Rhamnales.] 



RHAMNACE^. 



581 



Order CCXXII. RHAMNACE^.— Rhamnads. 



Rhamni, Juss. Gen. 376. (1789).— Rhamneae, DC. Prodr. 2. 19. (1825); Brongniart Memoire sur les 

 Bfianmdes ; Endl. Gen. ccxxxix. ; Meisner,p. 70. 



Diagnosis. — Bhamncd Exogens, with polypetalous floivos, a valvate cali/x, stamens opposite 

 the petals, and erect seeds. 



Trees or shrubs, often spiny. Leaves simple, alternate, very seldom opposite ; 

 stipules, if any, minute. Flowers small, generally green, axillary or tenninal, some- 

 times ^ ? by abortion. Calyx 4-5-eleft, valvate. Petals distinct, eucullate, or 



Fig. CCCXCIV, 



convolute, inserted into the orifice of the calyx, occasionally 0. Stamens definite, 

 opposite the petals. Disk fleshy. Ovary superior, or half superior, 2- 3- or 4-celled ; 

 ovules solitary, erect, anatropal. Fruit fleshy and indehiscent, or di'y and separating 

 in 3 divisions. Seeds erect ; albumen fleshy, seldom wanting ; embryo almost as long 

 as the seed, with large flat cotyledons, and a short inferior radicle. 



Under this name have been confounded four Orders, very different in characters, and 

 even in natural affinities, the pecuUarities of three of which have been pouited out by 

 Ad. Brongniart in his Memou' upon the subject, and a fourth has been distinguished 

 by myself. These Orders are Rhamnads propei'ly so called, Spindle-trees, Hollyworts, 

 and Bladder-nuts the respective affinities of which will be fomid under each. 

 Brongniart indicates the relation that Rhamnads bear, thus : — If we take the insertion 

 of stamens as the most important distinction of plants, it will be fovmd that among 

 polypetalous Orders with perigynous stamens, Appleworts are those to which Rhamnads 

 have the closest relation, agreeing with them in the ovary, the cells of wliich are deter- 

 minate in number, in the ascending ovules, and in theu' alternate leaves usually having 

 two stipules at their base ; the number and position of their stamens, and the stinictm-e 

 of their seeds, separate them widely. But if the insertion of the stamens is left out of 

 consideration, they will be found to have many characters in common ^v^tll Bytt- 

 neriads ; such as, the aestivation of the calyx, the form of the petals, the position of the 

 stamens in the front of those petals, the structm-e of the ovary and seeds in many 

 unportant pomts ; the principal diff'erences between them are, in fact, the stamens beuig 

 turned outwards in Byttneriads, the want in that Order of a disk, its hypog}-nous 

 stamens, and 2 or more ovules. Spurgewoi'ts are alhed to Rhamnads ; but the 

 constant separation of sexes in the foi-mer Order, their hypogynous stamens and 

 suspended o^aUes, are ob%4ous marks of distmction. Hollyworts ai-e monopetalous and 



Fig. CCCXCIV.— Zizyphus Baclei. 1. a flower seen from above ; 2. a fniit ; 3. the same cut verticaUy; 

 4. a seed divided vertically. 



