296 ON SEEDLINGS 



indicate the genera which are regarded as most closely allied, 

 but they are all well marked in the seeds, and the members 

 of different tribes do not much overlap one another. 



To the first group belong Ehynchotheca, Oxalis, Averrhoa, 

 and perhaps Dapania. The seed of Rhynchotheca contains a 

 small quantity of endosperm, a straight embryo, flat cotyle- 

 dons, and belongs to the tribe Wendtieas ; Wendtia itself does 

 not seem to have been described, and I have had no opportunity 

 of examining it. The others belong to the tribe Oxalidese. 

 Oxalis has a capsular, loculicidally dehiscent, five-celled fruit 

 with one or many seeds in each cell. The outer integument 

 of the seed is fleshy and breaks away elastically in the form of 

 an aril, while the testa is crustaceous. The endosperm is 

 fleshy, and the small embryo straight with broadly ovate coty- 

 ledons. The fruit of Averrhoa is baccate and indehiscent, 

 containing numerous naked or arillate seeds, with a small 

 quantity of fleshy endosperm, and a straight embryo. The 

 fruit of Dapania is fleshy and five-lobed, and the seed it con- 

 tains is covered by a lacerated, somewhat two-lipped aril, and 

 has a fleshy endosperm. The embryo is slightly curved, 

 leading to the next group ; and the oval cotyledons are cordate 

 at the base. 



2. The curved embryo is represented by Biebersteinia and 

 Viviania, belonging to distinct tribes (Geranieae and VivianesB 

 respectively). The seed of the former is curved and contains 

 a thin, fleshy, somewhat one-sided layer of endosperm. The 

 arched or bent embryo has rather thickened cotyledons, a 

 scarcely shorter, superior radicle, and conforms in outline to 

 that of the seed. Viviania has closely superposed geminate 

 ovules in each cell, and when both mature into seeds, the one 

 is ascending and the other descending, and they contain a 

 fleshy endosperm. The embryo is narrow, linear, and strongly 

 curved or circinate. 



3. The third type, represented by Balbisia, also contains a 

 thin fleshy layer of endosperm in its seeds, which are small, 

 many-angled by mutual compression, and arranged in a double 

 series. Its chief distinction consists in the cotyledons being 

 plicate and in the radicle being laid over the back of them or 

 enclosed in their folds. 



