This section is from the book "The Botanical Magazine; Or, Flower-Garden Displayed", by William Curtis. Also available from Amazon: The Botanical Magazine; or, Flower-Garden Displayed, Volume I.
Diosma Uniflora. One-Flowered Diosma
Cor. 5-petala. Nectaria 5, supra germen. Caps. 3. s. 5. coalitae. Sem. calyptrata.
DIOSMA uniflora foliis ovato oblongis, floribus solitariis terminalibus. Linn. Sp. Pl. ed. 3. p. 287. Syst. Vegetab. ed. 14. Murr. p. 239. Ait. Kew. v. 1. p. 276.
CISTUS humilis aethiopicus, inferioribus foliis rosmarini sylvestris punctatis, caeteris autem serpylli subrotundis, flore carneo. Pluk. mant. 49. t. 342. f. 5.
The Diosma uniflora another native of the Cape, that never failing source of vegetable riches, was introduced to the Royal Garden at Kew by Mr. Masson in the year 1775, it flowers in our Green-Houses from April to June, and is usually propagated by cuttings.
This plant forms a small bushy shrub, the leaves are thickly and irregularly set on the branches, quite up to the flowers, which stand singly on their summits, and are larger than those of any other known species of Diosma, expanding as we have found on trial beyond the size of half-a-crown, which the blossom does in our figure, though it will not appear to do so to the eye of most observers; they are without scent, the calyx is large and continuing, composed of five ovato-lanceolate leaves, reddish on the upper side, and if viewed from above visible between the petals; the petals are five in number, much larger than the calyx, and deciduous, of a white colour with a streak of red running down the middle of each, surface highly glazed, the stamina are composed of five short filaments, white and slightly hairy, broad at their base and tapering gradually to a fine point, by which they are inserted into the hind part of the antherae, near the bottom; the antherae are as long as the filaments, of a brown purple colour, bending over the stigma, and opening inwardly, each carrying on the upper part of its back a gland-like substance, of a pale brown colour: besides these parts there are five filamentous bodies alternating with, and of the same length as the stamina, of a white colour, and hairy, each dilating at its extremity where it is of a reddish hue, and presenting towards the antherae an oval somewhat concave surface, which secretes a viscous liquid; in some flowers that we have examined, and we regret seeing but few, we have observed these nectaries (for such they may be strictly called) closely adhering by their viscous summits to the glandular substances at the back of the antherae; the germen is studded with a constellation of little glands, which pour forth, and almost deluge it with nectar; the stigma is composed of five little round knobs: seed vessels we have not seen.
 What the use of this very extraordinary apparatus may be we can at present scarcely conjecture, future observation may perhaps enable us to speak more decisively; when we figure the Diosma ericoides we shall probably have more to say of this species.