CRUCIFERJE. 13 



placentas. Capsule unilocular, dehiscent by small valves at the top : intervalvolar placentas 

 not produced inwards, united at the top. Embryo axile. — Olaucescent herbs; leaves sessilo, 

 pinnatifid ; teeth spinulose. 



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

 — As. Gray, Gen. Bor. Amer. 1. t. 47 ; Desc. Fl. 5. t. 380. — Petals large, yellow, usually 6. 

 — Hab. Jamaica!; Caribbean Islands 1, common ; [tropical America; naturalized in oiher 

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



2. BOCCONIA, L. 



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

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

 united at the top. Seed single, erect. — Suftruticose herbs ; leaves petioled; flowers panicu- 

 late. 



2. B. frutescens, L. Leaves oval-oblong, siuuate-pinnatifid (uppermost sometimes not 

 divided), glaucescent beneath ; panicle pyramidal. — SI. t. 125 ; Desc. Fl. 1. t. 54. — Stem 

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

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



XII. CKUCIFEK^. 



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

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

 buniinous : radicle mostly reflexed. — Plants, mostly herbaceous ; leaves simple, without 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 (cf. Mac/. Fl.). The famous antiscorbutic properties prevailing 

 in all Crucifera depend upon a peculiar principle, containing sulphur in its elementary com- 

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



Tribe I. SILIQJJ0S2E. — Fruit elongated, bivalved (silique). 



1. CARD AMINE, L. 



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

 bent. 



1. C. hirsuta, L. 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, Macf. — Leaves glabrous, but the petiole ciliate 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. — Hab. Jamaica, on mountain rocks {Macf.) ; [northern tem- 

 perate zone, and tropical mountains in all continents]. 



2. NASTURTIUM, R. Br. 



Silique oblong-linear : valves convex, almost nerveless. Seeds biserial. Cotyledons ac- 

 cumbent. 



2. N. officinale, R. Br. Perennial; leaves pinnatisect : segments ovate, rcpand ; petals 

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

 their pedicel. — Hab. Jamaica, on the banks of mountain rivulets (Macf.); 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*. SISYMBRHJM, t. 

 Silique linear : valves convex, trinerved. Seeds uniserial. Cotyledons incumbent. 

 3*. S. officinale, Scop. Annual, hairy; leaves runcinate; flowers yellow; silique subu- 

 late-linear, tapering into the short style : pedicels very short, apprcssed to the axis and »t 



