310 THE BOTANICAL EXCHANGE CLUB OF THE BRITISH ISLES. 
P. deltoidea, Marsh., var. serotina, Hartig, [/*. nigra, auct. ang. 
p.m.p. P. monilifera, Ait,]. This tree, which is so extensively 
confounded with the true P. ?iigra by English writers, is much 
the more frequent of the two. It is an extremely rapid grower 
and therefore has been very frequently planted through England. 
It is the P monilifera, Aiton, and may be the P. canadensis of some 
authors. In a somewhat aggregate sense P. deltoides of Marshall’s 
‘Arbustum,’ io6 this plant. These are the autumnal 
leaves from a tree in Christ Church Meadow, Oxford, Sept, 1907. — 
G. Claridge Druce. Dode, the latest monographer of the genus, 
identifies this poplar as P. serotina, Hartig. These specimens are 
identical with material so named by Dode. Another better known 
name for this tree is P. mo 7 iilifera, Aiton. It is one of the com- 
monest planted poplars in Englaml, and is probably of American 
origin. It is the Black Poplar of many English botanists, but it 
differs from the true P. 7 iigra in its leaves, which are truncate 
and not cuneate at the base, with much shorter points, smooth 
bark, and sparser habit, — A. B. Jackson. 
Orchis incarfiata, L. Borth Bog, Cardiganshire, v.-c. 46, 
ist July T907. I gathered this plant in 1905 as O. latifolia, but 
having since discovered my error I send these specimens as 
vouchers of Mr. Pugsley’s find. See ‘J. of B. ’ 1906, p, 395. — 
W. H. Painter. Right. Preserved so well that the marking 
of the lip is discernible. — E. F. L. No ; O. latifolia, L. O. in- 
carnata has the stem-leaves hooded at the tips, and a conical spur; 
in this plant the leaf-tips are quite flat, and the spur more elongate- 
oblong. — E. S. M. 
O. ericetoru 77 i, Linton. Fairly abundant in rough strong moor- 
land grass at Alwoodley near Leeds, July 1907. — John Cryer. 
Correct, I believe; but my specimen is imperfect, as it does not 
shew the foliage properly. — E. S. M. 
Sisy 7 -t 7 ichiu 7 n calif or 7 iicti 7 n, Ait. In the marshy fields near 
Rosslare, Wexford, where Mr. Marshall first found it. A few miles 
south of this place is Carnsore Point, on which more wrecks have 
occurred than almost anywhere else in Ireland. It might easily 
have happened that some Californian produce from wreckage 
drifted here containing its seed, which is very freely produced. 
Now in this locality it is so abundant that in walking through 
the marshy fields the seeds are scattered in one’s progress. More- 
over the pads of earth scattered by horses had, I found, seeds 
attached, so that animals grazing there help to spread it. 'I'he 
fields too are subject to floods which also assist in its dispersal. 
'I'he locality is contiguous to the sea ; indeed the separating bank 
is not of ancient formation. It is an interesting example of the 
complete naturalisation of a Western American species. Some 
