OKD. I.] 21, TEESDALIA NUDICAULIS. 



403 



Diagnosis and Affinity. 



This plant has some resemblance to Draha verna, which 

 blooms somev/hat earlier however, and is much more com- 

 mon. Both are of nearly similar stature, but Draha verna 

 is commonly the smaller ; its individual flower- stalks are much 

 longer, the root leaves are tindivided, and furnished with 

 three-pointed hairs. The petals are deeply indented, and the 

 fruit is a longish, pointed silicle, with many seeds. Lepidium 

 nudicuule L., which grows about Montpellier, and is figured 

 by Magnol (Bot. Monsp. p. 187.), is also distinguished from 

 it^ by the smaller lobes of its lyre-shaped root-leaves. But 

 I>e Candolle has shewn (Flor. Franc. 4. 708.), that this plant 

 is only a subspecies of ours. TJdaspi Bursa^ also, has some- 

 times an appearance, which might lead us to take it for Tees^ 

 dalia, since it has lyre-shaped root leaves, and white flowers. 

 But its stem is always branched and furnished with leaves : 

 the siliclesj also, are inversely triangular, and contain many 

 seeds. Lepidium alpinum and petraum L. have also some 

 resemblance to it ; but they have peculiarly pinnated leaves, 

 which grow on the stem, and lanceolate siliculse, furnished 

 with pointed extremities. 



This plant is commonly classed with Iberis^ because its pe- 

 tals are somewhat unequal. But Iheris has the valves of its 

 siliculse distinctly marginated, and has no appendages to the 

 filaments. These two circumstances constitute the diagnostic 

 character of the two genera. This plant cannot be classed 

 with Lepidium, because, in this latter genus, the petals are 

 uniform, the filaments are without appendages, and the ra- 

 dicle of the embryon is turned towards the ridge of the coty- 

 ledons. Tldaspi is still further distinguished by the winged 

 or marginated valves of the silicul^, by the want of append- 

 ages to the filaments, by having many seeds in its locuii, and 

 by the direction of the radicle towards the ridge of the coty- 

 ledons. 



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