STANDLEY TREES AND SHRUBS OP MEXICO 1561 



Frutescent (?); branches rough-pubescent, bearing single pedunculate heads: 

 branch leaves ovate, 2 to 2.5 cm. long, subentire, harshlv whitish-pubescent with 

 appressed hairs; heads about 3.5 cm. wide. 



A doubtful species, known from a single collection. 



5. Encelia californica Nutt. Trans. Amer. Phil. Soc. n. ser. 7: 357. 1841 

 Northern Baja California. California and Arizona; type from Santa Barbara 



California. ' 



Frutescent below, up to 3.5 meters high; stem and peduncles cinereous with 



fine, chiefly incurved hairs; leaf blades ovate to lanceolate, entire or subentire, 



green, 3 to 6 cm. long; peduncles elongate; heads about 4 cm. wide. 



5a. Encelia californica asperifolia Blake, Proc. Amer. Acad. 49: 368. 1913. 

 Baja California and islands; type from Cedros Island. 

 Smaller and more woody; leaves smaller, the blades 1 to 3 cm. long, scabrid- 



pubescent; heads smaller. 



6. Encelia palmeri Vasey & Rose, Proc. U. S. Nat. Mus. 11: 535. 1889. 

 Baja California; type from Lagoon Head. 



Shrubby below, 1 meter high or less, canescent-hispidulous on the younger 

 parts; leaf blades ovate to rotund-ovate, 1.5 to 4 cm. long, nearly or quite as 

 wide, entire or bluntly toothed; heads 2.5 to 4 cm. wide. "Mirasol" (Baja 

 California) . 



7. Encelia halimifolia Cav. Icon. PL 3: 6. pi. 210. 1795. 

 Pallasia grandiflora Willd. Sp. PI. 3: 2261. 1804. 

 Encelia conspersa Benth. Bot. Voy. Sulph. 26. 1844. 



Sonora and Baja California; type from Mexico, without definite locality. 



Shrubby below; branches strigillose or hispidulous; leaf blades ovate or oblong- 

 ovate, 2 to 4 cm. long, entire, cuneate to truncate at base; heads 1.5 to 2.8 cm. 

 wide; phyllaries densely white-ciliate. 



8. Encelia stenophylla Greene, Bull. Torrey Club 10: 41. 1883. 

 Known only from the type locality, Cedros Island, Baja California. 

 Suffrutescent, about 30 cm. high, glutinous; leaves crowded on the lower part 



of the stems, narrowly linear, 1-nerved, 2.5 to 8 cm. long, 1 to 2 mm. wide; heads 

 numerous, cymose-panicled, j^ellow, about 1.5 cm. wide; achenes silky-villous, 

 2-awned. 



69. HYMENOSTEPHIUM Benth. (in Benth. & Hook. Gen. PI. 2: 382. 1873, 

 hyponym); in Hook. Icon. PI. 12: 48. pi. llS/,. 1873. 

 Suffrutescent or herbaceous; leaves (in ours) ovate, petioled, mostly opposite; 

 heads cymose or cymose-panicled, small or medium, radiate, yellow; involucre 

 2 or 3-seriate, graduate or subequal, the phyllaries ovate or lance-ovate, usually 

 without conspicuously herbaceous tips; achenes obovoid, somewhat compressed, 

 pubescent or glabrous; pappus of few unequal squamellae without awns, or none. 



Disk in anthesis 8 to 13 mm. thick; involucre 5 to 6 mm. high, the phyllaries 



ovate, their tips herbaceous, gradually acuminate 4. H. superaxillare. 



Disk in anthesis usually less than 8 mm. thick; involucre usually 4 mm. high or 

 less, the phyllaries mostly lance-ovate, with attenuate or very narrowl}^ 

 acuminate tips, these obscurely if at all herbaceous. 

 Heads in anthesis subcylindric, the disk usually about 3 mm. thick; pubescence 



of the stem usually appressed 1. H. microcephalum. 



Heads in anthesis campanulate, the disk usually 5 to 8 mm. thick. 

 Pubescence of stem and under leaf surface copious, spreading. 



2. H. guatemalense. 

 Pubescence of stem and under leaf surface sparse, appressed. 



3. H. cordatum. 



