Nightshade common in Nth Dn
THREE species of nightshades, found on footpaths and waste ground in North Dunedin, were brought to the museum last month. These not unattractive plants have flowers resembling those of the potato and tomato, and, like them, belong to the family Solanaceae.
Black nightshade (Solanum
nigrum) has small white grouped flowers with yellow centres similar to those of a potato. The leaves are not trilobed (unlike woody nightshade), the stem is smooth or slightly hairy, and the leaves are alternate, with long stalks. The plant has an unpleasant smell and contains poisonous alkaloids. It likes nitrogenrich loamy soil. In the past decade it has become very common on footpaths and against walls and hedges in North Dunedin streets in the student area, between the museum and the Botanic Garden. It is spread by birds — including blackbirds.
Woody nightshade or bittersweet (Solanum dulcamara) has small purple grouped flowers with yellow centres, similar to those of black nightshade. However, the leaves are often lobed, appearing tri lobed, with a large lobe and two small lobes. The stem is woody at the base. This plant also has a bad smell and contains poisonous alkaloids. It often grows in damp places. It is now common throughout Dunedin and elsewhere, including the Catlins, and occurs on disturbed soil and in waste places. It is common around some Dunedin buildings. It is spread by birds.
Deadly nightshade (Atropa
belladonna) has large purple drooping solitary flowers, greenishbrown on the outside and purplishbrown on the inside. Leaves occur in unequal pairs. The plant contains a
poisonous ethereal oil. The specific name ‘‘belladonna’’ (beautiful lady) refers to the effect on the eyes when the plant is eaten — the alkaloid atropine causes the pupils to dilate. This plant sometimes grows near shrubs and hedges.
Potato (Solanum tuberosum).
The flowers are purplishblue or white. The leaves are somewhat hairy. The stems have crinkly wings. The fruit is a round berry, black when ripe. Greened tubers (potatoes), green berries and sprouts from tubers are poisonous. The potato is included here to show its resemblance to its nightshade relatives.