Thlaspi.] CRUCIFERjE. 41 



Fields, &c, rather common ; rarer in Scotland ; E. Ireland ; Chan- 

 nel Islands ; (a colonist, Wats.) ; fl. May-July. — Stem 1-2 ft., usually 

 simple, slender, erect. Radical leaves petioled, cauline with prominent 

 auricles. Flowers f in. diam., white, homogamous. Pods in long racemes 

 §-| in. diam., flat, pedicels slender spreading, marginal nerve delicate, lobes 

 sometimes overlapping at the tip ; style very short ; seeds dark, oblong, 

 ridged and punctate. — Distrib. Europe to N. Africa, 1ST. and W. Asia to 

 N.W. India ; introd. in U. States. 



2. T. perfolia'tum, L. ; annual, cauline leaves cordate with converging 

 auricles, pods small obcordate, valves winged above, cells 4-6-seeded. 



On limestone; Oxford (extinct), E. Gloster; fl. April-May. — Paniculately 

 branched ; branches 4-6 in., ascending, flexuous. Leaves |-1 in. broad ; 

 radical spathulate, petioled. Flowers ^ in. diam., white. Pods £ in., and 

 pedicels horizontal ; valves turgid, wings short, marginal nerve stout, style 

 very short; seeds pale. — Distrib. Mid. and S. Europe, N. Africa, N. and 

 W. Asia. 



3. T. alpes'tre, L. ; perennial or biennial, cauline leaves sagittate, 

 pods obcordate retuse, valves winged above, cells 4-8-seeded. 

 Mountain districts, England, Wales and Scotland, ascending to 2,500 ft. in 



Forfarshire; fl. June- Aug.— Stem 6-10 in. Radical leaves long-petioled, 

 obovate, entire ; cauline § in. Flowers^ in. diam. Racemes of pods variable. 

 Pod J in., curved upwards, on spreading pedicels, longer than in the pre- 

 ceding species, and more narrowed at the base ; marginal nerve obscure ; 

 seeds red-brown. — Distrib. Europe, Himalaya. — I do not find that authen- 

 tically named specimens of the following varieties altogether tally with the 

 characters assigned to them. — Var. T. sylves'tre, Jord. ; notch of pod shallow, 

 style as long as its lobes. — Teesdale ; Allen river, Northumbd.; Glen Isla 

 and Glen Shee, Scotland. — Var. T. occita'num, Jord. ; notch of pod shallow, 

 style slender longer than its lobes, radicle at times incumbent (Syme). — 

 Limestone rocks, Settle, Yorkshire ; Llanrwst, N". Wales. — Var. T. vi'rens, 

 Jord. ; notch of pod minute, style slender much exceeding it. T. alpes'tre, 

 Sm. — Limestone rocks, Matlock. 



19. ibe'ris, L. Candy-tuft. 



Low, glabrous, branched, leafy herbs, often shrubby below. Leaves 

 entire or pinnatifid, often fleshy. Flowers corymbose, all or the outer only 

 with the 2 outer petals radiating. Sepals equal at the base. Petals white 

 or lilac, the two outer much the longest. Filaments without appendages. 

 Pods broad, much compressed, orbicular or ovate, tip entire or notched ; 

 valves keeled or winged ; septum very narrow, of two lamellae ; stigma 

 notched. Seeds 1 in each cell, not margined ; radicle accumbent, hori- 

 zontal, or ascending. — Distrib. Mid. and S. Europe, Asia Minor ; species 

 about 20. — Etym. Iberia (Spain), where many species grow. 



I. ama'ra, L. ; leaves oblong-lanceolate, pods suborbicular. 

 Cornfields and cultivated ground, on a dry soil, chiefly in the centre and E. of 

 England, rare in Scotland ; (a colonist, Wats.) ; fl. July -Aug. — Annual. 

 Stem 6-9 in., erect, corymbosely branched, ribbed, the ribs minutely downy. 



