OF THE GENUS PINUS. 579 
account of the different form of the cone-scales and the shorter 
seed-wing. So far as I have seen, the leaves are usually much 
shorter than in P. Ayacuite, denticulate at the edges, though 
figured by Sargent as entire; the cones are also shorter, obtusely 
cylindric rather than conic, with the cone-scales rounded obtuse 
at the recurved tips, and with nearly wingless seeds. 
It is a native of the mountains of Northern Arizona and of 
Chihuahua, at elevations of from 6000-8000 ft., usually growing 
singly. 
5. Pinus Ayacuire, Lhrenberg. 
This is a five-leaved Pine with long slender leaves, and usually 
with elongated cones. The cone-scales generally taper towards 
the apex and are there strongly recurved. The young shoots in 
the cultivated trees are generally covered with down, devoid of 
leaves at the base, but sometimes clothed with leaf-fascicles. 
The resin-canals are marginal, the stereome-cells abundant 
beneath the epidermis and around the resin-canals. Engelmann, 
however, describes them as few in number and not preseut around 
the ducts. The meristele is circular in section, and the fibro- 
vascular bundle unbranched. The endoderm-cells are about 24 
in number. The stomata are in four rows on the sides, but not 
on the back of the leaf. The wing of the seed is as long or 
longer than the seed itself. Cotyledons 12-15. 
The species is a native of the mountains of Northern Mexico 
and perhaps to the mountains of Southern Arizona. It seems 
more probable, as Sargent has pointed out, that the Arizona tree 
is a distinct species, with very narrow wings to the seed, and which 
he refers to P. strobiformis of Engelmann. 
6. P. scrrrontrormis (§ Strobus), Masters, in Bull. Herb. 
Boissier, April 1898, p. 270. 
This is one of Dr. Henry’s discoveries in Hupeh. It is one of 
the Strobus section, with oblong-obtuse cones, 38-5 centim. long, 
resembling a short stick, whence the name. 
The resin-canals are subepidermal. There are 4 or 5 rows of 
stomata on the sides of the leaf, but none on the dorsum. 
7. P.Srrosus, Linn.; Sorgent, Silva, xi. (1897) p. 17, t. 533; 
Britton § Brown, Illustrated Flora of the N. United States, Canada, 
ete., 1. (1896) p- 51, fig.; Beissner, Handbuch, ed. 2, p- 290. 
To the description of this well-known Pine, of which an authen- 
