OF THE GENUS PINUS. 593 
29. Pinus caNnaRIenstis, Chr. Smith, in Webb § Berthelot, 
Hist. Nat. des Iles Canaries, voi. iii. (1836) p. 280; AlLasters, in 
Gard. Chron. June 9, 1888, fig. 94. 
This tree is well-described and figured in the above-mentioned 
work. It may here be added that the leaves have a marked 
hypoderm, and that the resin-canals are imbedded in the cortical 
substance of the leaf. The meristele is elliptic in section and the 
vascular bundle is divided. 
The cotyledons are 6-8 in number, triangular in form, 
destitute of any proper epidermis and hypodermis. The cells 
of the cortex or mesophyll are polygonal, the endoderm-cells are 
not well-marked. The central bundle is undivided. The cone 
is similar to that of P. maritima (Pinaster), to which species it is 
nearly allied. 
30-31. P. ponperosa, Douglas; Sargent, Silva, xi. (1897) 
p- 77; Britton § Brown, i. p. 51; Beissner, p. 262, fig. 61. 
A Pine with a very wide distribution in Western America, from 
British Columbia in the north to the Mexican boundary on 
the south, and from the western slopes of the Sierra Nevada 
to Dakota, Nebraska, and Western ‘Texas. ‘A tree of such 
enormous range over a region of so many different climates has 
naturally developed many forms, and no other American pine-tree 
varies more in size and habit and the character ofits bark, length of 
leaves, and size of cones....One hundred photographs would not 
be too many to properly illustrate the appearance of P. ponderosa 
-..and an attempt to describe its different forins with any words 
at our command would be hopeless.”——Sargent, in ‘Garden and 
Forest,’ Oct. 2, 1895, p. 392. 
A peculiar feature of this species consists in the circumstance 
that the cones break off when ripe near to, but not quite at the 
base, so that a few scales are left on the bough while the bulk 
of the cone falls to the ground; hence the term Broken-Cone 
Pine given to it by Mr. Lemmon. The coustancy of this 
peculiarity is open to further investigation. An illustrated 
description is given in the ‘ Gardeners’ Chronicle,’ Nov. 15, 1890, 
p- 557. 
The base of the scale tapers gradually to a short stalk-like 
process which is flattened from side to side. This peculiar form 
may in some way be concerned in the detachment of the scales. 
Pinus ponderosa was, according to Sargent, first alluded to in 
the Journal of Lewis and Clark, 1804. It was afterwards found 
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