118 NORTH AMERICAN FLORA [Volume 34 



24. Hymenoxys Davidsonii (Greene) Coekerell, Bull. Torrey Club 



31: 508. 1904. 



Picradenia Davidsonii Greene, Pittonia 4: 240. 1901. 



A branched biennial or perennial; stems 2-3 dm. high, striate, sparingly striate, pilose; 

 leaves 3-4 cm. long, pinnatind into linear divisions, nearly glabrous; heads many, corymbose- 

 cymose; peduncles 4-8 cm. long; involucre nearly hemispheric, 5-6 mm. high, 8 mm. broad, 

 puberulent; outer bracts about 10, united one fourth their length, ovate4anceolate, the 

 herbaceous margin narrow; inner bracts similar but longer and broader; ligules 5-6 mm. 

 long, 2.5-2.8 mm. wide; disk-corollas 4 mm. long, sparingly glandular; tube 1 mm. long; 

 achenes 2 mm. long, hirsute; squamellae lance-ovate, acute or acuminate, 1 mm. long. 



Type locality: Clifton, Arizona. 

 Distribution: Arizona. 



25. Hymenoxys texana (Coult. & Rose) Coekerell, Bull. Torrey 



Club 31: 499. 1904. 



Aclinella texana Coult. & Rose, Bot. Gaz._ 16: 27. 1891. 

 Picradenia texana Greene, Pittonia 3: 273. 1898. 



A small slender annual; stem branched at the base, 5-15 cm. high, glabrous or nearly so; 

 leaves mostly basal, spatulate in outline, 2-3 cm. long, 3-nerved, round-lobed or toothed, or 

 entire, puberulent; stem-leaves few, narrowly oblanceolate or linear, entire or few-toothed; 

 heads few, cymose; involucre campanulate, 4-5 mm. high and about as broad; outer bracts 

 about 8, rigid, keeled, united only at the base, linear-lanceolate; inner bracts similar but 

 thinner and slightly longer; ligules minute, not exceeding the bracts; disk-corollas scarcely 

 1 mm. long; tube shorter than the campanulate throat; achenes 1 mm. long, obpyramidal, 

 hirsute; squamellae ovate, aristate-acuminate. 



Type locality: Hockley, Texas. 

 Distribution: Texas. 



64. PLUMMERA A. Gray, Proc. Am. Acad. 17: 215. 1882. 



Biennial or perennial herbs, with tap-roots. Leaves alternate, 1-3 times ternately 

 parted into linear divisions, impressed-punctate. Heads numerous in leafy flat-topped 

 panicles, radiate. Involucre obpyramidal; bracts in two series, of 4 or 5 bracts each; outer 

 bracts ovate or oblong, carinate, united above the middle, with narrow membranous margins; 

 inner bracts obovate-cuneate, with rounded apex, subscarious. Receptacle small, naked, 

 flat. Ray-flowers 2-5, pistillate and fertile; ligules broadly cuneate, 3-lobed. Disk-flowers 

 6-8, functionally staminate and sterile; corollas trumpet-shaped, with very short, somewhat 

 inflated tube, and 5 short obtuse lobes. Anthers obtuse at the base. Style short, bifid 

 without stigmatic lines. Achenes of the ray-flowers cuneate-obovoid, villous. Pappus 

 wanting. 



T}-pe species, Phimmera floribunda A. Gray. 



1. Plummera floribunda A. Gray, Proe. Am. Acad. 17: 215. 1882. 



A biennial or perennial herb; stem angled and striate, glabrous, branched above, 3-6 

 dm. high; leaves 3-8 cm. long, 1-3-ternately parted into linear divisions 1-1.5 mm. wide; 

 heads numerous; involucre about 4 mm. high and 3 mm. broad, impressed-punctate; ligules 

 yellow, 3 mm. long and 2 mm. wide, cuneate, deeply 3-cleft; disk-corollas 3 mm. long, densely 

 glandular; achenes 2.5 mm. long. 



Type locality: Apache Pass, Arizona. 

 Distribution: Arizona. 



Subtribe 13. GAILLARDIANAE. Heads mostly radiate, rarely discoid. 

 Involucre rotate; bracts spreading, either wholly or at least the tip reflexed 

 in age. Receptacle from convex to hemispheric or ovoid. Ray-flowers 



