228 NORTH AMERICAN FLORA [VoLuME 23 
A tall tree, 30-35 m. high ; bark rough and dark on the old trunks, smooth and pale on 
the young trunks and branches; twigs tomentose when young ; leaves with narrow sinuses, 
3-5-nerved, 3-5-lobed, entire or remotely dentate, cordate to truncate at the base, 15-25 cm. 
Jong and broad, tomentose on both sides when young, glabrescent above with age; leaf- 
lobes acuminate, divergent, the middle one about twice as long as broad and at least half 
as long as the blade; petioles pubescent, 5-8 cm. long ; stipules 2-3 cm. long, entire or den- 
tate; peduncles pubescent; fruiting heads 3-5, sessile, 2-2.5 cm. in diameter at maturity ; 
achene 7 mm. long, glabrous, much exceeding the basal hairs, rounded at the apex and 
tipped with a persistent style 2~3 mm. long. 
TYPE Locality: California. 
DISTRIBUTION : Central and southern California and Lower California. 
ILLUSTRATIONS: Nutt. loc. cit, pl. 15; Pacif.R.R. Rep. 6: pl. 2, 7.10; Dippel, Handb. Laubh. 
3: f. 151; Sargent, Silva N. Am. £2. 328; Sargent, Man. f 272; Britton, N. Am. Trees /. 367. 
3. Platanus Wrightii S. Wats. Proc. Am. Acad. 
10: 349. 1875. 
A tree, reaching a height of 25 m., bark smooth, light-colored, becoming rough and 
dark on the old trunks; twigs tomentose when young; leaves 15-20 cm. long and wide, 
3-5-nerved, 3-5-lobed, with narrow sinuses entire or nearly so, truncate or usually cordate 
with a deep sinus at the base, glabrous above, pubescent beneath ; lobes elongate, acute, 
divergent, the middle one about twice as longas wide and at least half as longas the blade; 
petioles pubescent or becoming glabrous ; stipules dentate or lobed; peduncles tomentose, 
bearing 3-5 heads; fruiting heads 2-2.5 cm. in diameter, on pedicels about equaling the 
heads ; achene glabrous, about 6 mm. long, exceeding the basal hairs, truncate and tipped 
with a short style seldom more than 1 mm. long. 
TYPE LOCALITY : Southeastern Arizona. 
DISTRIBUTION : New Mexico, Arizona, and Sonora. 
ILLUSTRATIONS : Sargent, Silva N. Am. f/. 329; Sargent, Man. f. 273; Britton, N. Am. Trees 
fF. 366 
4. Platanus mexicana Moric. Pl. Am. Rar. 12. 1830.— Bull. Bot. 
Seringe 175. 1830. 
A tall tree ; young twigs and foliage densely pubescent ; leaves 8-12 cm. long, 9-15 em. 
wide, 3-nerved, 3-5-lobed or rarely with two additional basal lobes, truncate or rounded at 
the base, in age green and shining above, closely and softly cinereous beneath; lobes 
divergent, shallow, with broad rounded sinuses, entire, or with a few teeth, acute or short- 
acuminate, the middle one about as broad as long and less than half as long as the blade; 
petioles pubescent, 4-6 cm. long; stipules rounded, entire; fruiting peduncles 8-14 cm. 
long, nearly glabrous; heads usually two, sessile, 2.5 cm. in diameter; achenes 6 mm. 
long, pubescent, equaled by the basal hairs, narrowed at the tip into a persistent style 2.5 
min. long. 
TYPE LOCALITY: Mexico. . 
DISTRIBUTION : Northeastern and central Mexico. 
ILLUSTRATION : Mém. Soc. Genéve 6: f/. 26. 
5. Platanus glabrata Fernald, Proc. Am. Acad. 36: 493. 1901. 
Platanus Lindeniana S. Wats. Proc. Am. Acad. 18: 155. 1883. Not P. Lindeniana Mart. & Gal. 
A tree, with closely and finely pubescent twigs ; leaves broad, 8-10 cm. long, 10-12 cm. 
wide, 3-nerved, 5-lobed, with broad rounded sinuses, truncate at the base, pubescent when 
young, with age becoming glabrous above and nearly so beneath; lobes short-acuminate, 
entire, the middle as broad as or broader than long, and less than half as long as the blade; 
petioles closely pubescent, 4-6 cm. long; stipules lobed or dentate; peduncles 8-10 cm. 
long, glabrous or nearly so; heads single and terminal, or rarely two and sessile, 1.5-2 cm. in 
diameter; achenes 5 mm. long, glabrous below, pubescent towards the tip, much longer 
than the basal hairs, abrubtly narrowed into a short style 1-1.5 mm. long. 
TYPE LOCALITY: Monclova, Coahuila. 
DISTRIBUTION: Northeastern Mexico. 
