18 TRANS, ST. LOUIS ACAD. SCIENCE. [178 
* Cones subterminal; leaves in threes to fives. uaustrales. 
P. oocarpa,** occidentalis, australis.*? 
* Cones lateral or mostly so; leaves in twos to threes. £/- 
liottie. 
P. Elliottit,+® Cubensis,+* Wrightit.+® 
NOTES. 
. Peuce, Griseb., may after all be distinct from P. excelsa; it has 
sigect shorter leaves and sheaths, and, if my specimen can be relied on, a 
short fruiting peduncle; the structure of the leaf is nearly the same in both. 
P. Peuce, excelsa, and monticola have a layer of strengthening aw) all , 
around under the epidermis, interrupted only by the stomata, and not in 
distinct bundles as in Lambertiana and csiagighin while ty 
oo and iit gt have scarcely any. all have regularly 
two sal duc nly. In P. excelsa T have ae pric found a third, 
upper, ps enh a parenchymatous one. 
2. P. parvifiora, Sieb. & Z A branch in Herb. Haenke in the 
Prague Museum, marked ‘ P. deters Mitta: Bec Nutka Island,” seems to 
‘belong to this species, which is distinguished by slender, ot and 
very ed serrulate leaves, and scarcely any strengthenin 
ga oe apartea, Roezl. Prof. E. Purkinje, of the Foresters’ Academ 
of welowaienr: Bohemia, who was probably the first to carefully study the 
microscopic anatomy of the pine-leaves with a view to the diagnosis of the 
lis 
extensive and copiously illustrated work, has directed my attention to the 
leaf-structure of this form. It deviates from all the other S¢rodz in having 
numerous, usually 7, ducts, 3 on the back and 2 on each of the upper sides, 
and having strengthening cells in numerous bundles all around and espe- 
cially in the angles. I find no stomata on the back. Roezl’s P. Don Pedri 
has exactly the same structure, but has 3 or 4 series of stomata on the 
back; both evidently belong together. Though I have not been able to 
study the flowers and fruit, I do not hesitate to pronounce it distinct from 
P. Ayacahuite, which, like P. Strobus, has scarcely any strengthening 
cells, and only 2 dorsal ducts. 
2 P. — Lin. The ducts, generally in the middle of the paren- 
aiiyes metimes nearly approach the epidermis, but I have always found 
them ieee from it by at least one layer of parenchymatous cells. 
5. P. monophylla, Torr. & Frem. The number of ducts is excessively 
variable; I have found from 3 to 14 in different leaves. The leaves are 
usually curved, and the upper side, proved to be such by the relative posi- 
on of the wood and bast cells (see p. igs is always directed towards 
the branch. Sometimes two-leaved bundles occur. It is an open question 
she the four species of the subsection Eeebroths may not properly 
ted into one, as the difference of flowers and fruit is very slight, and 
bak of the foliage only relative. 
