722 



HALORAGACEiE. 



[Epigynous Exogens. 



Order CCLXXVII. HALORAGACE^.— Hippurids. 



Halorageae, R. Brown in Flinders, 17. (1814); DC. Prodr. 3. 65 ; Bartl. Ord. Nat. 314. ; Endl. Gen. 

 cclxvi. ; Wight Illustr. 2. 23.— Hygrobiese, Rich. Anal. Fr. (1808).— HippuridejB, Link. Enum. 1. 

 5. (1821).— Cercodianae, Juss. Diet. Sc. Nat. (1817).— Hydrocaryes, Link Enum. Hort. Ber. 1. 141. 

 (1821).— Onagrarise, § Hydrocaryes, DC. Prodr. 3. 63. (1828). 



Diagnosis. — Myrtal Exogens, tvith a plurilocular ovary, polypetalous or apetalous flowers, 

 an open minute calyx., definite stamens, pendulous ovules, and minute cotyledons. 



Herbaceous plants or under-slirubs, often growing in wet places. Leaves either 

 alternate, opposite, or whorled. Flowers axillary, small, either in tenninal panicles or 



sessile, occasionally 

 monoecious or dioe- 

 cious by abortion. 

 Calyx adJierent, with 

 a minute limb, which 

 is 2- 4 -toothed, or 

 perfectly undi\dded. 

 Petals inserted into 

 the summit of the 

 calyx, or 0. Stamens 

 inserted in the same 

 place, equal in num- 

 ber to the petals, or 

 occasionally fewer. 

 Ovary adhering inse- 

 parably to the calyx, 

 with 1 or more cells ; 

 style none ; stigmas 

 equal in number to 

 the cells, papulose, 

 or pencil-formed ; 

 ovules pendulous, 

 anatropal. Fruit di'y, 

 indehiscent, mem- 

 branous, or bony, 

 with 1 or more cells. 

 Seeds sohtary, pen- 

 dulous ; albumen 

 fleshy or ; embryo 

 straight ; radicle su- 

 perior, large ; coty- 

 ledons much smaller. 

 These plants may 

 be regarded either 

 as a distinct Order, 

 or as a mere degene- 

 ration or imperfect 

 foiTu of Onagi'ads, 

 from which theu' mi- 

 nute calyx and soh- 

 tary pendulous seeds 

 Fig. CCCCLXXXII. distinguish them ; to 



■wliich may be added an evident tendency on the part of Hippurids to lose theu' petals 

 altogether. In Hippuris itself the flower is in the simplest possible form ; for it is re- 

 duced to a calyx of the smallest size, it has no petals, but one stamen and but one carpel. 

 It therefore furnishes an instance of the approach of MjTtals to the Asteral Alliance. 

 This reduction of the fruit to one carpel only, seems however to be very different in Hip- 

 puris from that of Fringe-myrtles ; for the latter have a multiplication and excessive deve- 

 lopment of every other organ, to which the pistil forms the exception ; but in Hippuris 



Fig. CCCCLXXXII.— Loudonia aurea. 1. a complete flower ; 2. a section of the ovary. 



