Amphistemon
| Amphistemon | |
|---|---|
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Gentianales |
| Family: | Rubiaceae |
| Subfamily: | Rubioideae |
| Tribe: | Spermacoceae |
| Genus: | Amphistemon Groeninckx |
| Type species | |
| Amphistemon humbertii Groeninckx | |
Amphistemon is a genus of 2 species of flowering plants in the Rubiaceae family. It is described by Inge Groeninckx in 2010 based on a molecular analysis of the Hedyotis-Oldenlandia group.[1] The genus name is based on the Greek 'amphi-' (=double or of two kinds) and 'stemon' (=stamen) referring to the dimorphic stamen position characteristic for this genus.
Description
Amphistemon are erect perennial herbs or subshrubs with the unique feature in the Hedyotis-Oldenlandia group of having stamens inserted at two distinct levels in the corolla tube, the lower stamens with filaments and anthers shorter than those of the upper stamens.[1]
Distribution and habitat
It is endemic to southwestern and western Madagascar and is found in dry spiny forest-thicket and coastal bushland.[1]
Taxonomy
According to molecular analysis of the genus, it is found to be closely related to Astiella of the species-group Hedyotis-Oldenlandia.[1]
Species
- Amphistemon humbertii Groeninckx
- Amphistemon rakotonasolianus Groeninckx