TETRADYNAMIA-SILICULOSA. Isatis. 181 



awl-shaped, distinct, simple. Ant k. roundish. Germ.almost 

 orbicular, notched at the summit, compressed. Stijle very 

 short. Stigma obtuse. Pouch ovate, transversely com- 

 pressed, bordered, of 2 cells, cloven at the top* into 2 

 acute lobes, between which stands the permanent, some- 

 what elongated, stijle ; valves 2, distinct, boat-shaped, 

 each with a dilated pointed keel; partition elliptical, mem- 

 branous, as w^ide as the valves. Seeds solitary in each 

 cell, pendulous, ovate ; cotyledons ovate, flat, accumbent. 

 Herbaceous, or in some degi'ee shrubby. Leaves rather 

 fleshy, undivided or pinnatifid, entire or toothed. FL 

 white, or purplish, never yellow ; the outer ones in each 

 corymbose head or cluster most irregular, somewhat ra- 

 diant. Pouches erect, or inflexed, racemose. DeCandolie 

 has 25 species. 



1. I. amara. Bitter Candy-tuft. 



Stem herbaceous. Leaves lanceolate, acute, partly notched. 

 Flowers in oblong clusters. 



o 

 I. amara. Linn. Sp. PL 906. TVilld.v.3.456. Fl.Br. 692. Engl. 



Bot.v. 1. t.52. DeCand.Syst.v. 2.398. 

 I. n. 520. Hall. Hist. v. 1 . 223. 

 Thlaspi amarum. Ger. Em. 263./; bad. 

 T. umbellatum arvense amarum. Bauh. Hist. v. 2.92b. f. 

 T. umbellatum arvense, iberidis folio. Moris, v. 2. 295. sect. 3. 1. 17. 



/. 1 8 J copied from Gerarde. 

 Thlaspidium foliis nasturtii. Riv. Tetrap. Irr. t. 112. 



In chalky fields, but rare. 



About Henley and other places in Oxfordshire. Huds. About 

 VVallingford, Berkshire, plentifully, and undoubtedly wild. 



Annual. Jnbj. 



Whole plant smooth, of a nauseous bitter flavour. Root small, 

 tapering". Stems diffuse, branched, leafy. Leaves lanceolate 

 and entire, or dilated and wedge-shaped, with several tooth-like 

 notclies. Corymlis soon lengthened out into clusters of hand- 

 some brilliant-white floiccrs, vvhicli have procured it a place, 

 among hardy annuals, in some gardens. 



3-:8. ISATIS. Woad. 



Linn. Gen. 3iA. Juss. 2\2. El. Br. 693. DeCand. Syst.v. 2.564. 

 Tourn.t. \00. Lam.t.bbA. Gccrtn. t. \42. 



Cat. ecjual at the base, coloured ; leaves ovate, concave, 

 spreading, deciduous. Pet. obovate, entire, equal, taper- 

 ing at the base into short claws. Filam. thread-shaped, 

 spreading, simple, as long as the calyx. Anth. roundish. 



