ViOLALES.] 



TAMARICACEiE. 



341 



Order CXVIII. TAMARICACEiE.— Tamarisks. 



Tamtjriscmess, Dewaux, in a Dissertation read before the French Institute (in 1S15,) according to the 

 Ann. Sc. Nat. i. 3ii. (1825); A. St. Hit. Man. Miis. 2. 205. (1H16) ; Ehrenh. in Annates des 

 Sciences, 12. 6S. (1827); DC. Prodr. 3. i)5. (1828) j Endl. Gen. ccxxi. ; Meisner, p. 129; Wight, 

 lUustr. 1. t. 24. 



Diagnosis. — Violal Exorjens, toith polypetalmis flotuers, a many-leaved calyx, liyporjynoxis 

 petals, distinct styles, consolidated fruit, and 00 basal comose seeds ivithout albumen. 



Shrubs or herbs, with I'od-Uke branches. Leaves alternate, resembling scales, entire, 

 usually with pits on the surface. Flowers in close spikes or 

 racemes. Calyx 4- or 5 parted, persistent, with an imbricated 

 aestivation. Petals inserted into the base of the calyx, wither- 

 ing ; with an imbricated sestivation. Stamens hypogynous, either 

 equal to the petals in number, or twice as many, distinct or 

 monadelphous. Anthers turned inwards, 2-celled, opening 

 longitudinally. Ovary superior ; styles 3 ; ovules numerous, 

 ascending, anatropal. Capsule 3-valved, 1 -celled, many-seeded ; 

 placentae 3, either at the base of the cavity, or along the middle 

 of the valves. Seeds erect or ascending, comose ; albumen 

 none ; embryo straight, mth an inferior radicle. 



Botanists are di\aded in opinion as to the proper place, in the 

 Natm'al system, of the Tamarisk, that common but beautiful 

 bush, and its aUies. De CandoUe stations it near Purslanes, 

 from which its straight embryo and want of albmnen remove it ; 

 others have suggested an affinity to Lythrads, or even to Ona- 

 grads ; Meisner adopts the \'iew of De Candolle, which I too 

 have formerly followed. Endlicher is inchned to station Tama- 

 risks next to Reaumm'iads, with which they not only agree in 

 habit, but in very many respects of structm^e. The main dif- 

 ferences consist in Reaumm'iads hax-ing a many-celled fruit, 

 axile placentae, mealy albumen round the seeds, and petals with 

 miequal sides, while Tamarisks have a 1 -celled finiit, with a 

 basal and partially parietal placentation, no albumen, and their 

 petals are equal-sided. Endhcher is also of opinion that a 

 tendency towards Lytlu*ads is observable among these plants. 

 I think, however, that, not\\'itlistanding the resemblances with 

 Reaumm'iads, the time place of the Order must be in tliis 

 Violal Alliance, where it may perhaps be regarded as a near 

 ally of Sauvageads and Houseleeks. The habit of some of the 

 latter is not very different from that of Tamarisks. The most 

 important distinctions are the total absence of albumen in Tam- 

 arisks, and the axile or sutural placentation of Houseleeks. The 

 presence of albumen is of less consequence than usual in an 

 AUiance whose embryo is so highly developed. The placenta- 

 tion is however of greater importance, and more than anythmg i 

 else throws doubt upon the affinity now suggested. 



The species are exclusively confined to the northern hemi- 

 sphere, and even to its eastern half, that is, to the Old World, on 

 which they extend as far as the Cape de Verds. They usually 

 grow by the sea-side, but occasionally by the edges of rivers and 

 torrents. The maximum of species and of individuals also is found in the basin of the 

 MediteiTanean. The Order appears bounded on the south by the 8th or 9th parallel of 

 N. lat., and on the north by that of 50° and 55'^ in Siberia, Gennany, and England. 



Theii- bark is slightly bitter, astringent, and probably tonic. Tamarix galhca and 

 africana are remarkable for the quantity of sulphate of soda which their ashes contam. 

 Ehrenberg found that the Manna of Momit Smai is produced by Tamai-ix manuifera. 

 This substance, bemg analysed by Mitscherlich, was ascertained to contam no crystallis- 

 able Mannite, but to consist wholly of pure mucilagmous sugar.* The galls of Tamarix 



* Ehrenberg considers it as an exudation produced by a species of Coccus (manniparus) which inhabits 

 the tree, and this is confirmed by Mr. Malcolmson, who in a note I received from hmi some tune smce, 



Fig. CCXXXIV.— Tamarix. 1. a flower; 2. a view of the interior of the ovary; 3. placenta; seen 

 from above J 4. a ripe seed-vessel split open; 5. a seed. 



Fig. CCXXXIV. 



