782 CONTRIBUTIONS FEOM THE NATIONAL HERBARIUM. 



17. Hibiscus ribifolius A. Gray, Proc. Amer. Acad. 5: 154. 1861. 

 Baja California ; type from Cape San Lucas. 



Shrub, 1 to 2.5 meters high, the branches stellate-pubescent; leaves deltoid- 

 ovate, 2 to 5.5 cm. long, acute or acuminate, coarsely serrate-dentate, often sub- 

 hastate, soon glabrate ; petals sulphur-yellow, 2.5 to 3.5 cm. long. 



18. Hibiscus coulteri Harv. ; A. Gray, PI. Wright. 1 : 23. 1852. 

 Sonora and Chihuahua to Hidalgo; type from Zimap^n, Hidalgo. 



Shrub, 1 meter high or less, or often herbaceous; leaves dimorphous, *he 

 lower ones rounded-ovate or ovate-oval and dentate, the upper ones mostly 

 parted into 3 narrow dentate lobes; petals white or pale yellow, 2 to 4 cm. 

 long. 



It is probable that the proper name for this species is H. acetosaefolius 

 DC The plate of Sesse and Mocino' upon which that name was based 

 agrees very well with specimens of H, coulteri, except for the small size of 

 the flowers, as illustrated. 



19. Hibiscus elegans Standi., sp. nov. 



Hidalgo, Puebla, and Oaxaca ; type from Tehuac^n, Puebla (Pringle 7505; U. 

 S. Nat. Herb. No. 305765.) 



Shrub, the branches stellate-strigose ; leaves elliptic to oval or ovate-rhombic, 

 1 to 3 cm. long, rounded or obtuse at apex, rounded or broadly cuneate at base, 

 crenate-dentate, green, stellate-hispidulous ; calyx 1.5 to 2 cm. long, the lobes 

 linear-lanceolate ; bractlets shorter than the calyx ; petals 3 to 4 cm. long, yel- 

 low, with red spot at base. 



20. Hibiscus acicularis Standi., sp. nov. 



Tamaulipas and Nuevo Le6n ; type from Monterrey, Nuevo Leon {Pringle 

 13880; U. S. Nat. Herb. No. 462430). 



Stems herbaceous or sufCrutescent, 60 cm. high, stellate-strigose; leaves 

 hastate-deltoid, obtuse to long-acuminate, crenate or serrate, green, thin, 

 sparsely pubescent with mostly 3-rayed and appressed hairs; flowers long- 

 pedunculate ; bractlets equaling or longer than the calyx ; calyx 1.5 to 2.5 cm. 

 long, the lobes linear-lanceolate ; petals 3 to 4 cm. long, white or pale yellow ; 

 seeds covered with long silky hairs. "Amor de un dfa " (Tamaulipas). 



DOUBTFUL SPECIES. 

 HiBTSciTs cYANOGYNUs DC. Prodr. 1: 455. 1824. Described from Mexico. 

 Probably not of this genus. 



18. GOSSYPIUM L. Sp. PI. 



Reference: George Watt, The wild and cultivated cotton plants of the world, 

 1907. 



Shrubs or large herbs, sometimes small trees ; leaves usually 3 to 9-lobed ; 

 flowers large, yellow or purplish, the calyx subtended by 3 large cordate bracts ; 

 calyx truncate or shallowly 5-lobate ; fruit a loculicidal capsule, the seeds com- 

 monly covered with long cotton. 



The cultivated species of the genus are greatly confused and poorly under- 

 stood. This is due chiefly to the fact that many of the cultivated forms are 

 the result of hybridization. 



Cotton is, of course, one of the most important plants of Mexico, where it 

 has been in cultivation from ancient times. The early European visitors men- 



* Prodr. 1 : 455. 1824. 



* DC. Calq. Dess. Fl. Mex. pi. 79. 



