NORTH AMERICAN FLORA [Volume 34 



39. TRICHYMENIA Rydberg, gen. nov. 



Perennial herbs. Leaves alternate, petioled, biternately divided into linear divisions. 

 Heads discoid, corymbose-paniculate. Involucre turbinate; bracts in two series, the inner 

 6-8 obovate or oblong, scarious and tinged with purple, the outer 4 or 5 linear, smaller and 

 more herbaceous. Ray-flowers wanting. Disk-flowers hermaphrodite; corollas pale-purplish 

 or almost white; tube slender, glandular; limb cleft nearly to the tube into oblong linear 

 lobes, equal or in the marginal flowers somewhat unequal. Anthers purple, wholly exserted, 

 bidentate at the base, tipped with ovate appendages. Style-branches flat, linear, with conic, 

 subulate- tipped appendages. Achenes elongate, obconic, 4-angled, villous. Pappus of 15-18 

 narrowly linear-lanceolate squameUae with strong midribs excurrent into short barbellate 

 awns. 



Type species, Hymenothrix Wrightii A. Gray. 



1. Trichymenia Wrightii (A. Gray) Rydberg. 



Hymenothrix Wrightii A. Gray, Pi. Wright. 2: 97. 1853. 

 Hymenopappus Wrightii H. M. Hall, Univ. Calif. Publ. 3: 179. 1907. 



A perennial herb; stem 6-10 m. high, sparingly hirsute below, glabrous above, striate; 



leaves bi- or tri-ternate, 5-10 cm. long, with linear divisions, the lower ones hirsute, the upper 



glabrous ; inflorescence paniculate, the heads corymbose on the branches ; involucre tiurbinate- 



campanulate, 6 mm. high, 8-9 mm. broad; corolla-tube 2.5 mm. long; throat practically 



none; lobes oblong-linear, acute, 2-3 mm. long; achenes 4 mm. long, 1 mm. thick, hirsute; 



squamellae 3-4 mm. long. 



Type locality: Hills between Barbocomori and Santa Cruz, Sonora. 

 Distribution: New Mexico to southern California and Sonora. 

 Illustration: Sitgreaves, Rep. Exp. Bot. pi. 6. 



40. FLORESTINA Cass. Bull. Soc. Philom. 1815: 175. 1815. 



Lepidopappus Moc. & Sess6; DC. Prodr. 5: 655, as synonym. 1836. 



Pubescent and more or less glandular annuals. Leaves petioled, the lower opposite, the 

 upper alternate, aU except the uppermost either pinnately, pedately, or palmately 3-7-divided, 

 or entire and triple-ribbed. Heads in flat-topped panicles, numerous, discoid. Involucre 

 turbinate or campanulate; bracts 5-10, obovate, with scarious margins and tips, flat or some- 

 what concave but not keeled. Flowers 10-20, hermaphrodite and fertile; corolla white, ochro- 

 leucous, or in two species purplish ; tube short, funnelform, glandular-puberulent ; lobes longer 

 than the tube, oblong. Style-branches terminated by long attenuate hispid appendages. 

 Achenes elongate-obpyramidal, tnmcate at the apex, 4-angled, pubescent. Pappus of 8 

 scarious squamellae, callous-thickened at the base, with or without distinct midrib, some- 

 times awn-tipped. 



Type species, Stevia pedata Cav. 



At least the middle leaves dissected. 



Lower leaves divided, the divisions linear; involucral bracts purplish. 

 Pappus-squamellae not awn-tipped. 

 Pappus-squatnellae awn-tipped. 

 Lower leaves simple, the middle ones 3-fid with oblong divisions; in- 

 volucral bracts with dull white tips and margins. 

 Leaves none dissected. 



Leaf -blades lanceolate, mostly entire-margined; corollas and tips of 



bracts whitish. 

 Leaf -blades broadly ovate or subcordate, doubly crenate-dentate ; corol- 

 las and bracts purplish. 

 Pappus-squamellae ovate or suborbicular, much shorter than the 



corolla. 

 Pappus-squamellae lanceolate awn-pointed, about equaling the 

 corolla. 



1. Florestina pedata (Cav.) Cass. Diet. Sci. Nat. Atlas 3: pi. 8. 



1816. 



Stevia pedata Cav. Ic. 4: 33. 1797. 

 ?Ageratum pedatum Ort. Desc. Dec. 38. 1797. 



