Forstera L. ex G.Forst.

Plants perennial, flowering each year; herbaceous. Leaves and stems glabrous except for a row of eglandular hyaline hairs c. 0.8 mm long in each leaf axil. Stems decumbent, almost always branched, 1.3–4.2 mm in diameter when dry and pressed, 1.2–4.4 mm in diameter when fresh; dead leaves eventually caducous and leaving scars on otherwise bare older parts of stems; new branches sometimes arising from old parts of the caudex. Fine roots arising along the horizontal parts of the stems where in contact with soil. Leaves imbricate, less often distant, uniform in size, not clustering in a terminal rosette, spirally arranged, sessile to very shortly petiolate, leaf base appressed to stem, young leaves at acute angle to the stem; leaves entire or with slight toothing in the upper half, elliptic, narrowly elliptic or subulate, flat or terete in section in the upper lamina, with a waxy appearance due to an epidermis of thick-walled hyaline cells on both surfaces and margins; stomata confined to abaxial leaf surface each side of a median triangular stripe that extends from leaf base to apex.

Monoecious. Flowers home on a long, smooth peduncle 20–150 mm long, 0.5–0.7 mm in diameter, crimson to red-brown or green. Peduncles 1–3 per plant, terminal from the branch apex hut becoming lateral by continued growth of the shoot, erect. Flowers solitary or in a cyme of 2–3(–5) flowers per peduncle, scentless, protandrous, 5–6-merous, actinomorphic, on pedicels 0.5–2.3 mm long when not solitary. A single narrowly triangular bract at the base of the pedicel; where flowers form a cyme, the bracts distant from each other. Two opposite and equalsized bracteoles at the base of the ovary, smaller than the bract, narrowly triangular with a rounded to acute apex, margins and axils with eglandular hyaline hairs. Calyx completely divided to the level of the hypanthium, sepals 6, subequal in length and width, narrowly ovate, slightly spreading, margins and axils with eglandular hyaline hairs, apices rounded. Corolla actinomorphic, campanulate, deeply lobed with 6(–8) equal or subequal lobes overlapping with 2 lobes lying outside the others, lobes spreading at anthesis to form a salviform flower; corolla lobes white, usually with crimson speckles on the inner surface of the lower half of each lobe; lobe sinuses yellow to orange or hyaline, sometimes surrounding pale green thickened tissue. Anther filaments fused into a column surrounding the style (the gynostemium). Anthers 2, forming a 2-part collar immediately below the stigmas, each bilocular, reniform, dark purple, dark violet, or cream, dehiscing on the horizontal long-axis outer wall. Pollen yellow, 35–45 pm in diameter, 3–5-colpate, tectate, baculate. Ovary inferior, outer surface glabrous, unilocular with a central cylindrical column attached at base and apex. Ovules many (c. 40–120 per ovary), clustered around a swollen central portion of the column. Stigmas 2; at anthesis pale yellow, hemispherical, small (0.3–0.5 mm long), and slightly papillose; in female phase elongating to 0.7–1.4 mm long, strongly recurved, becoming hyaline with long-projecting stigmatic cells, each stigma with a central groove of nonprojecting cells, the stigmas sometimes dividing along the groove to become bifid, then giving the appearance of 4 stigmas. Nectaries 2, originating from the outer edge of the hypanthium at 75–90° to the stigmas, subulate, clavate, or tapering-oblong and bifid, vertical, almost pressed against the corolla wall, 0.5–1.6 mm long, exuding nectar at their apices. Capsule dehiscing at the top of the ovary on drying, becoming dry, papery, and straw-yellow when seeds are ripe. Seeds red-brown, purple-brown, or pale brown, c. 0.9–1.9 mm long, ellipsoidal, biconvex, with a wing enclosing the seed body and forming a flat envelope beyond it, especially at the acute ends; testa reticulate.

[Reproduced from Glenny (2010, New Zealand J. Bot. 47: 285–315) with permission from The Royal Society of New Zealand.]