cbucifeejE, 77 



require some explanation. The calyx is said to be bisaccate when two of 

 the sepals, a little outside the two others, are broader at the base, forming 

 little protuberances or pouches. The pod is termed a silique or siliquose 

 when linear, at least three or four times as long as broad ; a silicu/e or 

 siliculose when short and broad — not twice as long as broad ; and a lomen- 

 tum or lomentose when it does not open in valves. The nerves on the pod, 

 often used as a generic character, can be best seen on dried specimens ; they 

 are even sometimes quite imperceptible on the fresh pod. The seeds are 

 said to be in one row when, from the narrowness of the pod or the length of 

 the seed-stalk, they occupy the centre of the cell, the two rows being as it 

 were blended into one ; or in two rows, when the two rows are distinct 

 without overlapping each other. In the embryo, the radicle is said to be 

 accumbent when it is bent down on the edges of the cotyledons, incumbent 

 when bent over the back of one of them ; in the latter case the cotyledons 

 are either flat or conduplicate, that is, folded longitudinally over the 

 radicle. 



It must be admitted, however, that, notwithstanding all these nice dis' 

 tinctions, the genera of Crucifers, as at present defined, are often as artificial 

 as they are ditficult. But as the remodelhng them is not a work to be 

 undertaken in a local Flora, I have selected, from those adopted in the best 

 modern Floras, such as have appeared to me the most natural. The follow- 

 ing Table is founded, as much as possible, on less minute characters, but, 

 even in the few British species, it is feared that the examination of the seed 

 cannot always be wholly dispensed with. 



rPod with a lougitudinal partition, generally opening ia two valves 2 



1 < Pod not dehiscent, with one seed, or with several seeds placed end to end and 



(. separated by transverse partitions (Lomentosk) 30 



n fPod at least 3 or 4 times as long as broad (SitiQUOSE) 3 



(.Pod not 3 times as long as broad (SiLicuLOsh) 15 



3 SiLioTTosK I Flowers white, purple, or red (never yellow) 4 



** \ Flowers yellow 11 



fTetals large, on long claws, purple or rarely white. Stigmas 2, very short, erect 

 4< and parallel 5 



vPetals small, or the claws scarcely longer than the calyx. Stigma entire . ... 6 



'Leaves hoary and soft. Stigmas thickened at the base. (Cotyledons accumbent.) 



5 



1. Stock. 



Leaves green, with coarse hairs. Stigmas not thickened. (Cotyledons incumbent.) 



8. Hespeeis. 



„ (■ Leaves all undivided 7 



\ Leaves, at least the lower ones, pinnate 8 



„(■ Leaves all stalked, large and broad 10. Alliaeia. 



(. Upper leaves sessile or auricled 5. Rockckess. 



c r Seeds in two distinct rows in each cell. Pod rathershort and curved. 4. Watebcekss. 

 \ Seeds blended into one row in each cell. Pod straight, long, or slender .... 9 



g (■ Stem-leaves undivided, narrowed at the base 5. Rockceess. 



\ Leaves aU pinnate or divided 10 



HQ f Pod linear. Leaves without bulbs 6. Bitteece ss. 



\ Pod lanceolate-Unear. Leaves usually with bulbs in their axils . . 7. Toothckess. 

 I All the leaves entire, or toothed only. Plant pale or hoary with minute appressed 



, , 3 hairs 12 



1 Leaves, at least the lower ones, pinnate or lobed at the base. Plant glabrous, or 



V hairy with rough or spreading hairs 13 



jt, ( Pod flattened. Cotyledons accumbent 3. Wallflowee. 



" t Pod nearly quadrangular. Cotyledons incumbent 11. Eutsimum. 



'Cotyledons accumbent. Pods ending in a style seldom above a line long. Plant 



glabrous, with lyrate or pinnate leaves 14 



Cotyledons incumbent. Valves of the pod opening to close vmder the stigma. 



\Z-i Plant hairy or glabrous, the leaves deeply pinnate 9. Sisymbrium. 



Cotyledons conduplicate. Pod ending in a beak or conical style, 1 to 6 lines 

 long. Leaves irregularly pinnate, or lyrate, or the upper ones undivided. 

 L 12. Beassica. 



b2 



