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Full text of "The genus Pinus"

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THE GENUS PINUS 



PUBLICATIONS OP THE ARNOLD ARBORETUM No. 



THE 



GENUS PINUS 



BY 



GEORGE RUSSELL SHAW 




Es giebt jedoch auch Arten und dieses ist fUr den 
Systematiker wie f Ur den Physiologen gleich wichtig 
welehe sich den wechselnden Bedingungen der Feuch- 
tigkeit so voUkommen anpassen, dass ihre extremen 
Fonnen zu ungleichen Arten zu gehbren scheinen. 

Schimper. 



CAMBRIDGE 

PRINTED AT THE RIVERSIDE PRESS 

1914 




QK 
Ptfc553 



REPRINTED 1958 BY THE MURRAY PRINTING COMPANY 
FORGE VILLAGE, MASSACHUSETTS 



CONTENTS 

-5 Page Plate 

PART 1 CHARACTERS OF THE GENUS 1 

Cotyledon, primary leaf, bud and branchlet 1, 2 I 

Secondary leaves 2 II 

External characters 4 

Internal characters 4 

Flowers and conelet 7 III 

Cone 8 IV 

Phyllotaxis 12 V 

Cone-tissues and seeds 12-16 VI 

Wood 17 VII 

Bark 18 

PART 2 CLASSIFICATION OF THE SPECIES 22 

Sections, subsections and groups 25 

Section Haploxylon 26 

Subsection Cembra 26 

Group Cembrae 26 

pinus koraiensis, cembra, albicaulis 26, 27 viii 

Group Flexiles 28 

PiNUS FLEXiLis, Armandi . 28, 30 IX 

Group Strobi 30 

PiNUS ayacahuite, Lambertiana 30, 32 X 

parviflora, peuce, excelsa 32, 34 XI 

monticola, strobu8 34, 36 xii 

Subsection Paracembra 36 

Group Cembroides 38 

PiNUs cembroides, Pinceana, Nelsonii 38, 40 XIII 

Group Gerardianae 40 

PiNUS BuNGEANA, Gerardlana 40, 42 XIV 

Group Balfourianae 42 

PiNus Balfouriana, aristata 42, 44 XV 

Section Diploxylon 44 

Subsection Parapinaster 44 

Group Leiophyllae ' 44 

PiNUS LBIOPHYLLA, LuMHOLTZII 44, 46 XVI 



CONTENTS 

Group Longifoliae 46 

PiNUS IiONGIFOUA, CANABIENSI8 46, 48 

Group Pineae 48 

PiNUS PINEA 48 

Subsection Pinaster 50 

Group Lariciones 51 

PiNUS RESINOSA, TROPICALI8 51, 62 

Massoniana, densiflora 62 

stlvestris, montana 54 

LUCHUENSI8, ThUNBERGII, NIGRA . . . . . . 56, 58 

MeRKUSII, SINENSIS, IN8ULARI8 58, 60 

Group Australes 62 

pinus pseudostrobus 62 

montezumae 64 

P0NDER08A 66 

TEOCOTE, Lawsonii 68 

occidentalis, palustris 70 

caribaea 70 

taeda, glabra, echinata 72, 74 

Group Insignes 76 

PiNUS Pringlei, oocarpa 76, 78 

halepensis, pinaster 78, 80 

virginiana, clausa 80 

rigida, 8erotina, pungens 82, 84 

Banksiana, contorta 84 

Greggii, patula 86 

muricata, attenuata, radiata 86, 88 

Group Macrocarpae 90 

PiNUS TORREYANA, SaBINIANA 90 

COULTERI 93 

INDEX 94 



xvn 



xvni 



XIX 

XX 

XXI 

xxn 

XXIII 

XXIV 

XXV 

XXVI 

XXVII 

xxvni 

XXIX 
XXX 

XXXI 

XXXII 

XXXIII 

XXXIV 

XXXV 

XXXVI 

XXXVII 

XXXVIII 
XXXIX 



INTKODUCTION 

This discussion of the characters of Pinus is an attempt to determine their taxonomic significance 
and their utility for determining the limits of the species. A systematic arrangement follows, based 
on the evolution of the cone and seed from the comparatively primitive conditions that appear in 
Pinus cembra to the specialized cone and peculiar dissemination of Pinus radiata and its associates. 
This arrangement involves no radical change in existing systems. The new associations in which 
some of the species appear are the natural result of another point of view. 

Experience with Mexican species has led me to believe that a Pine can adapt itself to various 
climatic conditions and can modify its growth in response to them. Variations in dimensions of leaf 
or cone, the number of leaves in the fascicle, the presence of pruinose branchlets, etc., which have 
been thought to imply specific distinctions, are often the evidence of facile adaptability. In fact 
such variations, in correlation with climatic variation, may argue, not for specific distinction, but 
for specific identity. The remarkable variation in the species may be attributed partly to this adapt- 
ability, partly to a participation, more or less pronounced, in the evolutionary processes that cul- 
minate in the serotinous Pines. 



PAKT I 

CHARACTERS OF THE GENUS 

THE COTYLEDON. Plate I, figs. 1-3. 

The upper half of the embryo in Pinus is a cylindrical fascicle of 4 to 15 cotyledons (fig. 1). The 
cross-section of a cotyledon is, therefore, a triangle whose angles vary with the number composing 
the fascicle. Sections from fascicles of 10 and of 5 cotyledons are shown in figs. 2 and 3. Apart from 
this difference cotyledons are much alike. Their number varies and is indeterminate for all species, 
while any given number is common to so many species that the character is of no value. 

THE PRIMARY LEAF. Plate I, figs. 4-6. 

Primary leaves follow the cotyledons immediately (fig. 4) and assume the usual functions of foliage 
for a limited period, varying from one to three years, secondary fascicles appearing here and there 
in their axils. With the permanent appearance of the secondary leaves the green primaries disappear 
and their place is taken by bud-scales, which in the spring and summer persist as scarious bracts, 
each subtending a fascicle of secondary leaves. At this stage the bracts present two important dis- 
tinctions. 

1. The bract-base is non-decurrent, like the leaf -base of Abies fig. 5. 

2. The bract-base is decurrent, like the leaf -base of Picea fig. 6. 

The two sections of the genus, Haploxylon and Diploxylon, established by Koehne on the single 
and double fibro-vascular bundle of the leaf, are even more accurately characterized by these two 
forms of bract-insertion. The difiference between them, however, is most obvious on long branchlets 
with wide intervals between the leaf-fascicles. 

The bracts of spring-shoots are the scarious bud-scales of the previous winter; but the bracts of 
summer-shoots have the form and green color of the primary leaf. 

THE BUD. Plate L figs. 7-11. 

The winter-bud is an aggregate of minute buds, each concealed in the axil of a primary leaf con- 
verted into a scarious, more or less fimbriate, bud-scale. Buds from which normal growth develops 
appear only at the nodes of the branches. On uninodal branchlets they form an apical group consist- 
ing of a terminal bud with a whorl of subterminal buds about its base. On multinodal branchlets 
the inner nodes bear lateral buds which may be latent. 

Fig. 7 represents a magnified bud of P. resinosa, first immersed in alcohol to dissolve the resin, then 
deprived of its scales. This bud contains both fascicle-buds, destined for secondary leaves, and larger 
paler buds at its base. These last are incipient staminate flowers, sufficiently developed for recogni- 
tion. Such flower-bearing buds are characteristic of the Hard Pines in distinction from the Soft 
Pines whose staminate flowers cannot be identified in the bud. 

The want of complete data leaves the invariability of this distinction in question, but with all 
species that I have examined, the flowers of Hard Pines are further advanced at the end of the sum- 
mer. In the following year they open earlier than those of Soft Pines in the same locality. The stami- 
nate flowers of some Hard Pines (resinosa, sylvestris, etc.,) are not apparent without removing the 
bud-scales, but, with most Hard Pines, they form enlargements of the bud (fig. 9). 



* GENUS PINTS 

Invisible or latent buds are present at the nodes and at the apex of dwarf shoots. The former are 
the origin of the numerous shoots that cover the trunk and branches of P. rigida, leiophylla and a few 
other species (fig. 10) . The latter develop into shoots in the centre of a leaf -fascicle (fig. 11) when the 
branchlet, bearing the fascicle, has been injured. 

The size, color and form of buds, the presence of resin in quantity, etc., assist in the diagnosis of 
species. Occasionally a peculiar bud, like that of P. palustris, may be recognized at once. 

THE BRANCHLET. Plate I, figs. 12-14. 

The branchlet, as here understood, is the whole of a season's growth from a single bud, and may 
consist of a single intemode (uninodal, fig. 12-a) or of two or more intemodes (multinodal, fig. 13), 
each internode being defined by a leafless base and a terminal node of buds. 

The spring-shoot is uninodal in all Soft Pines and in many Hard Pines, but, in P. taeda and its 
allies and in species with serotinous cones, it is more or less prevalently multinodal. 

The uninodal spring-shoot may remain so throughout the growing season and become a uninodal 
branchlet. Or a summer-shoot may appear on vigorous branches of any species with the result of 
converting a uninodal spring-shoot into an imperfect multinodal branchlet. The summer-shoot may 
be recognized, during growth, by its green, not scarious bracts and, at the end of the season, by the 
imperfect growth of its wood and foliage (fig. 14). 

The perfect multinodal branchlet is formed in the winter-bud (fig. 8-a) and the spring-shoot is 
multinodal. It is gradually evolved among the Hard Pines, where it may be absent, rare, frequent 
or prevalent, according to the species. In fact there is, in Pinus, an evolutionary tendency toward 
multinodal growth, with its beginnings in the summer-shoot and its culmination in the multinodal 
winter-bud, most prevalent among the serotinous Pines. 

The multinodal shoot is never invariable in a species, but is rare, common or prevalent. This con- 
dition prevents its employment for grouping species. For Pines are not sharply divided into multi- 
nodal and uninodal species, and no exact segregation of them, based on this difference, is possible. 
In fact the character is unequally developed among closely related species, such as P. palustris and 
caribaea. Both produce multinodal shoots, but the former so rarely that it should be classed as a 
uninodal species, while the latter is characteristically multinodal. The multinodal spring-shoot, how- 
ever, has a certain correlative value in its relation to other evolutionary processes that are obvious 
in the genus. 

The length of the branchlet is much influenced by different soils and climates. In species able to 
adapt themselves to great changes, the length of the internode may vary from 50 cm. or more to 
1 cm. or less. In the latter case the branch is a series of very short leafless joints terminated by a 
crowded penicillate tuft of leaves (fig. 12-b). Such a growth may be seen on any species (ponderosa, 
albicaulis, resinosa, etc.) that can survive exposure and poor nourishment. 

The presence of wax, as a bloom on the branchlet, is associated with trees in arid localities, espe- 
cially Mexico, where it is very common. With several species the character is inconstant, apparently 
dependent on environment, and is a provision against too rapid transpiration. 

The branchlet furnishes evidence of the section to which the species belongs, for the bract-bases 
persist after the bracts have fallen away. The color of the branchlet, its lustre, the presence of mi- 
nute hairs, etc., are often suggestions for determining species. 

THE SECONDARY LEAF. Plate H. 

Secondary leaves, the permanent foliage of Pines, are borne on dwarf-shoots in the axils of pri- 
mary leaves. They form cylindrical fascicles, rarely monophyllous, prevalently of 2, 3 or 5 leaves, 
occasionally of 4, 6, 7, or 8 leaves. The scales of the fascide-bud elongate into a basal sheath, decid- 




PLATE I. PRIMARY LEAF. BUD AND BRANCHLET 



4 GENUS PINUS 

uous (fig. 15) in all Soft Pines except P. Nelsonii, persistent (fig. 16) in all Hard Pines except P. leio- 
phylla and Lumholtzii. Inasmuch as these three species are easily recognized, the fascicle-sheath is 
useful for sectional distinctions. 

EXTERNAL CHARACTERS. 

The number of leaves in the fascicle is virtually constant in most species, the variations being too 
rare to be worthy of consideration. With some species, however, heteromerous fascicles are normal. 
The influences that cause this variation are not always apparent (echinata, etc.), but with P. pon- 
derosa, leiophylla, sinensis and others, the number of leaves in the fascicle is, in some degree, dependent 
on climatic conditions, the smaller number occurring in colder regions. In Mexico, for example, where 
snow-capped mountains lie on subtropical tablelands and extremes of temperature are in juxtaposi- 
tion, the conditions are favorable for the production of species with heteromerous fascicles, and the 
number of leaves in the fascicle possesses often climatic rather than specific significance. 

Among conifers, the leaf of Pinus attains extraordinary length with great variation, from 5 cm. or 
less to 50 cm. or more, the maximum for each species being usually much more than twice the mini- 
mum. Climate is the predominating influence; for the shortest leaves occur on alpine and boreal 
species, the longest leaves on species in or near the tropics. 

The length of the leaf is complicated by the peculiarities of individual trees and by pathological 
influences; as a general rule, however, the length of leaves is less or greater according to unfavorable 
or favorable conditions of temperature, moistiu*e, soil and exposure. Therefore the dimensions of 
the leaf may be misleading. It can be said, however, that certain species always produce short 
leaves, others leaves of medium length, and others very long leaves. 

Persistence of the leaf varies with the species and with the individual tree. But it is noteworthy 
that the longest persistence is associated with short leaves (Balfouriana, albicaulis, montana, etc.). 

INTERNAL CHARACTERS. 

Since the leaf-fascicle is cylindrical, the cross-section of a leaf is a sector, its proportional part, of 
a circle. Theoretically the leaf, in section, should indicate the number of leaves composing its fas- 
cicle. This is absolutely true for fascicles of two leaves only. No fascicle of five leaves, that I have 
examined, is equally apportioned among its five members. It may be divided in various ways, one of 
which is shown in fig. 18, where the leaf (a) might be mistaken for one of a fascicle of 3, and the leaf 
(b) for one of a fascicle of 6. Therefore if absolute certainty is required, a fascicle of triquetral leaves 
is best determined by actual count. 

The transverse section of a leaf may be conveniently divided into three distinct parts 1, the 
dermal tissues, epiderm, hypoderm and stomata (fig. 17-a) 2, the green tissue, containing the 
resin-ducts (fig. 17-b) 3, the stelar tissues, enclosed by the endoderm and containing the fibro- 
vascular bundle (fig. 17-c). 

THE DERMAL TISSUES OF THE LEAF. 

The stomata of Pine leaves are depressed below the surface and interrupt the continuity of epiderm 
and hypoderm. They are wanting on the dorsal surface of the leaves of several Soft Pines, constantly 
in some species, irregularly in others. In Hard Pines, however, all surfaces of the leaf are stomatifer- 
ous. In several species of the Soft Pines the longitudinal lines of stomata are very conspicuous from 
the white bloom which modifies materially the general color of the foliage. 

Under the action of hydrochloric acid the hypoderm is sharply diflFerentiated from the epiderm by 
a distinct reddish tint, but without the aid of a reagent the two tissues do not always differ in appear- 
ance. The cells of epiderm and hypoderm may be so similar that they appear to form a single tissue. 
In most species, however, the epiderm is distinct, while the cells of the hypoderm are either uniform. 




PLATE II. SECONDARY LEAVES 



6 GENUS PINUS 

with equally thin or thick walls or biform, with very thin walls in the outer row of cells and very 
thick walls in the inner row or rows of cells or multiform, with cell-walls gradually thicker 
toward the centre of the leaf. These conditions may be tabulated as follows 

Cells of epiderm and hypoderm similar fig. 19. 

Cells of epiderm and hypoderm distinct. 

Cells of hypoderm uniform, thin or thick figs. 20, 21. 

Cells of hypoderm biform fig. 22. 

Cells of hypoderm multiform fig. 23. 

The biform hypoderm is not always obvious (clausa, Banksiana, etc.,) where in some leaves there 
is but one row of cells. But with the examination of other leaves one or more cells of a second row 
will be found with very thick walls. Among Hard Pines there is no Old World species with a biform 
hypoderm. But there are a few American species with uniform hypoderm (resinosa, tropicalis, 
patula and Greggii) ; while, in some leaves of the few American Hard Pines with multiform hypoderm, 
the uniform hypoderm is a variation. \ 

THE GREEN TISSUE. 

In this tissue are the resin-ducts, each with a border of cells, corresponding in appearance and in 
chemical reaction with the cells of the hypoderm and with thinner or thicker walls. With reference 
to the green tissue the foliar duct may be in one of four positions. 

1. External . . against the hypoderm fig. 24. 

2. Internal . . against the endoderm fig. 28. 

3. Medial ... in the green tissue, touching neither hypoderm nor endoderm .... fig. 26. 

4. Septal .... touching both endoderm and hypoderm, forming a septum fig. 30. 

Among the Soft Pines the external duct is invariable in the subsection Paracembra. It is also 
characteristic of the Strobi, where it is sometimes associated with a medial duct. In the Cembrae 
and the Flexiles, however, the ducts are external in some species, or medial or both in others, without 
regard to the afiBnities of these species. 

Among the Hard Pines the external duct is characteristic of the Old World, there being but two 
American Pines with this character (resinosa and tropicalis) . The internal duct is peculiar to Hard 
Pines of the New World, its presence in Old World species being extremely rare. The medial duct 
is common to species of both hemispheres, either alone or in association with ducts in other positions 
(figs. 25, 27). The septal duct is peculiar to a few species (oocarpa, tropicalis, and less frequently 
Pringlei and Merkusii). I have also seen it in a leaf of P. canariensis. The internal and septal ducts 
appear to be confined to the species of warm-temperate or tropical countries. 

The number of resin-ducts of a single leaf may be limited to two or three (strobus, koraiensis, etc.), 
but in many species it is exceedingly variable and often large (pinaster, sylvestris, etc.). Eighteen 
or more ducts in a single leaf have been recorded. Such large numbers are peculiar to Pinus. Occa- 
sionally a single leaf, possibly the leaves of a single tree, may be without ducts, but this is never 
true of all the leaves of a species. 

THE STELAB TISSUES. 

The walls of the endoderm are, in most species, uniform, but, with P. albicaulis and some species 
of western North America, the outer walls of the cells are conspicuously thickened (fig. 32) . Both 
thin and thick walls may be found among the leaves of the group Macrocarpae and of the species 
longifolia. 

The fibro-vascular bundle of the leaf is single in Soft Pines, double in Hard Pines. This distinc- 
tion is employed by Koehne as the basis of his two sections, Haploxylon and Diploxylon. The double 
bundle is usually obvious even when the two parts are contiguous, but they are sometimes com- 



GENUS PINUS 7 

pletely merged into an apparently single bundle. This condition, however, is never constant in a 
Hard Pine, and a little investigation will discover a leaf with a true double bundle. 

Some cells about the fibro-vascular bundle acquire thick walls with the appearance and chemical 
reaction of the hypoderm cells. Among the Soft Pines this condition is most obvious in the group 
Cembroides. Among the Hard Pines it appears in all degrees of development, being absent (figs. 24, 
25), sometimes in irregular lines above and below the bundle (figs. 26, 27, 30, 31), or forming a con- 
spicuous tissue between and partly enclosing the two parts of the bundle (figs. 28, 29). 

The leaf-section furnishes sectional and other lesser distinctions. It is often decisive in separating 
species otherwise diflScult to distinguish (nigra and resinosa or Thunbergii and sinensis, etc.). Some- 
times it is sufiiciently distinct to determine a species without recourse to other characters (tropicalis, 
oocarpa, Merkusii, etc.). An intimate knowledge of the leaf -section, with an understanding of the 
limits of its variation, is a valuable equipment for recognizing species. 

THE FLOWERS. Plate HI, figs. 33-39. 

The flowers in Pinus are monoecious, the pistillate in the position of a long shoot, taking the place 
of a subterminal or lateral bud, the staminate in the position of a dwarf -shoot, taking the place of a 
leaf-fascicle but confined to the basal part of the internode. 

Pistillate flowers are single or verticillate. On multinodal shoots they are often multiserial, ap- 
pearing on two or more nodes of the same spring-shoot (fig. 33) . On uninodal shoots they are neces- 
sarily subterminal (fig. 34), the lateral pistillate flower being possible only on multinodal shoots (fig. 
35) where it is often associated with the subterminal flower (fig. 33) . Like the multinodal shoot, on 
which its existence depends, the lateral pistillate flower cannot be employed for grouping the species. 
It is merely the frequent, but not the essential, evidence of a condition of growth that is more perfectly 
characterized by the shoot itself. 

Staminate catkins are in crowded clusters, capitate or elongate (figs. 36, 37), but with much varia- 
tion in the number of catkins in each cluster. In P. rigida I have found single catkins or clusters of 
all numbers from two to seventy or more. In P. Massoniana and P. densiflora a cluster attains such 
unusual length (fig. 37) that this character becomes a valuable distinction between these species and 
P. sinensis, which has short-capitate clusters. The catkins differ much in size, the largest being found 
among the Hard Pines. 

In the connective of the binate pollen-sacs there is a notable difference (figs. 38, 39), the smaller 
form being characteristic of the Soft Pines. But this is not invariable (excelsa, sylvestris, etc.), and 
the absence of complete data does not permit an accurate estimate of its importance. 

THE CONELET. Plate IH, figs. 40-45. 

After pollination the pistillate fiower closes and becomes the conelet, the staminate flowers wither- 
ing and falling away. The conelet makes no appreciable growth until the following year. Like the 
pistillate flower it may be subterminal or lateral, but a subterminal pistillate flower may become a 
pseudolateral conelet by reason of a summer-growth (fig. 40-a). Such a condition may be recognized 
on the branchlets of the present, and of the previous year (fig. 40-b), by the very short internode 
and short leaves beyond the fruit. 

The conelet offers some distinctions of form, of color, and of length of peduncle, while in some 
species (sylvestris, caribaea, etc.) its reflexed position is an important specific character. The most 
important distinctions, however, are found in its scales, which may be 

1. entire subsection Cembra fig. 41. 

2. tuberculate tropicalis, etc fig. 42. 

3. short-mucronate . . . sylvestris, glabra, etc fig. 43. 

4. long-mucronate . . . .aristata, contorta, etc fig. 44. 

5. spinescent taeda, pungens, etc fig. 45. 



8 GENUS PINUS 

THE CONE. Plate IV. 

The cone of Pinus shows great differences of color, form and tissue ; these are useful for specific 
and sectional distinctions, while the gradual change from the primitive conditions of the Cembrae 
to the elaborate form, structure and mode of dissemination of some serotinous species are obvious 
evidence of an evolution among the si>ecies of remarkable taxonomic range. A form new among 
Coniferae appears, the oblique cone, and a new condition, the serotinous cone, both appearing 
at first alone and, finally, in constant association. 

COLOR OF THE CONE. 

With few exceptions the color of the ripe cone may be classified under one of the following shades 
of brown or yellow. 

Nut-brown The stain of the walnut-husk. 

Rufous brown . .A pronounced reddish nut-brown. 
Fulvous brown . . A yellowish nut-brown. 
Tawny yellow . .The color of the lion. 
Orange Ochre-yellow to red-orange. 

These colors may be paler or deeper. They may be obscured by a fuscous shade or may be modified 
by a dull or lustrous surface. The presence of two or more of these shades in a single species and the 
inherent difficulties of color description lessen the value of the character. Nevertheless certain 
allied species, such as P. nigra and Thunbergii, or P. densiflora and Massoniana, may be distinguished 
by the prevalent difference in the color of their cones. 

DIMENSIONS OF THE CONE. 

The cone is small, medium or large in different species, but varies greatly under the influences of 
environment or of individual peculiarities. The character possesses relative value only, for great 
variation is possible in the same locality and even on the same tree. 

THE PEDUNCLE. 

All conelets are pedunculate, but in some species the peduncle, even when long (patula), may 
become overgrown and concealed by the basal scales of the ripe cone. Articulation usually takes 
place between the peduncle and the branch, sometimes with the loss of a few basal scales which re- 
main temporarily on the tree (ponderosa, palustris, etc.) . With P. Nelsonii, and to a less degree with 
P. Armandi, there is articulation between the cone and its peduncle. 

There are several species bearing persistent cones with no articulation. This condition appears 
in other genera, such as Larix and Picea, but without obvious significance. In Pinus, however, the 
gradual appearance of the persistent cone, for it is rare, common, prevalent or invariable in differ- 
ent species, and its essential association with the serotinous cone, suggest an evolution toward a 
definite end. 

THE UMBO. 

The exposed part of the scale of the conelet is the umbo of the ripe cone, a small definite area 
representing the earlier part of the biennial growth of the cone. The position of the umbo on the 
apophysis is the basis of Koehne's subdivision of the section Haploxylon. 

1. Umbo terminal Subsection Cembra fig. 46-a. 

2. Umbo dorsal Subsection Paracembra fig. 46-b. 

Two other characters assist in establishing these subsections the conelet, unarmed in Cembra, 
armed in Paracembra the pits of the ray-cells of the wood, large in Cembra, small in Paracembra. 




33 




36 








43 





44 



9;^. 



PLATE ni. FLOWERS AND CONELET 



Id GENUS PINUS 

THE APOPHYSIS. 

The apophysis represents the later and larger growth of the cone-scale. With a terminal umbo the 
margin of the apophysis is free and may be rounded (fig. 49) or may taper to a blunt point (fig. 52), 
and any extension of the scale is a terminal extension. With the dorsal umbo all sides of the apophy- 
sis are confined between other apophyses, and any extension is a dorsal thickening of the apophysis 
or a dorsal protuberance. The outline of an apophysis with a dorsal umbo is quadrangular, or it is 
irregularly pentagonal or hexagonal, the different forms depending on the arrangement of the con- 
tiguous scales, whether of definite or indefinite phyllotactic order, a distinction to be considered 
later. 

The two positions of the umbo result from the relative growth of the dorsal and ventral surfaces 
of the cone-scale. With the terminal umbo the growth of both surfaces is uniform, with the dorsal 
umbo the growth is unequal. A true terminal umbo rests on the surface of the underlying scale, al- 
though several species with terminal umbos show the first stages of the dorsal umbo. The umbo of 
P. Lambertiana or of P. flexilis does not touch the surface of the scale below, and a small portion 
of the under side of the apophysis is brought into view on the closed cone. The cone of P. albi- 
caulis (Plate VIII, fig. 90) shows all degrees of development between a terminal umbo near the apex 
of the cone and a dorsal umbo near its base. 

The growth of the apophysis may be limited and constant (strobus, echinata, etc.) or exceedingly 
variable, ranging from a slight thickness to a long protuberance (pseudostrobus, montana, etc.). 
The protuberance is usually reflexed from the unequal growth of the two surfaces. With the terminal 
umbo the protuberance lengthens the scale, with the dorsal umbo it thickens the scale. It is some- 
times a specific character (ayacahuite, longifolia) appearing on all cones of the species, sometimes 
a varietal form, associated in the same species with an unprolonged apophysis (sylvestris, montana). 

On different parts of the same cone, base, centre or apex, the dimensions of the apophyses differ, 
but at each level the scales may be uniform on all sides of the cone. That is to say, the cone is sym- 
metrical with reference to any plane passing through its axis. This, the symmetrical cone, is charac- 
teristic of all other genera of the Abietineae, and is invariable among the Soft Pines and in many Hard 
Pines (figs. 47, 48, 52, 54). But among the Hard Pines there is gradually developed a new form of 
cone with smaller flatter apophyses on the anterior, and larger thicker apophyses on the posterior 
surface. This is the peculiar oblique cone of Pinus (figs. 50, 51, 53), symmetrical with reference to 
one plane only, which includes the axis of both cone and branch. The oblique cone is a gradual devel- 
opment among the Hard Pines ; in some species it is associated as a varietal form with the symmetri- 
cal cone, and finally, in some serotinous species, it is the constant form. 

THE OBLIQUE CONE. 

When the obhque cone is merely a varietal form (halepensis, etc.), it gives the impression of an 
accident, resulting from the reflexed position of the cone and the consequent greater development 
of the scales receiving a greater amount of light and air. But with the serotinous cones (radiata, 
attenuata), the advantages of this form become apparent. The cones of these species are in crowded 
nodal clusters, reflexed against the branch (fig. 50). The inner, anterior scales are perfectly pro- 
tected by their position, while the outer, posterior scales are exposed to the weather. These last only 
are very thick; that is to say, there is an economical distribution of protective tissue, with the great- 
est amount where it is most needed. The oblique form is {>eculiarly adapted for a cone destined to 
remain on the tree for twenty years or more and to preserve its seeds unimpaired. Like the 
persistent cone, the oblique cone finds in association with the serotinous cone a definite reason for 
existence. 




PLATE rv. THE CONE 



1 GENUS PINUS 

PHYLLOTAXIS. Plate V. 

There is an obvious difference between the cones of the two sections of the genus. Those of the 
Soft Pines (figs. 55, 56) have larger and fewer scales, those of the Hard Pines (figs. 57, 58) have more 
numerous and smaller scales, in proportion to the size of the cone. The former condition represents 
a lower, the latter condition represents a higher, order of phyllotaxis. 

DEFINITE PHYLLOTAXIS, 

On a cylindrical axis with scales of the same size, the spiral arrangement would appear as in fig. 62, 
where the scales are quadrangular and any four adjacent scales are in mutual contact at their sides 
or angles. These four scales lie on four obvious secondary spirals (fig. 59, a-a, b-b, c-c, d-d). Ac- 
cording to the phyllotactic order of the scales these may be the spirals of 2, 3, 5, 8 or of 3, 5, 8, 13 
or of 5, 8, 13, 21 etc., etc., from which combinations the primary spiral, on which the scales are in- 
serted on the cone-axis, can be easily deduced. Four quadrangular scales in mutual contact represent 
the condition of definite phyllotaxis. If the cone is conical, definite phyllotaxis would be possible 
among all the scales only when the size of the scales diminishes in equal measure with the gradual 
diminution of the cone's diameter. Such a hypothetical cone is shown in fig. 61. 

INDEFINITE PHYLLOTAXIS. 

On an imaginary cone of conical form and with scales of equal size throughout, there must be more 
scales about the base than about the apex of the cone. The phyllotactic conditions must differ, and 
the obvious spirals, in passing from base to apex, must undergo readjustment. If the scales at the 
base are in definite phyllotactic order and those at the apex are in the next lower order, it is evident 
that intermediate scales, in the gradual change from one condition to the other, must represent 
different conditions of indefinite phyllotaxis, while those in a central position on the cone may belong 
equally to either of two orders. 

A Pine cone is never absolutely cylindrical nor do its scales vary in size proportionately to the 
change of diameter. Most of the scales of a cone are in indefinite phyllotactic relation, while definite 
phyllotaxis is found only at points on the cone. 

As an extreme illustration, the cone of P. pinaster (fig. 60) shows four mutually contiguous quad- 
rangular apophyses at (a), lying on the obvious spirals 5, 8, 13, 21, at (b) four similar apophyses on 
the spirals 3, 5, 8, 13, and at (c) four others on the spirals 2, 3, 5, 8. Between these three points 
are apophyses of irregular pentagonal or hexagonal outline, with three scales only in mutual con- 
tact (figs. 63, 64). Such are the majority of the scales of the cone and represent more or less in- 
definite conditions of phyllotaxis. 

The cones of Hard Pines, by reason of relatively more and smaller scales and of a more conical form, 
attain a higher phyllotaxis and a more complex condition, two or even three orders being represented 
on a single cone; while the cones of Soft Pines, by reason of relatively fewer and larger scales and a 
more cylindrical form, are of lower phyllotaxis, with one order only more or less definitely presented. 
Therefore phyllotaxis furnishes another distinction between the two sections of the genus, but its 
further employment is exceedingly restricted on account of the constant rei>etition of the same orders 
among the species. 

THE CONE-TISSUES. Plate VI. 

The axis of the cone is a woody shell, enclosing a wide pith and covered by a thick cortex traversed 
by resin-ducts. By removing the scales and cortex from the axis (fig. 65) the wood is seen to be in 
sinuous strands uniting above and below fusiform openings, the points of insertion of the cone- 
scales. From the wood, at each insertion, three stout strands enter the scale, dividing and subdivid- 




PLATE V. PHYLLOTAXIS OF THE CONE 



14 GENUS PmUS 

ing into smaller tapering strands whose delicate tips converge toward the umbo. Fig. 70 represents 
a magnified cross-section of half the cone-scale of P. Greggii; at (a) is a compact dorsal plate of bast 
cells; at (c) is a ventral plate of the same tissue but of less amount; at (b) is the softer brown tissue 
enclosing the wood-strands (d, d) (the last much more magnified in fig. 69) and the resin-ducts (e, e). 

WOOD STRANDS. 

The wood-strands, forming the axis of the cone, dififer in tenacity in the two sections of the genus. 
Those of the Soft Pines are easily pulled apart by the fingers, those of the Hard Pines are tougher in 
various degrees and cannot be torn apart without the aid of a tool. This difference is correlated with 
differences in other tissues, all of them combining in a gradual change from a cone of soft yielding 
texture to one of great hardness and durability. 

If a cone scale of P. ayacahuite is stripped of its brown and bast tissues (fig. 66) and is immersed in 
water and subsequently dried, there is at first a flexion toward the cone-axis (fig. 67) and then away 
from it (fig. 68). The wood-strands are hygroscopic and cooperate with the bast tissues in opening 
and closing the cone. This appears to be true of all species excepting the three species of the Cem- 
brae, whose strands are so small and weak that they are not obviously affected by hygrometric 
changes. 

BAST TISSUE. 

With the exception of the three species of the Cembrae the inner part of the cone-scales is pro- 
tected by sclerenchymatous cells forming hard dorsal and ventral plates (fig. 70, a, c). In Soft 
Pines these cells are subordinate to the more numerous parenchymatous cells, but in Hard Pines 
the sclerenchyma increases in amount until, among the serotinous species, it is the predominating 
tissue of the cone-scale, giving to these cones their remarkable strength and durability. 

This bast tissue is hygroscopic and, with its greater thickness on the dorsal surface, there is a much 
greater strain on that side of the scale, tending to force the scales apart when they are ripe and dry, 
and subsequently closing and opening the cone on rainy and sunny days. 

The cone, during the second season's growth, is completely closed, its scales adhering together 
with more or less tenacity. In most species the hygroscopic energy of the scales is suflScient to open 
the cone under the dry condition of its maturity, but with several species the adhesion is so persistent 
that some of the cones remain closed for many years. These are the peculiar serotinous cones of the 
genus. 

THE SEROTINOUS CONE. 

As an illustration of the area to which the adhesion is confined, a section may be sawed from a cone 
of P. attenuata (fig. 71) . The axis and the scales that have been severed from their apophyses (b) can 
be easily pushed out of the annulus (a), which is composed wholly of apophyses so firmly adherent 
that they will successfully resist a strong effort to break them apart. When immersed in boiling 
water, however, the ring falls to pieces. An examination of these pieces discovers adhesion only on 
a narrow ventral border under the apophysis and on a corresponding dorsal border back of the 
apophysis. The rest of the scale is not adherent, so that the seed is free to fall at the opening of the 
cone. 

The serotinous cone is a gradual development, wanting in most species, rare in a few, less or more 
frequent in others. A similar evolution of the persistent cone, of the oblique cone and of the cone- 
tissues has been already discussed. All these progressive characters culminate in mutual associa- 
tion in P. radiata and its allies. The result is a highly specialized fruit that should convey taxonomic 
significance of some kind. 

With all serotinous species that I have seen, some of the trees open their cones at maturity, others 
at indefinite intervals. That is to say, the seed of a prolific year is not at the mercy of a single, per- 







s^. 



PLATE VI. CONE-TISSUES AND SEEDS 



16 GENUS PINTS 

haps unfavorable season. The chances of successful germination are much increased by the inter- 
mittent seed-release peculiar to these Pines. Such a method of dissemination must accrue to the ad- 
vantage of a species. In other words, this intermittent dissemination and the oblique form of cone 
with its jjerfected tissues all mark the highest development of the genus. 

THE SEED. Plate VI. Figs. 72-79. 

The seed of Pinus contains an embryo, with the cotyledons clearly defined, embedded in albumen, 
which is protected by a bony testa with an external membranous spermoderm, produced, in most spe- 
cies, into an effective wing. While the seed of other genera of the Abietineae shows no striking dif- 
ference among the species, that of Pinus is remarkably variable, presenting alike the most primitive 
and the most elaborate forms among the Conifers. These differences are valuable for the segregation 
of kindred species and for some specific distinctions. 

WINGI.ESS SEEDS. 

With wingless seeds the main distinction is found in the spermoderm, which is entire in one species 
only, P. koraiensis. In P. cembra it is wanting on the ventral surface of the nut, but on the dorsal sur- 
face, it is adnate partly to the nut, partly to the cone-scale. The nut of P. albicaulis and that of P. 
cembroides are quite bare of membranous cover. The spermoderm of P. flexilis is reduced to a mar- 
ginal border, slightly produced into a rudimentary wing adnate to the nut. 

THE ADNATE WING. 

In p. strobus, longifolia and their allies and in P. Balfouriana the spermoderm is prolonged into 
an effective wing-blade from a marginal adnate base like that of P, flexilis. This adnate wing cannot 
be detached without injury. 

THE ARTICULATE WING. 

The articulate wing can be removed from the nut and can be replaced without injury. An ineffec- 
tive form of this wing is seen in the Gerardianae and in P. pinea, where the blade is very short and 
the base has no effective grasp on the nut. 

The base of the effective articulate wing contains hygroscopic tissue which acts with the hygro- 
scopic tissue of the cone-scales. The dry conditions that open the cone and release the seeds cause 
the bifurcate base of the wing to grasp the nut more firmly. 

This articulate wing is found in P. aristata and in all Hard Pines except P. pinea, longifolia and 
canariensis. The wing-blade is usually membranous throughout, but in some species there is a 
thickening of the base of the blade that meets the membranous apical part in an oblique line along 
which the wing is easily broken apart. This last condition attains in P. Coulteri and its associates 
a remarkable development. 

Plate VI, fig. 72 shows the wingless seed of P. cembroides; fig. 73 represents the seed of P. flexilis, 
with a rudimentary wing; fig. 74 shows two seeds of P. strobus, intact and with the wing broken away; 
fig. 75 represents the articulate wing, whose bifurcate base when wet (fig. 76) tends to open and re- 
lease the nut. When dry (fig. 77) the forks of the base, in the absence of the nut, close together and 
cross their tips; figs. 78, 79 show the peculiar reinforced articulate wing of P. Coulteri. 

Such wide variation in so important an organ suggests generic difference. But here we are met 
by the association of the different forms in species evidently closely allied. The two Foxtail Pines 
are so similar in most characters that they have been considered, with good reason, to be specifically 
identical; yet the seed-wing of P. Balfouriana is adnate, that of P. aristata articulate. P. Ayacahuite 
produces not only the characteristic wing of the Strobi, adnate, long and effective, but also, in the 
northern variety, a seed with a rudimentary wing, the exact counterpart of the seed of P. flexilis. 



GENUS PINUS 17 

In both sections of the genus are found the effective adnate wing (Strobi and Longifoliae) and the 
inefficient articulate wing (Gerardianae and Pineae). A Httle examination of all forms of the seed 
will show that they blend gradually one into another. 

The color of the wing is occasionally peculiar, as in the group Longifoliae. There is usually no con- 
stancy in this character, for the wing may be uniform in color or variously striated in seeds of the same 
species. The length and breadth of the seed-wing, being dependent on the varying sizes of the 
cone-scale, differ in the same cone. They are also inconstant in different cones of the same species, 
and of this inconstancy the seed of P. ayacahuite furnishes the most notable example. 

THE WOOD. Plate VII. 

With the exception of the medullary rays, a very small proportion of the whole, the wood of Pinus, 
as seen in cross-section (fig. 82), is a homogeneous tissue of wood-tracheids with interspersed resin- 
ducts. In tangential section the medullary rays appear in two forms, linear, without a resin-duct, 
and fusiform, with a central resin-duct. In radial section the cells of the linear rays are of two kinds, 
ray-tracheids, forming the upper and lower limits of the ray, characterized by small bordered pits, 
and ray-cells, between the tracheids, characterized by simple pits. 

The walls of the ray-tracheids may be smooth or dentate; the pits of the ray-cells may be large or 
small. These conditions admit of four combinations, all of which appear in the medullary rays of 
Pinus, and of which a schematic representation is given in Plate VII. These combinations are 

Ray-tracheids with smooth walls. Soft Pines. 

Ray-cells with large pits Subsection Cembra fig. 80. 

Ray-cells with small pits Subsection Paracembra fig. 81. 

Ray-tracheids with dentate walls. Hard Pines. 

Ray-cells with large pits Group Lariciones fig. 83. 

Ray-cells with small pits Other Hard Pines fig. 84. 

This, the simplest classification of Pine-wood, is not without exceptions. P. pinea of the Hard Pines 
resembles, in its wood-characters, P. Gerardiana and P. Bungeana of the Soft Pines. The dentate 
ray-tracheids of P. longifolia are not always obvious. The tracheids of P. luchuensis, according to 
Bergerstein (Wiesner Festschr. 112), have smooth walls. My specimen shows dentate tracheids. 
There is also evidence of transition from small to large pits (I. W. Bailey in Am. Nat. xliv. 292). 
Both large and small pits appear in my specimen of P. Merkusii. 

Of other wood-characters, the presence or absence of tangential pits in the tracheids of the late wood 
establishes a distinction between Soft and Hard Pines. These pits, however, while always present 
in Soft Pines, are not always absent in Hard Pines. The single and multiple rows of resin-ducts in 
the wood of the first year may prove to be a reliable sectional distinction, but this character has not 
been sufficiently investigated to test its constancy. The wood-characters, therefore, however deci- 
sive they may be for establishing the phylogenetic relations of different genera, must be employed 
in the classification of the Pines with the same reservations that apply to external characters. 

Ray-tracheids with dentate walls and ray-cells with large pits are peculiar to Pinus. Therefore the 
presence of these characters, alone or in combination, is sufficient evidence for the recognition of Pine- 
wood. But the combination of smooth tracheids with small pits (subsection Paracembra) Pinus 
shares with Picea, Larix and Pseudotsuga. 

Among Hard Pines the size of the pits has a certain geographical significance. The large pits 
are found in all species of the Old World except P. halepensis and P. pinaster; the small pits in all 
species of the New World except P. resinosa and P. tropicalis. The Asiatic P. Merkusii with both 
large and small pits is not strictly an exception to this geographical distinctiion. The four excep- 
tional species by this and by other characters unite the Hard Pines of the two hemispheres. 



18 GENUS PESrUS 

THE BARK. 

Bark is the outer part of the cortex that has perished, having been cut oflf from nourishment by 
the thin hard plates of the bark-scales. In the late and early bark-formation is found a general but 
by no means an exact distinction between Soft and Hard Pines. In the Soft Pines the cortex re- 
mains alive for many years, adjusting itself by growth to the increasing thickness of the wood. The 
trunks of young trees remain smooth and without rifts. In the Hard Pines the bark-formation be- 
gins early and the trunks of young trees are covered with a scaly or rifted bark. The smooth upper 
trunk of older trees is invariable in Soft Pines, but in Hard Pines there are several exceptions to 
early bark-formation. These exceptions are easily recognized in the field, and the character is of 
decisive specific importance (glabra, halepensis, etc.). 

Among species with early bark-formation are two forms of bark: 1, cumulative, suflBciently per- 
sistent to acquire thickness and the familiar dark gray and fuscous-brown shades of bark long ex- 
posed to the weather ; 2, deciduous, constantly falling away in thin scales and exposing fresh red 
\ inner surfaces. The latter are commonly known as Red Pines, as distinguished from Black Pines 
with dark cumulative bark. Deciduous bark changes after some years to cumulative bark, and the 
upper trunk only of mature trees is red. Red Pines, although usually recognizable by their bark, are 
by no means constant in this character. Oecological or pathological influences may check the fall 
of the bark-scales, and then the distinction between the upper and lower parts of the trunk becomes 
lost. 

SUMMARY 

The various characters that have been considered in the previous pages may be classified under 
dififerent heads, some of them applicable to the whole genus, others to larger or smaller groups of 
species. 

GENERIC CHARACTERS 

Several characters, quite distinct from those of other genera, are common to all the species. 

1. The primary leaf appearing as a scale or bract throughout the life of the tree. 

2. The bud its constant position at the nodes. 

3. The internode its three distinct divisions. 

4. The secondary leaves in cylindrical fascicles with a basal sheath. 

5. The pistillate flower its constant nodal position and its verticillate clusters. 

6. The staminate flower its constant basal position on the internode and its compact clus- 

ters. 

7. The cone its clearly defined annual growths. 

Pinus is also peculiar in the dimorphism of shoots and leaves and in their constant interrelations 
with the diclinous flowers. Evolutionary processes develop features peculiar to Pinus alone (the 
oblique cone, etc.), but confined to a limited number of species. 

SECTIONAL CHARACTERS 

There are several characters that actually or potentially divide the genus into two distinct sections, 
popularly known as Soft and Hard Pines. 

1. The fibro- vascular bundle of the leaf, single or double. 

2. The base of the bract subtending the leaf-fascicle, non-decurrent or decurrent. 

3. The phyllotaxis of the cone, simple or complex. 

4. The flower-bud, its less or greater development. 






88 







^^^^^X 



TO 



^^ 



ra 



^^E 





PLATE VII. THE WOOD 



80 GENUS PINUS 

Some characters indicate the same distinction but are subject each to a few exceptions. 

5. The fascicle-sheath, deciduous or persistent. 

6. The walls of the ray-tracheids, smooth or dentate. 

7. The connective of the pollen-sacs, large or small. 

8. The formation of bark, late or early. 

8UBSECTIONAL CHARACTERS 

An exact subdivision of the Soft Pines is possible on the following characters. 

1. The umbo of the cone-scales, terminal or dorsal. 

2. The scales of the conelet, mutic or armed. 

3. The pits of the ray-cells, large or small. 

EVOLUTIONAL CHARACTERS 

The progressive evolution of the fruit of Pinus, from a symmetrical cone of weak tissues, bearing 
a wingless seed, to an indurated oblique cone with an elaborate form of winged seed and an intermit- 
tent dissemination, appears among the species in various degrees of development as follows 

The seed 

1. wingless. 

2. with a rudimentary wing. 

3. with an effective adnate wing. 

4. with an ineffective articulate wing. 

5. with an effective articulate wing. 

6. with an articulate wing, thickened at the base of the blade. 

The cone 

1. indehiscent. 

2. dehiscent and deciduous. 

3. dehiscent and persistent. 

4. persistent and serotinous. 

and as to its form 

5. symmetrical. 

6. subsymmetrical. 

7. oblique. 

These different forms of the seed and, to some extent, of the cone, are available for segregating 
the species into groups of closely related members; while the gradual progression of the fruit, from a 
primitive to a highly specialized form of cone and method of dissemination, points to a veritable 
taxonomic evolution which is here utilized as the fundamental motive of the systematic classification 
of the species. 

SPECIFIC CHARACTERS 

All aspects of vegetative and reproductive organs may contribute toward a determination of 
species, but the importance of each character is often relative, being conclusive with one group of 
species, useless with another. Characters considered by earlier authors to be invariable with species, 
such as the dimensions of leaf or cone, the number of leaves in the fascicle, the position of the resin- 
ducts, the presence of pruinose branchlets, etc., prove to be inconstant in some species. In fact, as 
the botanical horizon enlarges, the varietal limits of the species broaden and many restrictions 
imposed by earlier systems are gradually disappearing. 



I 



GENUS PINTS 21 

Variation is the preliminary step toward the creation of species, which come into being with the 
elimination of intermediate forms. Variation in a species may be the result of its participation in 
the evolutionary processes culminating in the serotinous Pines, or it may result from the ability 
of the species to adapt itself to various environments by sympathetic modifications of growth, or 
it may arise from some peculiarity of the individual tree. 

Evolutionary variation is associated with the gradual appearance of the persistent, the oblique 
and the serotinous cone, and of the multinodal spring-shoot. For these conditions appear in less or 
greater prevalence among the species of the genus. 

Variation induced by environment finds familiar illustrations among the species that can survive 
at the limits of vegetation and can meet these inhospitable conditions by a radical change of all grow- 
ing parts. Such variations are mainly of dimensions, but, with some species, the number of fascicle- 
leaves is affected and the shorter growing-season may modify the cone-tissues. In Mexico and 
Central America are found extremes of climate within small areas and easily within the range of dis- 
semination from a single tree. The cause of the bewildering host of varietal forms, connecting widely 
contrasted extremes, seems to lie in the facile adaptibility of those Pines, which are able to spread 
from the tropical base of a mountain to a less or greater distance toward its snow-capped summit. 

The peculiarities of individual trees that induce abnormally short or long growths, the dwarf or 
other monstrous forms, the variegations in leaf -coloring, etc., etc., are not available for classification, 
for they may appear in any species, in fact in any genus of Conifers. These variations are artificially 
multiplied for commercial and decorative purposes. But inasmuch as they are repeated in all species 
and genera of the Coniferae that have been long under the observation of skillful gardeners, their 
significance has a broader scope than that imposed by the study of a single genus. 



PART II 

CLASSIFICATION OF THE SPECIES 

The following classification is based on the gradual evolution of the fruit from a cone symmetrical 
in form, parenchymatous in tissue, indehiscent and deciduous at maturity, releasing its wingless seed 
by disintegration to a cone oblique in form, very strong and durable in tissue, persistent on the 
tree, intermittently dehiscent, releasing its winged seeds partly at maturity, partly at indefinite inter- 
vals during several years. This evolution embraces two extreme forms of fruit, one the most primi- 
tive, the other the most elaborate, among Conifers. 

Two sections of the genus. Soft and Hard Pines, are distinguished by several correlated characters, 
and moreover are distinct by obvious diflferences in the tissues of their cones as well as in the quality 
and appearance of their wood. 

With the Soft Pines the species group naturally under two subsections on the position of the umbo, 
the anatomy of the wood and the armature of the conelet. In one subsection (Cembra) are found 
three species, P. cembra and its allies, with the cone-tissues so completely parenchymatous that the 
cones cannot release the seeds except by disintegration. In both subsections there is a gradual evo- 
lution from a wingless nut to one with an effective wing, adnate in one subsection, adnate and 
articulate in the other. The different stages of this evolution are so distinct that the Soft Pines 
are easily separated into definite groups. 

Among the Hard Pines a few species show characters that are peculiar to the Soft Pines. These 
exceptional species form a subsection (Parapinaster) by themselves. 

With the remaining species, the majority of the Pines, the distinctions that obtain among Soft 
Pines have disappeared. The dorsal umbo, the articulate seed-wing, the persistent fascicle-sheath, 
the dorsal and ventral stomata of the leaf and its serrate margins, the dentate walls of the ray- 
tracheids have become fixed and constant. But a new form of seed-wing appears, with a thickened 
blade, assuming such proportions in P. Sabiniana and its two allies that these three constitute a 
distinct group, remarkable also for the size of its cones. 

Here also appear a new form of fruit, the oblique cone, and a new method of dissemination, the 
serotinous cone. Associated with the latter are the persistent cone and the multinodal spring-shoot. 
These characters do not develop in such perfect sequence and regularity that they can be em- 
ployed for grouping the species without forcing some of them into unnatural association. The 
oblique cone first appears sporadically here and there and without obvious reason. The persistent 
cone, the first stage of the serotinous cone, is equally sporadic in the earlier stages of evolution. The 
same may be said of the multinodal shoot. 

Nevertheless these characters show an obvious progression toward a definite goal, where they are 
all united in a small group of species remarkable for the form and texture of their cones, for a peculiar 
seed-release and for the vigor and rapidity of their growth. It is possible, with the assistance of other 
characters, to segregate these species in three groups in which the affinities are respected and the 
general trend of their evolution is preserved. 

The first group, the Lariciones, contains species with large ray-pits, cones dehiscent at maturity, 
and uninodal spring-shoots. They are, with two exceptions, P. resinosa and P. tropicalis. Old World 
species. 



GENUS PINTS 23 

The second group, the Australes, contains species with small ray-pits, cones dehiscent at maturity 
and spring-shoots gradually changing, among the species, from a uninodal to a multinodal form. 
They are, without exception, species of the New World. 

The third group, the Insignes, contains the serotinous species. The ray-pits are small and the 
spring-shoots are, with two exceptions, multinodal. With two exceptions, P. halepensis and 
P. pinaster, they are New World species. 

These three groups, being the progressive sequence of a lineal evolution, are not absolutely cir- 
cumscribed, but are more or less connected through a few intermediate species of each group. The 
systematic position of these intermediate species is determined by their obvious affinities. It can- 
not be expected that the variations, which take an important part in the evolution of the species, 
progress with equal step or in perfect correlation with each other. 

As to specific determinations, a little experience in the field discloses an amount of variation in 
species that does not always appear in the descriptions of authors; and species that are under the 
closest scrutiny of botanists, foresters or horticulturalists, attest by their multiple synonymy their 
wide variation. The possibilities of variation are indefinite and, with adaptable Pines, the range of 
variation is somewhat proportionate to change of climate. In mountainous countries, where there 
are warm sheltered valleys with rich soil below cold barren ledges, the most variable Pines are found. 
The western species of North America, for instance, are much more variable than the eastern spe- 
cies, while in Mexico, a tropical country with snow-capped mountains, the variation is greatest. 

Therefore in the limitation of species undue importance should not be given to characters respon- 
sive to envirormient, such as the dimensions of leaf or cone, the number of leaves in the fascicle, etc. 
Moreover, there are familiar examples (P. sylvestris, etc.) that show the possibility of wide differ- 
ences in the cone of the same species. 

In the following classification species only are considered without attempting to determine varietal 
or other subspecific forms. But varieties are often mentioned as one of the factors illustrating the 
scope of species. Synonymy serves a like purpose, but synonyms not conveying useful information 
are omitted, Roezl's list of Mexican species, for instance, and variations in the orthography of spe- 
cific names. 



PINUS 

1755 PiNUS Duhamel, Trait6 des Arbres, ii. 121. 

1790 Apinus Necker, Elem. Bot. iii. 269. 

1852 Cembra Opiz, Seznam, 27. 

1854 Strobus O^iz, Lotos, iv. 94. 

1903 Caryopitys Small, Fl. Southeast. U. S. 29. 

Leaves and shoots dimorphous, primary leaves on long shoots, secondary leaves on dwarf shoots. 
Flowers dicUnous, the pistillate taking the place of long shoots, the staminate taking the place of 
dwarf shoots. Growth of wood and fruit emanating from the nodes; buds, branchlets and cones, 
therefore, in verticillate association. Leaves and staminate flowers in internodal position, the pri- 
mary leaves along the whole length of the internode, subtending secondary leaf -fascicles on the apical, 
staminate flowers on the basal part. Buds compounded of minute buds in the axils of bud-scales, 
becoming the bracts of the spring-shoot. Branchlets of one or more internodes, each internode in 
three parts a length without leaves, a length bearing leaves and a node of buds. Cone requiring 
two, rarely three years to mature, displaying its annual growths by distinct areas on each scale. Seeds 
wingless or winged, edible and nutritious. 

The Pines are confined to the northern hemisphere, but grow in all climates and under all condi- 
tions of soil, temperature and humidity where trees can grow. Some of the species are of very re- 
stricted range, but others are adaptable and can cover wide areas. The sixty-six species are distri- 
buted as follows 

Eastern Hemisphere, 23. 

1 exclusively African (Canary Islands). 

2 exclusively European. 

3 about the Mediterranean Basin. 

2 common to Europe and northern Asia. 

14 exclusively Asiatic. 

Western Hemisphere, 43. 

28 in western North America, of which 12 are confined to Mexico and Central America. 

15 in eastern North America, of which 2 are exclusively West Indian. 

The two sections of the genus correspond with those of Koehne (Deutsch. Dendrol. 28 [1893]) and 
his two names, Haploxylon and Diploxylon, are adopted here, together with his two subsections of 
Haploxylon, Cembra and Paracembra. 

Of the two subsections of Diploxylon, Pinaster has been employed by Endlicher (Syn. Conif. 166 
[1847]) and later authors for smaller or larger groups of Hard Pines. The subsection Parapinaster 
is now proposed. 

The names of groups, Cembrae, Strobi, Cembroides, Gerardianae, Balfourianae, Pineae, Lari- 
ciones and Australes, are taken from Engelmann's Revision of the Genus Pinus (Trans. Acad. Sci. 
St. Louis, iv. 175-178 [1880]). The remainder, Flexiles, Leiophyllae, Longifoliae, Insignes and 
Macrocarpae, are here proposed. 

In order to bring the illustrations within the limits of the page the dimensions of cone and leaf, 
as shown on the plates, are a little smaller than life. In plates X and XXV the reproductions of the 
cones are reduced to |- life-size. 



SECTIONS, SUBSECTIONS, AND GROUPS 



Bases of the fascick-bracts non-decurrent A HAPLOXYLON 

Umbo of the cone-scale terminal a Cembka 

Seeds wingless. ' 

Cones indehiscent I Cembrae 

Cones dehiscent II. . . . Flexiles 

Seed with an adnate wing . III. . . Strobi 

Umbo of the cone-scale dorsal b Paracembra 

Seeds wingless IV. . . Cembroides 

Seed-wing short, ineffective V. . . . Gerardianae 

Seed-wing long, effective VI. . . Balfourianae 



Bases of the fascicle-bracts decurrent B DIPLOXYLON 

Fascicle-sheath or seed of Haploxylon c Parapinastkr 

Fascicle-sheath deciduous VII. . . Leiophyllae 

Fascicle-sheath persistent. 

Seed-wing of the Strobi VIII. .Longifoliae 

Seed-wing of the Gerardianae IX. . .Pineae 

Fascicle-sheath persistent, seed-wing articulate, eflFective d Pinaster 

Base of wing-blade thin or slightly thickened. 
Cones dehiscent at maturity. 

Pits of ray-cells large X. . . . Lariciones 

Pits of ray-cells small ; XI. . . Australes 

Cones serotinous, pits of ray-cells small XII. .Insignes 

Base of wing-blade very thick XIII. Macrocarpae 



HAPLOXYLON 

Bases of the bracts subtending leaf-fascicles not decurrent. Staminate flowers not sufliciently 
developed in the bud to be apparent. Spring-shoots uninodal. Fibro-vascular bundle of the leaf 
single. Cone symmetrical, of relatively fewer larger scales, its tissues softer. Bark-formation late, 
the trunks of young trees smooth. Wood soft and with little resin, of uniform color and with rela- 
tively obscure definition of the annual rings. Tracheids of the medullary rays with smooth walls. 

All the species of this section, except P. Nelsonii, have deciduous fascicle-sheaths. There are but two 
species of Diploxylon with deciduous sheaths, P. leiophylla and P. Lumholtzii, both of them easily 
recognized. The deciduous sheath, therefore, is an obvious and useful means for recognizing the 
Soft Pines. On the characters of the fruit and the wood Haploxylon can be divided into two sub- 
sections. 

a. Cembra Umbo of the cone-scale terminal. 

b. Paracembra .... Umbo of the cone-scale dorsal. 

Cembra 

Umbo of the cone-scale terminal. Scales of the conelet unarmed. Leaves in fascicles of 5, the 
sheath deciduous, the two dermal tissues distinct, the hypoderm-cells uniform. Pits of the cells of 
the wood-rays large. 

Seeds wingless. 

Cones indehiscent I. . . . Cembrae. 

Cones dehiscent II. . .Flexiles. 

Seeds with an adnate wing III. .Strobi. 

I. CEMBRAE 

Seeds wingless. Cones indehiscent, deciduous at maturity. 

In this group of species there is no segregation of sclerenchyma into an effective tissue. The cones 
are inert under hygrometric changes and may always be recognized in herbaria by their persistent 
occlusion and soft tissues. The seeds are released only by the disintegration of the fallen cone. There 
is, however, a vicarious dissemination by predatory crows (genus Nucifraga) and rodents. 

Leaves serrulate, their stomata ventral only. 

Cones relatively larger, the apophyses protuberant 1. koraiensis. 

Cones relatively smaller, the apophyses appressed 2. cembra. 

Leaves entire, their stomata ventral and dorsal 3. albicaulis. 

1. PINUS KORAIENSIS 

1784 P. STROBTJS Thunberg, Fl. Jap. 275 (not Linnaeus). 

1842 P. KORAIENSIS Siebold & Zuccarini, Fl. Jap. ii. 28. 

1857 P. MANDSCHURiCA Ruprccht in Bull. Acad. Sci. St. Petersb. xv. 382. 

Spring-shoots more or less densely tomentose. Leaves from 8 to 12 cm. long, serrulate, stomata 
ventral only, resin-ducts medial and confined to the angles. Conelets large, subterminal, or on 
young trees often pseudolateral. Cones indehiscent, from 9 to 14 cm. long, short-pedunculate, ovoid- 
conical or subcylindrical ; apophyses dull pale nut-brown, rugose, shrinking much in drying and 



GENUS PINUS 27 

exposing the seeds, prolonged and tapering to a more or less reflexed tip, the umbo inconspicuous; 
seeds large, wingless, the spermoderm entire. 

A species of the mountains of northeastern Asia with valuable wood and large edible nuts; hardy 
and often cultivated in cool-temperate climates. 

The P. koraiensis of Beissner (in Nuov. Giorn. Bot. Ital. n. ser. iv. 184) and of Masters (in Gard. 
Chron. ser. 3, xxxiii. 34, ff.) are P. Armandi and have led to an erroneous extension of the range of this 
species into Shensi and Hupeh. In the original description of the species the authors call attention 
to an error in the plate, where a cone of another species has been substituted. 

P. koraiensis resembles P. cembra in leaf and branchlet but not in the cone. It is often confused 
with P. Armandi, but can easily be distinguished by its tomentose branchlets, indehiscent cone and 
peculiar seed. The two species, moreover, do not always agree in the position of the foliar resin-ducts. 

Plate VIII. 

Fig. 85, Cone and seed. Fig. 86, Leaf-fascicle and magnified leaf-section. 

2. PINUS CEMBRA 

1753 P. CEMBRA Linnaeus, Sp. PI. 1000. 

1778 P. MONTANA Lamarck, Fl. Frang. iii. 651 (not Miller). 

1858 P. PtTMiLA Regel in Index Sem. Hort. Petrop. 23. 

1884 P. MANDSCHURiCA LawsoD, Pinet. Brit. i. 61, ff. (not Ruprecht). 

1906 P. siBiRiCA Mayr, Fremdl. Wald- & Parkb. 388. 

1913 P. CORONANS Litvinof in Trav. Mus. Bot. Acad. St. Petersb. xi. 23, f. 

Spring-shoots densely tomentose. Leaves from 5 to 12 cm. long, serrulate; stomata ventral only; 
resin-ducts medial or, in the dwarf form, often external. Conelets short-pedunculate, purple during 
their second season. Cone from 5 to 8 cm. long, ovate or subglobose, subsessile; apophyses dull nut- 
brown, thick, slightly convex, the margin often a little reflexed, the umbo inconspicuous; seeds 
wingless, large, the dorsal spermoderm adnate partly to the nut, partly to the cone-scale, the ventral 
spermoderm wanting. 

The Swiss Stone Pine attains a height of 15 or 25 metres and occupies two distinct areas, the 
Alps, from Savoy to the Carpathians at high altitudes, and the plains and mountain-slopes 
throughout the vast area from northeastern Russia through Siberia. Beyond the Lena and Lake 
Baikal it becomes a dwarf (var. pumila) with its eastern limit in northern Nippon and in Kamchatka. 
It is successfully cultivated in the cool-temperate climates of Europe and America. The wood is of 
even, close grain, peculiarly adapted to carving. The nuts are gathered for food and confections, 
but are destroyed in great numbers by squirrels, mice and a jay-like crow, the European Nutcracker. 
It is generally conceded, however, that these enemies assist in dissemination. 

Plate Vni. 

Fig. 87, Cone, seed and magnified leaf-section. Fig. 88, Tree at Arolla, Switzerland. 
Fig. 89, Cone, leaf-fascicle and magnified leaf-section of var. pumila. 

3. PINUS ALBICAULIS 

1853 P. FLEXILI8 Balfour in Bot. Exped. Oregon, 1, f. (not James). 

1857 P. CEMBROiDES Ncwbcrry in Pacif. R. R. Rep. vi-3, 44, f. (not Zuccarini). 

1863 P. ALBICAULIS Engelmann in Trans. Acad. Sci. St. Louis, ii. 209. 

1867 P. SHASTA Carri^re, Trait. Conif. ed. 2, 390. 

Spring-shoots glabrous or pubescent. Branchlets pliant and tough. Leaves from 4 to 7 cm. long, 
entire, stout, persistent for several years; stomata dorsal and ventral; resin-ducts external. Conelets 
short-pedunculat, dark purple during the second season, their scales often tapering to an acute 
apex. Cones from 5 to 7 cm. long, subsessile, oval or subglobose; apophyses nut-brown or fulvous 
brown, dull or slightly lustrous, very thick, the under surface conspicuous, meeting the upper surface 



f8 GENUS PINUS 

in an acute margin, and terminated by a salient, often acute umbo; seed wingless, the testa bare of 
spermoderm. 

This species ranges from British Columbia through Washington and Oregon, over the mountains 
of northern California and the Sierras as far south as Mt. Whitney, and, on the Rocky Mountains, 
through Idaho and Montana to northern Wyoming. It is found at the timber-line of many stations 
and forms, in exposed situations, flat table-like masses close to the ground. It is a species of no eco- 
nomical importance and is too inaccessible for the profitable gathering of its large nuts, which are 
devoured in quantity by squirrels and by Clark's crow, a bird of the same genus with the pinivorous 
Nutcracker of Europe. 

P. albicaulis is distinguished from its allies by its entire leaves with both dorsal and ventral stomata, 
from P. flexilis by its indehiscent cone, and from all of these species by its seed without membranous 
cover or rudimentary wing. It was united with P. flexilis by Parlatore and Gordon, and, later, was re- 
ferred to that species as a varietal form by Engelmann (in Brewer & Watson, Bot. Calif, ii. 124). 
Parrish's P. albicaulis (in Zoe, iv. 350), extending its range to the mountains of southern California, 
proves to be P. flexilis (Jepson, Silva Calif. 74). 
Plate VIII. 

Fig. 90, Two cones and seed. Fig. 91, Leaf -fascicle. Fig. 92, Magnified leaf -section. 

n. FLEXILES 

Seeds wingless, the spermoderm forming a narrow border with a rudimentary prolongation. Cones 
dehiscent at maturity. 

The dehiscent cone distinguishes this group from the Cembrae. Therefore confusion of P. koraiensis 
with P. Armandi, or P. albicaulis with P. flexilis should be impossible. The peculiar seed is found 
again only in the northern variety of P. ayacahuite. 

Leaves usually entire, the stomata dorsal and ventral 4. flexilis. 

Leaves serrulate, the stomata ventral only 5. Armandi. 

4. PINUS FLEXILIS 

1823 P. FLEXILIS James in Long's Exped. ii. 34. 

1882 P. REFLEXA Engelmann in Bot. Gaz. vii. 4. 

1897 P. STROBiFORMis Sargent, Silva N. Am. xi. 33, tt. 544, 545 (not Engelmann). 

Spring-shoots pubescent; branchlets very tough and pliant. Leaves from 3 to 9 cm. long, entire, 
or serrulate in the southern variety, persistent for five or six years; stomata dorsal and ventral or, in 
the south, sometimes ventral only; resin-ducts external. Cones from 6 to 25 cm. long, ovate or 
subcylindrical, short-pedunculate; apophyses pale tawny yellow, or yellow ochre, lustrous, often 
prolonged and more or less reflexed, thick, the margin together with the umbo raised above the 
surface of the cone. 

This species grows on the Rocky Mountains from Alberta in the Dominion of Canada to Chihua- 
hua in northern Mexico and ranges westward to the eastern slope of the Sierras and to the southern 
mountains of California. The wood, where accessible, is manufactured into lumber. It may be seen 
in the Arnold Arboretum and in the Royal Gardens at Kew. 

P. flexilis is recognized by its lustrous yellow cones. This and the constantly external ducts of its 
usually entire leaves distinguish it from P. Armandi. From P. albicaulis, with similar leaves, it differs 
by its dehiscent cone. At one extreme the cone of P. flexilis is not unlike that of P. albicaulis, at the 
other extreme it approaches the characteristic cone of P. ayacahuite, with prolonged reflexed scales. 
Hence the confusion of P. albicaulis with P. flexilis (Murray, Parlatore and others) and of P. flexilis 
with Engelmann's P. strobiformis. Sargent's P. strobiformis, illustrated in the Silva of North Amer- 
ica, is the form of this species known as var. reflexa of Engelmann. 
Plate IX. 

Fig. 93, Two cones and seed. Fig. 94, Leaf-fascicle. Fig. 95, Magnified leaf-section. 




PLATE Vni. P. KORAIENSLS (85. 86), CEMBRA (87-89). .ALBICAULIS (90-92) 



80 GENUS PINUS 

5. PINUS ARMANDI 

1884 P. Armandi Franchet in Nouv. Arch. Mus. Paris, s6r. 2, vii. 95, 96, t. 12. 

1898 P. SCIPIONIFORMI8 Masters in Bull. Herb. Boiss. vi. 270. 

1903 P. KORAIENSI8 Masters in Gard. Chron. ser. 3, xxxiii. 34, ff. 18, 19 (not Siebold & 

Zuccarini) . 
1908 P. Mastersiana Hayata in Gard. Chron. ser. 3, xliii. 194. 

Spring-shoots glabrous; branches and most of the trunk covered with a smooth gray cortex. 
Leaves from 8 to 15 cm. long, serrulate; stomata ventral only; resin-ducts external, external and 
medial, or medial, all three conditions sometimes occurring in leaves of the same branchlet. Cones 
from 6 to 20 cm. in length, pendent on peduncles of various lengths, the peduncle often remaining 
on the tree after the fall of the cone; apophyses fulvous brown, dull or sublustrous, the margin 
rounded or tapering to an acute apex, sometimes a little prolonged and reflexed, the umbo incon- 
spicuous. 

A tree of the mountains of central, southern and western China with an outlying station on the 
Island of Formosa. Recently planted in Europe and America, it has so far proved hardy. The nuts 
are gathered for food and some use is made of the wood. 

The glabrous shoots of P. Armandi distinguish it from P. flexilis and P. koraiensis. From the latter 
it is also distinct in its dehiscent cone and in its seed. The section of its leaf, with dorsal ducts 
often in two positions, is peculiar to this species among Soft Pines. 
Plate IX. 

Fig. 96, Two cones and seed. Fig. 97, Leaf-fascicle. Figs. 98, 99, Magnified sections of 
three leaves. 

m. STROBI 

Seed with a long effective wing adnate to the nut. 

The base of the seed-wing corresponds to the marginal spermoderm of the Flexiles but is prolonged 
into an effective adnate wing. This form of wing appears again in the species Balfouriana and in 
the group Longifoliae. 

Cones very long, usually exceeding 25 cm. 

Cone-scales prolonged and reflexed 6. ayacahuite. 

Cone-scales appressed 7. Lambertiana. 

Cones less than 25 cm. long. , 

Cone-scales prominently convex. 

Leaves less than 7 cm. long 8. parviflora. 

Leaves 9-12 cm. long 9. peuce. 

Leaves 12-18 cm. long 10. excelsa. 

Cone-scales thin, conforming to the surface of the cone. 

Cone relatively longer, its phyllotaxis ^ 11. monticola. 

Cone relatively shorter, its phyllotaxis -j^ 12. strobus. 

6. PINUS AYACAHUITE 

1838 P. AYACAHUITE Ehreubcrg in Linnaea, xii. 492. 

1848 P. STROBiFORMis Engclmanu in Wislizenus, Tour Mex. 102. 

1857 P. Veitchii Roezl, Cat. Graines Conif. Mex. 32. 

1858 P. BoNAPARTEA Roezl in Gard. Chron. 358. 
1858 P. LouDONiANA Gordon, Pinet. 230. 

Spring-shoots glabrous or pubescent. Leaves from 10 to 20 cm. long, serrulate, their stomata 
ventral only, their resin-ducts external, often numerous. Cones from 25 to 45 cm. long, pendent on 
long stalks, subcylindrical or tapering, often curved; apophyses pale nut-brown, dull or sub-lustrous, 
varying much in thickness, prolonged in various degrees, the prolongations patulous, reflexed, 



I 




PLATE IX. P. FLEXILIS (93-95), ARMANDI (9&-99) 



82 GENUS PINUS 

recurved or revolute; seeds of the southern typical form with a long wing, the wing diminishing 
and the nut increasing in relative size northward. 

The White Pine of Mexico and Guatemala grows on mountain-slopes and at the head of ravines. 
It is not very hardy in cultivation except in the milder parts of Great Britain and in northern Italy, 
where the forms of central and northern Mexico have been very successful. The species is best recog- 
nized by the prolonged apophyses of its large cone. 

The variations in the size of the cone and in the prolongations of its scales are many, but of far 
more significance is the remarkable variation of the seed-wing, which is long in the southern part 
of the range, short and broad in central Mexico, and rudimentary, like the seed of P. flexilis, in the 
north. This makes it possible to establish two well defined varieties Veitchii and brachyptera. 
The three forms of the species present a gradation from the long effective wing of the Strobi to the 
rudimentary form of the Flexiles. Many of the seed-wings of the var. Veitchii correspond, in their 
short broad form and opaque coloring, with the characteristic wing of P. Lambertiana. 
Plate X. (leaves and cones much reduced). 

Fig. 103, Cone and cone-scale of var. Veitchii. Fig. 104, Cone and seed of var. brachyptera. 
Fig. 105, Cone-scale of the typical form. Figs. 106, 107, Leaf-fascicles and magnified leaf- 
sections. 

7. PINUS LAMBERTIANA 

1827 P. Lambektiana Douglas in Trans. Linn. Soc. xv. 497. 
Spring-shoots pubescent. Leaves from 7 to 10 cm. long, serrulate; stomata dorsal and ventral; 
resin-ducts external or with one or two ventral medial ducts. Cones from 30 to 50 cm. long, pendent, 
subcylindrical, tapering to a rounded apex; apophyses pale nut-brown, thick, a narrow border of 
the under surface showing on the closed cone, the margin rounded or tapering to a blunt slightly 
reflexed tip ; seed with a large nut and a broad short opaque wing. 

The Sugar Pine is the tallest of the genus and attains a height of 50 or 60 metres. It grows on 
mountain slopes and the sides of ravines. Its southern limit is in Lower California on the plateau 
of San Pedro Martir, its northern limit is in western Oregon. The wood is valuable, its nuts are 
eaten by native Indians, and the sweet exudation, which gives the tree its popular name, is a manna- 
like substance of some oflBcinal value. P. Lambertiana is recognized by its long cone and by the 
constant dorsal stomata of its leaves. 

Plate X. (leaves and cone much reduced). 

Fig. 100, Cone and seed. Fig. 101, Conelet. Fig. 102, Leaf-fascicle and magnified leaf- 
section. 

8. PINUS PARVIFLORA 

1784 P. CEMBRA Thunberg, Fl. Jap. 274. (not Linnaeus). 

1842 P. PARVIFLORA Siebold and Zuccarini, Fl. Jap. ii. 27, t. 115. 

1890 P. PENTAPHYLLA Mayr, Mon. Abiet. Jap. 78, 94, t. 6. 

1908 P. MORRisoNicoLA Hayata in Gard. Chron. ser. 3, xliii. 194. 

1908 P. FORMOSANA Hayata in Jour. Linn. Soc. xxxviii. 297, t. 22. 

Spring-shoots pubescent or glabrous; branches becoming studded with prominent resin-cells of 
the cortex. Leaves from 3 to 8 cm. long, slender, serrulate; stomata ventral only; resin-ducts external 
and dorsal. Cones subsessile, often persistent, from 5 to 10 cm. long, patulous or horizontal, short- 
ovate, or elongate and slightly conical; apophyses nut-brown, abruptly convex near the apex, or 
irregularly warped, varying much in size, the umbo confluent with the thin margin of the scale and 
resting on the apophysis beneath; seeds with a large nut and a short broad wing, often temporarily 
adherent to the cone-scale and breaking apart at the fall of the nut. 

A tree of the mountains of Japan and Formosa, cultivated extensively. It is recognized by its very 
short quinate leaves and by its nearly sessile cones. The frequent but not invariable retention of 




PLATE X. P. LAMBERTIANA (100-102), AYACAHUITE (103-107) 



84 GENUS PINUS 

the seed-wing in the cone is due to adhesion. Many seeds fall with their wings intact, others break 
away from the wing which, after a while, loosens and also falls. 
Plate XI. 

Figs. 114, 115, Three cones and seed. Fig. 116, Leaf -fascicle and magnified leaf -section. 

9. PINUS PEUCE 

1844 P. PEUCE Grisebach, Spicil. Fl. Rumel. ii. 349. 

1865 P. EXCELSA Hooker in Jour. Linn. Soc. viii. 145. (not Wallich). 

Spring-shoots glabrous. Leaves from 7 to 10 cm. long, erect, serrulate; stomata ventral only; 
resin-ducts external. Connective of pollen-sacs small and narrow. Cones deciduous, from 8 to 15 cm. 
long, subcylindrical, often curved, the peduncle short; apophyses tawny yellow, prominently and 
abruptly convex, the umbo against the scale beneath; seed- wing long. 

A tree of the Balkan Mountains, very hardy and bearing abundant fruit in the gardens of both 
hemispheres. The cone resembles that of P. excelsa, but is prevalently much shorter and with a rela- 
tively shorter peduncle. Its leaves are also much shorter and are always erect. A curious difference 
is found in the connectives of the pollen-sacs, small in pence (fig. 113), large in excelsa (fig. 110). 
The convexity of its apophyses distinguishes the cone from those of P. monticola and P. strobus. 
Beissner followed Hooker and named this species excelsa, var. peuce, in the first edition of his 
Handbuch (1891), but in the second edition he restored the Balkan Pine to specific standing. 

Plate XI. 

Fig. Ill, Cone and seed. Fig. 112, Leaf -fascicle and magnified leaf -section. Fig. 113, Pollen:i 

sacs and connective magnified. 

10. PINUS EXCELSA 

1824 P. EXCELSA Wallich ex Lambert, Gen. Pin. ii, 5, t. 3. 

1845 P. NEPALENSis De Chambray, Arbr. Resin. 342. 

1854 P. Griffithii McClelland in Griffith, Notul. PI. Asiat. iv, 17; Icon. PI. Asiat. t. 365. 

Spring-shoots glabrous. Leaves from 10 to 18 cm. long, drooping, serrulate; stomata ventral only; 
resin-ducts external but often with a medial ventral duct. Connective of the pollen-sacs large. Cones 
from 15 to 25 cm. long, narrow-cylindrical; apophyses tawny yellow or pale fulvous brown, promi- 
nently convex, the umbo against the apophysis beneath; seeds with a long wing. 

A tree with gray-green drooping foliage, found, with some interruptions, along the Himalayas. 
It furnishes resin, tar and wood of considerable value. It is cultivated in all temperate climates and 
is a familiar tree of American and European gardens. Madden states that the foliage of P. excelsa is 
sometimes erect and is occasionally bright green. Such variations are often met in other species of 
Pinus. Usually the drooping gray-green foliage and the peculiar cone are sufficient for the recognition 
of this species. The not infrequent presence of a medial duct and the large connective are valuable 
aids for identifying it. 

Plate XI. 
Fig. 108, Cone and seed. Fig. 109, Leaf-fascicle and magnified section of two leaves. Fig. 

110, Pollen-sacs and connective magnified. 

11. PLNUS MONTICOLA 

1837 P. MONTICOLA Douglas ex Lambert, Gen. Pin. iii. t. 
1884 P. PORPHYROCARPA Lawson, Pinet. Brit. i. 83, ff. 

Spring-shoots pubescent. Leaves from 4 to 10 cm. long, serrulate; stomata ventral or rarely with 
a few dorsal stomata; resin-ducts external. Cones from 10 to 25 cm. long, cylindical or tapering, 
sometimes curved; apophyses brown-ochre or fulvous brown, thin, smooth, conforming to the sur- 
face of the cone, the apex sometimes slightly prolonged and reflexed, the umbo not quite touching the 
surface of the scale below. 




PLATE XI. P. EXCELSA (108-110). PEUCE (111-113). PARVIFLORA (114-110) 



S8 GENUS PDSrUS 

The western White Pine grows in southern British Columbia and on Vancouver Island, on the 
Rocky Mountains of Montana and Idaho, in Washington, on the Blue Mountains, Cascades and 
Coast Range of Oregon, across northern California and along the Sierras to the mountains of south- 
em California. Where it is abundant and accessible it furnishes valuable timber. It is hardy in New 
England and in northern and central Europe. 

It differs from P. strobus in the higher phyllotaxis of its cone, an obvious difference that may be 
seen by comparing cones of the two species of the same length (figs. 117, 119), the number of scales 
on the cone of P. monticola being much greater than that on the cone of P. strobus. Nuttall (Sylva, 
iii, 118) followed Hooker in considering it to be a variety of P. strobus. 

Plate XII. 

Fig. 117, Cone and cone-scale. Fig. 118, Leaf -fascicle and magnified leaf -section. 

12. PINUS STROBUS 

1753 P. STROBUS Linnaeus, Sp. PI. 1001. 

1855 P. NiVEA Booth ex Carrifere, Trait. Conif. 305. 

1862 P. ALBA-CANADENSis Provauchcr, Fl. Canad. ii. 554. 

1903 Strobus strobus Small, Fl. Southeast. U. S. 29. 

Spring-shoots pubescent. Leaves from 6 to 14 cm. long, serrulate; stomata ventral only; resin- 
ducts external. Cones from 8 to 24 cm. long, narrow cylindrical, sometimes curved; apophyses 
fulvous brown, or rufous brown, thin, the smooth or slightly rugose surface conforming to the general 
surface of the cone; seed with a long wing. 

A valuable timber-tree of singular beauty and rapid growth. The northern limit of its range ex- 
tends from Newfoundland to Manitoba; it grows throughout the northern states from Minnesota 
to the Atlantic, and, south of Pennsylvania, along the Appalachians to northern Georgia. Its trac- 
table and reliable wood, its adaptability to various soils and climates, its early maturity and stately 
habit, recommend it to the forester and gardener. 

Mature trees of P. strobus tower above the evergreens associated with it. It is also recognized by 
the color and horizontal massing of its foliage. The cone, when closed, is very narrow; its thin flat 
scales distinguish it from the cone of P. pence, and its phyllotaxis from the cone of P. monticola. To 
illustrate the possibilities of variation in the size of Pine cones, I once collected several in Tamworth, 
N. H., on the estate of Mr. Augustus Hemenway, on the same slope and within an area of one 
square kilometre. These cones varied in length from 6 to 24 cm., with all intermediate sizes. Also 
on each tree were cones of various lengths, but the longest were confined to two or three trees among 
the several hundred examined. Dimensions of leaves also varied with individual trees; not infre- 
quently the leaves of a tree were twice the length of those of an adjacent tree. Such variations ap- 
pear in many species and in many localities. 

Plate Xn. 

Fig. 119, Two cones. Fig. 120, Leaf -fascicle. Fig. 121, Magnified leaf -section. Fig. 122, 
Conelets. Fig. 123, A cultivated tree in Massachusetts. 

Paracembra 

Umbo of the cone-scale dorsal. Scales of the conelet mucronate or aristate. Epiderm and hypo- 
derm of the leaf similar, appearing as a single tissue; resin-ducts external. Pits of the ray-cells small. 

The wood of this subsection differs from that of other species, except that of P. pinea, in the Picea- 
like characters of the medullary rays tracheids with smooth walls combined with the thick walls 
and small pits of the ray -cells. On the character of the seeds the species may be divided into three 
groups. 

Seeds wingless IV. . Cembroides. 

Seeds with a short, ineffective, articulate wing V. . . Gerardianae. 

Seeds with a long and effective wing VI. . Balfourianae. 




PLATE XU, P. MONTICOLA (117, 118). STEOBUS (119-123) 



88 GENUS PINUS 

IV. CEMBROroES 

Seeds wingless, the nut large, wholly or partly bare of membranous cover. Cones varying from 
yellow-ochre to deep red-orange in color. 

These are the Nut Pines, growing on the arid slopes and table-lands above the great plateau of 
northern Mexico and its extension into the southwestern United States. There are three distinct 
species. 

Leaves entire, the sheath deciduous. 

Cones subglobose, subsessile 13. cembroides. 

Cones cylindrical, pedunculate 14. Pinceana. 

Leaves serrulate, the sheath persistent 15. Nelsonii. 

13. PINUS CEMBROIDES 

1832 P. CEMBROIDES Zuccarini in Abh. Akad. MUnch. i. 392. 
1838 P. Llaveana Schiede in Linnaea, xii. 488. 

1845 P. MONOPHYLLA Torrey in Fremont's Rep. 319, t. 4. 

1847 P. Fremontiana Endlicher, Syn. Conif. 183. 

1848 P. EDULis Engelmann in Wislizenus, Tour. Mex. 88. 

1848 P. OSTEOSPERMA Engelmann in Wislizenus, Tour. Mex. 89. 

1862 P. Parryana Engelmann in Am. Jour. Sci. ser. 2, xxxiv. 332 (not Gordon). 

1897 P. QUADRiFOLiA Sudworth, Bull. 14, U. S. Dep. Agric. 17. 

1903 Caryopitys edulis Small, Fl. Southeast. U. S. 29. 

Spring-shoots pruinose. Leaves from 2 to 6 cm. long, in fascicles of 1 to 5, the sheath-scales revo- 
lute at the apex, then deciduous; stomata ventral, or ventral and dorsal; resin-ducts external. Scales 
of the conelet armed with a minute prickle. Cones from 4 to 6 cm. long, subglobose, subsessile; 
apophyses lustrous ochre-yellow, crowned with a quadrilateral umbo bearing the minute prickle of 
the conelet; seed flaxen yellow when fresh, its testa bare, the spermoderm adnate to the cone-scale. 

A broad tree with a round head, similar in size and form, but not in ramification, to the cultivated 
Apple-tree; growing on arid slopes and table-lands. Its eastern limit is in southwestern Wyoming, 
central Colorado, Texas, western Tamaulipas and northwestern Vera Cruz. It ranges over Utah, 
Nevada, Arizona and the northern states of Mexico to the southern Sierras of California and to the 
northern and southern extremities of Lower California. It is recognized by its small cone, which 
expands, when open, into an irregular flat aggregate of loosely attached scales. The leaves are 
shorter than those of the other Pines of this group. 

The cone of this species always retains its peculiar character. The variations are mainly in the 
number of leaves in the fascicle. On this character this Nut Pine is divided by many authors into 
four species cembroides, with three slender leaves edulis, with two stout leaves ^ monophylla, 
with one leaf and Parryana, with four stout leaves. But there are intermediate forms that 
may be either cembroides or edulis, edulis or monophylla etc., and Voss's reduction of the four to a 
single species with three varieties seems to be justified (Mitt. Deutsch. Dendrol. Ges. xvi. 95). 
Plate XIII. 

Fig. 130, Cone, cone-scale and seed. Fig. 131, Open cone. Fig. 132, Branchlet with leaves 
and magnified leaf-section. 

14. PINUS PINCEANA 

1846 P. CEMBROIDES Gordon in Jour. Hort. Soc. Lond. i. 236, f. (not Zuccarini). 
1858 P. Pinceana Gordon, Pinet. 204. 

1882 P. LATisQTJAMA Engelmann in Gard. Chron. ser. 2, xviii. 712. f. 125 (as to cone only). 

Spring-shoots slender, pruin ose. Leaves in fascicles of three, the sheath revolute at the base, then 
deciduous; stomata ventral, or ventral and dorsal; resin-ducts external. Scales of the conelet mi- 
nutely mucronate. Cones from 6 to 9 cm. long, cylindrical, pendent on long peduncles; apophyses 




PLATE XIU. P. NELSONII (124-126). PINCEANA (127-129), CEMBROIDES (130-132) 



40 GENUS PINUS 

lustrous ochre-yellow, elevated in the centre, the umbo usually retaining the small prickle; seed 
large, bearing on its dorsal surface remnants of the spermoderm. 

A small bushy tree with long slender branchlets, clear gray cortex, persistently smooth except on 
the lower part of the trunk, and glaucous-green foliage. It grows along water-courses, dry in autumn 
and winter, from southern Coahuila to central Hidalgo, and is associated with P. cembroides, from 
which it may be distinguished by its longer leaves and much longer cylindrical cone. 

Plate XIII. 

Fig. 127, Cone, cone-scale and seed. Fig. 128, Branchlet with leaves. Fig. 129, Magnified 
leaf -section. 

15. PINUS NELSONII 

1904 P. Nelsonii Shaw in Gard. Chron. ser. 3, xxxvi. 122, f. 49. 
Spring-shoots slender, pruinose; branchlets very pliant and tough, summer-shoots abundant. 
Leaves with a persistent sheath, from 6 to 9 cm. long, united in threes along a portion of their ventral 
surface into pseudomonophyllous fascicles, serrulate on the two margins of the dorsal surface, entire 
on the ventral margin; stomata dorsal and with one row along the free portion of each ventral face. 
Conelets usually, if not always, pseudolateral by reason of the summer growth of the branchlets, and 
attaining in their first season an unusually large size. Cones from 6 to 12 cm. long, on very long 
stout and curved peduncles, cylindrical, deciduous by an articulation between the cone and its 
peduncle, leaving the latter for several years on the tree; apophyses dark lustrous orange-red, rugose, 
elevated along a sharp transverse keel, the umbo obscurely defined, the mucro usually broken away; 
nuts large, flaxen yellow, the spermoderm adnate to the cone-scale. 

A small bushy tree with long pliant branches, clear gray cortex all over the limbs and trunk, and 
sparse gray-green foliage. It grows, together with P. cembroides, on the lower slopes of the north- 
eastern Sierras of Mexico, near the boundary between the states of Tamaulipas and Nuevo Leon. 
It is apparently confined to a small area near the latitude of the city of Victoria, the capital of 
Tamaulipas, where its nuts are often exposed for sale. 

In many characters this species is unique. It can be recognized at once by the connate leaves that 
form the fascicle or by the remarkable stout curved peduncle of its cone. Such seeds as I have 
seen differ from those of P. cembroides by a reddish area at one end, but this can be seen with fresh 
seeds only. 

Plate XIII. 

Fig. 124, Cone, cone scale and seed. Fig. 125, Branchlet with leaves. Fig. 126, Magni- 
fied section of a leaf-fascicle. 

V. GERABDIANAE 

Seeds with a very short ineffective articulate wing. Leaves in fascicles of 3, serrulate, the sheath 
deciduous. Bark exfoliating in large scales, leaving parti-colored areas. 

These Asiatic Nut Pines are alike in leaf and cortex as well as in the peculiar seed-wing. The last 
often remains in the cone after the nut falls. The mechanical nature of this adhesion is apparent in 
P. Gerardiana, where the wing adheres not to its own, but to the adjacent scale. The two species 
are alike in their leaves but distinct in their cones and seeds. 

Cones smaller, the nut short-ovate 16. Bungeana. 

Cones larger, the nut long-cylindrical 17. Gerardiana. 

16. PINUS BUNGEANA 

1847 P. Bungeana Zuccarini ex Endlicher, Syn. Conif. 166. 
Spring-shoots glabrous, summer-shoots common on fruiting branches of young trees. Leaves from 
6 to 10 cm. long, serrulate; stomata dorsal and ventral; resin-ducts external. Conelets subterminal j 




^. <5 



PLATE XIV. P. GERARDIANA (133-137). BUNGEANA (13-142) 



42 GENUS PmUS 

or often pseudolateral, their scales gradually narrowed into a spine. Cones from 5 to 7 cm. long, 
short-pedunculate, short-ovate; apophyses dull pale nut-brown, elevated along a transverse keel, the 
dark brown umbo forming a spine with a broad base; seeds with a short loosely attached wing, some- 
times remaining in the cone when the short-ovate nut falls. 

A tree cultivated about the temples of China and recently found by Wilson growing on the 
mountains of Hupeh. The earlier parti-colored bark changes to chalky white on old trunks, by which 
the tree is recognized from a great distance. The stem of the tree is often multiple by the vertical 
growth of some of the lower branches. It is very hardy and is cultivated in Europe and America, 
although these cultivated trees are not yet of suflScient age to show the remarkable white trunk. 

Plate XIV. 

Fig. 138, Cone and cone-scale with adhering wing. Fig. 139, Seed and wing. Fig. 140, 
Leaf-fascicle and magnified leaf-section. Fig. 141, Parti-colored bark. Fig. 142, Tree with 
white trunk. 

17. PINUS GERARDIANA 

1832 P. Gerardiana Wallich ex Lambert, Gen. Pin. ed. 8vo, ii. t. 79. 
Spring-shoots glabrous. Leaves from 6 to 10 cm. long, serrulate; stomata dorsal and ventral; 
resin-ducts external. Scales of the conelet armed with a short spine. Cones from 9 to 15 cm. long, 
short-pedunculate, ovoid or oblong; apophyses fulvous brown, very thick, with a prominent reflexed 
or erect protuberance culminating in an umbo on which the spine is more or less persistent; nuts 
remarkably long, narrow, terete, the shell fragile, the short wing falling with the nut or adhering to 
the adjacent scale. 

A tree of the northwestern Himalayas foimd on the borders of Cashmere and Thibet and in Kafir- 
istan and north Afghanistan, and so highly prized for its nuts that it is rarely felled for its wood. 
It grows in dry regions and rarely attains a height of 20 metres. Attempts to cultivate this species, 
even in the milder parts of Great Britain, have generally failed. 

The apophysis of the cone varies much in prominence (figs. 134, 135), but the peculiar seed is 
invariable and quite unlike that of any other Pine. The general color of the trunk at a distance 
is silver-gray. 

Plate XIV. 

Fig. 133, Cone. Fig. 134, Cone-scale with adhering seed-wing. Fig. 135, Cone-scale of 
flatter form. Fig. 136, Seed and wing. Fig. 137, Leaf-fascicle and magnified leaf-section. 

VI. BALFOURIAXAE 

Seeds with long effective wings. Leaves entire, in fascicles of 5, the sheath deciduous. 

The two species known as Foxtail Pines are alike in their short entire falcate leaves, persisting for 
many years and forming long dense foliage-masses. They differ in the armature of their cones and 
in their seed- wings. The presence of both adnate and articulate wings in these closely related species 
suggests that these two forms of wing are not fundamentally distinct. 

Cone-scales short-mucronate, the seed-wing adnate 18. Balfouriana. 

Cone-scales long-aristate, the seed- wing articulate 19. aristata. 

18. PINUS BALFOURIANA 

1853 P. Balfotibiana Balfour in Bot. Exp. Oregon, 1, f. 
Spring-shoots somewhat puberulent. Leaves from 2 to 4 cm. long, persistent for many years; 
stomata ventral only; resin-ducts external. Scales of the conelet short-mucronate. Cones from 7 to 
12 cm. long, tapering to a rounded apex, short-pedunculate; apophyses dark terracotta-brown, 
tumid, the umbo bearing a short recumbent prickle; seed with a long adnate wing. 



I 




PLATE XV. P. ARISTATA (143-146), BALFOURIANA (147-150) 



44 GENUS PINTS 

An alpine species growing often at the timber-limit. It is found in two distinct stations in Califor- 
nia, on the northern Coast Range and on the southern Sierras. It is not often cultivated, but young 
plants may be seen in the Arnold Arboretum and in the Royal Gardens at Kew. 
Plate XV. 

Fig. 147, Cone, seed and enlarged cone-scale. Fig. 148, Leaf-fascicle. Fig. 149, Magnified 
leaf-section. Fig. 150, A branch with persistent leaves. 

19. PINUS ARISTATA 

1862 P. ARISTATA Engelmann in Am. Jour. Sci. ser. 2, xxxiv. 331. 
1871 P. Balfouriana Watson in King's Rep. v. 331 (not Balfour). 

Spring-shoots glabrous or temporarily pubescent. Leaves from 2 to 4 cm. long, persistent for many 
years; stomata ventral only; resin-ducts external. Scales of the conelet prolonged into long slender 
bristles. Cones from 4 to 9 cm. long, subcylindrical or tapering to a rounded apex, short-peduncu- 
late; apophyses terracotta or purple-brown, tumid, the long bristles of the umbo often partly or 
wholly broken away; seeds with a long articulate wing. 

A bushy tree, similar in foliage to the preceding species, growing at the timber-limit from Colorado 
through Utah, central and southern Nevada and northern Arizona into southeastern California, but 
separated from the nearest station of P. Balfouriana by an arid treeless desert. Engelmann (in 
Brewer and Watson, Bot. Calif, ii. 125) considered it to be a variety of P. Balfouriana. 
Plate XV. 

Fig. 143, Cone. Fig. 144, Seed and enlarged cone-scale. Fig. 145, Leaf-fascicle and mag- 
nified leaf-section. Fig. 146, Conelet. 

DIPLOXYLON 

Bases of the bracts subtending leaf-fascicles decurrent. Leaves serrulate; fibro-vascular bundle 
double; stomata dorsal and ventral. Cones with a dorsal umbo, the phyllotaxis complex. Wood 
hard, with dark resinous bands, the annual rings clearly defined. 

In this section there are a few species combining the essential characters of Diploxylon with 
important characters of Haploxylon. A subsection, Parapinaster, is established for these excep- 
tional species. 

c. Parapinaster .... Species with the fascicle-sheath or seed-wing of Haploxylon. 

d. Pinaster Sheath persistent, seed-wing articulate, eflfective. 

Parapinaster 

Sheath of the leaf -fascicle deciduous VII. . . . Leiophyllae. 

Sheath of the leaf-fascicle persistent. 

Seed-wing of the Strobi VLQ. . . Longifoliae. 

Seed-wing of the Gerardianae IX. . . .Pineae. 

Vn. LEIOPHYLLAE 

Sheath of the leaf-fascicles deciduous. 

Leaves short, erect, the fructification triennial 20. leiophylla. 

Leaves long, pendent, the fructification biennial 21. Lumholtzii. 

20. PINUS LEIOPHYLLA 

1831 P. leiophylla Schlechtendal and Chamisso in Linnaea, vi. 354. 
1848 P. CHIHUAHUANA Engelmann in Wislizenus, Tour. Mex. 103. 



I 




PLATE XVI. P. LEIOPHYLLA (151-154), LUMHOLTZIl (155-159) 



48 GENUS PINUS 

Spring-shoots uninodal. Leaves in fascicles of S, 4 or 5, the sheath deciduous, from 8 to 14 cm. 
long; resin-ducts medial with an occasional internal duct. Conelets single or verticillate, their 
scales mucronate; conelets of the second year only slightly enlarged. Cones maturing the third year, 
not exceeding 7 cm. in length, ovate or ovate-conic, subsymmetrical, more or less reflexed, persistent 
for several years on some trees, sometimes serotinous; apophyses lighter or darker brown, often with 
an olive or fuscous shade, thin or tumid, the umbo double, the mucro more persistent near the apex 
of the cone. 

This species grows at subtropical or warm-temperate altitudes in Mexico, from Oaxaca through 
the central and western states to southern Arizona and New Mexico. As it approaches the northern 
part of its range the leaves become thicker and more rigid and the number in the fascicle is reduced 
to 3 or 4 (var. chihuahuana, Shaw, Pines Mex. 14). Like P. rigida it sprouts freely along the 
branches and trunk, and stumps of felled trees put out shoots in great numbers. The species is easily 
recognized by the deciduous sheath and triennial cone. 

Plate XVI. 

Fig. 151, Branch with fruit of first, second and third years. Fig. 152, Leaf -fascicles. 
Fig. 153, Magnified leaf-section of the spjecies. Fig. 154, Magnified leaf-section of the variety. 

21. PINUS LUMHOLTZII 

1894 P. LuMHOLTZii Robinson & Femald in Proc. Am. Acad. xxx. 122. 
Spring-shoots uninodal, sometimes multinodal. Leaves in fascicles of 3, the sheath deciduous, 
from 20 to 30 cm. long, absolutely pendent; resin-ducts medial and internal. Conelets subterminal, 
or lateral and subterminal, mucronate. Cones not exceeding 7 cm. in length, symmetrical, pendent 
on slender peduncles, ovate-conic, early deciduous; apophyses sublustrous, nut-brown, tumid at the 
margins, flat on the surface, the umbo large, the mucro rarely persistent. 

A remarkable Pine with long pendent bright green foliage, confined to the western states of 
Mexico and ranging on the mountains from southern Jalisco to the latitude of the city of Chihuahua. 
Each season's growth of leaves hangs from the branchlet like a long beard, from which the tree 
receives, in some localities, the name "Pino barba caida. " In the herbarium the long leaves, decidu- 
ous sheaths, and the decurrent bases of the bracts, present a combination of characters not found in 
other species. 

Plate XVI. 

Fig. 155, Cone. Fig. 156, Cone. Fig. 157, Leaf-fascicle. Fig. 158, Magnified leaf-section. 
Fig. 159, Tree at Ferraria de Tula. 

Vin. LOXOIFOLIAE 

Seed-wing adnate to the nut. Leaves long, in fascicles of 3, the sheath persistent. 

Apophysis of the cone prolonged and reflexed 22. longifolia. 

Apophysis of the cone low-pyramidal 23. canariensis. 

22. PINUS LONGIFOLIA 

1803 P. LONGIFOLIA Roxburgh ex Lambert, Gen. Pin. i. 29, t. 21. 
1897 P. RoxBURGHii Sargent, Silva N. Am. xi. 9. 

Spring-shoots uninodal. Leaves in fascicles of 3, the sheath persistent, from 20 to 30 cm. long; 
resin-ducts external, the hypoderm often in large masses, some or all of the endoderm cells with thick 
outer walls. Cones from 10 to 17 cm. long, short-pedunculate, ovoid-conic; apophyses lustrous 
brown-ochre or fuscous brown, elevated into thick, often reflexed, beaks with obtuse mutic umbos; 
seeds with large nuts and adnate striated dark gray or fuscous brown wings. 




PLATE XVn. P. LONGIFOLIA (160-162). CANAIOENSIS (163-165) 



48 GENUS PINUS 

Of the three Pines of the Himalayas this species is the most important. It grows on the outer 
slopes and foot-hills from Bhotan to Afghanistan. The wood is used for construction and for the 
manufacture of charcoal, the thick soft bark is valuable for tanning, the resin is abundant and 
of commercial importance, and the nuts are gathered for food. The tree is not hardy in cool-tem- 
perate climates, but has been successfully grown in northern Italy. 

It differs from P. canariensis in the usually protuberant apophysis of the cone, in the thick outer 
walls of the leaf-endoderm and in the nearly smooth walls of the ray-tracheids of the wood. In 
the dimensions of cone and leaf, in the dermal tissues and resin-ducts of the leaf and in the peculiar 
coloring of the seed-wing, the two species are alike. 

Plate XVII. 

Fig. 160, Cone. Fig. 161, Leaf-fascicle. Fig. 162, Magnified leaf-section. 

23. PINUS CANARIENSIS 

1825 P. CANARIENSIS Smith in Buch, Canar. Ins. 159. 
Spring-shoots uninodal, pruinose. Bud-scales with conspicuously long free fimbriate margins. 
Leaves in fascicles of 3, the sheath persistent, from 20 to 30 cm. long; the hypoderm often in large 
masses, the resin-ducts external, the endoderm with thin outer walls. Cones from 10 to 17 cm. long, 
short-pedunculate, ovoid-conic; apophyses lustrous or sublustrous nut-brown, more or less pyram- 
idal, the umbo unarmed; seeds as in the last species. 

A species confined to the Canary Islands, but cultivated in northern Italy. The stately habit of 
this tree is seen in Schroter's portrait (Exc. Canar. Ins. t. 15). 

Plate XVII. 

Fig. 163, Cone and seed. Fig. 164, Magnified leaf-section. Fig. 165, Habit of the tree. 

IX. PIXEAE 

Seed-wing articulate, short, ineffective. Leaves binate, the sheath persistent. One species only. 

24. PINUS PINEA 

1753 P. PINEA Linnaeus, Sp. PI. 1000. 

1778 P. SATiVA Lamarck, Fl. Frang. ii. 200. 

1854 P. MADERiENSis Tcnorc in Ann. Sci. Nat. s6r. 4, ii. 379. 

Spring-shoots uninodal. Leaves from 12 to 20 cm. long; resin-ducts external. Conelet mutic, 
slightly larger in the second year. Cones triennial, from 10 to 14 cm. long, ovoid or subglobose ; 
apophyses lustrous nut-brown, convex, of large size, the umbo double ; seeds large with a short, 
loosely articulated, deciduous wing. 

A species of the Mediterranean Basin, from Portugal to Syria. Its northern limit is in southern 
France and northern Italy, but it is cultivated in the southern parts of the British Isles and is a 
familiar ornament of park and garden in southern Europe, and is valued for its peculiar beauty and 
for its large savory nuts. In wood anatomy as well as in the seed it agrees with the Gerardianae 
of the Soft Pines. 

Plate XVIII. 

Fig. 166, Fruit of three seasons. Fig. 167, Cone-scales and seed. Fig. 168, Magnified leaf- 
section. Fig. 169, Habit of the tree. 




PLATE XVni. PINUS PINEA 



50 GENUS PINUS 

Pinaster 

Bases of the bracts subtending leaf-fascicles decurrent. Seeds with an effective articulate wing. 
Umbo of the cone-scales dorsal. Leaves serrulate, stomatiferous on all faces, the sheath persistent. 
Walls of the tracheids of the medullary rays dentate. 

Forty-two of the sixty-six species of Pinus are included in this subsection. As a group they are 
clearly circumscribed by several correlated characters and are more closely interrelated than the 
twenty-four species previously described. The distinctions of umbo and seed have disappeared. 
The umbo here is invariably dorsal, the seed-wing invariably articulate. 

New forms, however, are gradually evolved the seed with a thick wing-blade, the indurated 
oblique cone, the serotinous cone with its intermittent seed-release, and the multinodal spring-shoot. 
There are, moreover, new forms of leaf-hypoderm and a new position of the resin-duct. 

Of these new characters, the thick wing-blade attains such proportions in the three species of the 
Macrocarpae that they can be grouped apart. But the characters that finally culminate in a lateral 
oblique serotinous cone are so gradually and irregularly developed that they offer no divisional dis- 
tinctions. With the aid of wood and leaf characters, however, groups can be established which pre- 
serve the evolutionary sequence and, at the same time, the obvious affinity of the species. 

Wing-blade thin or slightly thickened at the base. 
Cones dehiscent at maturity. 

Pits of the ray-cells large X. . . .Lariciones 

Pits of the ray-cells small XI. . . Australes 

Cones serotinous, pits of the ray-cells small XII. . . Insignes 

Wing-blade very thick XIII. .Macrocarpae 

The species of this subsection are very difficult, if not impossible, to classify by the usual method, 
which groups all species under a few characters assumed to be invariable and of fundamental impor- 
tance. Such a method can be successfully applied to the Soft Pines and to some of the Hard Pines, 
but cannot be applied to all the Hard Pines without forcing some of them into unnatural associations. 

To take an example, the group Pseudostrobus, characterized by pentamerous leaf -fascicles, appears 
in many systems. In this group are placed P. Torreyana and P. leiophylla. Another group, with 
trimerous fascicles, contains P. Sabiniana and P. taeda. Now there are no two species more obviously 
related by important peculiarities than P. Torreyana and P. Sabiniana; nevertheless they are, by this 
method, kept apart and associated with species which they resemble in no important particular. 

An attempt is made here to avoid such incongruities. Groups X, XI and XII represent different 
stages of evolution. In the Lariciones the cone is symmetrical, and dehiscent and deciduous at 
maturity, while the spring-shoot is uninodal. In the Australes there is a similar cone, but the spring- 
shoot gradually becomes multinodal. In the Insignes the cone is oblique, persistent and serotinous, 
and the spring-shoot is multinodal. 

These definitions state the degree of evolution attained by each group, but not all the species of a 
group conform exactly with its definition. In each group are species with a characteristic of another 
group. Among the Lariciones are a few species with both symmetrical and oblique cones, and two 
with persistent cones. Similar exceptions occur among the Australes. Among the Insignes are a few 
species with symmetrical cones, and two with cones that are rarely, if ever, serotinous. 

There is, however, no difficulty in fixing the systematic position of these exceptional species 
through other characters which show their true affinity. They are placed with the species which 
they most resemble. Their exceptional characters are merely the evidence of the evolution that 
pervades and unites the groups. Therefore the definition of a group is not necessarily the exact 
definition of its species, and a species is placed in a group because all its characters, specific and 
evolutional, show a closer affinity with that group than with the species of any other. 



GENUS PINUS 



<1 



X. LARICIONES 

Pits of the ray-cells large. Cells of the leaf-hypoderm uniform. Spring-shoots uninodal. Cones 
dehiscent at maturity. 

This group represents the first stage in the evolution of the Hard Pines. All the species, like the 
Soft Pines, are uninodal and the cones are dehiscent at maturity, but the trend toward the seroti- 
nous species is shown in the occasional appearance of the oblique cone as a varietal form of a few 
species, and in the persistent cone of the last two species of this group. 

All the species of this group are of the Old World except P. resinosa and P. tropicalis. These two 
are the only American Pines combining large pits with dentate tracheids, and are the only Ameri- 
can Hard Pines with external resin-ducts of the leaf. 

Cones deciduous at maturity. 
Cones ovate or ovate-conic. 

Conelet with tuberculate or entire scales. 

Resin-ducts external and medial 25. resinosa "^ 

Resin-ducts septal and external 26. tropicalis 

Conelet with mucronate scales. 
Resin-ducts mostly external. 
Conelet pedunculate, erect. 

Cone nut-brown 27. Massoniana 

Cone dull tawny yellow 28. densiflora 

Conelet pedunculate, reflexed 29. sylvestris 

Conelet subsessile, erect 30. montana 

Resin-ducts mostly medial. 

Bark-formation late 31. luchuensis 

Bark-formation early. 

Cone nut-brown 32. Thunbergii 

Cone lustrous tawny yellow 33. nigra 

Cones narrow cylindrical 34. Merkusii 

Cones tenaciously persistent. 

Leaves stout, relatively short 35. sinensis 

Leaves slender, relatively long 36. insularis 



25. PINUS RESINOSA 

1789 P. RESINOSA Aiton, Hort. Kew. iii. 367. 

1810 P. RUBRA Michaux f. Hist. Arbr. Am. i. 45, t. 1. 

Spring-shoots uninodal. Leaves binate, from 12 to 17 cm. long; resin-ducts external or external 
and medial; hypoderm uniform and inconspicuous. Scales of the conelet mutic. Cones from 4 to 6 
cm. long, subsessile, symmetrical, deciduous the third year, leaving a few basal scales on the tree; 
apophyses sublustrous, nut-brown, somewhat thickened along a transverse keel. 

From Nova Scotia and Lake St. John this species ranges westward to the Winnipeg River and 
southward into Minnesota, Michigan, northern New York and eastern Massachusetts, with rare 
occurrence on the mountains of Pennsylvania. Under cultivation it is a beautiful tree, adapted to 
cold-temperate climates. It was considered by Loiseleur (1812) and by Spach (1842) to be a vari- 
ety of P. nigra (laricio). The two species vary in the color of the cone, the anatomy of the leaves, 
the buds, and in the armature of the conelet. A fallen cone of this species is moreover usually im- 
perfect from the loss of a few basal scales. 



Plate XIX. 

Fig. 170, Cone and enlarged conelet. 



Fig. 171, Leaf -fascicle and magnified leaf -section. 



52 GENUS PINUS 

26. PINUS TROPICALIS 

1851 P. TROPICALIS Morelet in Rev. Hort. C6te d'Or, i. 105. 

1904 P. TERTHROCABPA Shaw in Gard. Chron. ser. 3, xxxv. 179, f. 74. 

Spring-shoots uninodal. Leaves binate, sometimes ternate, from 15 to 30 cm, long, rigid, erect; 
hypoderm of uniform thick- walled cells; resin-ducts of remarkable size, septal, or not quite touching 
the endoderm and technically external. Scales of the conelet minutely tuberculate. Cones from 5 to 
8 cm. long, short-pedunculate, erect or patulous; ovate-conic, symmetrical; apophyses rufous 
brown, low-pyramidal, the umbo mutic. 

Growing at sea-level within the tropics and confined to western Cuba and the Isle of Pines. On 
the island it is associated with P. caribaea. This species needs no other means of identification 
than its peculiar leaf -section. Septal ducts are found in P. oocarpa, Pringlei, Merkusii and rarely 
in other species, but they never attain the extraordinary size that appears to be invariable in 
P. tropicalis. 

Plate XIX. 

Fig. 172, Cone and enlarged conelet. Fig. 173, Branch with leaves, much reduced. 
Fig. 174, Leaf-fascicle and magnified leaf-section. Fig. 175, Trees on the Isle of Pines. 

27. PINUS MASSONIANA 

1803 P. Massoniana Lambert, Gen. Pin. i. 17, t. 12. 

1861 P. CANALiCTJLATA Miquel in Jour. Bot. Neerland. i. 86. 

Spring-shoots uninodal. Leaves binate, rarely ternate, from 12 to 20 cm. long, slender and pliant; 
hypoderm inconspicuous ; resin-ducts external. Staminate catkins often in long dense clusters. Cone- 
lets partly tuberculate or mucronate, partly mutic. Cones symmetrical, from 4 to 7 cm. long, ovate- 
conic, short-pedunculate, early deciduous; apophyses sublustrous, nut-brown, flat or somewhat 
elevated, the umbo usually mutic. 

The Chinese Red Pine is found in warm-temperate climates. It is native to southeastern China 
and follows the valley of the Yangtse River into Szech'uan. It has been confused by Loudon with 
P. pinaster, which it resembles in no respect, by Siebold with P. Thunbergii, from which it differs in 
leaf-dimensions and in leaf-section, and by Mayr with his P. luchuensis, whose peculiar cortex and 
whose leaf-section has no counterpart among Chinese Hard Pines. Its nearest relative is P. densi- 
flora, from which it differs in its longer leaves, in the color of its cone and in its conelet (Plate XX, 
figs. 176, 179). 

Plate XX. 

Fig. 176, Cone and enlarged conelet. Fig. 177, Two leaf-fascicles. Fig. 178; Magnified 
leaf-section. 

28. PINUS DENSIFLORA 

1842 P. DENSIFLORA Siebold & Zuccarini, Fl. Jap. ii. 22, t. 112. 
1854 P. scopiFERA Miquel in Zollinger, Syst. Verz. Ind. Archip. 82. 

Spring-shoots more or less pruinose, uninodal. Leaves binate, from 8 to 12 cm. long, slender; 
hypoderm of few inconspicuous cells; resin-ducts external. Staminate catkins in long dense clusters. 
Scales of the conelet conspicuously mucronate. Cones symmetrical, from 3 to 5 cm. long, ovate- 
conic, often persistent for a few years but with a weak hold on the branch; apophyses dull pale 
tawny yellow, flat or slightly elevated, the mucro more or less persistent. 

The Japanese Red Pine forms extensive fwests on the mountains of central Japan. It is perfectly 
hardy in cold-temperate climates. Wild specimens of China, ascribed to this species, are forms of the 




PLATE XIX. P. RESINOSA (170, 171), TROPICALIS (172-175) 



M GENUS PINUS 

variable P. sinensis. From P. Massoniana it differs in its shorter leaves and yellow cone, but particu- 
larly in the more prominent prickles and thicker scales of its conelet (figs. 176, 179). 

Plate XX. 

Fig. 179, Cones and enlarged conelet. Fig. 180, Leaf -fascicles. Fig. 181, Magnified leaf- 
section and more magnified dermal tissues of the leaf. 

29. PINUS SYLVESTRIS 

1753 P. 8YLVESTBI8 Linuacus, Sp. PI. 1000 (excl. var.). 

1768 P. BUBKA Miller, Gard. Diet. ed. 8. 

1768 P. TATABiCA Miller Gard. Diet. ed. 8. 

1781 P. MUGHUS Jacquin, Icon. PI. Rar. i. t. 193 (not Scopoli). 

1798 P. BESINOSA Savi, Fl. Pisa. ii. 354 (not Aiton). 

1827 P. HUMILI8 Link in Abhandl. Akad. Berlin, 171. 

1849 P. KocHiANA Hotzsch in Linnaea, xxii. 296. 

1849 P. ABMENA Koch in Linnaea, xxii. 297. 

1849 P. PONTiCA Koch in Linnaea, xxii. 297. 

1859 P. Frieseana Wichura in Flora, xlii. 409. 

1906 P. LAPPONiCA Mayr, Fremdl. Wald- & Parkb. 348. 

Spring-shoots uninodal. Leaves binate, from 3 to 7 cm. long; hypoderm inconspicuous; resin- 
ducts external. Conelet reflexed, minutely mucronate. Cones from 3 to 6 cm, long, reflexed, sym- 
metrical or sometimes oblique, ovate-conic, deciduous; apophyses dull pale tawny yellow of a gray 
or greenish shade, flat, elevated or protuberant and often much more prominent on the posterior face 
of the cone, the umbo with a minute prickle or its remnant. 

A tree of great commercial value, with a very extended range, from Norway, Scotland and south- 
ern Spain to northeastern Siberia. A vigorous hardy species and extensively cultivated. The red 
upper trunk, characteristic of this Pine, is not invariable. The dark upper trunk is suflSciently com- 
mon to be considered a varietal form (Mathieu, Flore Forest, ed. 4,582). In various localities may 
be found trees bearing oblique cones, their apophyses showing various degrees of protuberance 
up to the extreme development represented in Loudon's illustration of the variety uncinata (Arb. 
Brit, iv, f . 2047) . This cone is the beginning of the changes that cidminate in species with oblique 
cones only. In P. sylvestris, however, the purpose of this form of cone is not apparent except in 
connection with this evolution. 

Plate XXI. 

Figs. 182, 183, Cones. Fig. 184, Leaf-fascicle, magnified leaf-section and more magnified 
dermal tissues of the leaf. Fig. 185, Habit of the tree. 

SO. PINUS MONTANA 

1768 P. MONTANA Miller, Gard. Diet. ed. 8. 

1772 P. MUGHUS Scopoli, Fl. Cam. ii. 247. 

1791 P. PUMiLio Haenke in Jirasek, Beobacht. 68. 

1804 P. MUGHO Poiret in Lamarck, Encycl. Meth. v. 336. 

1805 P. UNCINATA Ramond ex De CandoUe, Lamarck, Fl. Frang. ed. 3, iii. 726. 
1813 P. SANGUiNEA Lapcyrouse, Hist. PL Pyren. 587. 

1827 P. BOTUNDATA Link in Abhandl. Akad. Berlin, 168. 
1830 P. OBLiQUA Sauter ex Reichenbach, Fl. Germ. Exc. 159. 
1837 P. UUGINOSA Neumann ex Wimmer, Arb. Schles. Ges. 95. 

Spring-shoots uninodal. Leaves binate, from 3 to 8 cm. long, the epiderm very thick, hypoderm 
weak; resin-ducts external. Conelets mucronate, nearly sessile. Cones from 2 to 7 cm. long, subsessile, 
ovate or ovate-conic, symmetrical or oblique, often persistent; apophyses lustrous tawny-yellow or 
dark brown, both colors often shading into each other on the same cone, flat, prominent or prolonged 



O" 



^,/0CO3^o.^ 



\ 






r-^^^ 




178 



I8i 




PLATE XX. P. MASSONIANA (176-178). DENSIFLORA (179-181) 



M GENUS PINUS 

into uncinate beaks of various lengths, the last much more developed on the posterior face of the 
cone, the umbo bordered by a narrow dark ring and bearing the remnant of the mucro. 

P. montana grows as a bush or as a small tree, the two forms often associated. It ranges from central 
Spain through the Pyrenees, Alps and Apennines to the Balkan Mountains, associated with P. cem- 
bra at higher, with P. sylvestris at lower altitudes. It grows indifferently in bogs and on rocky slopes. 
Its dwarf form, under the name of the Mugho Pine, is extensively cultivated as a garden ornament. 

On the differences of the cone this species has been divided into three subspecies : uncinata, with 
an oblique cone and protuberant apophyses; pumilio, with a symmetrical cone and an excentric 
umbo; mughus, with a symmetrical cone and a concentric umbo. Other segregations based on the 
degree of development of the apophysis and on the size and color of the cone, have received names of 
four or even five terms Pinus montana pumilio applanata or Pinus montana uncinata rostrata 
castanea etc., etc. These elaborations may be seen in the Tharand Jahrbuch of 1861, p. 166, and 
with them appear also Hartig's specifications of 60 forms of this species, each dignified with a Latin 
name. 

Plate XXI. 

Fig. 186, Cone of var. uncinata. Figs. 187, 188, Cones. Fig. 189, Leaf-fascicles, magnified 
leaf-section and more magnified dermal tissues of the leaf. Fig. 190, Tree and dwarf-form 
of the Pyrenees. 

31. PINUS LUCHUENSIS 

1894 P. LUCHUENSIS Mayr in Bot. Centralbl. Iviii. 149, f. 
Spring-shoots uninodal. Bark-formation late, the upper trunk covered with a smooth cortex. 
Leaves binate, from 12 to 16 cm. long, the epiderm thick, hypoderm of two or three rows of cells; 
resin-ducts medial or with an occasional external duct. Conelets mucronate toward the apex. Cones 
from 3 to 6 cm. long, ovate-conic, symmetrical; apophyses lustrous nut-brown, transversely carinate, 
the umbo unarmed. 

This Pine is known to me through Mayr's description and a single dried specimen. The smooth 
cortex of young trees distinguishes it from all other east- Asiatic Hard Pines. Mayr includes under 
this species the Pine of Hong Kong. But in this he must be mistaken, for there is no species yet 
found in China that agrees with the description of P. luchuensis. 

Plate XXII. 

Fig. 191, Cone. Fig. 192, Leaf -fascicle and magnified leaf -section. 

32. PINUS THUNBERGIt 

1784 P. SYLVESTRIS Thunberg, Fl. Jap. 274 (not Linnaeus), 

1842 P. Massoniana Siebold & Zuccarini, Fl. Jap. ii. 24, t. 113 (not Lambert). 

1868 P. Thunbergii Parlatore in DC. Prodr. xvi-2, 388. 

Spring-shoots uninodal. Buds of leading-shoots white and conspicuous. Leaves binate, from 6 to 
11 cm. long, the epiderm thick, hypoderm strong, resin-ducts medial. Conelets with short-mucronate 
scales. Cones from 4 to 6 cm. long, ovate or ovate-conic, symmetrical ; apophyses nut-brown, flat or 
convex and transversely carinate, the prickle of the umbo more or less persistent. 

The Black Pine of Japan has been cultivated for centuries, and by skillful Japanese gardeners has 
been trained into dwarf and other curious forms. It is hardy in cold-temperate climates. It is dis- 
tinct from P. densiflora by the medial ducts of its leaf, from P. nigra by the fewer, larger, brown 
scales of its cone, and from P. resinosa by the armature of its conelet. It appears in most determina- 
tions of Chinese collections, but there is no Chinese Pine with the white buds and the medial leaf- 
ducts of this species. 

Plate XXII. 

Fig. 196, Two cones. Fig. 197, Leaf-fascicle and magnified leaf-section. 




PLATE XXI. P. SYLVESTRIS (182-185). MONTANA (188-190) 



58 GENUS PINUS 

SS. PINUS NIGRA 

1785 P. NIGRA Arnold, Reise n. Mariaz. 8, t. 

1804 P. lARicio Poiret in Lamarck, Encycl. M6th. v. 339. 

1808 P. HALEPENSis Bieberstcin, Fl. Taur. Cauc. ii. 408 (not MUler). 

1809 P. PINASTER Besser, Fl. Galic. ii. 294 (not Aiton). 

1813 P. MARiTiMA Aiton, f. Hort. Kew. v. 315 (not Lambert). 

1816 P. SYLVE8TRI8 Baumgartcn, Stirp. Transsilv. ii. 304 (not Linnaeus). 

1818 P. PYRENAiCA Lapeyrouse, Hist. PI. Pyren. Suppl. 146. 

1824 P. Pallasiana Lambert, Gen. Pin. ii. 1, t. 1. 

1825 P. AUSTRiACA Hoss in Flora, viii-1, Beil. 113. 
1831 P. NIGRICANS Host, Fl. Austr. ii. 628. 

1842 P. DALMATiCA Visiani, Fl. Dalmat. 199, note. 

1851 P. Salzmanni Dunal in M6m. Acad. Montp. ii. 82, tt. 

1863 P. Heldreichii Christ in Verb. Nat. Ges. Basel, iii. 549. 

1864 P. LEUCODERMis Antoine in Oesterr. Bot. Zeitschr. xiv. 366. 
1896 P. PiNDiCA Formanek in Verb. Nat. Ver. Briinn, xxxiv. 272. 

Spring-shoots uninodal. Leaves binate, from 9 to 16 cm. long, the epiderm thick, hypoderm con- 
spicuous, resin-ducts medial. Conelets mucronate. Cones from 4 to 8 cm. long, subsessile, symmet- 
rical; apophyses lustrous, tawny yellow, transversely carinate, the keel strongly convex, the mucro 
of the umbo more or less persistent. 

A valuable tree unequally distributed over the mountain slopes of central and southern Europe 
and Asia Minor. The typical form, under the name of the Austrian Pine, is a familiar exotic of the 
Middle and Eastern States of America. As Mathieu states (Flore Forest., ed. 4, 597), this species is 
quite constant in cone and bark. It may be added that the anatomy of the leaf is also constant, while 
the dimensions of both leaf and cone present no unusual variations. The varieties generally accepted 
are founded on the habit of the tree, a character of forestal or horticultural rather than of botanical 
importance. 

Plate XXII. 

Fig. 193, Two cones. Fig. 194, Leaf-fascicle and magnified leaf-section. Fig. 195, Magni- 
fied dermal tissues of the leaf. 

34. PINUS MERKUSn 

1790 P. SYLVESTRis Loureiro, Fl. Cochinch. ii. 579 (not Linnaeus). 

1845 P. Merkusii De Vriese, PI. Nov. Ind. Bat. 5, t. 2. 

1847 P. FiNLAYSONiANA WalHch ex Blume, Rumphia, iii. 210. 

1849 P. Latteri Mason in Jour. Asiat. Soc. i. 74. 

Spring-shoots uninodal. Leaves binate, slender, from 15 to 20 cm. long, the hypoderm of uniform 
thick-walled cells, resin-ducts medial, or with internal or septal ducts, endoderm-cells very unequal 
in size, some of them large. Conelets unarmed. Cones from 5 to 8 cm. long, peculiarly narrow- 
cylindrical, symmetrical; apophyses lustrous, rufous brown, radially carinate, the transverse keel 
prominent. 

Of the habit of this Pine I know nothing. As a species it is very clearly defined by its peculiar cone 
and leaf-section. It grows in the Philippines, Sumatra, Lower Burmah and western Indo-China. 
In my specimen the pits of the ray-cells of the wood are both large and small. In this particular 
it may belong in either of two groups of species. Its uniform leaf-hypoderm associates it with this 
group or with P. halei)ensis of the Insignes. I have assumed the cone to be dehiscent at maturity and 
have placed it with the Lariciones, but if further information shows the cone to be serotinous, this 
species should be transferred to the serotinous group. 

Plate XXm. 

Fig. 198, Cone. Fig. 199, Magnified sections of two leaves. Fig. 200, Leaf-fascicle. 



r 




PLATE XXn. P. LUCHUENSIS (191, 102), NIGKA (193-195), THUNBERGn (196. 197) 



60 GENUS PINUS 

35. PINUS SINENSIS 

1832 P. SINENSIS Lambert, Gen. Pin. ed. 8vo. i. 47, t. 29. 

1867 P. TABtn^AEFORMis Carriere, Trait. Conif. ed. 2, 510. 

1881 P. LEUCOSPERMA Maximowicz in Bull. Acad. St. P^tersb. xxvii. 558. 

1899 P. YUNNANENSis Franchet in Jour, de Bot. xiii. 253. 

1901 P. FUNEBRis Komarow in Act. Hort. Petrop. xx. 177. 

1902 P. Henryi Masters in Jour. Linn. Soc. xxvi. 550. 
1906 P. DENSATA Masters in Jour. Linn. Soc. xxxvii. 416. 
1906 P. PROMiNENS Masters in Jour. Linn. Soc. xxxvii. 417. 
1911 P. WiLSONii Shaw in Sargent, PI. Wilson, i. 3. 

Spring-shoots uninodal, pruinose. Leaves binate, temate, or both, from 10 to 15 cm. long, stout 
and rigid; resin-ducts external, or external and medial. Staminate catkins in short capitate clusters. 
Conelets mucronate. Cones from 4 to 9 cm. long, ovate, symmetrical or oblique, tenaciously persist- 
ent, dehiscent at maturity; apophyses lustrous, pale tawny yellow at first, gradually changing to a 
dark nut-brown, tumid, the posterior scales often larger and more prominent. 

A tree of cold-temperate and subalpine levels, growing on the mountains of central and western 
China, and at lower altitudes in the north and in Corea. It is recognized by its tenaciously persist- 
ent cones with a remarkable change in color. It is constantly confused with P. Thunbergii and P. den- 
siflora, neither of which grows spontaneously in China. From the former it differs in leaf -section and 
bud (the bud of P. sinensis is never white) , from the latter in the lustre and the color variation of its 
cone, and from both in the frequent obliquity of its cone and in the frequent presence of trimerous 
leaf-fascicles. 

Of the two varieties of this species, densata and yunnanensis (Shaw in Sargent, PI. Wilson, ii. 17), 
the former represents the extreme oblique form of cone, the latter represents the longest dimensions 
of cone and leaf. The effect of environment on this species can be seen in figs. 202, 203, from a lower 
slope and rich soil, and fig. 204, from a high rocky ledge in the same locality. 

Plate XXIII. 

Fig. 201, Cone of var. densata. Fig. 202, Cone of var. yunnanensis. Fig. 203, Leaf-fas- 
cicle and magnified leaf-section of var. yunnanensis. Fig. 204, Cone and leaf-fascicle from a 
rocky ledge. Fig. 205, Cone, leaf-fascicle and magnified leaf-section of the typical form. 
Fig. 206, Seeds. Fig. 207, Conelet and its enlarged scale. 

36. PINUS INSULARIS 

1837 P. TAEDA Blanco, Fl. Filip. 767 (not Linnaeus). 

1847 P. INSULARIS Endlicher, Syn. Conif. 157. 

1854 P. KHASIANA Griffith, Notul. PI. Asiat. iv. 18; Icon. PI. Asiat. tt. 367, 368. 

1868 P. KASYA Royle ex Parlatore in DC. Prodr. xvi-2, 390. 

Spring-shoots uninodal, glabrous. Leaves from 12 to 24 cm. long, in fascicles of 3, rarely of 2, very 
slender; resin-ducts external, rarely with a medial duct. Conelets mucronate. Cones from 5 to 10 
cm. long, ovate-conic, symmetrical or oblique, tenaciously persistent; apophyses lustrous, nut-brown, 
convex or elevated along a transverse keel, the posterior scales of some cones larger and more promi- 
nent than the anterior scales, the mucro usually deciduous. 

A species of the Philippines and of northern Burmah. In both countries it is locally exploited for 
wood and resin. It differs from the common form of P. sinensis by its much longer leaves, and from 
its var. yunnanensis, which it more resembles, by its much more slender and pliant leaves. Moreover 
its cone, so far as I can learn, is not yellow at maturity, but brown. 

Plate XXIII. 

Figs. 208, 209, Three cones. Fig. 210, Leaf-fascicle and magnified leaf-section. 




PLATE XXin. P. MERKUSU (198-200), SINENSIS (201-207). INSULABIS (208-210) 



eS GENUS PINUS 

XI. AUSTRALES 

Pits of the ray-cells small. Leaf-hypoderm biform or variable. Spring-shoots uninodal in some, 
multinodal in other species. Cones dehiscent at maturity. 

This group combines the dehiscent cone of the Lariciones with the wood-anatomy of the seroti- 
nous Pines. Also the multinodal spring-shoot first appears here and is gradually developed among 
the species, absent in Nos. 37-39, sometimes present in Nos. 40-43, and prevalent in Nos. 44-47. 

All the species are of the Western Hemisphere, and among them may be found the biform hypo- 
derm of the leaf, the internal resin-duct, and the total absence of external resin-ducts, characters 
common in American Hard Pines. The eastern species are quite constant in their characters and 
present no varietal forms; the western species, on the other hand, are very variable. This difference 
may be due to the even level and slight climatic differences of the Atlantic states and to the remark- 
able diversity of altitude and climate of the western states and Mexico. 

Outer walls of the leaf-endoderm thick. 

Cones large, attaining 12 cm. or more in length. 
Prickles of the cone inconspicuous. 

Bark-formation late 37. pseudostrobus 

Bark-formation early 38. Montezumae 

Prickle of the cone conspicuous 39. ponderosa -^ 

Cones small, 7 cm. or less in length 40. teocote 

Outer walls of the leaf-endoderm thin. 
Spring-shoots mostly uninodal. 

Prickle of the cone slender, sometimes deciduous. 

Cones mostly oblique 41. Lawsonii 

Cones symmetrical 42. occidentalis 

Prickles of the cone stout and persistent 43. palustris v^ 

Spring-shoots multinodal. 

Resin-ducts internal 44. caribaea L/ 

Resin-ducts mostly medial. 

Prickle of the cone stout 45. taeda 

Prickle of the cone slender. 

Bark-formation late 46. glabra '>' 

Bark-formation early 47. echinata ~^ 



37. PINUS PSEUDOSTROBUS 

1839 P. PSEUDOSTROBUS Liudlcy in Bot. Reg. xxv. Misc. 63. 

1839 P. APULCENSis Lindley in Bot. Reg. xxv. Misc. 63. 

1842 P. TENUiFOLiA Bentham, PI. Hartw. 92. 

1846 P. ORiZABAE Gordon in Jour. Hort. Soc. Lond. i. 237, f. 

Spring-shoots uninodal, conspicuously pruinose. Bark-formation late, the cortex of young trees 
smooth. Leaves in fascicles of 5, sometimes of 6, from 15 to 30 cm. long, drooping; resin-ducts 
medial, hypoderm variable in amount, often in very large masses, the outer walls of the endoderm 
thick. Conelets mucronate. Cones from 7 to 14 cm. long, ovate or ovate-conic, symmetrical or 
oblique, deciduous and often leaving a few basal scales on the trees; apophyses rufous or fulvous 
brown, flat, elevated or, in one variety, prolonged in various degrees, the prolongations nearly uni- 
form or much more prominent on the posterior face of the cone, the mucro usually deciduous. 

A species of the subtropical and warm-temperate altitudes of Mexico and Central America. Its 
range includes both eastern and western slopes of the northern plateau. Its northern limit is in 
Nuevo Leon, and it probably reaches in Nicaragua the southern limit of pines in the Western 
Hemisphere. It is distinguished from all its associates by the smooth gray trunk of the young trees, 
by their long internodes, and by their drooping gray -green foliage. 




PLATE XXIV. PINUS PSEUDOSTHOBUS 



64 GENUS PINUS 

Some cones of this species develop protuberances of all degrees of prominence up to the curious 
cone collected in Oaxaca by Nelson (var. apulcensis, Shaw, Pines Mex. t. 12, fig. 8). There is also a 
remarkable difference in the amount of leaf-hypoderm. On many trees of the western part of the 
range this tissue forms septa across the green mesophyll. Such partitions are sometimes met in other 
species, P. Pringlei or P. canariensis, where the hypoderm is abundant. But in P. pseudostrobus they 
appear in some leaves of weak, as well as of strong hypoderm (var. tenuifolia, Shaw, Pines Mex. 1. 13, 
ff. 2, 4, 5, 7, 8). 

Plate XXIV. 

Fig. 211, Cone. Fig. 212, Two cones of var. tenuifolia. Figs. 213, 214, Two cones of var. 

apulcensis. Fig. 215, Magnified section of 3 leaves of var. tenuifolia. Fig. 216, Magnified 

section of 2 leaves of the species. Fig. 217, Bud destined to produce staminate flowers. 

Fig. 218, Ten-year old branch showing smooth cortex. Fig. 219, Young and mature trees in 

open growth. 

38. PINUS MONTEZUMAE 

1817 P. occiDENTALis H. B. & K. Nov. Gen. ii. 4 (not Swartz). 

1832 P. MoNTEZtJMAE Lambert, Gen. Pin. ed. 8vo, i. 39, t. 22. 

1839 P. Devoniana Lindley in Bot. Reg. xxv. Misc. 62. 

1839 P. Hartwegii Lindley in Bot. Reg. xxv. Misc. 62. 

1839 P. RussELLiANA Lindley in Bot. Reg. xxv. Misc. 63. 

1839 P. MACROPHYLLA Lindley in Bot. Reg. xxv. Misc. 63. 

1840 P. FiLiFOLiA Lindley in Bot. Reg. xxvi. Misc. 61. 

1841 P. SiNCLAiHii Hooker & Arnott, Bot. Beechy Voy. 392, t. 93 (as to cone). 
1841 P. RADiATA Hooker & Arnott, Bot. Beechy Voy. 443 (as to leaves). 
1847 P. Grenvilleae Gordon in Jour. Hort. Soc. Lond. ii. 77, f. 

1847 P. Gordoniana Hartweg in Jour. Hort. Soc. Lond. ii. 79, f. 

1847 P. Wincesteriana Gordon in Jour. Hort. Soc. Lond. ii. 158, f. 

1847 P. RUDis Endlicher, Syn. Conif. 151. 

1847 P. Ehrenbergii Endlicher, Syn. Conif. 151. 

1858 P. LiNDLEYANA Gordon, Pinet. 229, 

1891 P. Donnell-Smithii Masters in Bot. Gaz. xvi. 199. 

Spring-shoots uninodal, slightly or not at all pruinose. Bark-formation early, the branches becom- 
ing dark and rough. Leaves prevalently in fascicles of 5, but varying from 3 to 8, extremely variable 
in length, attaining 45 cm. at subtropical levels; resin-ducts medial, hypoderm sometimes uniform, 
more commonly multiform, the outer walls of the endoderm thick. Conelet mucronate, the prickle 
often reflexed. Cones of many sizes, attaining in warm localities 30 cm. in length, ovate-conic or 
long-conic, symmetrical, often curved, deciduous and often leaving a few scales on the tree; apophy- 
ses dull, rarely lustrous, nut-brown, or of various shades of fuscous brown to nearly black, flat, tumid, 
pyramidal or sometimes slightly protuberant, the prickle rarely persistent. 

This species ranges from the mountains of northern Durango to the volcanoes of Guatemala, or 
possibly farther south. It is found at all altitudes where Pines can grow except on the tropical levels 
of Guatemala. Its more hardy forms have been successfully grown in the milder parts of Great 
Britain and northern Italy. It is felled for lumber in many parts of Mexico. 

This sturdy Pine and its numberless variations present the most remarkable example of adapta- 
tion in the genus. The variations are mostly those associated with changes of environment 
dimensions of cone and leaf and the number of leaves in the fascicle. These are so accurately corre- 
lated with altitude and exposure, and are so imperceptibly graded, that no specific segregations 
among them have yet been successfully established. 

The type-specimen figured by Lambert does not show the longest cone and leaf of this species. 
They are better represented by specimens which have been named P. filifolia. Such dimensions 
prevail in subtropical localities. At temperate altitudes these dimensions are much reduced, but 
here are found a longer form of cone and leaf (var. Lindleyi, Loudon) and a shorter form (var. rudis. 




PLATE XXV. PINUS MONTEZUMAE 



k 




ee GENUS pmus 

Shaw). At still higher altitudes and up to the timber-limit the var. Hartwegii, Engelmann, with 
short leaves and a small nearly black cone is found. Among these varieties there is no such sharp 
distinction as these definitions imply. All dimensions of fruit and foliage and the various brown and 
black shades of the cone blend into each other through endless intergradations. A monograph of this 
species, by one who could devote some years to it on the superb volcanoes and in the delightful 
climates where this tree abounds, would be a valuable contribution to science. 

Plate XXV. (Cones and leaves much reduced.) 

Fig. 220, Cone and leaves of Lambert's plate. Figs. 221, 222, Longer cones and leaves of 
the species. Fig. 223, Cone and leaves of var. Lindleyi. Fig. 224, Cones and leaves of var. 
rudis. Fig. 225, Cone and leaves of var. Hartwegii. Fig. 226, Magnified leaf-sections. Figs. 
227, 228, Two forms of the dermal tissues of the leaf, magnified. Fig. 229, Habit of the tree. 

PINUS PONDEROSA i 

1836 P. PONDEROSA Douglas ex Lawson's Agric. Man. 354. 

1847 P. Benthamiana Hartweg in Jour. Hort. Soc. Lond. ii. 189. 

1848 P. BRACHYPTERA Engelmann in Wislizenus, Tour Mex. 89. 

1848 P. MACROPHTLLA Engelmann in Wislizenus, Tour Mex. 103 (not Lindley) . 

1853 P. Jeffrey: Balfour in Bot. Exp. Oregon, 2, f. 

1854 P. Engelmanni Carriere in Rev. Hort. 227. 

1855 P. Beardsleyi Murray in Edinb. Phil. Jour. ser. 2, i. 286, t. 6. 
1855 P. Craigana Murray in Edinb. Phil. Jour. ser. 2, i. 288, t. 7. 

1858 P. Parryana Gordon, Pinet. 2d2 (not Engelmann). 

1859 P. DEFLEXA Torrey in Emory's Rep. ii-1, 209, t. 56. 
1878 P. ARizoNiCA Engelmann in Wheeler's Rep. vi. 260. 
1889 P. LATiFOLiA Sargent in Gar. & For. ii. 496, f. 135. 
1894 P. APACHECA Lemmon in Erythea, ii. 103, t. 3. 

1897 P. Mayriana Sudworth in Bull. 14, U. S. Dept. Agric. 21. 
1897 P. scopuLORUM Lemmon in Gar. & For. x. 183. 
1900 P. PENiNSULARis Lemmon, W. Am. Conebear. 114. 

Spring-shoots uninodal, sometimes pruinose. Bark-formation early. Leaves prevalently in fas- 
cicles of 3, but varying from 2 to 5 or more, from 12 to 36 cm. long; resin-ducts medial, hypoderm 
uniform or multiform, outer walls of the endoderm thick. Conelet mucronate, the mucro often 
reflexed. Cones from 8 to 20 cm. long, ovate-conic, symmetrical, deciduous and usually leaving a 
few basal scales on the tree; apophyses tawny yellow to fuscous brown, lustrous, elevated along 
a transverse keel, sometimes protuberant and reflexed, the umbo salient and forming the base 
of a pungent, persistent prickle. 

This species ranges from southern British Columbia over the mountains between the Pacific and 
the eastern foot-hills of the Rocky Mountains, including the Black Hills of South Dakota, to the 
northeastern Sierras of Mexico, to northern Jalisco and Lower California, forming, in many locali- 
ties, large forests and furnishing the best Hard Pine timber of the western United States. It attains 
its best growth on the Sierras of California and is, next to P. Lambertiana, the tallest of the Pines. 

Like P. Montezumae, and under like influences, it shows much dimensional variation, and the 
leaf-fascicles are heteromerous, with the larger number in the southern part of its range. Many 
authors consider the variety Jeffreyi Vasey to be a distinct species; but here, it seems to me, too 
much importance is attached to the pruinose branchlet, clearly a provision against transpiration 
and associated rather with a dry environment than with a species. Most observers discover many 
intermediate forms between this variety and the species. The var. scopulorum Engelm. is the Rocky 
Mountain form with leaves in 2's and 3's and with small cones passing into P. arizonica, Engelm., 
a more southern form with small cones and leaves in fascicles of 3 to 5. The var. macrophylla 
(Shaw, Pines Mex. 24), in addition to its long and stout leaves, bears a cone with protuberant 
apophyses, somewhat comparable to the intermediate forms of P. pseudostrobus var. apulcensis 




PLATE XXVI. PINUS PONDEROSA 



i 



68 GENUS PmUS 

Shaw (1. c). Fascicles of 6 and 7 leaves are sometimes found, and specimens that I have collected in 
Sandia, Durango (issued by Pringle, through a misunderstanding, under the name P. Roseana, ined.) 
show such fascicles on the fertile branches. 

Plate XXVI. 

Fig. 230, Cone and seed of var. Jeffreyi. Fig. 231, Cone of var. macrophylla. Fig. 232, 
Cone of var. scopulorum. Fig. 233, Magnified leaf-section and cells of leaf-endoderm. Fig. 
234, Magnified dermal tissues of the leaf, showing uniform and multiform hypoderm. 

40. PmUS TEOCOTE 

1830 P. TEOCOTE Schlechtendal & Chamisso in Linnaea, v. 76. 

Spring-shoots uninodal, or sometimes multinodal. Leaves prevalently in fascicles of 3, but varying 
from 3 to 5, from 10 to 20 cm. long; resin-ducts medial, sometimes with an internal duct, hypoderm 
biform, endoderm with thick outer walls. Conelets mucronate. Cones usually very small, from 4 to 
6 cm. long, but with a larger varietal form, ovate to long-conic, synmietrical; apophyses nut-brown, 
flat or tumid, the mucro usually deciduous. 

This species grows at temperate altitudes from Chiapas to Nuevo Leon, associated with temperate 
Mexican species such as P. patula, P. leiophylla and others, and is easily recognized by its small cone. 
The variety with a larger cone (var. macrocarpa, Shaw, Pines Mex. t. 10) I have found growing in 
mixed groves of P. teocote and P. leiophylla. It resembles the latter in cone and leaf, but lacks the 
peculiar character that distinguishes P. leiophylla from all other Mexican species the triennial cone. 
Some of the specimens of Hartweg No. 441 belong here, as well as Pringle's specimens, Nos. 10013, 
10018, distributed as P. eslavae, ined. 

Plate XXVII. 

Fig. 235, Two cones of the species and the larger cone of the variety. Fig. 236, Leaf-fas- 
cicle and magnified sections of two leaves. Fig. 237 a, Dermal tissues of the leaf magnified; 
b, magnified cells of the leaf-endoderm. Fig. 238, Habit of the tree. 

41. PINTS LAWSONH 

1862 P. Lawsonii Roezl ex Gordon, Pinet. Suppl. 64. 

1905 P. Altamirani Shaw in Sargent, Trees & Shrubs, i. 209, t. 99. 

Spring-shoots conspicuously pruinose, uninodal or not infrequently multinodal. Leaves in fas- 
cicles of 3, 4 or 5, not exceeding 24 cm. in length; resin-ducts internal, often with one or two medial 
ducts, hypoderm biform, endoderm usually with thin outer walls. Conelets mucronate. Cones from 
5 to 7 cm. long on pliant peduncles, ovate or ovate-conic, oblique or sometimes symmetrical, de- 
ciduous, or persistent with a weak hold on the branch; apophyses nut-brown, flat or tumid, often pro- 
tuberant on the posterior face of the cone, the umbo usually large and salient, forming a roimded 
button-like projection, on which the mucro is wanting. 

A subtropical species of central and western Mexico, growing alone or associated with P. oocarpa, 
P. Pringlei and the subtropical forms of P. Montezumae and P. pseudostrobus. It is recognized among 
its associate species by its conspicuously glaucous foliage. The cone is very variable on trees of the 
same grove, both in size and in the protuberance of its apophyses. Gordon's specimen in the Kew 
herbarium consists of a single detached cone and a few leaves. The leaves differ from all that I 
have examined in showing thick-walled endoderm cells, but the cone corresponds with many of my 
own collection. 

Plate XXVn. 

Fig. 239, Three cones. Fig. 240, Leaf-fascicle and magnified leaf-section. Fig. 241, Magni- 
fied cells of the leaf-endoderm. 




PLATE XXVn. P. TEOCOTE (235-238), LAWSONn (239-241) 



70 GENUS PINUS 

42. PINUS OCCIDENTALIS 

1788 P. OCCIDENTALIS Swartz, Nov. Gen. & Sp. PI. 103. 

1862 P. CUBEN8I8 Grisebach in Mem. Am. Acad. ser. 2, viii. 530. 

1880 P. Wrightii Engelmann in Trans. Acad. Sci. St. Louis, iv. 185. 

Spring-shoots uninodal, pruinose. Leaves in fascicles of 2 to 5, from 15 to 22 cm. long; resin-ducts 
internal, hypoderm biform, endoderm with thin outer walls. Conelets erect, aristate. Cones from 
5 to 8 cm. long, reflexed, ovate, symmetrical, deciduous; apophyses nut-brown, lustrous, flat or 
tumid, the umbo often thin and, together with the slender prickle, bent sharply downward. 

This species is confined to San Domingo, Hayti and eastern Cuba. Its erect conelet and reflexed 
cone distinguish it from P. caribaea, which has both its conelet and cone reflexed. Moreover the 
conelet is usually, perhaps always, subterminal in P. occidentalis. 

Plate XXVIII. 

Fig. 247, Cone. Fig. 248, Conelet and enlarged aristate scales. Fig. 249, Magnified sec- 
tions of two leaves and more magnified dermal tissues. 

43. PINUS PALUSTRIS W 

1768 P. PALUSTRIS Miller, Gard. Diet. ed. 8. 

1810 P. AUSTRALis Michaux f. Hist. Arbr. Am. i. 64, t. 6. 

Spring-shoots uninodal, rarely multinodal. Buds peculiarly large, white, and conspicuously 
fringed with the long free cilia of the bud-scales. Leaves in fascicles of 3, from 20 to 45 cm. long, 
rigid; resin-ducts internal, hypoderm biform, endoderm with thin outer walls. Conelets short-mu- 
cronate. Cones from 15 to 20 cm. long, narrow, tapering from a rounded base to a blunt point, sym- 
metrical, deciduous and usually leaving a few scales on the tree; apophyses dull nut-brown, elevated 
along a transverse keel, the umbo salient and forming the broad base of a small persistent prickle. 

Its thin sap-wood, its very strong heavy wood of large dimensions with abundant resin of excellent 
quality make this the most valuable species of the genus. It ranges over the sandy plain that bor- 
ders the Atlantic and the Gulf of Mexico, from southeastern Virginia to eastern Texas. The north- 
ern limit is approximately the centre of the Southern and Gulf States, with a northern extension in 
Alabama to the base of the Appalachian Mountains and to northwestern Louisiana. Its southern 
limit lies near the centre of the Florida peninsula. 

Among its associates this species is recognized by its large white fringed bud and its elongated cone. 
Its leaves attain, on vigorous trees, the maximum length among Pines, but on most trees the leaves 
do not differ in length from the longer forms of those of P. caribaea or P. taeda. A peculiarity, which 
it shares with P. caribaea, is the deciduous scaly bark of mature trees, constantly falling away in thin 
irregular scales. 

Plate XXVin. 

Figs. 242, 243, Cones and seed. Fig. 244, Bud. Fig. 245, Magnified leaf-section. Fig. 

246, Magnified cells of the leaf-endoderm. The dermal tissues of fig. 249 also apply to this 

species. 

44. PINUS CARIBAEA ^^ 

1851 P. CARIBAEA Morelet in Rev. Hort. C6te d'Or, i. 105. 

1864 P. BAHAMENSis Grfsebach, Fl. Brit. W. Ind. 503. 

1880 P. Elliottii Engelmann in Trans. Acad. St. Louis, iv. 186, tt. 1-3. 

1884 P. cuBENSis Sargent in Rep. 10th. Cens. U. S. ix. 202 (not Grisebach). 

1893 P. HETEROPHYLLA Sudworth in Bull. Torrey Bot. Club, xx. 45. 

1903 P. RECURVATA Rowlcy in Bull. Torrey Bot. Club, xxx. 107. 

Spring-shoots multinodal, more or less pruinose. Buds pale chestnut-brown. Leaves in fascicles 
of 2 and 3, or more in its southern range, from 12 to 25 cm. long; resin-ducts internal, hypoderm 
biform, endoderm with thin outer walls. Conelets reflexed on long peduncles, mucronate. Cones 




PLATE XXVm. P. PALUSTRIS (242-46), OCCIDENTALIS (247-249) 



72 GENUS PINUS 

from 5 to 15 cm. long, ovate or oblong-ovate, symmetrical, deciduous and leaving often a few basal 
scales on the branch; apophyses lustrous, rufous-brown, tumid, the umbo somewhat salient and 
minutely mucronate. 

The northern limit of the range of P. caribaea extends from the coast of southeastern S. Carolina 
through southeastern Georgia and southern Alabama to southeastern Louisiana. It is associated 
with P. palustris, taeda, serotina, echinata and glabra in this part of its range. It continues through 
Florida, where it encounters P. clausa. On the Bahamas it is the only Pine. On the Isle of Pines it 
finds in P. tropicalis another associate. It also grows in Honduras and Guatemala. The wood and 
resin of this species are of such excellent quality that no commercial distinction is made between P. 
caribaea and P. palustris. 

Plate XXIX. 

Fig. 250, Cone from the Isle of Pines. Fig. 251, Small form of cone. Fig. 252, Large form 
of cone and binate leaf-fascicle. Fig. 253, Conelet. Fig. 254, Magnified sections of leaves 
from binate and ternate fascicles. Fig. 255, Habit of the tree, contrasted with a tree of P. palus- 
tris in the middle-distance. 

45. PINUS TAEDA '^ 

1753 P. TAEDA Linnaeus, Sp. PI. 1000. 

1788 P. LUTEA Walter Fl. Carol. 237. 

1903 P. HETEROPHYLLA Small, Fl. Southeast. U. S. 28 (not Sudworth). 

Spring-shoots multinodal. Leaves in fascicles of 3, from 12 to 25 cm. long; resin-ducts medial, 
sometimes with an internal duct, hypoderm biform, endoderm with thin outer walls. Conelets erect, 
their scales jJrolonged into a sharp point. Cones from 6 to 10 cm. long, ovate-conic, symmetrical; 
apophyses dull pale nut-brown, rarely lustrous, elevated along a transverse keel, the whole umbo 
forming a stout triangular spine with slightly concave sides. 

The species ranges from southern New Jersey to southern Arkansas, Oklahoma, eastern Texas 
and southwestern Tennessee, but does not occur in the lower half of the Florida peninsula. It is an 
important timber-tree, manufactured into all descriptions of scantlings, boarding and finish, but the 
wood is of various qualities. It may be recognized by the spine of its cone in both years of growth. 
Excepting the formidable armature of the cone of P. pungens, the spines are the strongest and 
most persistent of all the species of eastern North America. 

Plate XXX. 

Fig. 264, Cone. Fig. 265, Leaf-fascicle. Fig. 266, Magnified leaf-section. Fig. 267, Mag- 
nified scales of the conelet. 

46. PINUS GLABRA 

1788 P. GLABRA Walter, Fl. Carol. 237. 
Spring-shoots multinodal. Bark-formation late, the upper trunks of mature trees smooth. Leaves 
in fascicles of 2, from 9 to 12 cm. long; resin-ducts medial, hypoderm weak, sometimes of a single row, 
biform when of two rows, endoderm with thin outer walls. Conelets reflexed, mucronate. Cones 
from 4 to 7 cm. long, reflexed, ovate, symmetrical, deciduous on some trees, persistent on others; 
apophyses pale dull nut-brown, thin or slightly thickened, the prickle usually deciduous. 

A tree that sometimes attains important dimensions, growing singly or in small groves from the 
neighborhood of Charleston, S. C, to eastern Louisiana and central Mississippi, most abundant in a 
strip of territory on either side of the northern boundary of Florida. Among the Pines of the south- 
eastern United States it is the only species with late bark-formation, and is therefore easily iden- 
tified. 

Plate XXX. 

Fig. 256, Cone. Fig. 257, Enlarged scale of the conelet. Fig. 258, Leaf-fascicle and 
magnified leaf-section. Fig. 259, Dermal tissues of the leaf magnified, with a double row of 
hypoderm cells. 




PLATE XXIX. PINUS CARIBAEA 



I 



74 GENUS PmUS 

47. PINUS ECHINATA "2^ 

1768 P. ECHINATA Miller, Card. Diet. ed. 8. 

1788 P. 8QUARR08A Walter, Fl. Carol. 287. 

1803 P. MITI8 Michaux, Fl. Bor. Am. ii. 204. 

1803 P. VARIABILIS Lambert, Gen. Pin. i. 22, t. 15. 

1854 P. RoYLEANA Jamieson in Jour. Hort. Soc. Lond. ix. 52, f. 

Spring-shoots multinodal, somewhat pruinose. Bark forming early, rough on the upper trunk. 
Leaves in fascicles of 2 and 3, from 7 to 12 cm. long: resin-ducts medial, with an occasional internal 
duct, hypoderm weak, biform when of two rows of cells, endoderm with thin outer walls. Cone- 
lets mucronate. Cones from 4 to 6 cm. long, ovate-conic, symmetrical, often persistent; apophyses 
dull pale nut-brown, thin or somewhat thickened along a transverse keel, the umbo salient, the 
mucro more or less persistent. 

This species ranges from southeastern New York to northern Florida, to West Virginia and east- 
em Tennessee, and through the Gulf States to eastern Louisiana, eastern Texas, southern Missouri 
and southwestern Illinois. It is extensively manufactured into material of all kinds that enters 
into the construction of buildings. It differs from P. virginiana in its longer leaves, brittle branches, 
and much greater height, from P. glabra in its rough upper trunk, and from both by the frequent 
presence of trimerous leaf-fascicles. 

Of the six or seven pines of the southeastern United States, this species covers a larger area and 
ascends the slopes of the Alleghany Mountains far enough to meet the northern species, P. virginiana, 
P. rigida, and P. strobus. Unlike the western members of this group, P. echinata and its associates 
are not variable. Their characters are singularly constant, as their limited synonymy and total lack 
of varietal names attest. 

Plate XXX. 

Fig. 260, Cone. Fig. 261, Leaf-fascicle and magnified leaf-section from a ternate fascicle. 
Fig. 262, Magnified leaf-section from a binate fascicle. Fig. 263, Multinodal branchlet bear- 
ing lateral and subterminal conelets and a ripe cone. Figs. 257, showing mucronate scales 
of the conelet, and 259, showing dermal tissues of the leaf, are applicable also to this species. 




PLATE XXX. P. GLABRA (856-259), ECHINATA (260-263), TAEDA (26*-267) 



u^ 



76 GENUS PINUS 

xn. msiGNES 

Pits of the ray-cells small. Cones tenaciously persistent, serotinous in various degrees. Conelets 
mucronate or spinose. 

Spring-shoots uninodal. 

Resin-ducts mostly internal 48. Pringlei 

Resin-ducts mostly septal 49. oocarpa 

Spring-shoots multinodal. 
Cones symmetrical. 
Leaf-hypoderm not biform. 

Bark-formation late 50. halepensis 

Bark-formation early 51. pinaster 

Leaf-hypoderm biform. 

Cones with slender spines. "^^ 

Leaves binate. 

Cones dehiscent at maturity 52. virginiana 

Cones serotinous 53. clausa \y^ 

Leaves ternate. 

Cones dehiscent at maturity 54. rigida ^ 

Cones serotinous 55. serotina 

Cones with stout spines 56. pungens 

Cones oblique or unsymmetrical. 

Cones and leaves very short, not exceeding 6 cm. 

Cones curved or warped 57. Banksiana 

Cones straight 58. contorta u^ 

Cones and leaves much longer, more than 7 cm. 
Posterior cone-scales gradually larger than anterior scales. 

Bark-formation late 59. Greggii 

Bark-formation early 60. patula 

Posterior cone-scales abruptly larger than anterior scales. 

Cones with very stout spines 61. muricata v 

Cones with minute or deciduous prickles. 

Bark-formation late 62. attenuata i^ 

Bark-formation early 63. radiata \^ 

48. PINUS PRINGLEI 

1905 P. Pringlei Shaw in Sargent, Trees & Shrubs, i. 211, t. 100. 

Spring-shoots uninodal, sometimes pruinose. Leaves ternate, from 15 to 25 cm. long; resin-ducts 
internal or with an occasional septal duct, hypoderm biform, in thick masses, often projecting far 
into the green tissue and sometimes touching the endoderm. Conelets mucronate. Cones from 5 to 
10 cm. long, reflexed on a rigid peduncle, subsymmetrical or more or less oblique, tenaciously per- 
sistent, often serotinous; apophyses sublustrous tawny yellow or fulvous brown, convex, the pos- 
terior scales often more prominently developed, the mucro usually wanting; seed with a perceptibly 
thickened wing-blade. 

A tree with long erect bright green foliage, confined, so far as known, to the subtropical altitudes 
of western Mexico. As it grows in Uruapan, Michoacan, there are two forms of the cone, large and 
small, both with the same long rigid leaf. 

Plate XXXI. 

Figs. 268, 269, Three cones and seed. Fig. 270, Leaf-fascicle and magnified leaf-section. 










PLATE XXXI. P. PRINGLEI (268-270). OOCARPA (271-274) 



I 



78 GENUS PINUS 

49. PESTUS OOCARPA 

1838 P. OOCARPA Schiede in Linnaea, xii. 491. 

1842 P. OOCABPOIDE8 Lindlcy ex Loudon, Encycl. 1118. 

Spring-shoots uninodal, pruinose. Leaves in fascicles of 3, 4 or 5, from 15 to 30 cm. long, erect; 
resin-ducts mostly septal, sometimes internal, hypoderm biform or multiform. Conelets on very 
long peduncles, mucronate. Cones from 4 to 10 cm. long, long-pedunculate, broad-ovate to ovate- 
conic, symmetrical or sometimes oblique, persistent, more or less serotinous; apophysis gray-yellow 
or greenish yellow of high lustre, flat or variously convex, delicately and radially carinate, the umbo 
often salient, the prickle usually broken away; seed- wing appreciably thickened at the base of the 
blade. 

A subtropical species, ranging from Guatemala to the northern border of Sinaloa in northern 
Mexico; remarkable for the length of the peduncle of the cone and for the prevalence of septal resin- 
ducts in the leaf. 
Plate XXXI. 

Fig. 271, Three cones and seed. Fig. 272, Leaf -fascicle and magnified leaf -section. Fig. 
273, Cone from northern part of the range. Fig. 274, Leaf -fascicle and magnified leaf -section 
from near the northern limit. 

50. PINUS HALEPENSIS 

1762 P. 8TLVESTRIS Gouan, Hort. Reg. Monspel. 494 (not Linnaeus). 

1768 P. HALEPENSIS Miller, Gard. Diet. ed. 8. 

1803 P. MARiTiMA Lambert, Gen. Pin. i. 13, t. 10. 

1812 P. RE8IN08A Loiseleur, Nouv. Duham. v. 237, t. 77 (not Aiton). 

1815 P. BRUTiA Tenore, Cat. Hort. Neap. Appx. 1, 75. 

1826 P. ARABiCA Sieber ex Sprengel, Syst. Veg. iii. 886. 

1833 P. PYRENAiCA David in Ann. Soc. Hort. Paris, 186 (not Lapeyrouse). 

1834 P. HISPANICA Cook, Sketches in Spain, ii. 337. 
1838 P. PITYUSA Steven in Bull. Soc. Nat. Mosc. xi. 49. 
1841 P. CARiCA Don in Ann. Mag. Nat. Hist. vii. 459. 
1847 P. PERsiCA Strangways ex Endlicher, Syn. Conif. 157. 
1855 P. ABASiCA Carrifere, Trait. Conif. 352. 

1855 P. LoisELEURiANA Carrifere, Trait. Conif. 382. 

1856 P. Parolinii Visiani in Mem. 1st. Venet. vi. 243, t. 1. 
1902 P. ELDARiCA Medwejew in Act. Hort. Tiflis. vi-2, 21, f. 

Spring-shoots often multinodal. Bark-formation late, the branches ashen gray and smooth for 
several years. Leaves binate, from 6 to 15 cm. long; resin-ducts external, hypoderm uniform. Cone- 
lets obscurely mucronate near the apex. Cones from 8 to 12 cm. long, ovate-conic, symmetrical or 
subsymmetrical, persistent, often serotinous; apophyses red with a lighter or deeper brownish shade, 
lustrous, flat, convex or low-pyramidal, radially carinate, the umbo often ashen gray and unarmed. 

A tree ranging from Portugal to Afghanistan, and from Algeria to Dalmatia and to northern Italy 
and Southern France. It is a vigorous species in its own home, growing readily in poor soils, but not 
successful in colder climates. The wood is resinous and valuable for fuel. The turpentine industry, 
once associated with this species, has gradually been abandoned for the more copious product of 
P. pinaster. 

It is recognized by its lustrous red cones and by the ashen gray cortex of its branches and upper 
trunk. Tenore's P. brutia (pyrenaica of some authors) is founded on a difference in the length of 
the leaf and on an erect cone with a shorter peduncle. To recognize species on such distinctions 
would not be consistent with the purpose and spirit of this discussion. 
Plate XXXII. 

Fig. 279, Two cones. Fig. 280, Cone. Fig. 281, Lateral conelet. Fig. 282, Magnified leaf- 
section. Fig. 283, Dermal tissues of the leaf magnified. 




PLATE XXXU. P. PINASTER (275-278), HALEPENSIS (279-283) 



80 GENUS PINUS 

51. PINUS PINASTER 

1768 P. SYLVESTRis Miller, Gard. Diet. ed. 8 (not Linnaeus). 

1789 P. PINASTER Aiton, Hort. Kew. iii. 367. 

1798 P. LARicio Savi, Fl. Pisa. ii. 353 (not Poiret). 

1804 P. MARiTiMA Poiret in Lamarck, Encycl. M6th. v. 337 (not Lambert). 

1826 P. ESCARENA Risso, Hist. Nat. ii. 340. 

1835 P. Lemoniana Bentham in Trans. Hort. Soc. Lond. ser. 2, i. 512, t. 

1845 P. Hamiltonii Tenore, Cat. Ort. Nap. 90. 

Spring-shoots sometimes multinodal. Bark-formation early. Leaves binate, from 10 to 20 cm. 
long, stout and rigid; resin-ducts medial, hypoderm multiform, the inner cells gradually larger, 
remarkably large in the angles of the leaf. Conelets minutely mucronate. Cones from 9 to 18 cm. 
long, nearly sessile, ovate-conic, symmetrical or subsymmetrical, persistent, sometimes serotinous; 
apophyses lustrous nut-brown or rufous brown, conspicuously pyramidal, the umbo salient and 
pungent. 

A maritime tree corresponding nearly, in its range, with the preceding species, but more hardy 
in cooler climates. It grows from Portugal to Greece, and from Algeria to Dalmatia, but its area has 
been much extended by cultivation. Under favorable conditions it attains large dimensions, but its 
exploitation for resin and turpentine tends to diminish its size and disfigure its habit (Mathieu, Fl. 
Forest, ed. 4, 611). Its rapid growth, strong root-system, and its ability to thrive on poor sandy soil, 
have led to the employment of this species for the forestation of sand-dunes in France. 

The tree can be recognized by its long stout leaves and persistent brown cones. Its leaf-section is 
peculiar in the remarkable size of the inner cells of the hypoderm, especially in the angles of the leaf. 

Plate XXXII. 

Figs. 275, 276, Cones. Fig. 277, Magnified leaf-section. Fig. 278, Magnified dermal tissues 
in the angle of the leaf. 

52. PINUS VIRGINIANA ' 

1768 P. VIRGINIANA Miller, Gard. Diet. ed. 8. 
1789 P. iNOPS Aiton, Hort. Kew. iii. 367. 

Spring-shoots multinodal, pruinose; branchlets pliant and tough. Bark-formation slow, the cortex 
not rifted for some years. Leaves binate, from 4 to 8 cm. long; resin-ducts niedial, or with an occa- 
sional internal duet; hypoderm biform. Conelets with long tapering sharp scales. Cones from 4 to 6 
cm. long, ovate or oblong-ovate, symmetrical, persistent, dehiscent at maturity; apophyses lustrous 
nut-brown, somewhat elevated along a transverse keel, the umbo salient, forming a long slender 
prickle with a broad base. 

Western Long Island to central Georgia and north Alabama, and from eastern Tennessee to south- 
ern Indiana and southeastern Ohio. It is a low bushy tree in the north, but in the south and west it 
attains small timber-size and is locally exploited. It is hardy beyond the limits of its natural range, 
growing readily in the vicinity of Boston. Its short binate leaves, the persistent long prickles of its 
cone, and its tough branches, combine to distinguish this Pine from its associates. The obvious re- 
lationship of P. virginiana and P. clausa places the former in this, rather than in the preceding group. 

Plate XXXIII. 

Fig. 284, Cones. Fig. 285, Conelet and its enlarged spinose scale. Fig. 286, Leaf-fascicle, 
magnified leaf-section and more magnified dermal tissues of the leaf. Fig. 287, Buds. 

53. PINUS CLAUSA ^S 

1884 P. CLAUSA Vasey ex Sargent, Rep. 10th Cens. U. S. ix. 199. 

Spring-shoots multinodal. Bark-formation slow, as in the preceding species. Leaves binate, from 
6 to 9 cm. long; resin-ducts medial, or with an occasional internal duct, hypoderm biform when of 



1 




PLATE XXXm. P. VmCINIANA (284-287), CLAUSA (288-291) 



88 GENUS PINTS 

two rows of cells. Conelets with long tapering acute scales. Cones from 5 to 8 cm. long, reflexed, 
ovate-conic, symmetrical, persistent, often serotinous; apophyses lustrous nut-brown, elevated along 
a transverse keel, the umbo forming a triangular persistent spine. 

A species of limited range, confined to the sandy coast of Alabama and to Florida. It sometimes 
attains timber-size, but is usually a low spreading tree of no commercial importance and never seen 
in cultivation. It is recognized by its smooth branches, binate leaves and numerous, often multi- 
serial, clusters of persistent, often closed, cones. It is associated with P. caribaea and, in the northern 
part of its range, it grows with the other Southern species. By its close resemblance it may be con- 
sidered the serotinous form of P. virginiana. 

Plate XXXIII. 

Fig. 288, Three nodal groups of cones of the same year. Fig. 289, Conelet and its enlarged 
scale. Fig. 290, Leaf-fascicle and magnified leaf-section. Fig. 291, Larger form of the tree. 



54. PINUS RIGIDA 



/^ 



1768 P. RIGIDA Miller, Gard. Diet. ed. 8. 

1909 P. 8EROTINA Long, in Bartonia, ii. 17 (not Michaux). 

Spring-shoots multinodal. Leaves temate, from 7 to 14 cm. long; resin-ducts medial, or with an 
occasional internal duct, hypoderm biform. Scales of the conelet abruptly prolonged into a spine. 
Cones from 3 to 7 cm. long, ovate-conic, symmetrical, persistent, dehiscent at maturity or rarely 
serotinous; apophyses lustrous tawny yellow, elevated along a transverse keel, the umbo salient and 
forming the broad base of a slender sharp prickle. 

A tree with bright green foliage in spreading tufts. The northern limit of its range is in southwest- 
ern New Brunswick, southern Maine, central New Hampshire and Vermont, the Thousand Islands 
of the St. Lawrence River and central Ohio. It ranges into Pennsylvania and Delaware at low 
levels and thence over the AUeghanies into northern Georgia. It is associated with P. strobus and 
P. resinosa and, further south, with P. virginiana. The cones are rarely serotinous, but it is remark- 
ably like P. serotina in many characters, and is therefore placed in this group. 

Plate XXXIV. 

Fig. 292, Cones. Fig. 293, Leaf-fascicle, magnified section through a fascicle, and magni- 
fied dermal tissues of the leaf. Fig. 294, Upper part of a tree. 

65. PINUS SEROTINA 

1803 P. SEBOTiNA Michaux, Fl. Bor. Am. ii. 205. 

Spring-shoots multinodal. Leaves ternate, from 12 to 20 cm. long; resin-ducts medial or medial 
and internal, hypoderm biform. Conelet long-mucronate. Cones from 5 to 7 cm. long, subglobose or 
short-ovate, symmetrical, persistent, serotinous; apophyses lustrous tawny yellow, slightly elevated 
along a transverse keel, the umbo forming the broad base of a slender, rather fragUe prickle. 

This species is confined to low wet lands from southeastern Virginia to northern Florida and cen- 
tral Alabama. It is one of the associated six timber-Pines of the Southern States and the only one 
of them with serotinous cones. Its wood is of like value with that of P. taeda, the two species being 
constantly confused by lumbermen. It is never associated with P. rigida, but its resemblance to that 
Pine is so great that it may be regarded as its serotinous form. Its leaf is longer, its cone usually 
more orbicular and the prickle weaker. 

Plate XXXTV. 

Fig. 295, Cone. Fig. 296, Conelet and its enlarged scale. Fig. 297, Leaf-fascicle and mag- 
nified leaf-section. 




v^^"--0^^ 



e.c:.,^ '-' .."v,vV(.v_v' J 







i"- '."".V:'-.f^::'.^4ff . . ..-^< 




PLATE XXXIV. P. RIGIDA (292-294), SEROTINA (295-297), PUNGENS (298-SOO) 



84 GENUS PINUS 

56. PINUS PUNGENS -7,^ 

1805 P. TAEDA Lambert, Gen. Pin. i. t. 16, (as to cone), (not Linnaeus). 

1806 P. PUNGENS Lambert in Ann. Bot. ii. 198. 

1852 P. MONTANA Noll, Bot. Class Book, 340. (not Miller). 

Spring-shoots multinodal. Leaves binate or ternate, from 3 to 7 cm. long; resin-ducts medial, or 
with an occasional internal duct, hypoderm biform. Scales of the conelet much prolonged into a very 
acute triangle. Cones from 5 to 9 cm. long, symmetrical or subsymmetrical, tenaciously persistent, 
serotinous; apophyses lustrous or sublustrous fulvous brown, much elevated along a transverse keel, 
the umbo forming a stout formidable spine, uniform or nearly uniform on all faces of the cone. 

A mountain species ranging from central Pennsylvania to northern Georgia, with isolated stations 
in western New Jersey and Maryland. It is remarkable among the Pines of eastern North America 
for the size and strength of the spines of its cone. The armature resembles that of the cone of the 
western P. muricata, but with the difference that the western cone is strongly oblique, the anterior 
and posterior spines varying greatly in size. 

Plate XXXIV. 

Fig. 298, Cone. Fig. 299, Conelet and its enlarged scale. Fig. 300, Leaf-fascic^ and mag* 
nified leaf-section. 

57. PINUS BANKSIANA ^ 1 

1803 P. Banksiana Lambert, Gen. Pin. i. 7, t. 3. 

1804 P. HUDSONiA Poiret in Lamarck, Encycl. M6th. v. 339. 

1810 P. BUPESTRis Michaux f. Hist. Arbr. Am. i. 49, t. 2. 

1811 P. DiVARiCATA Dumont de Courset, Bot. Cult. ed. 2, vi. 457. 

Spring-shoots multinodal. Leaves binate, from 2 to 4 cm. long; resin-ducts medial, hypoderm 
biform. Conelets minutely mucronate. Cones from 3 to 5 cm. long, erect, ovate-conic, oblique, 
much curved or variously warped from the irregular development of the scales, serotinous; apophy- 
ses lustrous tawny yellow, concave, flat or convex, the umbo small and unarmed. 

The most northern American Pine, growing near the Arctic Circle in the valley of the Mackenzie 
River, whence it ranges southeasterly to central Minnesota and the south shore of Lake Michigan, 
and easterly through the Dominion of Canada to northern Vermont, southern Maine, and Nova 
Scotia. In the northern part of its range it is the only Pine, but further south it is associated with 
P. strobus and P. resinosa. It is easily identified by its curious curved or deformed cones. 

Plate XXXV. 

Fig. 301, Cones. Fig. 302, Biserial cones of the same year. Fig. 303, Leaf -fascicle and 
magnified leaf-section. Fig. 304, Habit of the tree. 

58. PINUS CONTORTA /^ 

r 
1833 P. INOPS Bongard in Mem. Acad. Sci. St. Petersb. ii. 163, (not Alton). 
1838 P. CONTORTA Douglas ex Loudon, Arb. Brit. iv. 2292, f. 2211. 

1853 P. MuRRAYANA Balfour in Bot. Exp. Oregon, 2, f. 

1854 P. B0UR8IERI Carriere in Rev. Hort. 225, ff. 16, 17. 

1868 P. BoLANDERi Parlatore in DC. Prodr. xvi-2, 379. 

1869 P. TAMRAC Murray in Gard. Chron. 191, ff. 1-9. 
1898 P. TENUIS Lemmon in Erythea, vi. 77. 

Spring-shoots multinodal. Leaves binate, from 3 to 5 cm. long; resin-ducts medial, hypoderm 
biform. Conelets long-mucronate. Cones from 2 to 5 cm. long, sessile, ovate-conic, symmetrical or 
very oblique, persistent, serotinous; apophyses lustrous tawny-yellow, flat or protuberant, on 
oblique cones abruptly larger on the posterior face; the umbo armed with a slender fragile prickle. 




PLATE XXXV. P. BANKSIANA (301-304), CONTORTA (305. 306) 



88 GENUS PESrUS 

It grows from the valley of the Yukon, near the Alaskan boundary, along the Pacific coast to 
Mendocino county, California. It covers the plains and slopes of British Columbia and follows the 
Rocky Mountains into western Colorado, with an outlying station on the Black Hills of South Dakota. 
It grows on the Sierras and mountains of southern California and in northern Lower California. On 
the seashore this Pine is of low dense growth, but inland it is a slender tree with a long tapering stem. 
It is easily recognized by its very short leaves and very small cone. 

Plate XXXV. 
Fig. 305, Cones. Fig. 306, Leaf -fascicle and magnified leaf -section. 

59. PINUS GREGGII 

1868 P. Greggii Engelmann ex Parlatore in DC. Prodr. xvi-2, 396. 
Spring-shoots uninodal and multinodal, pruinose. Bark-formation late, the branches and upper 
trunk smooth. Leaves ternate, from 7 to 10 cm. long, erect; resin-ducts medial, hypoderm of uni- 
form thin-walled cells. Conelets mucronate. Cones from 6 to 12 cm. long, ovate-conic, oblique, 
serotinous, reflexed; apophyses lustrous tawny yellow, convex, the posterior gradually larger and 
more prominent than the anterior scales, the umbo flat or depressed, the mucro deciduous. 

This species is known, at present, from specimens collected in the vicinity of the city of Saltillo, in 
northeastern Mexico. Were it not for the difference of bark it might be considered to be a north- 
em variety of P. patula with shorter erect leaves. With both species the long peduncle of the conelet 
becomes overgrown by the basal scales of the ripe cone, which appears to be sessile. With both, the 
cones are in crowded nodal clusters, reflexed against the branch. They are so much alike that earlier 
descriptions of P. patula included the smooth gray bark of P. Greggii. The first correct description 
of the scaly red bark of P. patula appeared in the second edition of Veitch's Manual of Conifers. 

Plate XXXVI. 

Fig. 311, Cone. Fig. 312, Conelet. Fig. 313, Leaf-fascicle and magnified leaf-section. 
Fig. 314, Branch showing erect leaves. 

60. PINUS PATULA 

1831 P. PATULA Schlechtendal & Chamisso in Linnaea, vi. 354. 
Spring-shoots multinodal, more or less pruinose. Bark-formation early, the scales deciduous, the 
upper trunk and branches red. Leaves prevalently ternate but sometimes in fascicles of 4 or 5, from 
15 to 30 cm. long, slender and gracefully drooping; resin-ducts medial or with an occasional internal 
duct, hypoderm weak, of uniform thin-walled cells. Conelets mucronate. Cones from 6 to 11 cm. 
long, in crowded verticillate clusters, sessile, reflexed, ovate-conic, oblique, persistent and serotinous; 
apophyses lustrous nut-brown, more or less tumid, the posterior gradually larger than the anterior 
scales, the umbo flat or depressed, the mucro wanting. 

Patula grows in the warm-temperate climates of Hidalgo, Puebla and Vera Cruz, in eastern and 
central Mexico. It can be at once recognized by its slender drooping foliage, its persistent cones, 
and its red upper trunk. It is cultivated in northern Italy and in the warmer parts of Great Britain. 

Plate XXXVI. 

Fig. 307, Cone. Fig. 308, Conelet. Fig. 309, Leaf-fascicle and magnified leaf-section. 
Fig. 310, Branchlet with drooping leaves. 

61. PINUS MURICATA -J^ 

1837 P. MXJRiCATA D. Don in Trans. Linn. Soc. xvii. 441. 
1848 P. Edgariana Hartweg in Jour. Hort. Soc. Lond. iii. 217. 

Spring-shoots multinodal. Leaves binate, from 10 to 15 cm. long; resin-ducts medial, hypoderm 
biform. Scales of the conelet prolonged into a triangular spine. Cones from 5 to 9 cm. long, in ver-- 
ticillate clusters, sessile, reflexed, ovate-conic, oblique, serotinous; apophyses lustrous nut-brown, 




PLATE XXXVI. P. PATULA (307-310), GREGGII (311-314) 



86 GENUS PINUS 

abruptly much larger on the posterior face of the cone, each armed with a formidable spine varying 
in size with the varying size of the apophysis. 

This species grows on the coast of California, in scattered stations between Mendocino and San 
Luis Obispo Counties, and on the northwest coast of Lower California and on Cedros Island. It is 
recognized by its oblique cones, conspicuously spinose, indefinitely persistent and very serotinous. 
The unequal development of its cone-scales distinguishes the cone from the more symmetrically 
developed cone of P. pungens. Fruiting trees of P. muricata may be seen in the Royal Gardens at Kew. 

Plate XXXVII. 

Fig. 315, Cone. Fig. 316, Leaf-fascicle and magnified leaf-section. 

62. PINUS ATTENUATA \ ^ . 

1847 P. CALIFORNICA Hartwcg in Jmir. Hort. Soc. Lond. ii. 189, (not ? P. californiana, Loise- 

leur). 

1849 P. TUBERCULATA Gordou in Jour. Hort. Soc. Lond. iv. 218, f. (not D. Don). 
1892 P. ATTENUATA Lcmmou in Mining & Sci. Press, Ixiv. 45. 

Spring-shoots multinodal. Bark-formation late, the branches and upper trunk smooth. Leaves 
temate, from 8 to 16 cm. long; resin-ducts medial or with one or more internal ducts,, hypoderm 
biform. Scales of the conelet prolonged into a triangular spine. Cones from 8 to 16 cm. long, in ver- 
ticillate clusters, sessile, reflexed, long-ovate, oblique, persistent and remarkably serotinous; 
apophyses lustrous tawny yellow, abruptly larger and more prominent on the posterior face of the 
cone, where they are usually prolonged into acute pyramids with a small incurved spine. 

A tree of slender habit and gray-green foliage, the trunk studded with persistent nodal cone-clus- 
ters; growing on dry mountain slopes, from southwestern Oregon over the foothills of the northern 
moimtains of California and its coastal ranges as far as the southern slopes of the San Bernardino 
Mountains. It attains its best development in the northern part of its range, but is never a tree of 
importance. The serotinous habit is more pronounced in this than in any other species. It is dis- 
tinct from P. radiata, its nearest relative, by the color of the cone, by its smooth upper trunk and by 
its much smaller size. 

The possibility of identifying P. californiana Loiseleur (Nouv. Duham. v. 293), through a cone said 
to have been sent to the Museum at Paris, may cause this name to be applied, by reason of its early 
date (1812), to some existing species. Don's radiata and tuberculata, although considered to be the 
same species, were nevertheless founded on different forms of the cone. Under a very narrow con- 
ception of specific limits tuberculata Don might therefore acquire specific rank. These considera- 
tions seem to make it advisable to abandon for this species the names californica Hartw. and tuber- 
culata Gord. for the later name attenuata. 

Plate XXXVII. 

Fig. 317, Cone. Fig. 318, Magnified leaf-section. 

63. PINUS RADIATA \ '^ 

1837 P. RADIATA D. Don in Trans. Linn. Soc. xvii. 442, 

1837 P. TUBERCULATA D. Don in Trans. Linn. Soc. xvii. 442. 

1838 P. iNSiGNis Douglas ex Loudon, Arb. Brit. iv. 2265, f. 2171. 

1841 P. SiNCLAiRii Hooker & Arnott in Bot. Beechy Voy. 392, t. 93 (as to leaves). 

Spring-shoots multinodal. Bark formation early, the branches and upper trunk rough. Leaves 
temate or binate, from 10 to 15 cm. long; resin-ducts medial or with an occasional internal duct, 
hypoderm biform. Conelets mucronate, the mucro small and dorsal. Cones from 7 to 14 cm. long, 
in verticillate clusters, sessile, reflexed, ovate or oblong, oblique, serotinous; apophyses nut-brown, 
lustrous, tumid in various degrees, the posterior scales abruptly larger and very prominent, the 
umbo bearing the minute prickle or its remnant. 




PLATE XXXVn. p. MURICATA (315, 316), ATTENUATA (317. 318), RADIATA (319-323) 



90 GENUS PINUS 

A tall tree with rich green foliage, growing on a strip of coast south of San Francisco, particulariy 
in Monterey County. It grows also on the islands forming the Santa Barbara Channel and on the 
Island of Guadeloupe, Lower California. It is remarkably successful in the warmer climates of Eu- 
rope and of Australasia. The species is distinct in its peculiar cone with rounded apophyses. 
Plate XXXVn. 

Figs. 819, 820, Cones. Fig. 321, Leaf-fascicle and magnified leaf-section. Fig. 322, Leaf- 
section from a binate fascicle. Fig. 323, Magnified dermal tissues of the leaf. 

Xm. MAGROCARPAE 

Pits of the ray-cells small. Wing-blade of the seed thick. Cones large. Leaves long and stout. 

This group is remarkable for the size of leaf, conelet, and cone. The peculiar thick seed-wing is 
more or less obscurely present among the species of the Insignes, but never attains the development 
that diflFerentiates this group from all other Pines. The leaf-section is notable for the large amount 
of hypoderm and for the presence of both thick and thin outer walls of the endoderm-cells, both 
forms appearing in the same leaf. 

Wing-blade with a short membranous extension. 

Leaves in fascicles of 5 64. Torreyana 

Leaves in fascicles of 3 65. Sabiniana 

Wing-blade with a long membranous extension, leaves in fascicles of 3. . .66. Coulteri 

64. PINUS TORREYANA -^ ^ 

1855 P. Torreyana Parry ex Carri^re, Trait. Conif. 326. 
1860 P. LOPHOSPERMA Lindlcy in Gard. Chron. 46. 

Spring-shoots uninodal, pruinose. Leaves in fascicles of 5, from 20 to 33 cm. long, very stout; 
resin-ducts medial, hypoderm uniform or somewhat multiform and of many cells. Conelets large, 
mucronate. Cones from 10 to 15 cm. long, on stout peduncles, broad-ovate, symmetrical, somewhat 
persistent; apophyses chocolate-brown, prominently pyramidal, the umbo salient and capped with 
a small mucro; seed- wing short, very thick, the dorsal surface of the nut spotted with the black rem- 
nants of the spermoderm. 

A tree 10 or 12 metres high, often semi-prostrate in exposed positions, confined to a restricted area 
on the coast north of San Diego, California, and to the Island of Santa Rosa. This species resem- 
bles P. Sabiniana in the length of its seed-wing and in the color of its cone, but is distinct in the short 
triangular umbo, in its pentamerous leaf -fascicles and in the mottled dorsal surface of its nut. 

Plate XXXVni. 

Fig. 324, Cone and seed. Fig. 325, Magnified leaf-section. 

65. PINUS SABINIANA ) 

1833 P. Sabiniana Douglas in Trans. Linn. Soc. xvi. 747. 

Spring-shoots mijtinodal, pruinose. Leaves in fascicles of 3, from 20 to 30 cm. long; resin-ducts 
medial, hypoderm multiform. Conelets large, their scales tapering to a sharp point. Cones from 15 to 
25 cm. long, reflexed, ovate, slightly oblique, persistent; apophyses chocolate-brown, very prominent, 
the curved umbo confluent with the apophysis and with it forming a very large talon-like armature 
with a sharp apex and a broad thick base; seed-wing very thick, with a short membranous margin, 
the dorsal surface of the nut uniform in color. 

A tree with sparse gray-green foliage, growing in small groves on the foothills of the Sierra Nevada 
and Coast Ranges of California. Its three leaves and the uniform color of the nut distinguish it from 



^#^<^'^''^g;. 




PLATE XXXVm. P. TORREYANA (324. 325), SABmiANA (326-328) 




^^mw^^^^ 



^ 






332 



PLATE XXXIX. PmuS COULTERI 



GENUS PINTS 9S 

P. Torreyana. From P. Coulteri it diflFers in the length of the membranous portion of the seed- 
wing and in its gray-green leaves. 

Plate XXXVIII. 
Fig. 326, Cone. Fig. 327, Seed, nut and wing. Fig. 328, Magnified leaf-section. 



\^ 



66. PINUS COULTERI 

1837 P. Coulteri D. Don in Trans. Linn. Soc. xvii. 440. 
1840 P. MACBOCARPA Lindley in Bot. Reg. xxvi. Misc. 62. 

Spring-shoots multinodal, pruinose. Leaves in fascicles of 3, from 15 to 30 cm. long, very stout; 
resin-ducts medial, or with an occasional internal duct, hypoderm multiform and of many cells. 
Conelet very large, the scales tapering to a long sharp point. Cones from 25 to 35 cm. long, reflexed, 
ovate or oblong-ovate, somewhat oblique, persistent; apophyses sublustrous tawny yellow, very 
protuberant, with a narrow shoulder from which springs the umbo in the form of a large stout curved 
talon; seed- wing nearly equally divided between the very thick base and the membranous apex. 

Remarkable among Pines for the size and weight of its cones, many times heavier than the longer 
cones of P. Lambertiana, illustrating the great change that the cone-tissues undergo in the gradual 
evolution of the species. It is a tree with dark-green foliage, growing from northern Lower Cali- 
fornia over the mountains of southern California to the Santa Lucia range and to Mt. Diablo. It is 
of no value except for fuel and for its large nuts. It is best recognized by its seed. The cone differs 
from the others of this group in its yellow color, not unlike that of boxwood. 

Plate XXXIX. 

Fig. 329, Cone of small size. Fig. 330, Seed, nut and wmg. Fig. 331, Magnified leaf-section. 
Fig. 332, Conelet. 



INDEX 



Adnate wing 16 

Apinus, Neck. = Pinus 24 

Apophysis of cone 10 

Armature of conelet 7 

Articulate wing 16 

Australes-Group 6i 

Balfourianae-Group 42 

Bark 18 

Bases of bracts decurrent and non-decurrent 1 

Bast-tissue of cone 14 

Biform hypoderm 6 

Bloom on branchlet 2 

Bracts, bases of 1 

Branchlet, multinodal 2 

uninodal 2 

Bud, latent 2 

leaf 1 

staminate 1 

Caryopitys, Small = Pinus 24 

Caryopitys edulis Small = Pinus cembroides S8 

Cembra, Opiz = Pinus 24 

Cembra-Subsection 26 

Cembrae-Group 26 

Cembroides-Group 38 

Characters of the genus 1 

Classification of spiecies 22 

Color of cone 8 

Cone, apophysis of 10 

bast tissues of 14 

color of 8 

dimensions of 8 

oblique 10 

peduncle of 8 

persistent 8 

phyllotaxis of 12 

serotinous 14 

symmetrical 10 

Conelet, lateral 7 

pseudolateral 7 

subterminal 7 

Conspectus of Sections &c 25 

Connective of pollen-sacs 7 

Cotyledons 1 

Decurrent bases 1 

Definite phyllotaxis 12 

Dermal tissues of leaf 4 

Dimensions of cone 8 

leaf 4 

Diploxylon-Section 44 

Dorsal umbo 8 

Endoderm 6 

Evolutional characters 20 

External resin-ducts 6 

Fibro-vascular bundle 6 

Flexiles-Group 28 

Flowers, lateral 7 

pistillate 7 

staminate : 7 

subterminal 7 

Generic characters 18 

Genus, characters of 1 



Geographical distribution 24 

Gerardianae-Group 40 

Green tissue of leaf 6 

Haploxylon-Section 26 

Hyixxlerm, biform 6 

multiform 8 

uniform 6 

Indefinite phyllotaxis IS 

Insignes-Group 76 

Internal resin-ducts 6 

Lariciones-Group SI 

Latent buds S 

Lateral flowers 7 

conelet 7 

Leaf, dermal tissues of 4 

dimensions of 4 

fibro-vascular bundle of 6 

green tissue of 6 

persistence of 4 

^ primary 1 

. resin-ducts of 6 

secondary 2 

stelar tissues of 6 

stomata of 4 

tissues of 4 

Leiophyllae-Group 44 

Longif oliae-Group 46 

Macrocarpae-Group 90 

Medial resin-ducts 6 

Multiform hypoderm 6 

Multinodal branchlet 2 

spring-shoot 2 

Non-decurrent bases 1 

Oblique cone 10 

Paracembra-Subsection 86 

Parapinaster-Subsection 44 

Peduncle of cone 8 

Persistence of leaf 4 

Persistent cone 8 

Phyllotaxis, of cone 12 

definite 12 

indefinite 12 

Pinaster-Subsection 60 

Pineae-Group 48 

Pinus _ 24 

Pinus abasica Carr. = halepensis 78 

alba-canadensis Prov. = strobus 86 

albicaulis Engelm 27 

Altamirani Shaw = Lawsonii 68 

apacheca Lemm. = ponderosa 68 

apulcensis Lindl. = pseudostrobus 62 

arabica Sieb. = halepensis 78 

aristata Engelm 44 

arizonica Engelm. = ponderosa 66 

Armandi Franch 80 

armena Koch = sylvestris 54 

attenuata Lemm 88 

australis Michx. = palustris 70 

austriaca H8ss = nigra 68 

ayacahuite Ehrenb SO 



INDEX 



05 



Pinus bahamensis Grise. = caribaea 70 

Balfouriana Balf 42 

Balfouriana Wats. = aristata 44 

Banksiana Lamb 84 

Beardsleyi Murr. = ponderosa 66 

Benthamiana Hartw. = ponderosa 66 

Bolanderi Pari. = contorta 84 

Bonapartea Roezl = ayacahuite SO 

Boursieri Carr. = contorta 84 

brachyptera Engelm. = ponderosa 66 

brutia Ten. = halepensis 78 

Bungeana Zucc 40 

californica Hartw. = attenuata 88 

canaliculata Miq. = Massoniana 52 

canariensis Smitii 48 

caribaea Mor 70 

carica Don = halepensis 78 

cembra L 27 

cembra Thunb. = parviflora 82 

cembroides Gord. = Pinceana 38 

cembroides Newb. = albicaulis 27 

cembroides Zucc 38 

chihuahuana Engelm. = leiophylla 44 

clausa Vasey 80 

contorta Dougl 84 

coronans Litv. = cembra 27 

Coulteri D. Don 93 

Craigana Murr. = ponderosa 66 

cubensis Grise. = occidentalis 70 

cubensis Sarg. = caribaea 70 

dalmatica Vis. = nigra 58 

deflexa Torr. = p>onderosa 66 

densata Mast. = sinensis 60 

densiflora Sieb. & Zucc 52 

Devoniana Lindl. = Montezumae 64 

divaricata Dum. Cours. = Banksiana 84 

Donnell-Smithii Mast. = Montezumae 64 

echinata Mill 74 

Edgariana Hartw. = muricata 86 

edulis Engelm. = cembroides 38 

Ehrenbergii Endl. = Montezumae 64 

eldarica Medw. = halep>ensis 78 

Elliottii Engelm. = caribaea 70 

Engelmanni Carr. = ponderosa 66 

escarena Hiss. = pinaster 80 

excelsa Hook. = pence 34 

excelsa Wall 34 

filifolia Lindl. = Montezumae 64 

Finlaysoniana Wall. = Merkusii 68 

flexilis James 28 

flexilis Balf. = albicaulis 27 

formosana Hay. = parviflora 32 

Fremontiana Endl. = cembroides 38 

Frieseana Wich. = sylvestris 54 

funebris Kom. = sinensis 60 

Gerardiana Wall 42 

glabra Walt 72 

Gordoniana Hartw. = Montezumae 64 

Greggii Engelm 86 

Grenvilleae Gord. = Montezumae 64 

Griffithii McClell. = excelsa 34 

halepensis Bieb. = nigra 58 

halei>ensis Mill 78 

Hamiltonii Ten. = pinaster 80 

Hartwegii Lindl. = Montezumae 64 

Heldreichii Chr. = nigra 68 

Henrjd Mast. = sinensis 60 

heterophylla Small = taeda 72 

heterophylla Sudw. = caribaea 70 

hispanica Cook = halepensis 78 

hudsonia Poir. = Banksiana 84 

humilis Link = sylvestris 64 

inops Ait. = virginiana 80 



Pinus inops Bong. = contorta 84 

insignis Dougl. = radiata 88 

insularis Endl 60 

Jeffreyi Balf. = ponderosa 66 

kasya Royle = insularis 60 

khasiana Griff. = insularis 60 

Kochiana Klotzsch = sylvestris 54 

koraiensis Mast. = Armandi 30 

koraiensis Sieb. & Zucc 26 

Lambertiana Dougl 32 

lapponica Mayr = sylvestris 64 

laricio Poir. = nigra 58 

laricio Savi = pinaster 80 

latifolia Sarg. = ponderosa 66 

latisquama Engelm. = Pinceana 38 

latteri Mason = Merkusii 58 

Lawsonii Roezl 68 

leiophylla Schl. & Cham 44 

Lemoniana Benth. = pinaster 80 

leucodermis Ant. = nigra 58 

leucosperma Max. = sinensis 60 

Lindleyana Gord. = Montezumae 64 

Llaveana Schiede = cembroides 38 

Loiseleuriana Carr. = halepensis 78 

longifolia Roxb 46 

lophosperma Lindl. = Torreyana 90 

Loudoniana Gord. = ayacahuite 30 

luchuensis Mayr 56 

Lumholtzii Rob. & Fern 46 

lutea Walt. = taeda 72 

macrocarpa Lindl. = Coulteri 93 

macrophylla Engelm. = ponderosa 66 

macrophylla Lindl. = Montezumae 64 

maderiensis Ten. = pinea 48 

mandschurica Laws. = cembra 27 

mandschurica Rupr. = koraiensis 26 

maritima Ait. = nigra 58 

maritima Lamb. = halepensis 78 

maritima Poir. = pinaster 80 

Massoniana Lamb 52 

Massoniana Sieb. & Zucc. = Thunbergii 56 

Mastersiana Hay. = Armandi 30 

Mayriana Sudw. = ponderosa 66 

Merkusii De Vriese 58 

mitis Michx. = echinata 74 

monophylla Torr. = cembroides 38 

montana Lam. = cembra 27 

montana Mill 54 

montana Noll = pungens 84 

Montezumae Lamb 64 

monticola Dougl 34 

morrisonicola Hay. = parviflora 32 

mugho Poir. = montana 54 

mughus Jacq. = sylvestris 54 

mughus Scop. = montana 54 

muricata D. Don 86 

Murrayana Balf. = contorta 84 

Nelsonii Shaw 40 

nepalensis De Chamb. = excelsa 34 

nigra Arnold 58 

nigricans Host = nigra 58 

nivea Booth = strobus 36 

obliqua Saut. = montana 54 

occidentalis H. B. K. = Montezumae 64 

occidentalis Swartz 70 

oocarpa Schiede 78 

oocarpoides Lindl. = oocarpa 78 

orizabae Gord. = pseudostrobus 62 

osteosi>erma Engelm. = cembroides 38 

Pallasiana Lamb. = nigra 58 

palustris Miller 70 

Parolinii Vis. = halepensis 78 

Parryana Engelm. = cembroides 38 



96 



INDEX 



Pious Parryana Gord. ponderosa 00 

parviflora Sieb. & Zucc 82 

patula Schl. & Cham 86 

peainsularis Lemm. = ponderosa 66 

pentaphylla Mayr = parviflora 82 

persica Strangw. = halepensis 78 

peuce Grise 84 

pinaster Ait 80 

pinaster Bess. = nigra 58 

Pinceana Grord 88 

pindica Form. = nigra 58 

pinea Linn 48 

pityusa Stev. = halepensis 78 

ponderosa Dougl 66 

pontica Koch = syl vestris 54 

porphyrocarpa Laws. = montieola 34 

Pringlei Shaw 76 

prominens Mast. = sinensis 60 

pseudostrobus Lindl 62 

pumila Regel = cembra 27 

pumilio Haenke = montana 54 

pungens Lamb . . 84 

pyrenaica David = halepensis 78 

pyrenaica Lap. = nigra 68 

quadrifolia Sudw. = cembroides 38 

radiata D. Don 88 

radiata Hook. & Am. = Montezumae 64 

recurvata Rowl. = caribaea 70 

reflexa Engelm. = flexilis 28 

resinosa Ait 51 

resinosa Loise. = halepensis 78 

resinosa Savi = sylvestris 54 

rigida Mill 82 

rotundata Link = montana 54 

Roxburghii Sarg. = longifolia 46 

Royleana Jam. = echinata 74 

rubra Michx. = resinosa 51 

rubra Mill. = sylvestris 54 

rudis Endl. = Montezumae 64 

rupestris Michx. = Banksiana 84 

Russelliana Lindl. = Montezumae 64 

Sabiniana Dougl 90 

Salzmanni Dun. = nigra 58 

sanguinea Lap. = montana 54 

sativa Lam. = pinea 48 

scipioniformis Mast. = Armandi 30 

scopifera Miq. = densiflora 52 

scopulorum Lemm. = ponderosa 66 

serotina Long = rigida 82 

serotina Michx 82 

shasta Carr. = albicaulis 27 

sibirica Mayr = cembra 27 

Sinclairii Hook. & Am. = Montezumae 64 

= radiata 88 

sinensis Lamb 60 

squarrosa Walt. = echinata 74 

strobiformis Engelm. = ayacahuite SO 

strobiformis Sarg. = flexilis 28 

strobus Linn 36 

strobus Thunb. = koraiensis 26 

sylvestris Baumg. = nigra 58 

sylvestris Gouan = halepensis 78 

sylvestris Linn ._ 54 

sylvestris Lour. = Merkusii 58 

sylvestris Mill. = pinaster 80 

sylvestris Thunb = Thunbergii 56 

tabulaef ormis Carr. = sinensis 60 

taeda Blanco = insularis 60 

taeda Lamb. = pungens 84 

taeda Linn 72 



Pinus tamrac Murr. = contorta 84 

tatarica Mill. = sylvestris 54 

tenuifolia Benth. = pseudostrobus 62 

tenuis Lemm. = contorta 84 

teocote Schl. & Cham 68 

terthrocarpa Shaw = tropicalis 52 

Thunbergii Pari 56 

Torreyana Parry 90 

tropicalis Mor 52 

tuberculata D. Don = radiata 88 

tuberculata Gord. = attenuata 88 

uliginosa Neum. = montana 54 

unrinata Ram. = montana 54 

variabilis Lamb. = echinata 74 

Veitchii Roezl = ayacahuite 80 

virginiana Mill 80 

Wilsonii Shaw = sinensis 60 

Wincesteriana Gord. = Montezumae 64 

Wrightii Engelm. = occidentalis 70 

yunnanensis Franch. = sinensis 60 

Pistillate flower 7 

Primary leaf 1 

Pseudolateral conelet 7 

Resin-ducts of the leaf external 6 

internal 6 

medial 6 

septal 6 

Secondary leaf 2 

Sectional characters 18 

Seed, wing of 16 

winged 16 

wingless 16 

Septal resin-ducts 6 

Serotinous cone 14 

Species, classification of 22 

Specific characters 20 

Spring-shoot 2 

Staminate flowers 7 

Stelar tissues of leaf 6 

Stomata of leaf 4 

Strobi-Group 30 

Strobus, Opiz = Pinus 24 

Strobus strobus SmaU = Pinus strobus 36 

Subsectional characters 20 

Subterminal conelet 7 

flower 7 

Symmetrical cone 10 

Terminal umbo 8 

Tissues of the cone 12 

leaf 4 

wood 17 

Umbo of the cone dorsal 8 

terminal 8 

Uninodal branchlet 2 

spring-shoot 2 

Uniform hypoderm 6 

Variation 21 

Wing of seed, adnate 16 

articulate 16 

Winged seed 16 

Wingless seed 16 

Wood 17 

Wood-strands of the cone 14 

Wood-tissues 17 



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