536 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



KEY TO THE GENERA. 



Nutlet 1, the other cells abortive; inflorescence capitate; 



sepals linear-subulate 1. Pttxocalyx (p. 536). 



Nutlets 4; inflorescence axillary; sepals linear-lanceolate. 

 Nutlets cohering by their inner faces so as to form a 

 smooth depressed-globose fruit; stamens equal- 

 ly inserted; plants woody almost throughout, 



canescent 2. Stegnocarpus (p. 536). 



Nutlets roughened, cohering by the inner angle to 

 form a 4-parted fruit; stamens unequally in- 

 serted; plants woody only at the base if at all, 

 hispid 3. Eddya (p. 536). 



1. PTILOCALYX Torr. 



Low, much branched shrub with small ovate leaves and white flowers in short- 

 capitate clusters; calyx lobes filiform-subulate, densely hairy; corolla campanulate, 

 the lobes rotund to obovate, crenulate; stamens included, equally inserted near the 

 base of the corolla; ovary 4-lobed, 4-celled, with an obscure glandular ring at the base; 

 styles 2-parted above; fruit 1-seeded by abortion. 



1. Ptilocalyx greggii Torr. U. S. Rep. Expl. Miss. Pacif. 2: 110. pi. 8. 1855. 



Coldenia greggii A. Gray, Syn. Fl. 2 1 : 182. 1878. 

 Type locality: Near Buena Vista, Mexico. 



Range: "Western Texas and southern New Mexico and southward. 

 New Mexico: Bishops Cap (Wooton & Standley). Dry hills, in the Lower Sonoran 

 Zone. 



2. STEGNOCARPUS Torr. 



Prostrate perennial with slender, much branched, woody stems 10 cm. long or less; 

 leaves appressed-canescent; flowers pale pink, axillary; calyx of 5 lanceolate sepals; 

 corolla campanulate-funnelform, the lobes orbicular-obovate, crenulate; ovary ovoid, 

 slightly 4-lobed; fruit of 4 smooth rounded triangular nutlets. 



1. Stegnocarpus canescens (DC.) Torr. U. S. Rep. Expl. Miss. Pacif. 2: 169. pi. 7. 

 1855. 

 Coldenia canescens DC. Prodr. 9: 559. 1845. 

 Type locality: " In Mexico inter Santander et Victoria." 

 Range: Western Texas to Arizona. 



New Mexico: Berendo Creek; Tortugas Mountain; Organ Mountains; White 

 Mountains; Guadalupe Mountains; Lakewood. Dry hills and plains, in the Lower and 

 Upper Sonoran zones. 



3. EDDYA Torr. 



Small, prostrate, densely hispid perennials with much branched slender stems about 

 10 cm. long, from thick woody roots; leaves small, crowded; flowers small, axillary, 

 solitary; corolla salverform or funnelform, with a broad limb; ovary 4-lobed; nutlets 4, 

 cohering by the inner angle, muricate-scabrous. 



key to the species. 



Plants merely hispid; leaves linear, revolute; corolla 5 mm. long. . 1. E. hispidissima. 

 Plants white with villous or canescent pubescence; leaves spatu- 



late, flat; corolla 10 mm. long 2. E. gossypina. 



1. Eddya hispidissima Torr. U. S. Rep. Expl. Miss. Pacif. 2: 170. pi. 9. 1855. 

 Coldenia hispidissima A. Gray, Proc. Amer. Acad. 5: 340. 1862. 

 Type locality: "Common on the Rio Grande about El Paso." 



