Schweiggeria

Schweiggeria is a genus of flowering plants in the violet family Violaceae, with one or two species, found in eastern Brazil.

Description
Shrubs, with oblanceolate (wider near tip) leaves. White flowers are strongly zygomorphic (bilaterally symmetrical), rarely solitary, in axillary fascicles, with caducous corolla with the bottom petal longer than the others and clawed with a well exserted spur. The stamens have free filaments, with the lowest two being calcarate (spurred) and possessing a large dorsal connective appendage that is entire and oblong-ovate. In the gynoecium, the style is rostellate (beaked) or lobed. The fruit is a thick-walled capsule with three obovoid seeds per carpel.

Taxonomy
The genus Schweiggeria was first described by Sprengel, with the single species Schweiggeria fruticosa, placing it in the family Ionidia, named for the genus Ionidium in 1821. In 1846, Lindley classified both Schweiggeria and Ionidium in Violaceae, within the Violales, although Bentham and Hooker (1862) called the family Violarieae.

Historically Schweiggeria was placed within Violaceae in the subfamily Violoideae, tribe Violeae, subtribe Violinae, together with Anchietea, Calyptrion, Noisettia and Viola. Still these divisions are artificial and not monophyletic. Molecular phylogenetic studies show that Violaceae is best considered as four clades rather than taxonomic ranks. Schweiggeria occurs in Clade I of the family, consisting of Viola, Schweiggeria, Noisettia, and Allexis, in which Schweiggeria and Noisettia are monotypic and form a sister group to Viola.

Etymology
Sprengel named the genus in honour of his colleague August Friedrich Schweigger (1783–1821).

Subdivision
Four species have been described;


 * Schweiggeria floribunda A.St.-Hil.
 * Schweiggeria fruticosa Spreng.
 * Schweiggeria mexicana Schltdl.
 * Schweiggeria pauciflora (Mart.) Lindl.

of which two, S. fruticosa and S. mexicana are accepted by Plants of the World Online, considering S. floribunda and S. pauciflora as synonyms of S. fruticosa. Other authors consider Schweiggeria to be monotypic for S. fruticosa.

Distribution and habitat
Eastern Brazil.