37 
1 lous ; style filiform, thickened at the base ; stigma capitate. Fruit hard, indehiscent, 
j 1 -celled, 1-seeded, crowned by the indurated segments of the calyx. Seed solitary, large, 
j pendulous; albumen none; cotyledons 2, very unequal . — Floating plants, hovsier leaves 
. opposite, upper alternate ; those under water cut into capillary segments ; petioles tumid in 
the middle. Flowers small, axillary. 
I Affinities. From tnie Onagracese these plants are distinguished by their 
solitary pendulous ovules ; from Halorageae, by their very large seeds with un- 
j equal cotyledons, developed calyx, and want of albumen ; agreeing with them, 
especially with Myriophyllum, in habit. 
Geography. Found in the south of Europe, the East Indies, and 
China. 
Properties. The great seeds of Trapa are sweet and eatable. Those of 
T. bispinosa form an extensive article of cultivation in Cashmere and other 
parts of the East, where they are a common food, under the name of Sing- 
hara nuts. 
GENUS. 
Trapa, L. 
I Tribuloides, Tourn. 
I Sub-Order. HALORAGE^. 
I Halorage^e, R. Brown in Flinders, 17. (1814) ; DC. Prodr. 3. 65. (1828) ; Lindl. Synops. 
j 110. (1829) ; Bartl. Ord. Nat. 314. (1830) ; Martius Conspectus, No. 228 (1835). — 
j HvGROBiEyE, Rich. Anal.Fr. (1808). — Hippuridea:, Link Enum. 1. 5. (1821) handb. 
I 1. 288. (1829). — Cercodian.®, Juss. Diet. Sc. Nat. (1817). 
Essential Character. — Calyx superior, with a minute limb. Petals minute, inserted 
into the summit of the calyx, or wanting. Stamens inserted in the same place, equal in 
number to the petals, or occasionally fewer. Ovary adhering inseparably to the calyx, with 
j 1 or more cells ; style none ; stigmas equal in number to the cells, papulose, or pencil- 
I formed; pendulous. Fruit dry, indehiscent, membranous, or bony, with 1 or more 
j cells. Seeds solitary, pendulous; albumen de%h.y -, embryo straight, in the axis ; radicle 
superior, long and taper ; cotyledons minute. — Herbaceous plants or under-shrubs, often 
growing in wet places. Leaves either alternate, opposite, or whorled. Flowers axillary, 
sessile, occcisionally monoecious or dioecious. 
Affinities. Placed by Link among Monocotyledons, but inseparable 
from Dicotyledons, and apparently a degeneration or imperfect form of Ona- 
gracese, from which the minute calyx and albuminous solitary pendulous seeds 
chiefly distinguish them. The presence or absence of albumen when it is only 
I deposited in small quantities, is a character of much less importance, than was 
once supposed ; and the pendulous ovules will hardly be allowed much value 
by themselves. Among other evidences of these being merely an imperfect 
i form of Onagracese, may be adduced the general reduction in size of all the 
! parts, and the occasional want of petals. Callitrichacese, although placed 
. among Halorageae, seems to be referred by the achlamydeous flowers to Im- 
perfectse. See order 142. 
Geography. Damp places, ditches, and slow streams, in Europe, North 
America, southern Africa, Japan, China, New Holland, and the South Sea Is- 
lands, are the resort of this order. 
Properties. Of no importance. 
j GENERA. 
Myriophyllum, L. Mejonectes, R. Br. Serpicula, L. Riesenbachia, Presl. 
Ptilophyllum, Nutt. Cercodia, Murr. Laurembergia, Berg.? Sponclylantha, Presl. 
Purshia, R?A\r\. Haloragis, Forst. Hippuris, L. Gongylocarpus, Schlec. 
Proserpinaca, L. Go/?ioc«/7Hi5,Thunb. Limnopeuce, Vaill. 
Trixis, Mitch. Gonatocarpus, W. 
