554 
** Leaves 2 or 3, cach with two fibro-vascular bundles: sheath close: woody scales of the 
cones thickened at apex and usually spiny-tipped. 
+ Cones lateral; scales much thickened at apex, mostly spiny. 
++ Leaves in threes. 
2.P.Tedal. A tree 15 to 45m. high: leaves long (15 to 25em.), with elongated 
sheaths: cones elongated-oblong (7 to 12cm, long) and tapering; scales tipped with 
very stout incurved spines: seed with 3 strong rough ridges on the under side.— 
Extending from the Gulf States to the valley of the Colorado, ‘Loblolly pine.” 
“Old-field pine.” 
++ 4+ Leaves in twos. 
3. P. mitis Michx. <A straight tree 15 to 30 m. high: leaves sometimes in threes, 
from long sheaths, slender (7 to 12 cm. long): cones ovate or oblong-conical (barely 
5em. long), the scales with a minute weak prickle.—Extending into eastern Texas 
from the Atlantic and Gulf States. ‘‘Yellow pine.” ‘‘Short-leaved pine.” ‘‘Spruce 
pine.” Bull pine.” 
4. P. glabra Walt. A tree 24 to 30m. high, with smoothish bark and soft white 
wood, branching near the ground: branches and branchlets smooth, whitish: leaves 
slender (7 to 10 em, long), scattered: cones generally solitary, somewhat cylindrical 
(5 em, long), spines nearly obsolete.—Extending into eastern Texas from the Gulf 
States. ‘Cedar pine.” “Spruce pine.” ‘‘ White pine.” 
+ + Cones terminal or subterminal, 
++ Leaves tn twos (rarely threes), 
5. P. edulis Engelm. <A low round-topped tree, 6 to 9m. high, branched below: 
leaves 2.5 to 83cm. long, rigid, curved orstraightish, spreading: cones sessile, subglo- 
bose, 5 em. long; tips of the scales thick, truncate, raised pyramidal, but without 
awns or prickles: seeds brown, wingless, edible.—In the mountains of western Texas 
and westward. One of the trees known as ‘‘pifion” or ‘ nut-pine,” 
++ 4+ Leaves in threes. 
= Scales spiny, 
6. P. ponderosa Dougl. A very large tree (60 to 90 m. Ligh, and 35 to 45 dm. in 
diameter), with very thick reddish-brown bark, deeply furrowed and split into large 
plates: leaves 12 to 17 em. long: cones oval, 7 to 12 em. long and 4 em. thick, rich 
brown, sessile (or nearly so), often 3 to 5 together; scale-tips with a stout recurved 
prickle: seeds dark brown, 8 mm. long, with wings 20 to 25 mm. long, and widest 
above the middle.—Guadalupe and Limpia mountains and northward. ‘ Yellow 
pine.” “Bull pine.” 
7. P, palustris Mill. <A large tree, with thin-scaled bark and very hard resinous 
wood: leaves from long sheaths, very long (15 to 37 cm.), crowded at the summit of 
very scaly branches: cones large, cylindrical or conical-oblong (15 to 25 em. long), 
the thick scales armed witha short reeurved spine. (P. australis Michx.)—Sandy 
soils, extending from the Gulf States as far as Trinity River. ‘‘Long-leaved pine.” 
“Georgia pine.” ‘Southern pine.” ‘Yellow pine.” ‘Hard pine.” 
&. P. Chihuahuana Engelm. <A middle-sized tree: leaves closely serrulate, 6 to 
10 em. long; sheaths loose, glistening (12 mm. long), deciduous after the first season : 
cones oval, small, 3 cm. long; scale-tips bearing recurved deciduous prickles.—Ex- 
tending from the mountains of northern Mexico to those of western Texas and 
Arizona. 
” 
