pdf 25 MB - BSBI Archive

352
NOTE ON AIRA SETACEA, Hudson (A. ULIGINOSA, IFelhe).
By Heney Trimen, M.B., F.L.S.
{Botanical Department, British Museum.)
Ill the Banksian herbarium is a grass labelled by Sir Joseph Banks
" Aira setacea, Cawston decoy, 12 miles north of - Norwich—Mr. Briant,
1776." It is the plant known by modern botanists as Aira uUginosa,
found in T^rance, Germany, and Kussia, and to which attention has
lately been directed in this country by Baker, More, and Watson
(m/e 'Journal of Botany,' Vol. IV. 176 ; Vol. V. 72 ; Vol. VII. 265,
281).
A. setacea was founded by Hudson (Fl. Aug. ed. i. 30) on a plant
collected by Mr. Stillingfleet on Stratton Heath, Norfolk, a locality a
few miles distant from Mr. Briant's, above quoted. A specimen from
" Stratton Heath, 1780," is in the Smithian herbarium, on the sheet
labelled " A.Jlexmsa, (3, Fl. Brit.," but is too young for complete iden-
tification. In the second edition (p. 35) Hudson refers the plant to
Aira montana, L. ; he repeats the Norfolk station, and adds that the
plant is common on sandy heaths in Yorkshire and Lancashire. A
detailed description is given, from which it is evident that the species
intended is A. nUgiuosa, of Weihe ; the long acute membranous ligule,
the smaller more erect and closer panicle, the equal glumes and stalk
to the upper floret being all mentioned. It is thus also evident that
the specimen in the Banksian herbarium is correctly named.
A. montana of Linnaeus, to which Hudson subsequently referred the
plant, is ill all probability a mountain form of A. fiexuosa, with darker
glumes and a more contracted panicle. The short diagnoses in Fl. Lapp.
49, Fl. Suec. 25, and Sp. Plant, ed. i. 65, are insufficient for certain
determination, but the reference to Scheuchzer's ' Agrostographia,' 216,
and the habitat given, in dry sunny places, tend to show that the grass
meant was not the one in Question. Unfortunately the Linnsean her-
barium throws no light on the subject, the three specimens named A.
montana being, according to Colonel Munro (Journ. Linn. Soc. Bot.
vi. 42), all dift'erent, and all members of other genera than Aira. In
Scandinavia this alpine form appears to be very common, and Fries
states that there exists a complete series of plants connecting A.
setacea {uliginosu) with it. The two plates (107, 108) in Parncirs
' British Grasses' represent such northern states of A, Jlexuosa, some-