CRUCIFERJI. 13 



placentas. Capsule unilooolar, dehiscent by small valves at the top : intervalvnlar placentas 

 not produced inwards, united at the top. Embryo axile. — Glaucescent herbs ; leaves sessile, 

 pinnatifid; teeth spinulose. 



/ 1. A. mexicana, L, Leaves half-clasping, pricHy, with white spots ; capsule prickly- 

 •—As. Gray, Gen^Bor. Amer. 1. *. 47 ; Besc. Fl. 5. t. 380.— Petals large, yellow, usually 6. ' 

 — Hab. Jamaica 1 ; Caribbean Islands I, common ; [tropical America ; naturalized in other 

 tropical continents, and in the warm parts of both temperate zones of the globe]. 



2. BOCCONU, Z. 



Sepals 2. Petals 0. Stamens 8-24. Carpels 2 : style with two stigmas, opposite to 

 the placentas. Capsule unilocular, bivalved at the base : intervalvular placentas filiform, 

 united at the top. Seed single, erect. — SufEruticose herbs ; leaves petioled; flowers ^aMJcMr 

 late. 



2. B. irutescens, Z. Leaves oval-oblong, siuuate-pinnatifid (uppermost sometimes not 

 divided), glaucescent beneath ; panicle pyramidsd. — SI. t. 125 ; I)ese. M. 1. t. 54. — Stem , 

 4'-9' high ; leaves 6"-18" long ; panicle often above a foot long. — Hab. Jamaica !, all col- 

 lectors; Caribbean Islands I, common ; [Cuba!; Mexico 1 to Peru]. 



XII. CEUCIFEE^. 



Sepals and petals 4. Stamens hypogynous, mostly 6, four longer. Pistil paracarpous. 

 'Fruit usually bilocular by a placentary, spurious, intervalvular dissepiment. Embryo exal- 

 bnminous : radicle mostly reflexed. — ^Plants, mostly herbaceous ; leaves simple, vdthoiit sti- 

 pules ; flowers usually racemose, with the bracts suppressed. 



The West Indian species are almost all cultivated pot-herbs, as Cabbage, Turnip, Mustard, 

 Horse-radish, and Radish {ef. Maqf. Fl.). The famous antiscorbutic properties prevailing 

 in aU Cruciferis depend upon a peculiar principle, containing sulphur in its elementary com- 

 position. The embryo developes a large quantity of fixed oil in its tissue. 



Tkibe I. SIIIQUOSM — fruit elongated, bivalved (siliquej. 



1. CARDAMINE,i. 



Clique linear : valves flat, nerveless. Seeds uniserial ; funicles free. Cotyledons accum- 

 bent. 

 /^ 1. C. hirsnta, Z. Leaves pinnatisect : segments of the supraradical leaves orbicular, 

 of the upper ones longer and cuneate ; stamens usually 4 ; silique erect : stigma nearly ses- 

 sile. — C. sylvatica, Matf. — Leaves glabrous, but the petiole ciHate towards the base ; flowers 

 small, white. — I have not seen this plant from Jamaica, and borrow the diagnosis from Mac- 

 fadyen's description, which, by the number of stamens, proves that it is not the form called 

 C. sylvatica, Lk., in Europe. — Hae. Jamaica, on mountain rocks (JUacf.) ; [northern tem- 

 perate zone, and tropical mountains in all continents]. 



2. NASTURTIUM, B. Br. , 



l&lique oblong-linear : valves convex, almost nerveless. Seeds biserial. Cotyledons ac- 

 cumbent. 

 f 2. M. officinale, M. Br. Perennial ; leaves pinnatisect : segments ovate, repand ; petals 

 white, double the length of the calyx ; hypogynous glands 4 ; siliques spreading, equalling 

 their pedicel. — Hab. Jamaica, on the banks of mountain rivulets {Maqf.); Dominica (DC); 

 [both the temperate zones of the Old World and of Western America; a few highland loca- 

 lities in the tropics, e.g. Cuba !]. 



3*. SISYMBRIUM, L. 

 Silique linear : valves co^ivex, trinerved. Seeds uniserial, Cotyledons incumbent. 

 '' 3*. S. officinale, 5co^. Annual, hairy ; leaves runcinate ; flowers yellow ; silique snbu- 

 late-linear, tapering into the short style : pedicels very short, appressed to the axis and at 



