143 



opening, the petals affording some purchase ; but after they are 

 fully open the radiating stamens form an efficient barrier. 



2. Hesperaster nudus {Bartonia nuda Pursh, Fl. Am. Sept. 

 328. 1 8 14). Vespertine. 



3 . Hesperaster laevicaulis {Bartonia laevicaulis Dougl. ; Hook. 

 Fl. Bor.-Am. 1: 221. 1833). Diurnal. 



4. Hesperaster Rusbyi {Mentzelia Rusbyi Wooton, Bull. Torr. 

 Club, 25: 261. 1898). Vespertine. Its distribution in New- 

 Mexico is peculiar ; I have found it in the Sacramento Mountains 

 and around Las Vegas, where there is no H. vudtiflorus. The 

 latter occurs at Santa Fe, Raton and in the Mesilla Valley, to the 

 exclusion of H. Rusbyi. 



5. Hesperaster multiflorus {Bartonia multiflora Nutt. Journ. 

 Acad. Phila. II. 1: 180. 1848). Diurnal. The flowers are 

 erroneously stated by Coulter to be deep yellow. They are in 

 reality little darker than those of H. decapetalus. They are freely 

 visited by bees, especially Perdita. 



6. Hesperaster perennis {Mentzelia perennis Wooton, Bull. 

 Torr. Club, 25 : 260. 1898). Diurnal (?) 



7. Hesperaster pumilus {Mentzelia pnmila T. & G. Fl. N. 

 Am. 1 : 535). Vespertine, according to Miss Eastwood, Proc. 

 Cal. Ac. Sci. II. 6 : 291. 



8. Hesperaster chrysantfms {Mentzelia chrysantha Engelm.; 

 Brandegee, Fl. S. W. Col. 237). Diurnal (?). 



9. Hesperaster densus {Mentzelia densa Greene, Pittonia, 3 : 

 99. 1896). 



" H. perennis (Wooton), and H. densus (Greene) are perennials ; 

 the others apparently all biennials. The latter is a Colorado 

 species and has probably been confused with H. midtiflorus . I 

 have been greatly indebted to Dr. Rydberg for advice when pre- 

 paring these notes. 



East Las Vegas, New Mexico. 



SHORTER NOTES 



Explosive Fruits. — During the present year a portion of our 

 experiment grounds has been in Polemoniaceae, including spe- 



l^ 



