BOTANICAL DESCRIPTION. 49 



HOOT, STEM, AND IIRANCII SYSTEM. 



The Longleaf Pine attains a height averaging 100 feet, rarely exceeding 110 feet, with a 

 diameter breast high, wlien fully grown, varying between L'O and .'!(> inches, rarely more. The 

 tall, straight, very gradually tapering trunk arises from a massive taproot which, iu favorable 

 situatious, penetrates the soil to a deptli of from 12 to l."> feet, and sometimes much more. It 

 has several stout, comparatively short lateral roots, which assist tiie tree in its hold by slant- 

 ing deeply into the ground, and some of greater length are placed more or less near the surface. 

 Its crown is open and elongated, of irregular shape, about one half to one third of its height. 

 The stout limbs are rarely over 20 feet in length, twisted and gnarled and S[)aring]y branched. 

 The trunk is covered with a reddish-brown bark, one-fourth to three- fourths of an imh thick, 

 lurrowed tlnoughout its full length, crossed horizontally by deep lissures, and scaiiug off in tliiu, 

 bluish, almost transparent rhombic flakes. 



LEAVES AND THEIU MOniFICATIONS. 



Like all the pines, this species produces during various stages of its growth seven difi'ereut 

 modifications of leaves as recognized by botanists, all more or less specific in character: 



(1) Cotyledouary, or seed leaves (first leaves of the embryo), which soon wither and disappear 

 (PI. VII, «, b). (2) Primary leaves succeeding the former immediately on the main axis (PI. VII, c), 

 which either wither or later on are transformed into, or succeeded by, more or less permanent 

 bracts or scales covering the branches (PI. V, «)• (3) The secondary or foliage leaves rising from 

 the buds produced in the axils of the primarj' leaves or of the bud scales by which they are repre- 

 sented (PI. VII, d), permanent foliage of the tree, with three leaves in one sheath. (4) The bud 

 scales forming the slieaths of the foliage leaves (PI. IV, b, c, <1) at base. (5) Involucral bracts of 

 the male flower (PI. V,/). (0) Involucral scales of the female inflorescence (ament) (PI. V, c). 

 (7) The bracts which support the cari)ellary scale bearing the seed (PI. V, /t).' 



The primary leaves, which succeed the cotyledons on the primary axis, are in form and structure 

 true leaves. They are softer than the final foliage leaves, have a broad base, are rounded on tlie 

 dorsal side and not channeled, the whitish transparent margins being finely but distinctly den- 

 ticulate. It is rare that secondary leaves i)roceed from the axils of these chlorophyll-bearing 

 primary leaves. Witii the more frequent appearance of the ordinary leaves, these primary leaves 

 wither and henceforth appear as triangular scale-like coriaceous persistent bracts, with broad, 

 hyaline, long-fringed edges, in the axils of which the undeveloped branchlets are produced bearing 

 the secondary or foliage leaves. 



The chlorophyll-bearing primary leaves exhibit a simple structure. The flbro-vascular bundle 

 is single, embedded iu a wider ring of large cells free from chlorophyll, and the resinous ducts fewer 

 in number, one, or rarely more than two, being irregularly situated in the chlorophyll bearing 

 parenchymatous tissues, and mostly external, i. e., close to the thiclc epidermis. But few of these 

 leaves are formed after the appearance of the foliage leaves, and a few of them persist throughout 

 the first season.'^ The cataphyllary leaves forming the sheath of the foliage leaves are in this 

 species composed of eight successive pairs of bud scales; those of the first pair are blunt, flat, 

 deeply concave and coriaceous, with sharp edges; the others are more membranaceous and with 

 fringed edges, the closely interwoven edges entwining the base of the fascicle. In the secondary 

 leaves the very numerous stomata form, on both sides, regular longitudinal rows. Parallel with 

 these, at regular distances between them and embedded in the parenchymatous tissue, are found 

 bundles of numerous, elongated, thick- walled cells, the so-called hypodermal or strengthening cells. 

 The resin ducts, not over five in number, described by Engelmaua as internal, have been ftmnd in 

 the specimen examined rather parenchymatous, invariably so on the dorsal side. 



Three of the secondary or true foliage leaves are united into one bundle, inclosed at the base 

 by a persistent sheath from one-half inch to an inch in length, formed by the bud scales or 

 cataphyllary leaves. On the older trees the leaves are rarely over S inches iu length, but during 

 the periods of most active growtii they are found 12 to IS inches long. They are finely serrulate, 

 rounded on the back, channeled, and obtusely triangular in cross section. 



' George Engelmanu : Revision of the Geuiis Piuus. Transactions of the St. Louis Academy of Science, 1882. 

 ^Eugelmauu: Rovision of Genus Pinus, Trans. St. Louis Academy of Science, 1882, p. 5. 

 17^33_]Sfo. 13 1 



