50 CRUCIFER^. [Draba. 



from the British American Flora. — Tlie fiowers of this are not known, autl it may he considered doubtful if 

 any true Alyssum is found in North America. 



12. DRABA. Linn. 



. Silicula sessilis, ovalis aut oblonga, valvis planis couvexisve. Semina pluiima iiumar- 

 ginata. Calyx a^qualis. Petala Integra. Stamina omnia edentula. Z)C 



* Perennes, Scapi plerumque aphyllL 



1. Z>. algida ; flaccida, scapis brevibus nudis patenti-pilosisj foliis oblongis planis caly- 

 cibusque pilosis, pilis plerumque simplicibus, siliculis subcorymbosis ellipticis glabris, 

 stylo perbrevi, (floribus flavis). — " Adams in Herb, Fisch'' De Cand. Prodr, i\ 1. p. 167. 

 Cham, et Schlecht, in Linncea^ v, 1, p, 2\, 



y, hrachycarpa., DC; siliculis brevioribus. De Cand. Prodr. L c. 

 5, breviscapa ; scapo foliis glabriusculis immerso. 



Hab. Sea coast between the Mackenzie and Coppermine Rivers. Dr. Richardson. 5. In deep sand. — I 

 have not had any opportunity of seeing authentic specimens of D, algida : but its characters agree mth 

 those of our present plant, and, according to De Candolle and Chamisso, it must be very nearly allied to 

 i>. alpirta; so much so, that the latter author doubts if what he describes as the y. hrachycarpa be not a 

 dwarf state of alpina. De Candolle says that it is known from that species and all the yellow-flowered 

 ones, by its simple not branched hairs. In our plant, however, it must he confessed there are a few branched 

 hairs mixed with the more abimdant simple ones, . The roots are long and slender, the lower part of the 

 numerous, dichotomously divided branches shaggy with the remains of former years' leaves ; the perfect 

 leaves, as well as the stem, are soft and flaccid, oblongo-spathulate, hairy principally at the margin : the 

 scapes scarcely twice the length of the leaves, even when bearing fruit, hairy or glabrous, as is the calyx, 

 even on the same plant. Pedicels always glabrous. Petals twice the length of the calyx, obovate. 

 Capsules elliptical or elliptic -oblong, shortly oval in y., and sometimes also in a. Style short, but distinct. 

 Stigma oblong, lobed. In 5, the flower is quite immersed among the leaves. 



2. D, alpina ; subrigida, scapis nudis pubescenti-liirsutis, foliis lanceolatis planis pilis 

 plerumque ramosis, petalis calycem plusqiiam duplo longioribus (plerumque flavis) siliculis 

 subcorymbosis oblorigo-ellipticis, stylo brevi. — Linn. Sp, PI. p. 896. FL Dan, f, 56. (foliis 

 nimis latis.) Wahl, Lapp, v, 1. p. 173. t, II. f, 4, (sed stigmata breviore quam in nostr. 

 exempl.) Br. in Parry^s \st Voy. App. p. 265. Rich, in Frank!, \st Journ. ed. 2. App. p, 

 21. Hook, in Parry's 2d Voy. App. p. 385. 



«. siliculis glabris. " Herb, Linn^ Br, I, c, 



(i. siliculis pilosis. Br. I. c, — D. alpina. Br. Spitzb. PL in Scoresby's Arctic Reg. 



3. floribus albis. 



Hab. From lat. 60° on the Mountains, to the shores of the Arctic Sea, and on the islands adjacent, where 

 it principally abounds, extending westward to Kotzebue's Sound, ( Captain Beeckei/s Collection), and the 

 Island of St. Lawrence, ( Chamisso) : found by all the Arctic Travellers. S. Only on the sea shore, westward 

 of the Mackenzie River. Captain Sir J. Franklin and Captain Back. — De Candolle says of this, that the 

 flowers are smaller than those of Z). aizoides. It is not so in our specimens; they are remarkable for their 

 size and generally fine yellow colour, rarely w^hite, or very pale yellow. The calyx, peduncle, and scape, 

 are liable to vary in their degree of hairiness. This does not appear to grow farther south than lat. 60°, nor 

 did Mr. Drummond or Mr. Douglas find it at the greatest elevation of the Rocky Mountains, where they 

 crossed the chain. In that alpine and southern latitude, the species seems to be replaced by the following 

 very closely allied one. 



