196 BOTANY. 



spuriously two-celled and dehiscing by two valves, which separate from the 

 replura, one- or many-seeded. Seeds campylotropous, pendulous, attached 

 in a single row by a funiculus to each side of the placentas ; perisperni 

 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 flowei-s, 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. Pleurorhizeoe. Cotyledons accumbent. Radicle lateral. 

 Tribe 1. Arahideoe. Siliquose. Cotyledons plane, parallel with the straight 

 septum, linear. Examples : *Cheiranthus, *]Srasturtium, *Arabis. Tribe 2. 

 Alyssinem. Silicules separating in two plane or concave valves. 

 Cotyledons plane, parallel with the large and oval septum. Example : 

 *Draba. Tribe 3. Tldasjpidem. Silicules separating in two navicular 

 valves. Cotyledons plane, perpendicular to the straight septum. Example : 

 *Thlaspi. Tnbe 4. Eudidea'. Silicula indehiscent. Cotyledons plane, 

 parallel with the septum, which is sometimes wanting. Example : Euclidium. 

 Tribe 5. Anastaticeoe. Silicula longitudinally dehiscent, crossed by many 

 transverse septa. Cotyledons plane, parallel with the septum. Example : 

 Morettia. Tribe 6. Cakilinece. Silicula lomentaceous. Cotyledons plane, 

 parallel with the septum, when present. Example : Cakile. 



Siih-order 2. NotorMzece. Cotyledons incumbent ; radicle dorsal. Tribe 

 7. Sisymbriece. Siliquose. CotyledoEfs plane, perpendicular to the septum. 

 Example : *Sisymbrium. Tribe 8. CamelinecE. Silicula separatmg into 

 two concave valves. Cotyledons perpendicular to the elliptic septum, 

 broader than high. Example : *Camelina. Tribe 9. LepidinecE. Silicula 

 separating into two navicular valves. Cotyledons parallel with the straight 

 septum. Example : *Lepidium. Tribe 10. Isatidem. Silicula indehiscent, 

 one-locular, one-seeded. Examples : *Thysanocarpus, Isatis. Tribe 11. 

 Atichoniece. Siliqua or silicula lomentaceous. Example : Morisia. 



Sub-order 3. Orthoplocem. Cotyledons conduplicate ; radicle dorsal. 

 Trihe 12. Brassicem. Siliquose. Examples : Brassica, Sinapis. Tribe 13. 

 Velleoe. Silicula separating into two concave valves. Septum elliptic. 

 Example : Vella. Trihe 14. Psychinece. Silicula separating into two 

 navicular valves. Septum straight. Example : Schouwia. Tribe 15. 

 ZMlece. Silicula indehiscent, with one or two one-seeded cells. Example : 

 Zilla. Tribe 16. Raphanew. Siliqua or silicula lomentaceous, the joints 

 one- or few-seeded. Example : Raphanus. 



Sub-order 4. Spirolobece. Cotyledons twice folded; radicle dorsal. 

 Tribe IT. Buniadeoe. Silicula indehiscent, divided into four one-seeded 

 cells by one longitudinal and one transverse septum. Example : Bunias. 

 Tribe 18. Erucariem. Silicula lomentaceous, the lower joint two-celled, 

 the upper one-celled. Example : Erucaria. 



Sijd)-order 5. Diplecolobeoe. Cotyledons three times folded ; radicle 

 dorsal. Tribe 19. Senebierieoe. Silicula didymous, of two one-seeded 

 cells. Example : Senebieria. Tribe 20. Subulariece. Silicula separating 

 196 



