1872 . ] 
AQUATICS.-CHAPTER VIII. 
275 
with any other cultivator, since Mr. Leach astonished the orchid-growing world 
in the summer of 1862 with his splendidly grown plants of this species. 
There are many species of Disci indigenous to the Cape district, one or two 
of which have been offered for sale at u Stevens’ Rooms ” during the past summer. 
One of the best of the unintroduced species is D. macrcintha , a plant that sports 
into numerous beautiful varieties, which vary in colour from nearly white to the 
deepest rose, heavily spotted and blotched with crimson. This would form a 
fine companion plant to its glorious congener at present under discussion, if some 
resident collector would carefully pack up the plants when at rest, and send them 
“to enrich our collections, which, it must be confessed, are strikingly deficient in 
terrestrial orchids, although rich in sub-terrestrials, and epiphytes proper. 
Disa grandifiora is one of the few orchids, comparatively speaking, that have 
been raised true from seed. The seeds of this plant, and also those of Cypripedium 
■ 
Schlimmi , germinate very freely on living sphagnum moss, and their progeny 
appears to vary but slightly from the parent plant, while most other orchids vary 
more or less, even if fertilised with pollen taken from a plant of the same 
species as the parent. In order to obtain seed from the Dk, the club-shaped 
pollen-masses (a.) must be removed from the elongated anther-cases (a., fig. 3) 
and brushed, or drawn gently over the rounded viscid stigmatic surface (A, fig. 3), 
after which the flower soon commences to wither, and the ovary or seed-vessel to 
•enlarge. Mr. James Anderson, of Meadow Bank, near Glasgow, has succeeded 
in germinating the seeds of Disa by the hundred! ( Gard . Chron ., 1872, 603.) 
The surface of the pan in which this, and, indeed, nearly all other orchids are 
grown, should be covered with a layer of fresh living sphagnum, which is one of 
the best natural indicators of the humidity of the house in which it grows. We 
have here upwards of fifty imported Discis , and hope to be successful with them, 
treated as above recommended.—F. W. Burbidge, Fairfield Nurseries. 
AQUATICS.— Chapter VIII. 
’HE great Yellow American Water-Lily, Nuphar aclvena, was first sent to 
this country from Carolina, in the year 1772. There is a good plate of 
it in the Botanical Magazine , t. 684. It is the Nymphcea aclvena of the 
Hortus Kewensis , and is by far the most robust of all the Nympheea 
tribe, its nearest congener being Nuphar lutea , which, like it, has very strong 
rhizomes, but it may be distinguished at first sight by its more erect habit, as 
the greater portion of the leaves stand upright above the surface of the water, 
and wave about with the wind ; moreover, they are larger and more oval in 
shape than in the N. lutea. There is one peculiarity about this plant which is 
so unusual that it is worth recording, namely, that it will grow in salt water . 
Now this is an ordeal that few fresh-water plants will stand ; nevertheless, I saw, 
once on a time, large tufts of the glaucous Elymus , growing by its side on the 
sands near the harbour at Ostend, the roots and tops of both plants being 
immersed in salt water at every flow of the tide; and it appeared to be growing 
