Densely branched perennial herb to 40 cm or so tall, often grown as an annual. Leaves close together, linear, 2-2.5 cm long, stalkless. Calyx tube veined. Corolla mauve to violet with a yellow eye, the tube about 1 cm long with spreading, rounded lobes; spring to summer. Fruit capsule 3-4 mm long.
S America
var. violacea Millán. Leaves to 2.5 cm long, longer than those of the type; flowers violet-blue.As up to 12 varieties are sometimes recognised, the precise position of garden variants is sometimes unsure. [N. caerulea Sealy] This variety has been recorded as a garden escape between Sydney and Inverell, chiefly on waste ground, and is suspected of toxicity to horses and poultry.
Source: (2002). Solanaceae. In: . Horticultural Flora of South-eastern Australia. Volume 4. Flowering plants. Dicotyledons. Part 3. The identification of garden and cultivated plants. University of New South Wales Press.
Nierembergia hippomanica 'Purple Robe'
A mat-forming plant to 20 cm or so tall with deep blue-violet flowers.
The true name of this plant is uncertain and, although it is often listed under N. hippomanica, it is probably a cultivar of N. frutescens Durieu.
The cultivar N. 'Mont Blanc' is also listed.