50 CRUCIFERyE. 



the persistent placentae (rarely indehiscent). Seeds without albumen ; embryo 

 with the cotyledons folded on the radicle. — Herbs, or very rarely (never in 

 North America) somewhat shrubby plants, with a pungent or acrid watery 

 juice. Leaves alternate, often divided, without stipules. Flowers in racemes 

 or corymbs, mostly without bracts to the pedicels. 



CONSPECTUS OP THE TRIBES. 



1. SlLlQUOS^B. 



Tribe I. Arabidk*. Silique usually elongated (except sometimes in Nasturtium), dehiscent ; the valves somewhat 

 plane : dissepiment linear. Cotyledons plane, accumbent (i. e. the radicle is applied to their edges, 0=), 

 parallel with the septum (i. e. with their edges applied to the placentae). 



Tribe II. SiSYMBBEiE. SiUque longitudinally dehiscent; valves nearly plane or somewhat terete and carinate : septum 

 Unear. Cotyledons plane, incumbent (i. c. with the radicle cpplied to the back of one of the cotyledons, 

 K 0)i contrary to (i. e. with the edges towards) the septum. Seeds not bordered. 



Tribe III. BRASsicEa;. Silique dehiscent ; septum linear. Style often enlarged, with a seminiferous cell at the base. 

 Seeds globose. Cotyledons incumbent, conduplicate or longitudinally plicate, with the radicle lyino in the 

 sinus (0>>')- 



2. SlLICULOSA. 



Tribe IV. ALYSsiNEffi. Silicle dehiscent ; valves plane or convex : septum broadly oval and tnembranaceous. Seeds 



compressed, often margined. Cotyledons plane, accumbent, parallel ts the septum, 

 l^be V. Camelineje. SiUclc dehiscent, ovoid or oblong, compressed parallel to the septum, or turgid j valves plane 



or convex : septum elliptical or ovate, sometimes incomplete or none. Cotyledons plane, incumbent, 



contrary to (i. e. their margin looking towards) the dissepiments. 

 Tribe VI. Thlaspideje. Silicle dehiscent, compressed contrary to the very narrow septum: valves boat-shaped. 



Cotyledons plane, accumbent, contrary to the septum. 

 Tribe VII. LiPiDiNEffi. Silicle usually dehiscent, compressed contrary to the narrow septum (sometimes I-celled) ; 



valves boat-shaped, or rarely ventricose. Cotyledons plane, incumbent, parallel to the septum. 



3. LOHENTACE^. 



Tribe VIII. CAKiLiNEiE. SiUque or silicle separating transversely into several 1-ceIled, 1-seeded joints. Seeds usually 



compressed, not margined. Cotyledons plane, accumbent. 

 Tribe IX. Raphaneje. Silique or silicle indehiscent, transversely separating into one- (or few-) seeded joints. Seeds 



globose. Cotyledons conduplicate (as in Brassicacea). 



1. SILiaUOSiE. 



Thibb I. ARABIDE^. DC. 



Silique usually elongated ; the valves somewhat plane ; dissepiment linear. Cotyledons 

 ' plane, accumbent (i. e. the radicle applied to their edges, o = ), parallel with the septum 

 {i, e. with their edges applied to the placentae). 



CONSPECTUS OF THE GENERA. 



1. Nastcrtiom. Silique nearly terete, sometimes short ; valves neither nerved nor keeled. Sepals spreading. Seeds 



irregularly disposed in a double series. 



2. Barbarea. Siliqvie 4-angled and somewhat 2-edged : valves nerved or keeled. Seeds in a single row. 



3. Tdrritib. Silique linear, 2-edged : valves nerved or keeled. Seeds in a double row. 



4. Arabis. Silique linear, flattish: valves one-nerved in the middle. Seeds in a single row. 



5. Cardamine. Silique linear ; valves flat, generally separating elastically, without nerves. Funiculus slender. 



6. Dentaria. Silique narrowly lanceolate, tapering : valves flat, generally separating elastically, nerveless. Funicolus 



t>road. 



