kingdom Plantae - plants »  divisio Magnoliophyta - flowering plants »  class Rosopsida - eudicots » order Malpighiales »  family Violaceae »  tribus Violeae > genus Viola > Viola sect. Erpetion  (Sweet) Benth. & Hook f.  

Viola curtisiae (L.G.Adams) K.R.Thiele

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Synonyms: Viola hederacea subsp. curtisiae L. G. Adams; Viola hederacea subsp. nov. (Baw Baws) sensu Ross 1993 

Distributional Range: Native Australasia AUSTRALIA: Australia [ Victoria: southern rim of the Baw Baw Plateau ] ; Tasmania [Lake Dobson–Mt Mawson area in Mount Field National Park, and near Mount Wellington]

Description: Perennial herb spreading widely by stolons; rootstock sometimes somewhat swollen and bulbous at the stem bases. Stems contracted with leaves forming rosettes, never elongate with caulescent leaves. Leaves with petioles (0.5–)2–5 cm long; lamina ±semi-circular to slightly reniform, the largest 6–15 mm long, 8–22 mm wide, c. 1.2–2 times wider than long, broadly cuneate, truncate or broadly cordate at base, with 7–13 indistinct teeth, glabrous or sparsely hispid with scattered unicellular hairs c. 0.5 mm long on the upper surface mostly toward the margins, dark green and usually slightly glossy above, dull greyish-green beneath; stipules 2–3 mm long, narrowly triangular or trifid, usually with several small, glandular teeth on each side. Flowers on scapes to 3 cm long, mostly shorter than the leaves (often considerably so), rarely subequal to or slightly longer than leaves. Bracteoles at the base or in the basal 1/2 of the scape, narrowly triangular, c. 3 mm long, c. 0.5 mm wide. Sepals 2.5–4 mm long. Petals concolorous or slightly discolorous, white adaxially sometimes with faint purplish venation or pale violet patches towards the centre-lines of some petals, abaxially white or variably purple-flushed; segments not widely opening but with ±reflexed apices; entire corolla often ±broadly cylindrical to broadly campanulate; anterior petal 5–7 mm long, 3–5 mm wide, broadly elliptic, widest at or very near the middle, broadly emarginate, 3(–5)-nerved at base, the nerves dividing and becoming indistinct above midway; lateral petals 5–6.5 mm long, 2.5–3.5 mm wide ±rectangular, slightly falcate, broadly emarginate at apex, not twisted, glabrous (i.e. beardless); dorsal petals 5–6.5 mm long, 2.5–3.5 mm wide, obovate, rounded to truncate, usually emarginate, occasionally minutely apiculate in the notch. Anthers c. 1.5 mm long, cream; anther appendages exceeding anthers by 1–2 mm, the terminal portion slightly dilated and straw-coloured, minutely papillate, the proximal portion white, pilose; glands on ventral anthers cream to green, shorter than the anther cells, irregularly rugose, ±allantoid; pollen and interior margins of the anther cells white to cream. Ovary pale green, faintly lilac-mottled; style 1.2–1.8 mm long, erect but distinctly geniculate at its insertion on the ovary. Fruit broadly ellipsoid, 6–8 mm long, cream at maturity. Seeds ovoid, 1.9–2.1 mm long, c. 1.3 mm diam., uniformly dull brown or with indistinct, minute, pale mottling, ±smooth. 

Habitat: In Tasmania it occurs in sheltered, east-facing sites beneath Eucalyptus coccifera woodland with scattered Nothofagus cunninghamii, whereas in Victoria it occurs beneath tall forest of Eucalyptus regnans, E. nitens, E. delegatensis and E. glaucescens with scattered N. cunninghamii, in both cases at elevations above 1000 m. 

Notes:Notes: Violacurtisiae is a distinctive species that is clearly localised and rare, even if some populations have been overlooked. Its leaves are semi-circular to slightly reniform and not much broader than long, very similar to those of V.  hederacea sens. str. In having concolorous to slightly discolorous flowers it is similar to V. cleistogamoides, V. fuscoviolacea, V. sieberiana and V. silicestris 

The epithet, which commemorates Dr Winifred M. Curtis, is similar to that of Viola curtisii E.Forst., the basionym of V.saxatilis subsp. curtisii (E. Forst.) Kirschner & Skalický and V. tricolor subsp. curtisii (E. Forst.) Syme (the currently accepted name for the taxon; see The Plant List 2013); this species commemorates William Curtis (Rix 2014). Given the different genders and, now, different ranks, we do not consider these to be confusable epithets 

References:

1. 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.