ChamaebuxusTourn.
This genus comprises one species in North America and five in Europe and North Africa. Its separation from Polygala is strongly supported by phylogenetic analyses (Pastore et al., 2019). Chamaebuxus Tourn., published in 1753 in the Encyclopédie de Diderot y D’Alembert, takes priority over Polygaloides Haller. In North Africa, it is represented by three more or less woody species. C. balansae is the most robust and the only one that can be considered more or less shrubby; the others are only slightly woody at the base of their stems.
C. munbyana (Boiss. & Reut.) Stapf [Polygala munbyana Boiss. & Reut., Polygaloides munbyana (Boiss. &
Reut.) O. Schwarz], glabrescent, with quadrangular stems, shortly winged, and with flowers pink or yellow; endemic to the littoral and sublittoral mountains of NE Morocco (from littoral Bokkoyas towards the E) and the coastal mountains of central-western Algeria.
C. webbiana (Coss.) Stapf [Polygala webbiana Coss., Polygaloides webbiana (Coss.) O. Schwarz], easily differentiated by its densely pubescent branchlets; present in southern Spain (Malaga) and NW Morocco (calcareous mountains of the western Rif and, although rarer, also in the Middle Atlas, in Bab Metik).
In Algeria C. munbyana is included in the List of protected non cultivated flora (Executive Decree 12-03 on 4-Jan-2012).
Key to species
1 Subshrub up to 0.8(1.5) m in height, spiny Chamaebuxus balansae
1 Chamaephyte up to 0.5 m, non spiny 2
2 Quadrangular stems, shortly winged, glabrous Chamaebuxus munbyana
2 Rounded stems, pubescent Chamaebuxus webbiana
Updated by: A. Lahora