Chapter VI 

 GENLISEA 



Discovery. — Early studies. — Two kinds of leaves. — Anatomy of trap-leaf. 



The specimens on which the genus Genlisea is based were discovered 

 by AuGUSTE DE Saint-Hilaire in Brazil in 1833. Most of the species 

 are found in the New World in Brazil, the Guianas and Cuba, while 

 two are known from west tropical Africa. The Cuban species, found 

 many years ago by C. Wright at the time he found Biovularia olivacea, 

 has never again been collected. 



For our information about these plants we are indebted first of all 

 to Warming (1874) and to Goebel (1891). All the species are small 

 plants which inhabit swampy places and apparently live mostly sub- 

 mersed in shallow water, only the inflorescence, as in Utricularia, pro- 

 jecting above the surface. This is to be inferred from the absence of 

 stomata and from the fact that colonies of algae have been observed by 

 me attached to the surfaces of the leaves. Benjamin in the Flora Bra- 

 siliensis says merely "herbae paludosae." The close relationship to 

 Utricularia is shown by the fact that the structure of the flower is the 

 same in the two genera, that of Genlisea differing in having a five- 

 parted calyx instead of the two-parted calyx of Utricularia. All are 

 rosette plants with two kinds of leaves, foliage and trapping, arising 

 from a vertical or sometimes nearly prostrate rootstock. Like Utric- 

 ularia, there are no roots, though the trap leaves look superficially 

 much like them and have been mistakenly so regarded by some (p — 7 ; 



The first thorough description, though lacking in an important de- 

 tail, was published by Warming in 1874. This work was known to 

 Darwin, whose son Francis repeated Warming's observations and 

 afforded the description given by Darwin in his Insectivorous 

 Plants (P. 360, 2nd ed. of 1875). Goebel's description of 1891, though 

 incorrect in certain details, leaves otherwise little to be desired. The 

 plant which these authors studied was Genlisea ornata, the largest 

 known species. The present account is based on herbarium specimens 

 (British Museum of Natural History and Kew) but more particularly 

 on alcohol material kindly sent to me by Dr. F. C. Hoehne, collected 

 in Butantan, Brazil. As far as the anatomy is concerned the genus is 

 very homogeneous. Darwin, it is true, described G. filifor?nis ^ as 

 bearing bladders like those of Utricularia and being devoid of ''utricu- 

 Hferous leaves" characteristic of the other species. I examined all 

 the specimens of Genlisea filiformis at Kew, which was the source of 

 Darwin's material, but could find no evidence to corroborate him. 

 It seems quite certain that he examined a plant which had been grow- 

 ing with a Utricularia whose stolons had intermixed with the Genlisea 

 leaves. Indeed, I saw a case of this. 



There are two kinds of leaves, true foliage leaves, linear or spatulate 



