56 



XLVIII. HALORAGE.E. 



Halorage*, 7?. Brown in Flinders, 17. (1814) ; Dec. Prodr. 3. 65. (1828) ; LAndl. Synops. 110. 

 (1829).— Hygrobie-e, Rich. Anal. Fr. (1808).— Hippurideje, Link Enum. 1. 5. (1821); 

 handb. 1. 288. (1829).— Cercodianje, Juss. Diet. Sc. Nat. (1817.) 



Diagnosis. Polypetalous dicotyledons, with definite perigynous stamens, 

 concrete carpella, an inferior ovarium with pendulous definite ovula, a depau- 

 perated calyx, and embryo in the midst of fleshy albumen. 



Anomalies. Petals often wanting. Hippuris has the habit of an Equi- 

 setum. 



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. Ovarium adhering inseparably to the calyx, with 1 or 

 more cells ; style none ; stigmata equal in number to the cells, papulose, or pencil-formed ; ovula 

 pendulous. Fruit dry, indehiscent, membranous, or bony, with 1 or more cells. Seeds soli- 

 tary, pendulous ; albumen fleshy ; 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, occasionally monoe- 

 cious or dioecious. 



Affinities. Placed by Link among Monocotyledons, but inseparable from 

 Dicotyledons, and especially related to OnagrariEe, from which the minute 

 calyx and albuminous solitary pendulous seeds chiefly distinguish them. Very 

 closely akin also to Circaeaceee and Hydrocaryes, both which see. The affinity 

 of Callitrichinese is probably not very great, although M. Decandolle has con- 

 sidered it a mere section of the order. 



Geography. Damp places, ditches, and slow streams, in Europe, North 

 America, Southern Africa, Japan, China, New Holland, and the South Sea 

 Islands, are the favourite resort of this order. 



Properties. Of no importance. Many are troublesome weeds. 



Examples. Haloragis, Hippuris, Myriophyllum. 



XLIX. CIRC^EACEiE. The Enchanter's Nightshade Tribe. 



Circ^eaceje, Lindl. Synops. p. 109. (1829.) 



Diagnosis. Polypetalous dicotyledons, with definite perigynous stamens, 

 concrete carpella, an inferior ovarium of 2 cells, with definite erect ovula. 

 Anomalies. 



Essential Character.— Calyx superior, deciduous, tubular, with a two-parted limb. Pe- 

 tals 2, alternate with the lobes of the calyx. Stamens 2, alternate with the petals inserted into 

 the calyx. Disk large, cup-shaped, filling up the whole of the tube of the calyx, and projecting 

 beyond it. Ovarium 2-celled, with an erect ovulum in each cell ; style simple, arising out of 

 the disk; stigma emarginate. Fruit 2-celled, 2-valved, 2-seeded. Seeds solitary, erect; acu- 

 men none; embryo erect; radicle short, inferior.— Herbaceous plants. Leaves opposite, toothed, 

 stalked. Flowers in terminal and lateral racemes, covered with uncinate hairs. 



Affinities. This order differs from Onagrariee in its large fleshy disk, 

 which fills up the tube of the calyx, in its solitary erect ovula, and in the binary 

 division of the flower. It is connected with that order through Lopezia, with 

 which it cannot, however, be absolutely associated ; and bears about the same 

 relation to Onagrarias as is borne by Haloragea?. 



