Viola curtisiae
(L.G.Adams) K.R.ThieleStoloniferous perennial herb. Leaves tufted; lamina more or less semicircular to slightly reniform, 6–15 mm long, 8–22 mm wide, c. 1.2–2 times wider than long, base broadly cuneate, truncate or broadly cordate at base, apex obtuse, margins with 7–13 indistinct teeth, glabrous or sparsely hispid with scattered unicellular hairs; petioles (0.5–)2–5 cm long; stipules free, narrowly triangular or trifid, 2–3 mm long, usually with several small glandular teeth on each side. Flower-scapes to 3 cm long, mostly shorter than the leaves (often considerably so), bracteoles at base or in the basal half of the scape. Sepals lanceolate, 2.5–4 mm long, acute, basal appendages small; petals 5–7 mm long, concolorous or slightly discolorous, white adaxally sometimes with faint purplish venation or pale violet patches towards centre-lines of some petals, abaxially white or variably purple-flushed, all petals shallowly emarginate, and all more or less the same width (the corolla then almost actinomorphic); lower (anterior) petal broadly elliptic, lacking a spur, the central 3 longitudinal nerves not strictly parallel and often anastomosing, lateral petals glabrous (i.e. beardless), gently reflexed but not twisted. Capsule broadly ellipsoid, 6–8 mm long. Seeds ovoid, 1.9–2.1 mm long, uniformly dull brown or with indistinct, minute, pale mottling, more or less smooth. Flowers in late spring and summer.
HSF, HNF, VAlp. Also Tas. In Victoria apparently confined to the Baw Baw Plateau (near Mt Erica and Baw Baw village) and there occurring in tall open forest above 1000 metres altitude, dominated by combinations of Eucalyptus regnans, E. nitens, E. delegatensis and E. glaucescens, with scattered Nothofagus cunninghamii.
Occurrences of Viola curtisiae in Victoria have previously been treated as a local, diminutive form of V. hederacea confined to the Baw Baw Plateau (e.g. Entwisle 1996). Informal names have been used for the species reflecting that distribution. Viola curtisiae (as V. hederacea subsp. curtisiae) had been a poorly understood taxon, and until recent studies across its range (Thiele et al. 2018), the identity of the Baw Baw plants was unclear.
Viola curtisiae may be distinguished from all other taxa in Viola sect. Erpetion by the combination of semi-circular to slightly reniforn leaves, flowers concolorous white to slightly discolorous on short scapes shorter than the leaves, all petals more or less emarginate, lateral petals glabrous and gently reflexed but not twisted (Thiele et al 2018).
Entwisle, T.J. (1996). Violaceae. In: Walsh, N.G.; Entwisle, T.J., Flora of Victoria Vol. 3, Dicotyledons Winteraceae to Myrtaceae, pp. 361–370. Inkata Press, Melbourne.
Thiele, K.R.; de Salas, M.; Walsh, N.G.; Messina, A.; Little, R.J.; Prober, S.M. (2018). Viola curtisiae, a new rank for a poorly understood species, with notes on V. hederacea subsp. seppeltiana. Muelleria 36: 107–111.
