68 GENUS PINUS 



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. 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. 



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. PINUS LAWSONII 



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 rounded 

 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 XXVII. 



Fig. 239, Three cones. Fig. 240, Leaf-fascicle and magnifled leaf-section. Fig. 241, Magni- 

 fied cells of the leaf-endoderm. 



