herb, herbaceous plant - a plant lacking a permanent woody stem; many are flowering garden plants or potherbs; some having medicinal properties; some are pests

genus Nierembergia - genus of tropical American erect or creeping herbs with solitary flowers

Nierembergia repens, Nierembergia rivularis, whitecup - prostrate woody South American herb with white tubular flowers often tinged with blue or rose

Nierembergia frutescens, tall cupflower - shrubby Chilean herb having bluish-white tubular flowers used as an ornamental