[2.17] Viola sect. Tridens 

Viola sect. Tridens W. Becker in Nat. Pflanzenfam., ed. 2 [Engler & Prantl], 21: 376. 1925.

—Type (Shenzhen Code Art. 10.8): Viola tridentata Sm.

Description.—Perennial procumbent herb, forming perennial herbaceous mats with branched stems. Axes morphologically differentiated in elongated rhizome and lateral, short floriferous stems with distichous phyllotaxy. Stipules completely adnate to the pseudopetiole or only with the free end forming a short tooth. Leaves tridentate on floriferous shoots, bilobate or entire on sterile shoots, small, imbricated, fleshy. Corolla small, white with violet striation. Spur short. Anthers with scattered hairs. Style cylindrical, at base curved, slightly tapering towards apex, filiform. Cleistogamous flowers not produced. Allohexaploid. Secondary base chromosome number x’ = 20.

Diagnostic characters.—Leaves tridentate, distichous, imbricate.

Ploidy and accepted chromosome counts.—6x; 2n = 40.

Age.—Crown node age not applicable (monotypic lineage); stem node 9.2 (1.0–14.7) Ma [28].

Included species.—1. Viola tridentata Sm.

Distribution.—Southernmost South America: Argentina, Chile, Falkland/Malvinas Islands (Figure 1).