FLOWERING PLANTS AND FERNS OF ARIZONA 575 



3. Stems and leaves sparsely to densely silvery-lepidote with scalelike hairs, 



leaf blades triangular-lanceolate to triangular-ovate, longer than wide, 

 acutish to acuminate at apex; involucel none; petals while when 

 fresh; carpels dehiscent at apex 3. S. lepidota. 



2. Flowering stems not from rootstocks; plants not conspicuously whitish 

 canescent or lepidote; leaf blades not or scarcely oblique at base; petals 

 orange yellow when fresh; carpels more or less dehiscent at apex, rugose 

 or reticulate on the sides (4). 



4. Stems decumbent or prostrate, these and the petioles sparingly hirsute 



with long, spreading, very slender, simple hairs, also finely stellate- 

 canescent or puberulent, and with short, glandular hairs; flowers 

 axillary, solitary, on long, slender peduncles; calyx usually both 



long-hirsute and puberulent 4. S. diffusa. 



4. Stems erect or ascending or, if somewhat decumbent, then the flowers 



clustered at the ends of the stems and branches; stems, petioles, and 



pedicels finely stellate-canescent or puberulent, without long simple 



hairs; calyx not hirsute (5). 



5. Plant perennial, without a definite axis, the stems diffuse, several or 



numerous from a woody root; leaf blades linear or narrowly oblong 



(the lowest sometimes ovate), serrate; petals fading pink; carpels 



muticous or short-mucronate, rugulose only at the edges, scarcely 



differentiated apically and basally 5. S. nbomexicana. 



5. Plant normally with a definite axis, this and the branches erect or 



nearly so, virgate; leaf blades narrowly lanceolate to ovate, crenate 



or crenate-dentate; petals not fading pink; carpels with a smooth 



dehiscent apical portion sharply differentiated from the reticulate 



indehiscent basal portion (6). 



6. Taproot slender, not woody; plant annual, herbaceous; leaf blades 



narrowly lanceolate, not more than 8 mm. wide, acuminate at 



apex, finely crenate-dentate, dowers mostly in small clusters in 



the upper axils and at the ends of the main stem and branches; 



peduncles usually less than 1 cm. long; carpels commonly bicus- 



pidate or biaristate, the basal portion rugose-tuberculate. 



6. S. ANGUSTIFOLIA. 



6. Taproot thick, woody; plant perennial, often suffrutescent; leaf blades 

 ovate or oblong-ovate, mostly 10 to 20 mm. wide, obtuse or 

 acutish at apex, coarsely crenate; flowers solitary, axillary (by 

 reduction of the upper leaves the inflorescence sometimes appear- 

 ing as an elongate, terminal raceme); peduncles 1 to 3 cm. long; 

 carpels bimucronate, the basal portion :oarsely reticulate. 



7. S. TRAGIAEFOLIA. 



1. Sida hastata St, Hil., Fl. Bras. Mer. 1: 190. 1827. 



Sida physocalyx A, Gray, Boston Jour, Nat. Hist. 6: 163. 1850. 



Cochise, Santa Cruz, and Pima Counties, 3,500 to 5,000 feet, 

 rather frequent in rich soil in canyons, also at Beaver Creek, Yavapai 

 County {Pur pus 57), March to October. Texas to Arizona and northern 

 Mexico. 



Readily distinguished from all other species of Sida in Arizona by 

 the inflated, strongly 5-angled calyx and the large, tuberlike root. 



2. Sida hederacea (Dougl.) Torr. in A. Gray, Amer. Acad. Arts and 



Sci. Mem. ser. 2, 4: 23. 1849. 



Malva hederacea Dougl. ex Hook., Fl. Bor. Amer. 1 : 107. 1830. 

 Disella hederacea Greene, Leaflets 1: 209. 1906. 



Apache County to Coconino, Pinal, and Yuma Counties, 1,000 to 

 5,000 feet, moist, often saline soil, usually near streams, May to 

 October. Oklahoma and Texas to Washington. California, Arizona, 

 and Mexico. 



286744°— 42- 



