442 



NATURAL HISTORY OF PLANTS. 



are free except in a variable extent of the lower part, and the 

 anthers are bilocular, introrse, dehiscent by two longitudinal clefts. 

 The gynEeceum is composed of three ovaries, almost or completely 

 independent, from whose base rises a style, or more rarely two or 

 three (unequal in that case), whose stigmatiferous apex is more or 

 less dilated. In the internal angle of each ovary is found a placenta 

 supporting a descendent anatropal ovule with superior micropyle, 

 finally lateral. The fruit is formed of one to three samarse, whose 

 backs are surmounted by a vertical wing, analogous to those of 



Ja^usia guaranitica. 



Pig. 451. Flower (a).. 



Pig. 452. Longitudinal section of flower. 



Banisteria (fig. 439), and whose cavity contains a bent seed, with 

 ventral hilum, coats thin covering a fleshy embryo, superior short 

 radicle, and thick cotyledons usually unequal. Schwannia consists 

 of climbing shrubs ; five species ^ have been distinguished, natives 

 of tropical Brazil. The leaves are opposite, and the flowers are 

 arranged in small umbelliform cymes, often quadrifloriate, generally 

 collected in compound terminal clusters. 



Janusia (fig. 451, 452) is allied to Schwannia ; the petals are 

 entire, and the stamens, ten in number, may all be fertile ; but it also 

 happens that one or a small number of them remain sterile. The 

 fruit is also formed of two or three samarse. But the most re- 

 markable fact observed in this genus, and which will be found in 

 all those following it, is, that beside the normal flowers, there are. 



' Grisbb. Linnaia, xiii. 188 {JFimlriaria) ; Rep. 9, t. 1. — Walp. Rep. v. 353; Ann. vij. 

 Mart. M. Bras. Malpigh. 101, 102, t. 221 476. 

 {Janusia). — G-aiSBB. Pacif. Surv. vii. Sot. ^Red. 



