196 ON BRASSICA POLYMORl'HA.
troublesome weed in Sweden, it could not be Urysimnm orienlale, Br. ; and Koch, Babington and Watson may be right, as far as the evidence from books goes, in looking upon it as a wald state of Rupa. The authentic specimens, however, in the Linnpean Herbarium, although not very satis- factory, will hardly support this view. Two sheets are named " cam- pestris ; " the first contains a " top," and an indeterminate example of an annual plant, apparently the same as that on the second sheet. This last is about a foot in height, in flower (the inflorescence decidedly corymbose where the petals are still unfallen), yet still preserving the radical leaves. These lower leaves are only sparingly hispid, the pairs being confined to tlie ribs, and they are also distinctly ghiucous ; in fact, they appear to me quite the same in appearance as those of a young seedling Swede sent me by Mr. Watson. The young leaves of the Thames-side Brassica are not in the least glaucous, and are, as Mr. Watson says, " much hispid," the hairs being by no means conTined to the ribs. The Smithian Herbarium yields little information, as none of the specimens have young leaves. The cmnpestris of the Linnsean herbarium and of Mr. Watson appear, therefore, by no means to be the same thing. The Swedisli plant seems to be nearly allied to the Swede and the Rape of English agriculturists ; the Thames-side plant is indubitably a wilding Turnip. The only question remains, how is the existing nomenclature to be adjusted to our English plants. The first step would be to eliminate B. Najjus ; apparently, as far as England is concerned, a purely spectral plant, if one with wholly glabrous radical leaves is intended. Koch retains Napns, including under it the plants of De Candolle's campedris, making, as stated above, the campeatrls of Linnseus, a variety of Eapa. Napus, at any rate, has only a prescriptive right to a place in English Floras.
As to the name 'polymotpha,' Boswell Syme, by a curious error, says (Eng. Bot. i. 136) that he gives it to the aggregate species " in pre- ference to B. cmnpestris, as that name has been applied exclusively to the ' form with glabrous (not hispid) radical leaves," which is apparently the opposite of the fact. Dr. Hooker, however (' Student's Flora,' p. 29), con- siders that B. polymorpha should not supersede B. campestris.
The synonymy of these plants would seem to stand as follows : — Brassica poli/morpha, Boswell Syme, E. B. i. 133, non Murr.* B. campestris, Hook. Stud. Fl. 29. I. B. campestris, De Cand. Syst. ii. 588. a. oleifera, De Cand. B. campestris, L. Herb. Rape, Colza. /3. Napo- Brassica, De Cand. Swede. II. B. Rapa, L. Sp. 931 ; De Cand. a. rapifera, Koch, Syn. ed. 2. i. 59.
Turnip. /3. campestris, Koch, ibid. ; Watson, 1. c. ' Navew,' Watson, 1. c. [III. B. Napus, L. Sp. 931. a. oleifera, De Cand. /3. esculeuta, De Cand.]
- B. i^ohjmorpha, Murr. and W. & ^.=: Sisymbrimn junceum, Marsch. v. Bieb.