MALLOW FAMILY 91 



A genus of over 100 species, distributed in the temperate and subtropical regions of North and South 

 America, South Africa, and Australia. Type species, Sida tricuspidata DC. 



Involucellate bractlets inconspicuous, equaling the calyx-tube or shorter. 



Pubescence on apex of carpels of erect, stellate hairs, harsh, at least near the base of the style, not ap- 

 pressed-horizontal. 



Calyx constricted at apex of the tube; lobes of leaves acute. 1. M.Hallii. 



Calyx not constricted; lobes of leaves rounded or obtuse. 



Inflorescence interrupted-spicate; inner surface of calyx-lobes glabrous; pubescence of calyces long, 



hirsute. 2. M. orbiculatum. 



Inflorescence paniculate; inner surface of calyx-lobes tomentose, at least near the apex; calyces 

 pubescent with short-rayed hairs. 



Leaves cordate, thick; inflorescence many-flowered, pyramidal; pubescence harsh. 



3. M. Davidsonii. 

 Leaves truncate or cuneate at the base, thin; inflorescence narrowly racemose-paniculate; 

 pubescence velvety. 4. M. Jonesii. 



Pubescence on carpels of appressed, horizontally spreading stellate hairs. 



Buds broadly ovoid; calyces broadly campanulate at anthesis; pubescence fine or coarse, but the central 

 rays erect. 



Pubescence on calyces uniform, short-rayed; leaves thin, not rugulose; petioles slender, 1 mm. 

 thick or less. 5. M, fasciculatum. 



Pubescence on calyces of coarse, long-rayed and finer, short-rayed hairs; leaves thick, rugose; 

 petioles stout. 6. M. arcuatiim. 



Buds oblong; calyces narrowly campanulate to nearly cylindrical at anthesis; pubescence minute, of 

 fine-rayed, horizontally appressed stellate hairs. 7. M. nesioticum. 



Involucellate bractlets conspicuous, about equaling or surpassing the calyx-lobes. 



Inflorescence capitate; involucellate bractlets ovate to suborbicular. 8. M. Palmeri. 



Inflorescence not capitate; bractlets linear to lanceolate. 



Buds distinctly plicate-angled; bractlets ovate-lanceolate. 



Inflorescence interrupted-spicate; floral bracts 1-3-dentate; inner surface of calyx-lobes tomentose 

 to base. 9. M. aboriginum. 



Inflorescence paniculate; floral bracts simple; calyx-lobes tomentose only on upper half of inner 

 surface. 10. M. Abbottii. 



Buds not plicate-angled; bractlets linear or setaceous. 



Pubescence of the inflorescence thick-lanate, obscuring the calyx-lobes; buds globose; leaves densely 

 and nearly equally stellate-pubescent on both sides. 11. M. Fremontii. 



Pubescence of the inflorescence harsh or fine, but not obscuring the calyx-lobes; buds ovoid to ovoid- 

 acuminate; leaves more densely pubescent beneath than above. 



Calyces clothed with simple, purplish glandular hairs intermingled with the stellate-pubescence; 

 inflorescence divaricately paniculate. 12. M. gracile. 



Calyces without coarse glandular hairs; inflorescence interrupted-spicate. 



Upper surface of leaves sparsely pubescent to glabrate; inflorescence silky white-tomentose. 



13. M. clementinttm. 



Upper surface of leaves moderately stellate-pubescent, not glabrate; pubescence harsh, 



tawny, not white nor silky. 

 Stipules 4-8 mm. long; leaves more or less 3-S-lobed, the margins irregularly crenate. 



Leaves not rugose; calyces hirsute, the lobes acuminate; stipules 4-5 mm. long. 



14. M. densiflorutn. 



Leaves strongly rugose; calyces harshly stellate-pubescent, not hirsute; stipules 

 5-8 mm. long. ^. M. arcnatum. 



Stipules 10-12 mm. long; leaves scarcely at all lobed, the margins serrate-dentate. 



15. M. marrubioides. 



I. Malvastrum Hallii Eastw. Hall's Malvastrum. Fig. 3177. 



Malvastrum Hallii Eastw. Leaflets West. Bot. 1: 216. 1936. 

 Sphaeralcea fasciculata var. Elmeri Jepson, Fl. Calif. 2: 501. 1936. 



Erect shrub 1-2 m. high with long slender branches, densely canescent with fine, short-rayed 

 stellate hairs. Leaves ovate to suborbicular, irregularly crenate, shallowly 3-5-lobed, broadly 

 cuneate to shallowly cordate at the base, 1-6 cm. long, rugulose, paler and prominently veined 

 beneath; petioles stout; stipules lance-subulate, 5-8 min. long; inflorescence paniculate; pedicels 

 2-6 mm. long; involucellate bractlets linear, 1.5-3 mm. long; calyx campanulate, often slightly 

 constricted at the apex of the tube, 4-5.5 mm. long, the lobes deltoid, 2 mm. wide, 2-2.5 mm. 

 long, densely stellate-canescent ; petals 10-15 mm. long, pink to rose; stamineal column slender, 

 glabrous, half as long as the petals; carpels 2.5-3 mm. high, densely stellate-pubescent on the 

 summits and about one-third the way down the backs with erect, bristly, several-rayed hairs and 

 intermingled with a few smaller, appressed stellate hairs ; seeds ovate-reniform, 2 mm. high, dark 

 brown, sparsely and irregularly puberulent. 



Stony south slopes and canyon sides, Upper Sonoran Zone; Inner Coast Ranges from Mount Diablo to the 

 vicinity of Pacheco Pass, Santa Clara County, California. Type locality: west side of Mount Diablo north of 

 Pine Canyon, Contra Costa County, California. May-Aug. 



Malvastrum mendocinense Eastw. Leaflets West. Bot. 2: 188. 1939. Leaves somewhat broader, the pubes- 

 cence more tawny, and the calyx-tube scarcely or not at all constricted, may be conspecific with or a variety of 

 M. Hallii. Between Ukiah and Booneville, Mendocino County. June-July. 



2. Malvastrum orbiculatum Greene. Round-leaved Malvastrum. Fig. 3178. 



Malvastrum orbiculatum Greene. FI. Fran. 109. 1891. 

 Malacothamniis orbiculatus Greene, Leaflets Bot. Obs. 1 : 208. 1906. 

 Malvastrum Fremontii var. orbiculatum I. M. Johnston, PI. World 22: 109. 1919. 

 Sphaeralcea orbiculata Jepson, Fl. Calif. 2:499. 1936. 



Suffrutescent, stout erect branches 1-2 m. high, densely stellate-tomentose throughout with 



