196 BOTANY. 
spuriously two-celled and dehiscing by two valves, which separate from the 
replum, one- or many-seeded. Seeds campylotropous, pendulous, attached 
in a single row by a funiculus to each side of the placentas; perisperm 
none ; embryo with the radicle folded upon the cotyledons which are next 
the placenta. Herbaceous plants, seldom undershrubs, with alternate leaves, 
and yellow or white, rarely purple flowers, without bracts. This order is 
well distinguished by having tetradynamous stamens. Most of the plants 
belonging to the order are European. The species, however, are found 
scattered all over the world. | 
Sub-order 1. Pleurorhizee. Cotyledons accumbent. Radicle lateral. 
Tribe 1. Arabidee. Siliquose. Cotyledons plane, parallel with the straight 
septum, linear. Examples: *Cheiranthus, *Nasturtium, *Arabis. Z7dbe 2. 
Alyssinew. Silicules separating in two plane or concave valves. 
Cotyledons plane, parallel with the large and oval septum. Example: 
*Draba. Tribe 3. Thlaspideew. Silicules separating in two navicular 
valves. Cotyledons plane, perpendicular to the straight septum. Example: 
*Thlaspi. Zribe 4. Huclideew. Silicula indehiscent. Cotyledons plane, 
parallel with the septum, which issometimes wanting. Example: Euclidium. 
Tribe 5. Anastaticee. Silicula longitudinally dehiscent, crossed by many 
transverse septa. Cotyledons plane, parallel with the septum. Example: 
Morettia. Zribe 6. Cakilinee. Silicula lomentaceous. Cotyledons plane, 
parallel with the septum, when present. Example: Cakile. : 
Sub-order 2. Notorhizee. Cotyledons incumbent; radicle dorsal. Tribe 
7. Sisymbriew. Siliquose. Cotyledons plane, perpendicular to the septum. 
Example: *Sisymbrium. Tribe 8. Camelinee. Silicula separating into 
two concave valves. Cotyledons perpendicular to the elliptic septum, 
broader than high. Example: *Camelina. Tribe 9. Lepidinee. Silicula 
separating into two navicular valves. Cotyledons parallel with the straight 
septum. Example: *Lepidium. TZiribe 10. Jsatedew. Silicula indehiscent, 
one-locular, one-seeded. Examples: *Thysanocarpus, Isatis. Zrabe 11. 
Anchoniee. Siliqua or silicula lomentaceous. Example: Morisia. 
Sub-order 3. Orthoplocee. Cotyledons conduplicate; radicle dorsal. 
Tribe 12. Brassiceew. Siliquose. Examples: Brassica, Sinapis. Z7ibe 13. 
Vellee. Silicula separating into two concave valves. Septum elliptic. 
Example: Vella. Zribe 14. Psychimew. Silicula separating into ‘two 
-navicular valves. Septum straight. Example: Schouwia. TZribe 15. 
Zillee. Silicula indehiscent, with one or two one-seeded cells. Example: 
Zilla. Tribe 16. Raphanee. Siliqua or silicula lomentaceous, the joints 
one- or few-seeded. Example: Raphanus. 
Sub-order 4. Spirolobew. Cotyledons twice folded; radicle dorsal. 
Tribe 17. Buniadew. Silicula indehiscent, divided into four one-seeded 
cells by one longitudinal and one transverse septum. Example: Bunias. 
Tribe 18. Erucarieew. Silicula lomentaceous, the lower joint two-celled, 
the upper one-celled. Example: Erucaria. 
Sub-order 5. Diplecolobew. Cotyledons three times folded; radicle 
dorsal. Tribe 19. Senebiercee. Silicula didymous, of two one-seeded 
cells. Example: Senebieria. Tribe 20. Subulariew. Silicula separating 
196 
