NYCTAGINACEJE. 5 



Nyctaginia capitate? has the same vegetative organs, the same 

 flowers, and the same fruit as Mirabilis, but it has been made into a 

 distinct genus because its flowers are united in great numbers into a 

 terminal false capitulum, in an involucre formed of numerous bracts, 

 and because its stamens and capitate style protrude from the perianth, 

 instead of remaining included. It is a herb of Mexico and Texas. 



Okenia hypogced 1 is a Mexican herb, the glutinous branches of 

 which are prostrate on the sand, and bear terminal solitary flowers, 

 in form like those of Mirabilis. But these flowers have from twelve 

 to eighteen stamens, a style peltate and stigmatiferous at the apex, 

 and the fruit surrounded, like that of Mirabilis, by an indusium of 

 similar nature, buries itself in the sand to ripen, while the peduncle 

 which supports it bends and lengthens greatly. The involucre 

 surrounding the enlarged portion of the perianth is here formed of 

 three leaves more developed than those of Acleisanthes, smaller 

 than those of the true Mirabilis, imbricate at first, but afterwards 

 caducous. 



In Pentacrophys JFrigl/fii, 3 an herbaceous plant from Texas, the ter- 

 minal or leaf-opposed sessile flowers are constructed almost like those 

 of the preceding genera, but they have an involucre of three subulate 

 bracts, a diandrous androceum, and the base of the perianth, which 

 persists around the fruit, takes the form of a truncated cylinder, 

 traversed lengthwise by five prominent, thick, obtuse ribs, terminated 

 by a glandular swelling. The apex of the indusium presents a small 

 opening into the cavity, which contains a small fruit, formed, in 

 fact, like that of Mirabilis. 4 



Selinocarpus' has the same organs of vegetation as all the pre- 

 ceding plants, and bracts and flowers like those of Acleisanthes, but 

 the androceum is composed of from two to five stamens, and the five 

 ribs of the indusium expand around the fruit into five vertical 

 wings, or into a smaller number of those membranous expansions 

 which make the fruit resemble in form certain Urn bell if era. 



1 CHOIS., in Mem, Soc. Gen., xii. ; Prodr., there are two sorts of flowers. In some the 

 429, n. 3.— Boerhaavia capitata, Pav., mss. (ex perianth is quite developed; in others it is 

 Chois.). arrested sooner or later, and moreover the 



2 Schtede ex Schltl et Cham., in Linncea, gynreceum is fertilised in the hud, and hecomes a 

 v. (1830), 92.— Chois., Prodr., 449, n. 14. fertile fruit. 



3 A. Gray, Brief Char., 4. 5 A. Okast, Brief Char., 4. 



4 In this plant, as in most of the allied genera, 



