kingdom Plantae - plants »  divisio Magnoliophyta - flowering plants »  class Rosopsida - eudicots » order Malpighiales »  family Violaceae »  tribus Violeae > genus Viola > Viola sect. Viola  L. > Viola subsect. Rostratae Kupffer    

Viola laricicola Marcussen

| Bio Lib |Actaplantarum| Florealpes| 

Common name:  Violette du mélèzin, Viola dei larici 

Description:  Glabrous perennial, rosulate-caulescent herb, 6– 10 cm tall. RHIZOME densely articulate, 3 mm thick, occasionally in parts remotely noded and slenderer, 1 mm thick, often branched; terminal rosette fewleafed; lateral floriferous stems 1–many, erect, glabrous. LEAVES 1.5–2.2 cm, crenulate, glabrous or sparsely pubescent, hairs very short, 0.1–0.2 mm long; basal leaves long-petiolate with petiole 4–6 cm, lamina cordate- or orbicular-reniform, slightly broader than long, open and shallowly cordate at base, apex obtuse, rarely acute; cauline leaves towards stem apex gradually more elongate and acute or acuminate and with a shorter petiole; upper leaves sessile, triangular-cordate with concave margins. STIPULES lanceolate, 2–3 ¥ 9–12 mm; basal stipules hyaline, whitish or purple-tinged, fimbriate, fimbriae 1– 1.5 mm long; cauline stipules progressively larger towards apex of stem, foliaceous and green, remotely and indistinctly fimbriate, fimbriae c. 0.5 mm long, or dentate; upper stipules entire with ciliate margins. PEDUNCLES 4–7 cm long and exceeding the foliage, glabrous, bibracteolate above middle, bracteoles 3– 4 ¥ 1 mm, shortly glandular-fimbriate at base. FLOWERS scentless, 12–20 mm long, transverse rectangular in frontal view; corolla bluish-violet (dark or pale). SEPALS 6–8 ¥ 1.5–2.5 mm, lanceolate, acute; margin distinctly hyaline; appendix c. 1 mm, rounded. PETALS obovate, 8–12 ¥ 4–7 mm, broad and overlapping; lateral petals bearded at base; lower petal veined with dark purple, spurred. SPUR 3–3.5 ¥ 2–3 mm, straight, tapering towards tip, white to pale greenish. OVARY ovoid, glabrous; style c. 2 mm long; stigma densely papillose. CAPSULE 6–10 mm long, trigonousellipsoid, acute, glabrous. SEEDS 2.2 ¥ 1.2 mm, rather large, elliptical, pale brown, with inconspicuous elaiosome. 

Taxonomic Note: Viola laricicola differs from other similar species in a number of characters; from V. canina by the presence of a basal leaf rosette, and in having broader, often reniform leaves and large pale brown seeds (in V. canina small and dark brown); from V. rupestris in the absence of a papillose indument and in larger size in general, and in seed size and colour (very small and blackish brown in V. rupestris); from V. reichenbachiana in having smaller and reniform, glabrous leaves (not acutely cordate and scattered long-pubescent), broader and green stipules, broad petals, and a straight and pale spur (not downwards directed and violet); from V. riviniana, to which it is particularly similar, by smaller size and almost complete glabrescence (not scattered long-pubescent), larger and non-membraneous green stipules, by spur colour, white or greenish-yellowish in V. laricicola, white to dark violet in V. riviniana, and by slightly larger seeds. 

Distributional Range:  Native Europe SOUTHEASTERN EUROPE: Italy [Piemonte ] SOUTHWESTERN EUROPE: France [HautesAlpes ]

Habitat: Protected sunny places on limestone soils, 1800–2000 m alt; glades and edges of semi-moist Larix forests, or among rocks. Flowering from May to June.

Note: Thomas Marcussen, the discover of this new specie wrote: "During field work in May 2000 for the author’s PhD project on systematics and evolution within the Viola riviniana Reichenb. complex, two morphologically deviant populations were collected from Col du Lautaret and Col de Vars in the French Alps. Upon closer investigation, which included chromosome counts, allozyme electrophoresis, and cpDNA sequencing (Marcussen, Steen, Kauserud, unpubl. data), these proved distinct and merit consideration as a separate species. The two sites were revisited in May 2002 for the collection of type material. Searches of numerous possible sites resulted in the discovery of one additional population on the French–Italian border (Col de Montgenèvre). 

References:

1. Marcussen T. (2003) A new violet species (Violaceae) from the south-west Alps Botanical Journal of the Linnean Society 142(1):119 - 123. 10.1046/j.1095-8339.2003.00160.x