COMPOSITA. 211 
154, HECUBAEA. 
Hecubea, DC. Prodr. v. p. 665; Benth. et Hook. Gen. Plant. ii. p. 400. 
An herbaceous monotype. | 
1. Hecubza scorzonerefolia, DC. Prodr. v. p. 665; Deless. Ic. Sel. iv. t. 43. 
Helenium scorzonerefolium, var. ghiesbreghtii, A. Gr. in Proc. Amer. Acad. vii. p. 359. 
South Mexico, Desierto Viejo, valley of Mexico (Bourgeau, 833), Chiapas, &c. 
(Ghiesbreght, 118, 527). Hb. Kew. | 
155. RIDDELLIA. 
Riddellia, Nutt.in Trans. Amer. Phil. Soc. ser. 2, vii. p. 871; Benth. et Hook. Gen. Plant. ii. 
p. 401. 
Three herbaceous or half-shrubby species, inhabiting the North-Mexican region from 
Texas to California. 
1. Riddellia arachnoidea, A. Gr. Pl. Fendl. p. 94. 
Psilostrophe gnaphalodes, DC. Prody. vii. p. 261. 
Texas; New Mexico; Cotorapo.—Norra Mexico, Ojo de San Bernardo (Gregg), 
Monterey (Berlandier, Edwards), Buena Vista and Saltillo (Gregg). Hb. Kew. 
2. Riddellia tagetina, Nutt. in Trans. Amer. Phil. Soc. ser. 2, vii. p. 371, ex 
Torr. & Gr. Fl. N. Am. ii. p. 362; Torr. in Emory’s Rep. App. t. 5. 
Texas; New Mexico.—Nortu Mexico, Chiricahui Mountains (Torrey), Camp Bowie, 
S. Arizona (fothrock), common on the frontier (ex A. Gray). Hb. Kew. 
156. HYMENOPAPPUS. 
Hymenopappus, Lhér. Diss. cum Ic. ex DC. Prodr. v. p. 658; Benth. et Hook. Gen. Plant. ii, 
p. 402. 
An exclusively North-American genus of seven herbaceous species. 
1, Hymenopappus flavescens, A. Gr. Pl. Fendl. p. 97. 
Texas ; New Mexico.—Nortu Mexico, Frontera (Wright). 
157. BAHIA. 
Bahia, Lag. Elench. Pl. Hort. Matr. Gen. et Sp. Nov. p. 30; Benth. et Hook. Gen. Plant. ii. 
p- 402. 
Shrubs, undershrubs, or herbs inhabiting North America, chiefly the west, and Extra- 
tropical South America. About twenty species are known. 
1. Bahia absinthifolia, Benth. Pl. Hartw. p. 18. 
Nortu Mexico, region of San Luis Potosi, 6000 to 8000 feet (Parry & Palmer, 493), 
Frontera (Wright); Sour Mexico, Aguas Calientes (Hartweg, 128). Hb. Kew. 
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