Drosera
(from droseros, dewy; the plants appear as if covered with dew, in consequence of being beset with glandular hairs). Sundew. ORD. Droseraceae. A genus of about a hundred species of annual or perennial glandular (very rarely glabrous) herbs, sometimes bulbous. They are small-growing, but very beautiful, plants, of insectivorous notoriety. Some of the species, too, are climbers. Droseras are scattered over most parts of the world, and usually prefer marshy places. Some, however--several Australian kinds especially--grow in the driest ground, where their bulbous roots remain dormant for the greater part of the year, reviving with the first rains. Flowers in scorpioid revolute cymes, rarely solitary. Leaves ornamented with reddish irritable glandular hairs, discharging from their apices a drop of viscid, acrid fluid. Droseras are of easy culture, and the majority of those in cultivation thrive in a compost of living sphagnum and a little peat. Plenty of drainage is essential, and the pots in which they are grown should be stood in a pan of water. Thorough exposure to the light is also important. Propagated by seeds, which should be sown so soon after gathering as possible. D. binata, which is, of the exotic species, mostly grown, was formerly increased by the tedious method of sub-divisions of the crowns. It is now found, however, that roots taken from strong plants, and cut into pieces of 1/2in. or 1in. in length, will serve the purpose admirably. These are laid on the surface of shallow earthenware pans, in sandy peat soil, and covered about 1/2in. deep with the same material. They are then placed under a bell glass, and transferred to a damp, warm propagating house. In the course of a fortnight, swellings begin to appear on the surface of the detached roots, which increase in length till they reach the top of the soil. This generally takes place about five weeks after being put in. When about 2in. or so in height, they are separated, and put into small pots, in similar soil to that into which the roots were originally placed, with the addition of some chopped sphagnum. If carefully attended to, they soon make excellent plants. All the species (even the British ones, which, as a matter of course, are perfectly hardy) do well treated as greenhouse plants.
D. binata (twin-leaved).* fl. pure white, large; raceme dichotomous. June to September. l. all radical, on long footstalks, deeply parted with two linear lobes. h. 6in. Australia, 1823. Plant stemless. SYN. D. dichotoma (of gardens). (B. M. 3082.) Perennial.
D. capensis (Cape). fl. purple; scape rather ascending, somewhat hairy, longer than the leaves. June, July. l. sub-radical, oblong-linear, obtuse, tapering at the base; footstalks glabrous, shorter than the limbs of the leaves. h. 6in. Cape of Good Hope, 1875. Perennial. (B. M. 6583.) D. dichotoma (dichotomous). A synonym of D. binata.
D. filiformis (thread-formed).* fl. purple, large; scapes erect, hardly equal in length to the leaves. June to August. l. filiform, very long, from a bulb-like base or corm; footstalks woolly at the base, much shorter than the leaves. h. 1ft. North America, 1811. (B. M. 3540.) Perennial. D. lunata (crescent-leaved). fl. yellow; racemes lateral, few-flowered; sepals ovate, acute, beset with glandular hairs on the margins. July and August. l., radical ones roundish-reniform; cauline ones scattered, stalked, moon-shaped, peltate. Stem erect, glabrous. h. 6in. Nepaul. A very beautiful annual plant, rarely seen in cultivation.
D. pauciflora (few-flowered). fl. white; scapes beset with glandular hairs, one or two-flowered. July, August. l. ovate-oblong, tapering at the base. h. 3in. Cape of Good Hope, 1821. Perennial.
D. peltata (peltate).* fl. pink, racemose. l. spaced along an elongated stem, forming minute flattened cups with the foot-stalks attached, not to one margin, but to the bottom; the inner surface and the edges of the cups are studded with tentacles. h. 1ft. Australia. Annual. (G. C. n. s., xix. 436.) There are two varieties of this species: foliosa, with white flowers; and gracile, with pink.
D. rotundifolia (round-leaved).* fl. white; scapes erect, four or five times higher than the leaves. July, August. l. orbicular; footstalks hairy, longer than the limb. The whole disk of the leaf, but especially its margin, is beset with red inflexed hairs. h. 4in. Northern hemisphere (Britain). Annual. Other native species are: anglica and intermedia.
D. spathulata (spathulate-leaved).* fl. purple, almost sessile, disposed in short racemes; scape glandular at the top, as well as the calyces. July. l. oblong-spathulate, tapering somewhat into the footstalk. h. 3in. Australia, 1861. Perennial. (G. C. n. s., xvi. 852.) D. Whittakeri (Whittaker's). fl. white. Australia, 1862. A very rare species, much resembling D. spathulata in habit, but more erect. It is a deciduous form, and requires a long rest. Before starting into new growth, it must be taken out of the old soil and repotted. Perennial.