272 FLORA ANTARCTICA. [Fuegia, the 



It is very difficult to decide upon the limits of species in this genus, which, like most aquatic plants, is sufficiently 

 Protean. My own specimens are ban-en, but those of Dr. Gillies and Bridges, from the Andes and west coast of 

 South America, are in flower and monoecious, and from them I have described the ripe carpels. Gaudichaud 

 distinguishes M. elatinoides from M. ternatum, by the former being dioecious ; but D'Urville, in re-describing it, asserts 

 the contrary. 



In its normal state, the upper leaves of the present species are much broader than those of any other ; but at 

 times, the whole foliage is uniformly capillaceo-multifid, when it can hardly be discriminated from some forms 

 of the European M. vertkillatum. 



2. HIPPUEIS, L. 



1. Hippuius vulgaris, Linn. Sp. PI. 3. Engl. Bot. t. 763. 



Hab. Strait of Magalhaens ; Port Famine, Capt. King. 



These specimens, which are barren, do not seem to differ from others of European growth. Both Capt. King's 

 and ]\Ir. Anderson's collections contain the plant, so that although the above be the only reported station for it in 

 the southern hemisphere, I have no reason to doubt its authenticity. The range of Hippuris vulgaris, in the 

 temperate latitudes of the northern parts of the world, is very wide, extending from the arctic regions of Europe and 

 Asia (Lapland 70°, Iceland 65°, Siberia and Kamschatka), south to Montpellier, lat. 43° in western Europe ; probably 

 reaching 50° in the central', and the Caucasus, or 44° in the east parts of our continent. The late Dr. Griffith 

 collected it in Afghanistan, lat. 32°, its only known habitat in Central Asia. In North America this species is 

 equally diffused, from the latitudes of 55° and 70° on the west coast, and from New York, 41°, to Labrador and 

 Greenland, lat. 70°, on the east. From the interior I have only seen specimens, gathered by Dr. Richardson near 

 Hudson's Bay, between 55° and 60°. 



Hippuris is very closely allied to Myriopliyllum, and differs chiefly in the reduction of the four carpels to a 

 solitary one, with an accompanying solitary stamen, placed on one side of the carpel, within the obsolete margin of 

 the calyx. 



3. CALLITRICHE, L. 



1. Calliteiche verna, L., rid. Fl. Antarct. parti, p. 11. Antliapla, W. Anderson in Bill. Banks. 



Var. 0, terrestris ; El. Antarct. 1. c. 



Hab. Fuegia, the Falkland Islands, and Kerguelen's Land, abundant ; Anderson (in Cook's 3rd Voyage), 

 /. I). H. Var. /3, Hermite Island and the Falkland Islands. 



Callitriche differs from the typical genera of the Order Ilaloragece in having generally caducous bracts at 

 the base of the flowers, in its 4-carpellary ovarium with only two styles, in the entire absence of a limb to the 

 calyx, of a corolla in the female, or of any perianth whatever in the male flower. The latter are truly achlamydeous, 

 but not the former, the calyx being equally obsolete in the carpels of MyriophyUum and in the present genus ; 

 whilst the general symmetry of the parts, the structure of the seed and embryo, of the recurved styles, covered 

 uniformly with stigmatic papillae, and the form of the pollen, are alike in both, indicating a very close natural 

 affinity. In the first part of this work, I alluded to the real form of the anthers in the southern specimens of 

 C. verna, as not differing from the ordinary structure of that organ in Phaenogamic plants, even in appearance, 

 before their dehiscence, and only presenting the hippocrepiform suture on the curling up of the valves, and the 

 union of the two loculi and their lines of dehiscence above. 



Callitriche verna is universally diffused throughout the temperate regions of both hemispheres, even entering 



