Myosotis macrantha

Myosotis macrantha plants are rosettes. The rosette leaves have broad petioles that are about as long as the leaf blades. The rosette leaves are 30–120 mm long by 6–20 mm wide (length: width ratio c. 5–6: 1), and the leaf blade is obovate to lanceolate-spathulate, widest below, at or above the middle, with a subacute apex. Both surfaces of the leaf are uniformly and sparsely to densely covered in patent to erect hairs. The upper surface of the leaf has densely distributed appressed to erect antrorse (forward-facing) whereas on the lower surface the hairs are mostly appressed and retrorse (backward-facing) except for some antrorse hairs near the tip. Each rosette has several ascending to erect, ebracteate inflorescences that are up to 300 mm long. The cauline leaves are similar to the rosette leaves, but are smaller and become smaller toward the top of the inflorescence, lanceolate, and subacute, and have hairs similar to the rosette leaves except the upper cauline leaves may not have retrorse hairs on the lower surfaces. The flowers are many per inflorescence, and each is borne on a short pedicel, without a bract. The calyx is 6–9 mm long at flowering and fruiting, lobed to one-half tor more of its length, and densely covered in patent to erect, antrorse hairs that are mostly antrorse, but some are retrorse near the base and others are hooked. …

Myosotis macrantha is a forget-me-not that occurs in high-elevation habitats in the South Island of New Zealand, particularly along the western side, in Western Nelson, Canterbury, Westland, Otago and Fiordland. Myosotis macranthais likely to be an outcrossing species, with plants requiring a pollinating vector to achieve pollination and seed set.

Myosotis macrantha (Hook.f.) Cheeseman is in the plant family Boraginaceae. The species was originally described as Exarrhena macrantha Hook.f. in 1867 by Joseph Dalton Hooker in Handbook of the New Zealand Flora. Thomas Cheeseman transferred it to Myosotis saxosa (Hook.f.) Cheeseman in 1885. Myosotis macrantha is not mentioned in Genera Plantarum by Bentham and Hooker, and therefore ‘M. macrantha (Hook.f.) Benth. & Hook.f,’ is not the correct author citation. The most recent treatment of this species was done by Lucy B. Moore in the Flora of New Zealand. The original specimens (syntypes) of Myosotis macrantha were collected by several different collectors at multiple sites in the South Island, New Zealand, and are likely lodged at Kew Herbarium (e.g. K000787875). Three varieties have been described within M. macrantha:

M. macrantha var. pulchra Cheeseman M. macrantha var. westlandica Petrie M. macrantha var. diversa G.Simpson & J.S.Thomson M. macrantha var. macrantha (autonym) Since their descriptions, these varieties have not been used or referred to often in the literature, and Lucy Moore suggested that none of these varieties "is sufficiently distinct to be maintained without further evidence". Vegetatively, Myosotis macrantha is similar to M. explanata, whereas the flowers are similar to those of M. arnoldii.