Page:The Botany of the Antarctic Voyage.djvu/370

334 2. LIMOSELLA, Linn.

1. Limosella aquatica, Linn. Sp. PI. p. 881. Engl. Bot. t. 357. Benth. in DC. Prodr. vol. x. p. 427.

"Var. /3, tenuifolia. L. tenuifolia, Nutt. Gen. N. Am. vol. ii. p. 43. Gaudic/iaud, in Ann. Sc. Nat. vol. v. p. 102, et in Freyc. Voy. Bot. p. 133. D' Urv. in Mem. Soc. Linn. Paris, vol. iv. p. 607. Benth. in DC. Prodr. vol. x. p. 427. L. australis, Brown, Prodr. p. 443.

Hab. Falkland Islands, Gaudichav.d, J. D. H. Kerguelen's Land, /. D. H.

I am convinced there is no specific distinction between the Limosella aquatica, L., and L. tenuifolia, Nutt., and have consequently united them. In the specimens from the southern hemisphere which I have examined, the leaves do not attain the breadth which those of the northern temperate regions generally present ; though, on the other hand, both European, Asiatic, and North American plants of the L. aquatica have the foliage narrow as that of L. tenuifolia, to which variety some Arctic individuals of L. aquatica are quite simdar.

The range of this species is nearly identical with that of Callitriche aquatica and Montia fontana, and there is also a considerable resemblance in the mode and extent of their variation between these three plants. This is not remarkable with regard to Callitriche and Montia, which are very frequently seen associated together, invariably so in Kerguelen's Land, in the Falkland Islands, in Lord Auckland's Group and Campbell's Island, and thus are influenced in common by every fluctuation of climate and temperature, and by the depth or rapidity of the current, when growing in the water ; but the Limosella does not occur mixed with these two genera, even though inhabiting the same islands.

In Kerguelen's Land the Limosella is found in the muddy bottom of a lake, and probably flowers all the year round. I gathered it in the month of July (mid-winter), beneath two feet of water, covered with two inches of ice; even then it had fully-formed flowers, whose closely imbricating petals retained a bubble of air, the anthers were full of pollen and the ovides apparently impregnated. The climate of Kerguelen's Land being such, that this lake is perhaps never dried, it follows that the plant has here the power of impregnation when cut off from a free communication with the atmosphere, and supplied with a very small portion of atmospheric air generated by itself. My Falkland Island specimens are in a very poor state. Gaudichaud, who first detected it in that Island, considers it identical with the European plant.

3. VERONICA, L.

1. Veronica elliptica, Forst.; Ft. Ant. part 1. p. 58. V. decussata, Ait. et auctor.

Hab. Strait of Magalhaens to Cape Horn in Fuegia, Commerson, Banks and Solander, and all succeeding vovagers. West Falkland Island, chiefly on the southern and western coasts.

2. Veronica serpyllifolia, Linn. Sp. PI. p. 15. Engl. Bot. t. 1075. Gaud, in Ann. Sc. Nat. vol. v. p. 102, et in Freyc. Voy. Bot. p. 133. D'Urv. in Mem. Soc. Linn. Paris, vol. iv. p. 607.

Hab. Falkland Islands, abundant near the colonized parts of the Islands; D'Urville, fyc.

This species, in affecting principally the vicinity of the settlements and ground much frequented by cattle, was probably introduced originally from Europe into the Falkland Islands. It is found no where else in the southern hemisphere, except the neighbourhood of Quito, where Mi -. Kunth doubts its being indigenous, or in equally equivocal situations.

4. OURISIA, Comm.

1. Ourisia Magellanica, Joss.; caule repente, foliis subradicalibus longe petiolatis cordato-ovatis