ACAULESCENT SPECIES OF MALVASTRUM. 217 
furnished with coarse strigose hairs. In M. Rich and M. Weberbauer, 
however, the tomentum is composed of many-rayed stellate hairs. The 
leaf-teeth are furnished with two or three cilia in several species. The 
flowers often form a dense cluster in the centre of the leaf-rosette : they may 
be borne singly on the peduncles in the majority of cases, but in a few species 
the peduncles are 2-flowered (M. acaule, M. Meridæ, and M. alismatifolium), 
and in M. Purdiaei the flowers are borne 3-6 together in a small terminal 
cluster or capitulum. The involucral braets may be either caducous or 
persistent, and they vary in shape from broadly ovate to filiform. In M. nubi- 
gena and М. oriastrum, Weddell thought them to be absent, but they have 
been notieed in the former species and are probably occasionally present in 
the latter also. The calyx is usually hairy on the inside of the segments and 
in every species appears to be furnished with 5 large, more or less triangular, 
glandular nectaries at the base, as in the genus Nototriche. The corolla is 
like that in Nototriche ; the corolla-tube, however, is only from 1-2 mm. in 
length and the petal bases and the base of the column are covered with 
stellate hairs. The stamens are usually numerous and arranged in a globose 
or cylindrical head ; in M. nubigena the filaments all spring from the tube 
at the same spot and the anthers are arranged in a corymbose fashion. The 
carpels are of three types: two species possess beaked carpels like those 
found in Nototriche, but in all the others the carpels are reniform and rounded 
at the apex. This larger group, however, can be broken up into two sub- 
groups, in one of which the carpels are wrinkled on the back, while in the 
other they are smooth and covered with stellate hairs. 
The Acaulescent Malvastra, though showing a somewhat similar geo- 
graphical distribution to Nototriche, and similar biological features, appear 
to prefer very different situations. Instead of growing in volcanic ash or on 
bare hillsides, as is usually the case with Nototriche, these Malvastra are to 
be found on the argillaceous soils of the valleys or growing in conjunction 
with other plants. 
The range of this acaulescent section extends from the Sierra of Santa 
Martha in Venezuela as far as the south of Bolivia and Northern Argentina. 
No acaulescent species have been recorded from Chile, though M. humile 
from the Cordillera of Santiago has assumed a somewhat similar habit of 
growth. 
The comparison of the geographical range of this section with that of 
Nototriche is of some interest, since the A/alvastra extend to the extreme 
north of South America, but do not attain to the southern limits reached by 
Nototriche. 
The section Acaules contains at present 18 species, a key to which and 
descriptions, with notes, now follow. 
