Picradeniopsis schaffneri var. aristata (Rydb.) B. G. Baldwin

Bahia aristata Rydberg, sp. nov
A decumbent annual, branched at the base; stem about 2 dm. high, hirsutulous-canescent; leaves opposite or the uppermost alternate, bipinnatifid into linear divisions, 2-4 cm. long, canescent-hirsutulous ; peduncles 3-5 cm. long; involucre turbinate, 6-7 mm. high, about
1 cm. broad; bracts obovate, rounded at the apex, hirsutulous; ligules about 10, oblong,
2 mm. long; disk-corollas yellow, many, 3 mm. long; tube shorter than the throat; achenes
3 mm. long, sparingly hispidulous; pappus-squamellae lanceolate, with an excurrent midrib, together with the awn nearly equaling the corolla.
Type collected on alkaline plains. Hacienda de Angostura, San Luis Potosi, 1891, Pringle 5127 (Gray Herb.).
Distribution: San Luis Potosi.