural History Museur
BOTANY SERIES

Vol. 27, No. 2, November 1997