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. GERARDIAXAE 



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. BUNGKA.NA 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 



