454 ROSACEAE 



The above description is of the typical form, which is common in the California Coast Ranges from Sonoma 



Cuyamaca Mountains 'the foliage becomes soft-downy beneath. Several species have been proposed for these 

 variations. 



5. Cercocarpus minutiflorus Abrams. Smooth Mountain-mahogany. Fig. 2488. 



Cercocarpus minutiflorus Abrams, Bull. Torrey Club 37: 149. 1910. 



Shrub 2-3 m. high, with herbage glabrous throughout. Leaves obovate, cuneate at base, 

 serrate-toothed on the rounded summit, 1-2 cm. long, shining yellowish green beneath ; pedicels 

 slender, 6-7 mm. long; hypanthium tube 10-12 mm. long, 1 mm. broad, the limb 2-3 mm. broad, 

 minutely and sparsely tomentulose ; sepals subulate-triangular. 



Chaparral slopes, Upper Sonoran Zone; hills and mountain slopes of San Diego County, California. Type 

 locality: dry chaparral-covered hills near San Dieguito (Bernardo). March-April. 



6. Cercocarpus ledifolius Nutt. Curl-leaved Mountain-mahogany. Fig. 2489. 



Cercocarpus ledifolius Nutt. ex Torr. & Gray, Fl. N. Amer. 1 : 427. 1840. 

 Cercocarpus hypoleucus Rydb. N. Amer. Fl. 22: 424. 1913. 



A small tree or shrub, 2-9 m. high, with red-brown furrowed bark covered with persistent 

 scales, the branchlets canescent, soon becoming glabrous. Leaves narrowly lanceolate, 1-3 cm. 

 long, acute at the apex, narrowed at base to a short petiole, the margins revolute, entire, thick- 

 coriaceous, usually glabrous above, resinous and tomentulose beneath; flowers solitary or in 

 axillary clusters of 2 or 3, sessile; hypanthium white-villous-tomentose. 



Open rocky ridges, Arid Transition and Canadian Zones; eastern Washington to Montana, and southward 

 of the Cascade-Sierra Nevada Divide to southern California and Colorado.. Type locality: "Rocky Mountains in 

 alpine situations on the summits of the hills of Bear River [Idaho]." April-May. 



7. Cercocarpus intricatus S. Wats. Little-leaved Mountain-mahogany. 



Fig. 2490. 



Cercocarpus intricatus S. Wats. Proc. Amer. Acad. 10: 346. 187S. 

 Cercocarpus ledifolius var. intricatus M. E. Jones, Zoe 2: 14. 1891. 



Low intricately branched shrub, 5-15 dm. high, young branchlets pubescent. Leaves oblong, 

 but strongly revolute, 5-10 mm. long, thick, dark green and glabrate above, white-tomentose 

 beneath; hypanthium tube 4-6 mm. long, tomentulose, the limb 3 mm. wide; persistent style 

 of achene 2-4 cm. long. 



Desert ranges and mountain slopes, mainly Arid Transition Zone; (White, Panamint, and Providence Moun- 

 tains) California to Utah and Arizona. Type locality: American Fork Canyon, Utah. May. 



29. COLEOGYNE Torr. PL Frem. 8. 1853. 



Shrubs with opposite spinescent branches and minute stipules. Leaves in opposite 

 fascicles, linear-clavate, entire, deciduous. Flowers solitary terminating short branchlets, 

 subtended by trifid bracts. Hypanthium coriaceous. Sepals 4, united at the base, persistent. 

 Corolla none. Stamens 30-40; filaments filiform. Pistil 1 ; ovary 1-celled; ovule 1, hemitro- 

 pous ; style lateral, filiform, exserted, bent and twisted, villous. Fruit an achene. [Name 

 Greek, meaning sheath or scabbard and ovary.] 



A monotypic genus of western North America. 



1. Coleogyne ramosissima Torr. Black Bush. Fig. 2491. 



Coleogyne ramosissima Torr. PI. Frem. 8. 1853. 



Shrub 0.5-2 m. high with divergent branches, ashy gray, becoming black in age. Leaves 

 linear-clavate, 5-15 mm. long, flat on the upper surface, with 5 rounded longitudinal ridges on 

 the lower, strigose; sepals oblong-lanceolate, acute and mucronate, 7-8 mm. long, coriaceous 

 and strigose, the inner with broad, scarious, brownish or yellowish margins; sheath between 

 the pistil and stamens 4-5 mm. long ; achene about 5 mm. long, brown. 



Desert mesas and foothills, Upper and Lower Sonoran Zones; Mojave and Colorado Deserts, southern Cali- 

 fornia, to southern Utah, southwestern Colorado, and Arizona. Type locality: sources of the Mojave and Virgin 

 Rivers. April-July. 



30. RUBUS [Tourn.] L. Sp. PL 492. 1753. 



Low shrubs or trailing vines, usually prickly, with alternate leaves, the stipules adnate 

 to the petioles. Flowers terminal or axillary, solitary, racemose or panicled, white or 

 purplish, mostly perfect. Hypanthium persistent, bractless. Sepals 5. Petals 5. Stamens 

 many, inserted on the hypanthium, distinct. Carpels many, inserted on a convex or elon- 

 gated receptacle, ripening into drupelets and forming an aggregate fruit. Ovules 2, 1 abor- 

 tive; style terminal, slender. Seed pendulous. [The ancient name of the bramble, from 

 ruber, red.] 



About 200 species, widely distributed, but most abundant in the north temperate zone. Type species, Rubus 

 fruticosus L. 



