Tetratheca
(from tetra, four, and theke, a cell; the anthers are sometimes four-celled). ORD. Tremandreae. A genus embracing eighteen species of small, very pretty, glabrous or glandular-hairy, greenhouse, Australian shrubs. Flowers four or five-parted, rarely three-parted, possessing the peculiarity of only opening during bright sun and on fine days, but closing on the approach of evening, or when rain is imminent; stamens sub-biseriate. Leaves alternate, whorled, or scattered, Heath-like and entire or flat and toothed, or reduced to minute scales. A selection of the introduced species is here presented. They are rather difficult to cultivate. A compost of fibry peat, with plenty of silver sand intermixed, is most suitable. Water must be very carefully administered at all times, and only soft rain-water should be used. Propagation may be effected by cuttings of the young wood, inserted in sand, under a bell glass, and kept well shaded.
T. ciliata (hair-fringed). fl. pink; sepals bearing a few glandular hairs or bristles; petals about 1/2in. long. July. l. almost all whorled in threes or fours, broadly ovate or nearly orbicular, obtuse or slightly acute, rarely exceeding 1/2in. in length, the margins flat or scarcely recurved, ciliated or nearly glabrous. Stems slender, erect, or diffuse, 1ft. to 3ft. long. T. ericifolia (Heath-leaved). fl. pink, on slender pedicels usually longer than the leaves; sepals not reflexed. July. l. mostly whorled, narrow-linear with the margins closely revolute, or rarely oblong-lanceolate and more open, mostly under 1/2in. in length. h. 1ft. or less. 1820. Plant diffuse. (S. E. B. i. 20.) T.ericoides (Heath-like). A synonym of T. pilosa.
T. glandulosa (glandular). A synonym of T. pilosa denticulata. T. hirsuta (hairy).* fl. pink, rather large, on slender pedicels 3/4in. to 1in. long; sepals lanceolate; petals oblong. March. l. mostly alternate, a few whorled, ovate-lanceolate to oblong-linear, obtuse, 1/2in. to 1in. long, the margins recurved, more or less hirsute above, villous or pubescent beneath. Stems rigid and erect, 6in. to 18in. high, often hispid with reddish hairs. 1843. (B. R. 1844, 67; P. M. B. xiii., p.53.) T. juncea (Rush-like). fl. purple; sepals four, small, ovate, obtuse; petals four, about 1/2in. long; pedicels in the upper axils. July. l. few, small and distant, scale-like, rarely 1/4in. long. Stems erect or ascending, slender, Rush-like or wiry, 1ft. to 2ft. long, with two or three acute angles or very narrow wings. 1803.
T. nuda (naked). fl. crimson, on slender pedicels; sepals and petals five each. May. l. very minute and distant, or a very few linear or oblong ones two or three lines long. Rhizome woody, with numerous erect, slender, rigid, but Rush-like stems, 9in. to 18in. high, often ending in an almost pungent point. 1843.
T. pilosa (pilose).* fl. purple, rather small, on pedicels usually shorter than the leaves; petals narrow. July. l. usually linear, with the margins much revolute, four to six lines long, but in very luxuriant shoots sometimes broadly lanceolate or oblong, with an obtuse base. h. 1ft. to 1 1/2ft. 1823. Plant Heath-like. (F. d. S. 1065, under name of T. ericoides.) T.p. denticulata (denticulate-leaved). fl., calyx and pedicels slightly glandular-hairy. l. narrow, revolute, occasionally opposite. 1822. (S.E.B.i. 21, under name of T. glandulosa.) T.thymifolia (Thyme-leaved). fl.purple; sepals ovate-lanceolate, seldom reflexed. July. l. almost all whorled in threes or fours, ovate-elliptic or lanceolate, the margins more or less recurved or revolute. h. 1ft. to 3ft. 1824. Plant very pubescent or hirsute. (S. E. B. i. 22.) T. verticillata (whorled). A synonym of Platytheca galioides.