Yellow montane violet (Viola praemorsa) COSEWIC assessment and status report: chapter 3

Species Information

Name and classification

Scientific name:
Viola praemorsa Dougl. ex Lindl. ssp. praemorsa
Common name:
yellow montane violet, canary violet, upland yellow violet, violette jaune des monts
Family:
Violaceae, violet family
Major plant group:
Eudicot flowering plant

Yellow montane violet has been treated as Viola nuttallii Pursh ssp. praemorsa Dougl. ex Lindl. but that synonym is no longer considered valid (ITIS 2006). It is a well-defined subspecies, one of three in the species. The closely related ssp. linguifolia (Nutt.) M.S. Baker & J.C. Clausen ex M.E. Peck, which occurs in southeast Alberta, has longer and narrower cauline leaves that tend to be less sharply serrated along the margin (Fabijan et al. 1987). The third subspecies, ssp. flavovirens, has not been reported from Canada.

Throughout this report the name yellow montane violet refers specifically to the subspecies praemorsa found in British Columbia and only includes the entire species when considering its global range.

Morphological description

Yellow montane violet is a 5-20 cm tall perennial herb from a fibrous root (Figure 1). The short stem is erect and partially underground. The basal leaves are egg-shaped to lance-shaped and with regular teeth along the margins. They are sparsely to densely hairy, 2-10 cm long, 1-3.5 cm wide and on leaf stalks 3-15 cm long. The short stem may be leafless or bear a few reduced leaves.

Figure 1. Illustration of yellow montane violet (L.M. Richards in Douglas et al. 2000)

Figure 1. Illustration of yellow montane violet

The showy flowers are borne singly at the end of long stalks that emerge from the axils of leaves. The 5-15 mm long flowers are bilaterally symmetric, as in other species of violets. The outer ring of flower parts (calyx) consists of five lance-shaped sepals. The petals are yellow. The lowest petal is pencilled with brownish-purple markings and is spurred at the base, while the two lateral petals are bearded. The two upper petals are slightly smaller than the lower three and tend to be brownish on their back. There are two pairs of stamens (male parts), of unequal length. The female structure (pistil) bears a single style and stigma (receptive surface).

As with many other species in the genus, yellow montane violet also produces less conspicuous cleistogamous flowers. These are self-fertilized and do not open up to reveal showy petals, as in conventional flowers. The cleistogamous flowers of yellow montane violet are usually borne on short stalks near the base of the shoot and often escape attention.  

In both conventional and cleistogamous flowers, the ovary matures into a dry, 6-11 mm long capsule containing several dark-brown seeds.

Genetic description

Yellow montane violet, at the species level, has a chromosome count of 2n=36 or 48 (Little 1993).  No studies have been conducted on genetic differences among the subspecies of Viola praemorsa.  

Designatable units

There are two designatable units for the species in Canada. The present update report deals with ssp. praemorsa, which only occurs in a geographically restricted region of British Columbia. A second designatable unit is the Alberta subspecies linguifolia, which is ranked as S2 (imperilled) in the province. This subspecies is also eligible for status report preparation.

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