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 Shaw (l. 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.
[Illustration: PLATE XXVI. PINUS PONDEROSA]
40. PINUS 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, symmetrical; 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.
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