IS JCORUS CALAMUS A NATIVE? By Henry Trimen, M.B., F.L.S.
The late Dr. Bromfield, in liis eatalogue of Hampshire phints, thus writes (Phytol. iii. p. 1009), — "I have a lurking suspicion that the Sweet Flag may not be aboriginal to Britain ;" and he gives as a reason for this doubt the absence of any record of the plant as wild in the herbals of Turner, Gerarde, and Parkinson. I am informed by Mr. Hemslry that Mr. Borrer also considered it " probably planted " in the county of Sussex, where, as well as in Hampshire, it is confined to a single station.* In the Thames valley, however, the Acorns holds a far n.ore prominent place, and is common by the side both of t]»e main stream and of its tributaries as well as round ponds ; in the eastern counties it is stated to be equally or more common. Its area is pretty wide, extending from the south coast to Lancashire and York. In the neighbourhood of London it is thoroughly wild, and this is doubtless the case elsewhere in England, for, with the exception of Dr. Bromfield above quoted, all the writers on our flora have deemed it a native. Watson says (Cyb. Brit. iii. 31) "apparently a true native," and (Compend. 848) " native " ; Babington and Hooker pass it witliout a doubt ; Benthani says (' Handbook,' ed. 2. p. 436) " believed to be indigenous only in some of the eastern counties of England " ; and A. de CandoUe does not include it in his list of species certainly or probably naturalized in Great Britain (Geog. Bot. 645-097).
My attention has been lately directed to the matter by reading M. Devos's notes on the naturalized and introduced plants of Belgium in the Bull. Soc. Bot. Belg. 1870, pp. 5-122, where, after a review of the history of the plant on the Continent, lie points out that in Belgium, as in all western Europe, the Acorns, though now very well and widely established, was unknown before nearly the end of the sixteenth century. He therefore classes it with the " denizens," using that term as Mr. H. C. Watson has employed it. "With tlie view of seeing whether any and what countenance the history of the plant in Britain gives to this view, I have looked over the botanical literature of our country, and I may say at once that the general result is a corroboration of M. Devos's inferences.
M. A. de Candolle classes the data upon which conclusions with regard to naturalization n)ust be based, in the absence of positive proofs, under the three groups of historical, linguistic, and botanical. I will in the case before me take them in that order.
William Turner, in his first' book, the ' Libellus novus ' of 1538, fol- lowed Brunfels in making Acorns (of the ancients) to be Iris Psend- acorus. He soon discovered his error, and in the names of plants (1548) says, that " Acorns groweth not in England." He knew no more of it than the root, then largely sold as a drug, which he describes in his 'Herball,' pt. 1. B. ii. (ed'. 1, 1551), and p. 21 (ed. 2, 1568). Lobel, however, in 1575, was able to examine a living plant in the garden of " .Tohainies Dilsins," at Liege, which had been sent by Clusius, who ob'- taiiu'd it from l^ithjnia (' 01)servationes,' p. 20). The plant seen by Lobel had no flowers, but he has very well described the root and
- Mr. Hemsley has since observed it in a second one, in Arundel Park, where
he tJiinks, it may have been planted.