200 
Spring Flora of Oklahoma 
naked. Rays none. Disk-flowers all perfect and fertile. 
Achenes obovoid or obpyramidal, 4-5 angled, the faces usu¬ 
ally prominently 1-3 nerved. Pappus of 10-20 thin obtuse 
scales. 
Bracts of the involucre broadly ovate or oval, bright 
white. 1. H. carolinensis. 
Bracts obovate to oblong, grefen or with white tips. 
2. H. tenuifolius. 
1. Hymenopappus carolinensis (Lam.) Porter. White-bracted 
Hymenopappus. Biennial. Stem wholly pubescent or glabrate. 
Leafy below, corymbosely branched, 2°-3° high. Basal and lower leaves 
1-2-pinnately parted or deeply pinnatifid into linear or oblong lobes, 
more or less white tomentose beneath. Upper leaves less divided. 
Heads commonly numerous, corymbose, 6"-10" broad. Bracts of the 
involucre oblong, ovate, white, puberulent or glabrate. Corolla 
white. 
In dry sandy soil. April-June. Common. 
2. Hymenopappus tenuifolius Pursh. Woolly White Hymeno¬ 
pappus. Biennial. Stem slightly tomentose, 12'-24' high. Lower and 
basal leaves 1-3 pinnately parted into linear, filiform lobes, woolly 
pubescent beneath, at least when young. Upper leaves much smaller 
and less compound. Heads numerous, corymbose, 4"-6" broad. Corolla 
white. Acheues densely villous, pubescent. Pappus of several 
ribbed scales. 
On dry prairies. May-September. Common. 
XXII. TETRANEURIS Greene. 
Usually scapose, annual or perennial herbs with mostly 
basal, entire, often punctate leaves and long-pedunculate 
heads. Disk-flowers and rays bright yellow. Involucre 
hemispheric, of. 2 or 3 series of similar, appressed, imbri¬ 
cated bracts. Receptacle convex or conic, naked. Achenes 
turbinate, 5-10 ribbed or angled, variously pubescent. Pap¬ 
pus of 5-12 scarious, aristate, truncate or acuminate scales. 
Stem leafy, branching; stem leaves linear; annual or 
biennial. 1. T. linearifolia. 
Stems tufted, simple, scapose; leaves basal; perennials. 
2. T. stenophylla. 
1. Tetraneuris linearifolia (Hooik.) Greene. Pine-leaved 
Tetraneuris. Annual or biennial. Stem slender 6'-15' high. 
