Myosotis uniflora
Myosotis uniflora is a species of flowering plant in the family Boraginaceae, endemic to the South Island of New Zealand. Joseph Dalton Hooker described the species in 1867. Plants of this species of forget-me-not are perennial with a prostrate, compact, cushion or mat habit, short bracteate inflorescences, and cream to yellow corollas.
M. uniflora is distributed among cushion-fields and river terraces in the Canterbury and Otago regions. It is listed as Naturally Uncommon by the New Zealand Threat Classification System.
Description
Myosotis plants are compacted cushions or mats that can reach 50 cm in diameter. The many imbricate rosette leaves have petioles 1–4 mm long that are glabrous but with erect hairs on the edges. The rosette leaf blades are 1–4 mm long by about 1 mm wide, lanceolate to ovate or triangular, widest at or below the middle, with an acute apex. The upper and lower surfaces of the leaf are sparsely to densely covered in long, flexuous, appressed to patent, antrorse hairs that are oriented parallel to the mid vein.Each rosette has few prostrate to ascending, once-branched, bracteate inflorescences that are up to 60 mm long. The cauline leaves are similar to the rosette leaves but smaller. Each inflorescence has a solitary flower, borne on a short pedicel, with a bract. The calyx is 1–4 mm long at flowering and 2–5 mm long at fruiting, lobed to about half its length, and densely covered in long, antrorse, flexuous, mostly appressed hairs. The corolla is cream to yellow, 2–7 mm in diameter, with a cylindrical tube, petals that are obovate to very broadly obovate or ovate to very broadly ovate, and flat, and small yellow scales alternating with the petals. The anthers are usually fully included, or sometimes partially included with the tips only surpassing the scales. The four smooth, shiny, dark brown nutlets are 1.4–1.7 mm long by 0.8–1.4 mm wide and narrowly ovoid to broadly ovoid in shape.
M. uniflora has M. uniflora type pollen. The breeding system of Myosotis uniflora is outcrossing, as the flowers are 'always herkogamous', with a high pollen : ovule ratio.
It flowers and fruits from September–March, with the main flowering period October–January and the main fruiting period November–March.
Taxonomy
Myosotis uniflora Hook.f. is in the plant family Boraginaceae and was described in 1867 by Joseph Dalton Hooker. It is morphologically most similar to the other two cushion- or mat-forming species, M. pulvinaris and M. glabrescens. Myosotis uniflora differs from these two species in its ecology and morphology, including its cream to yellow corollas; acute, lanceolate to ovate narrow rosette leaf lamina; and narrow petioles.The lectotype specimen of Myosotis uniflora is lodged at Kew Herbarium. Two isolectotypes are also found on the same sheet as the lectotype, and a third isolectotype is at the Allan Herbarium of Manaaki Whenua - Landcare Research.
The specific epithet, uniflora, is derived from Latin for 'one-flowered'.