21. Amphistemon rakotonasolianus (EDGE species)

Belongs to the ditypic genus: A. humbertii and A. rakotonasolianus; Subfamily: Rubioideae; Tribe: Spermacoceae.

Erect perennial herb, slender, c. 30 cm tall; well-developed tap root up to more than 40 cm long. Leaves decussate sessile, fused with the stipule base. Stipules fimbriate. Inflorescences terminal, compound dichasia, many-flowered. Capsules broadly obovate to transversely broadly obovate. Seeds numerous, elliptic; wing absent.

Flowering time: January

Population: 3 subpopulations

Lower elevation limit: 20 metres

Fruiting time:

Trends:

Upper elevation limit: 100 metres

Distribution

A. rakotonasolianus is endemic to southwestern Madagascar, in the Atsimo-Andrefana and Menabe Regions of Toliara Province.

Number of locations: 3

EOO: 1,235 km²

AOO: 12 km²

Habitat and Ecology

Subarid forest in southwestern coastal bushland on white sand dunes, in the shadow of shrubs.

Threats

Extension of agricultural land, logging (wood collection and charcoal production) and fires. The other one occurrence, despite the presence in protected area, is threatened by illegal logging.

Conservation

This species occurs in Kirindy Mite (Cat. II) Protected Area.

It is not reported in ex situ collections (BGCI 2022).

21. Amphistemon rakotonasolianus Groeninckx

GE Score

EDGE Score

ED Score