Solanaceae

Description

Nicandra physalodes (L.) Gaertn., the shoo-fly plant or apple-of-Peru, is an annual herb native to the Andean region of South America (notably Peru) but now naturalised almost worldwide as a weed of cultivation and waste ground. The very large GBIF occurrence record spans Europe, North and South America, southern Africa, Australasia, China and beyond, reflecting its cosmopolitan ruderal status. In the Himalaya it is a familiar plant of cultivated fields, village margins and disturbed ground; the records from Dunai in west Nepal at 2,150 m in July and from Sitel in Garhwal, India, at 1,850 m in September document its occurrence as a monsoon-season weed in the western and central Himalayan hill zone.

Nicandra is a robust, erect, glabrous annual reaching up to 1–1.5 m, with stout, angular, branching stems. The leaves are alternate, ovate to elliptic, with coarsely sinuate-dentate or lobed margins. The solitary, axillary flowers are pale blue to lilac with a paler, often whitish throat; the corolla is broadly campanulate and shallowly five-lobed. Most distinctive is the persistent, accrescent calyx with five deeply sagittate-cordate, sharply angled lobes that enlarge and become inflated and papery, enclosing the dry, many-seeded berry in a manner resembling the husk of Physalis, hence the epithet physalodes.

The genus Nicandra is monotypic and forms an isolated lineage within Solanaceae, placed in its own subfamily Nicandroideae and of long-standing interest in phylogenetic studies of the family. The plant is mildly toxic, containing withanolide-type compounds, and has been used traditionally as an insect repellent, accounting for the vernacular name shoo-fly. Its remarkable success as a global colonist makes it a textbook example of a New World species turned cosmopolitan agricultural weed.

Author: (L.) Gaertn. · Sources: POWO (Kew), GBIF, Flora of China Vol. 17, Flora of Pakistan (Solanaceae), Hunziker: The Genera of Solanaceae