338 THE JOURNAL OF BOTANY 



subcrustaceoiTS, not thick ; albumen white, firmly fleshy, not thick ; 

 embryo straight, axile, oblong, white, about -4 mm. long, terete ; 

 the cotyledons rather shorter than the radicle. 



This narrow-leaved variety is very widely diffused ; specimens 

 in our herbaria are extant from the following countries : — Scandi- 

 navia, Germany, Austria, Russia in Asia, island of Fernando Po, 

 the Coast, Kalahari, and eastern regions of the Cape Flora, Mada- 

 gascar, New Zealand, Tasmania, Australia, Falkland Islands, Nova 

 Scotia, the United States of North America, Columbia, Bolivia, 

 Ecuador, Argentina, Chili, and Patagonia, 



There are specimens in the Sloane herbarium, vol. xii. fol. 46, 

 in the National Herbarium, gathered at Dr. Uvedale's, Hampton 

 Court, by Sir Hans Sloane, the name of which is given as Ranun- 

 culus jxilustris foli'is turn f/raminosis turn rotundis, &c. ; the specimens 

 show both the small ordinary form of Limosella aquatica L. and the 

 tenuifolia variety without stolons. 



The plate of Limosella aquatica in English Botany, t. 357 (Nov. 

 1st, 1796), was drawn by Sowerby from a specimen sent to him 

 from Bedfordshire, July 16th, 1795, by the Rev. C. Abbot ; it is 

 instructive to note that accompanying this specimen there are others 

 sent by Abbot with it, in Sowerby's herbarium, now in the National 

 Herbarium, which show a gradation of form down to and including 

 the tenuifolia variety. 



The division of the genus Limosella into species is exceedingly 

 difficult, on account of the numerous connecting forms ; the 

 following key is an attempt to differentiate what might be regarded 

 as species, if only inconveniently cross and intermediate specimens 

 are ignored : — 

 Corolla exserted beyond the calyx ; flowers more or less stalked. 



Corolla-lobes shorter than the calyx. 

 Calyx not strongly nerved. 



Leaves subterete or narrowly linear, without dilated 

 blade. 

 Scapes or peduncles shorter than the leaves 



1. L. subulata Ives (1817). 

 Scapes or peduncles equalling the leaves 



2. L. tenuifolia Hoffm. (1804). 

 Leaves furnished with dilated blade. 



Leaf-blade either very narrow or at the base ob- 

 tuse, 2-20 mm. long 



3. L. aquaticah. (1753). 

 Leaf-blade not very narrow, attenuate at the base, 



12-40 mm. long 4. L. maior Diels (1898). 

 Calyx strongly 5-nerved 5. L.longijiora 0. Kuntze (1898). 

 Corolla-lobes equalling or exceeding the calyx. 



Corolla-limb 4-6 mm. in diameter ; leaf-blade 2-16 mm. 

 long . . .6. L. capensis Thunb. (1800). 



Corolla-limb 8-12 mm. in diameter; leaf-blade 6-44 mm. 

 long . . . 1. L. grandiflora Benth. (1847). 



Corolla included within the calyx ; flowers sessile 



8. L, Curdieana F. Muell. (1875). 



