ROSE FAMILY 453 



15 or more, inserted in two or three rows on the limb of the hypanthium. Pistil 1 ; style 

 terminal ; ovule solitary, ascending. Fruit a coriaceous terete villous achene, included in 

 the elongated persistent hypanthium and tipped with the elongated twisted plumose style; 

 seed linear. [Greek, meaning shuttle and fruit, in allusion to the fruit and its twisted 

 plumose style.] 



Approximately 10 species, confined to the Rocky Mountains and Pacific Coast region of the United States, 

 extending southward through the Cordilleras of Mexico. Type species, Cercocarpus fothergilloides H. B. K. 



Leaves serrate or dentate. 



Upper surface of the leaves with impressed veins, the lower conspicuously white-tomentose. 



1 . C. Traskiae. 

 Upper surface of the leaves with the veins not impressed, the lower surface glabrate, strigose or somewhat 

 tomentose. 

 Leaves with coarse ovate teeth. 2. C. montanns. 



Leaves with short triangular apiculate teeth. 



Leaves more or less pubescent beneath and grayish; sepals broadly triangular. 



Hypanthium villous-tomentose; petioles 4-10 mm. long; leaves mostly over 2.5 cm. long. 



3. C. alnifolius. . 



Hypanthium appressed-pubescent; petioles 2-4 mm. long; leaves mostly less than 2.5 cm. long. 



4. C. betuloides. 



Leaves glabrous or essentially so beneath and bright yellowish-green; sepals nearly subulate. 



5. C. minutiflorus. 

 Leaves with entire more or less revolute margins, linear to oblong-elliptic. 



Leaves 15-30 mm. long, the margins only slightly revolute. 6. C. ledifolius. 



Leaves 5-15 mm. long, the margins strongly revolute almost to the midrib. 7. C. intricatus. 



1. Cercocarpus Traskiae Eastw. Trask's Mountain-mahogany. Fig. 2484. 



Cercocarpus Traskiae Eastw. Proc. Calif. Acad. III. 1: 136. 1898. 



Shrub or small tree, 3-7 m. high, with a trunk up to 20 cm. in diameter, the bark rough, 

 grayish brown, the branchlets densely tomentose. Leaves rounded to oval, 25-60 mm. long, obtuse 

 at the apex, subcordate, truncate or rarely cuneate at base, dentate or nearly entire, glabrous 

 and shining above in age, densely white-tomentose beneath; lateral veins 7-8, very prominent 

 beneath ; flowers in fascicles of 3-7 ; hypanthium about 1 cm. long, densely villous-tomentose, its 

 limb and broadly triangular sepals 5-8 mm. in diameter ; style in fruit about 5 cm. long. 



A rare insular species, known only from Santa Catalina Island, southern California. March-April. 



2. Cercocarpus montanus Raf. Colorado Mountain-mahogany. Fig. 2485. 



Cercocarpus montanus Raf. Atlant. Journ. 146. 1832. 



Cercocarpus parvifolius Nutt. ex Hook. & Arn. Bot. Beechey 337. 1838. 



Cercocarpus macrourus Rydb. N. Amer. Fl. 22: 420. 1913. 



Shrub 1-3 m. high with thin grayish brown bark and sparingly villous branchlets soon be- 

 coming glabrous. Leaves oval to obovate, 25-50 mm. long, coarsely dentate above the middle, 

 dark green and eventually glabrous above, pale and finely tomentose beneath, rounded or obtuse 

 at apex, cuneate at base ; hypanthium villous-pilose, its limb and sepals about 6-7 mm. in diam- 

 eter ; fruiting style 5-8 cm. long. 



Dry hills and mountain slopes, Upper Sonoran and Transition Zones; South Dakota and New Mexico west 

 to Montana and Utah; also in northeastern California and adjacent Oregon. The western plants are C. macrourus 

 Rydb. Type locality: Rocky Mountains [Colorado]. March-May. 



3. Cercocarpus alnifolius Rydb. Island Mountain-mahogany. Fig. 2486. 



Cercocarpus betulaefolius var. Blancheae C. K. Schneid. Mitt. Deuts. Dendr. Ges. 14: 127, in part. 1905. 

 Cercocarpus alnifolius Rydb. N. Amer. Fl. 22: 421. 1913. 



Small tree, 5-10 m. high, with rough grayish bark, young branchlets sparsely tomentose, 

 soon glabrate and reddish brown. Leaves oval to ovate-oval or round-oval, 3-6 cm. long, spar- 

 ingly appressed-pubescent above when young, thinly tomentulose beneath, dentate with short 

 broad teeth, lateral veins 6 or 7 pairs ; hypanthium tube about 12 mm. long, villous-tomentose, 

 the limb 6-7 mm. wide ; sepals broadly triangular ; styles 5-6 cm. long in fruit, usually strongly 

 curved. 



Hillsides and canyons, Upper Sonoran Zone; Santa Cruz and Santa Catalina Islands, California. Type 

 locality : Avalon, Santa Catalina Island. March-April. 



4. Cercocarpus betuloides Nutt. California Mountain-mahogany. Fig. 2487. 



Cercocarpus betuloides Nutt. ex Torr. & Gray, Fl. N. Amer. 1: 427. (June) 1840. 

 Cercocarpus betulaefolius Nutt. ex. Hook. Ic. PI. pi. 322. (Oct.) 1840. 

 Cercocarpus parvifolius var. glaber S. Wats. Bot. Calif. 1: 175. 1876. 

 Cercocarpus parvifolius var. betuloides Sarg. Silva 4: 66. 1892. 

 Cercocarpus Douglasii Rydb. N. Amer. Fl. 22: 421. 1913. 

 Cercocarpus rotundifolius Rydb. loc. cit. 



Shrub or small tree, 3-8 m. high, with smooth bark, covered with deciduous scales, the 

 branchlets glabrous or sparingly hairy. Leaves obovate or oval, 2-5 cm. long, rounded at the 

 apex, cuneate at base, serrate above the middle, sparingly appressed-hairy when young, soon 

 glabrate, dark green above, paler beneath ; hypanthium silky-tomentose, its limb 6 mm. broad ; 

 sepals broad-triangular ; fruiting style 6-10 cm. long. 



A common component of the chaparral, Upper Sonoran Zone; southwestern Oregon to northern Lower Cali- 

 fornia. Type locality: Santa Barbara, California. March-April. Hardtack. 



