Rydberg : Studies on the Rocky Mountain flora 111 



months earlier. As the latter is the type of Hookera, Brodiaea 

 becomes a pure synonym. Dr. Greene,* who was the first to 

 segregate into genera the members of Brodiaea taken in the sense 

 of Dr. Watson, retains both genera. Evidently he regarded 

 Smith's second species, Brodiaea congesta, as the type. This 

 can scarcely be done, as B. grandiflora is not only the first species, 

 but it is more extensively described and discussed. Greene 

 himself afterwards discarded Brodiaea and adopted Dichelostemnia, 

 proposed by Kunth on Brodiaea congesta Smith. Alphonso Wood 

 had extended Kunth's genus to include also B. capitata Benth. 

 and B. voluhilis Baker {Stropholirion californicum Torr.). Wood 

 was followed by Greene in including these species in the 

 genus. Stropholirion has been generally recognized as a genus, 

 even by S. Watson. The typical species of Dichelostemma, i. e., 

 D. congesta (Smith) Kunth and its relative D. midtiflora (Benth.) 

 Heller, have only 3 stamens alternating with 3 staminodia and 

 differ from the typical species of Hookera only in the rounded 

 base of the perianth and the subcapitate inflorescence. If they 

 are kept distinct then Seicbertia should be regarded distinct from 

 Triteleia. Brodiaea capitata has 6 fertile stamens with subulate 

 filaments. At the base of each of the inner three there are two 

 lanceolate lobes partly adnate to the perianth, forming together 

 a crown of 6 instead of 3 members. To the new genus proposed 

 here, belong: 



Dipterostemon capitatus (Benth.) 



Brodiaea capitata Benth. PI. Hartw. 339. 1857. 



Dipterostemon paucifiorus (Torr.) 

 Brodiaea capitata pauciflora Torr. Bot. Mex. Bound. Surv. 218. 



1859. 



Dipterostemon insularis (Greene) 



Brodiaea insidaris Greene, Bull. Calif. Acad. Sci. 2: 134. 1887. 



Dipterostemon pulchellus (Salisb.) 

 Hookera pidchella Salisb. Parad. 2: pi. 117. i\ 

 New York Botanical Garden. 



* Bull. Calif. Acad. Sci. 2: 125-144. 1886. 



