496 MALVACEAE 



Caljx with long stellate-hirsute hairs ; heads several along the naked summit of branches ; 



San Jacinto Mts. to eastern San Diego Co 5. S. densiflora. 



Calyx stellate-pubescent. 



Bractlets ovate; s. Monterey Co 6. S. ahoriginum. 



Bractlets lanceolate to linear. 



Herbage covered with a dense white tomentum. 



Flower-buds merely tomcntulose, the calyx-lobes not concealed. 



Leaf-blades round-cordate or pentagonal; corolla rose-color, some- 

 times aging yellow. 

 Panicle Avith the glomerules sessile or subsessile, thus interrupted- 

 spicate, not leafy ; leaf -blades relatively thin, not mark- 

 edly rugose; mts. bordering west half Mohave Desert.... 



7. S. orbiculata. 

 Panicle with mostly racemose-peduncled branches, leafy through- 

 out or the leaves reduced at summit; leaf -blades thick, 



rugose; cismontane S. Cal 8. A davidsonii. 



Leaf -blades ovate, conspicuously rugose ; corolla yellow ; Santa Clara 



and Santa Cruz Cos 9. S. arcuata. 



Flower-buds heavily invested in a dense wool, the calyx -lobes concealed; 

 corolla rose-pink ; leaf-blades pentagonal or roundish, cordate at 

 base, the lobes roundish ; Great Valley foothills.. ..10. S. fremontii. 



Herbage finely stellate-pubescent; South Coast Eanges; S. Cal 



11. <S. fasciculaia. 



B. Carpels 2-ovuled, one to S-seeded; ours perennial. — Subgenus Eusphaeralcea. 



Mature carpels one-seeded; upper empty portion of carpels minute and inconspicuous; plants 



leafy; racemes from upper axils; corolla small, vermilion; Colorado Desert 



12. S. orcuttii. 

 Mature carpels one to 3-seeded ; upper portion of carpels not conspicuously reduced. 



Carpels glabrous or merely canescent on back, more or less reticulate on lower portion of 

 sides. 

 Leaf -blades palmately parted or divided with cleft or toothed lobes ; Panamint Eange.... 



13. S. eremicola. 

 Leaf -blades crenate or shallowly lobed. 



Leaf -blades mostly lanceolate or oblong to linear ; deserts chiefly. 



Flowers few in the leaf axils; leaves thickish, rugose 14. S. angustifolia. 



Flowers numerous in an elongated panicle; leaves thin, not rugose 



15. S. fendleri. 

 Leaf -blades broader, cordate to orbicular-ovate; flowers numerous in elongated 

 thyrsoid panicles. 

 Flowers apricot-color to salmon-red; leaves thickish; deserts....l6. S. amhigua. 

 Flowers pink, drying violet-purple ; leaves thinnish ; mts. on west side of Colo- 

 rado Desert 17. S. rosacea. 



Carpels covered on back with long bristles, thua forming a somewhat bur-like fruit ; flowers 

 large, sparse ; corolla rose-color. 

 Calyx-lobes ovate, acute or acuminate ; leaf -blades deeply 5-lobed, truncate or subcordate 



at base, 2% to 6 inches long; Humboldt Co 18. S. rivularis. 



Calyx -lobes round-ovate, abruptly acute; leaf -blades typically cuneate-obovate, % to 1 

 inch long; Shasta and Modoc Cos 19. S. baheri. 



1. S. rotundifolia Jepson. Five-spot Mallow. Stem erect, branching, 4 to 

 16 (or 24) inches high; herbage hirsute; leaves few, the blades orbicular-cordate, 

 crenate, % to 2 inches wide, the petioles 1 to 3 inches long; bractlets filiform; flow- 

 ers in terminal corymbs or corymbose racemes; petals rose-pink with a large red- 

 purple spot below middle of petal, 9 to 13 lines long; carpels 35 to 45, very flat, 

 narrow on the back, black, rugose-reticulate. 



Washes, lava plains and sandy-gravelly slopes or mesas, -280 to 3800 feet : Inyo 

 Co.; eastern Mohave Desert; Colorado Desert. East to Arizona. Apr.-May. 



Field note. — A frequent annual, everywhere in the deserts, in years of rainfall, though never 

 closely colonizing any considerable areas. The aestivation of the lilac or pink-crimson petals in 

 anthesis is such as to form a globose corolla, the circular crimson or maroon spot at the base of 

 each petal large and showy. 



Locs. — Inyo Co. : Shoshone, R. S. Ferris 8004 ; Argus Mts., Purpus 5316 ; Bad Water, Death 

 Valley, J. Grinnell; Furnace Creek, Funeral Mts., Jepson 6922. Mohave Desert: Needles, Jepson 

 5479; Newberry, Newlon 505; Yermo, Jepson 15,861; Ord Mt., Jepson 15,498; Barstow, Jepson 



