238 



NATURAL mSTORY OF PLANTS. 



belonirinfr to South America. In this the flower and fruit are exactly 

 tliose ot'tlio Indian species, except that the six small outer leaves of 

 tlie perianth, all similar to one another, are a little broader at the 

 base, and that the single ovule in each ovary is inserted quite at the 

 hase of the internal angle. 



As anotlier section of this genus Phceanthis, we also class those 

 African plants which have been termed Pijjfostigma^ for their flowers 



possess a convex receptacle," three large inner sepals 

 veined like those of the Asiatic species of Phtsan- 

 Iht/s, and three outer petals that are much shorter, 

 acute, and quite analogous to sepals, like those of 

 lleteropetahim hrasU'iense. The stamens, indefinite 

 in number, have wedge-shaped anthers surmounted 

 by a truncate prolongation of the connective. 

 The carpels, few in number, have styles that, 

 as in Heteropetalum, swell into thick irregular 

 stigmatiferous heads which all stick together. The 

 Ph^anthmheteropetaiv.. ^^^jy diff'erence of any valuc that we can state here 



Fiower"buci. ^^ ^^^^ ^^^^ ovules are numerous, and arranged in two 



vertical rows.^ In this respect Piptostif/ma is to the 

 American and Asiatic species of PhcBaniluis exactly what the pluri- 

 ovulate species of Miliusa are to the uni- or biovulate species of the 

 same group, and can no more be considered a distinct genus.^ The 

 two known species of this section have been observed in the western 

 regions of tropical Africa. 



Thus constituted," the genus P/Ksanthus contains half a dozen 

 trees with alternate leaves, and flowers either lateral, or axillary to 

 leaves or bracts, solitary, or grouped into small cymes. 



styles nre tcrnrmatcd by thick dilatations, 

 which all stick togetlur to fovui a coinnion head, 

 as in Piptostigma. The only species yet known 

 hnalx'en observed in Hrazil and Guiana. 



' Oi.iv., Jouni. I.i.iii. Soc, viii. 158, t. 2 ; 

 Fl. Trap. Afr., 18.— H. H., Gen., 'J57, n. 25 a.— 

 \\. Hn., Adiin-wnia, viii. 3143. 



- In r. glnhrescens Oliv., the part of the re- 

 ceptacle that bears the carpels is slightly con- 

 cave. 



* This arrangement is constant in the two 



known species. There are from three to five in 

 each row. 



■» It is said (Oliv., Fl. Trop. Afr., 19) that 

 in the fruit of P. pilosum Olit., the carpels 

 cohere into a single mass containing the seeds 

 surrounded by scanty pulp. 



' 1. Hiiphfcanthus. Ovules 1, 2 ven- 

 tral. 

 2. IIefero2^efal:im. Ovule 1, sub- 



basilar. 

 ^3. Fiptostigma. Ovules oo , ventral. 



PTi(Eantlius 

 Sections 3. 



