Solanum douglasii Dunal
Family: Solanaceae
Green-Spot Nightshade,  more...
[Solanum nigrum var. douglasii (Dunal) A. Gray]
Solanum douglasii image

PLANT: Annual or short-lived perennial herbs, sometimes turning woody with age, usually less than 1 m tall, without tubers or stolons, unarmed; herbage glabrous to pubescent to variously strigose; stems terete to angled, sometimes with small, antrorselycurved teeth on the angles.

LEAVES: alternate or sub-opposite, simple, 2-9 cm long, 1-5 cm wide, ovate to lance-elliptic; margin entire to coarsely-toothed; base truncate to attenuate; apex broadly acute to acuminate; petiole (1-)2-6(-8) cm long.

INFLORESCENCE: umbel-like racemes, lateral, borne between nodes or sometimes at nodes opposite leaves, (1-)3-8(-12)-flowered; peduncle 8-30 mm long.

FLOWERS: actinomorphic (Fig. 3B); pedicel 2-12 mm long; calyx 1.5-2.5 mm long, the lobes lanceolate to rounded, about as long as to 1/4 the length of the tube; corolla rotate-stellate to reflexed, white or white tinged with purple, sometimes gland-dotted, sometimes with basal brownish star, 8-25 mm in diam.; style as long as stamens or up to 3 mm longer, pubescent ± half its length; stamens of ± equal length, (2.5-)3-4(-4.5) mm long; anthers connivent; filaments 1/5 or less as long as anthers, usually much less than 1 mm long.

FRUITS: subglobose, 6-12 mm wide, green, orange-brown or blackish at maturity, not enclosed in the calyx; sclerotic granules 0-5; seeds orbicular, minutely pitted, 1-1.6 mm wide.

NOTES: Agricultural weeds also found in waste places and riparian areas: All cos. exceptApache (Fig. 1D); 50-2500 m (~200-8000 ft); throughout the year; s. U.S. from AL to CA; Mex.; probably native to N. Amer.

REFERENCES: Chiang, F. and L.R. Landrum. Vascular Plants of Arizona: Solanaceae Part Three: Lycium. CANOTIA 5 (1): 17-26, 2009.

Bates et al. 2009, Royal Botanical Society 1914

Duration: Perennial

Nativity: Native

Lifeform: Subshrub

General: Herbaceous annuals or short-lived perennials, sometimes turning woody with age, usually less than 1m tall, without tubers or stolons, unarmed; herbage glabrous to pubescent to variously strigose; stems terete to angled, sometimes with small, antrorsely curved teeth on the angles.

Leaves: Alternate or sub-opposite, simple, 2-9 cm long, 1-5 cm wide, ovate to lance-elliptic; margin entire to coarsely-toothed; base truncate to attenuate; apex broadly acute to acuminate petiole (1-)2-6(-8) cm long.

Flowers: Inflorescences umbel-like racemes, lateral, borne between nodes or sometimes at nodes opposite leaves, (1-)3-8(-12)-flowered; peduncle 8-30 mm long. Flowers actinomorphic; pedicel 2-12 mm long; calyx 1.5-2.5 mm long, the lobes lanceolate to rounded; corolla rotate-stellate to reflexed, white or white tinged with purple, sometimes with basal brownish star, 8-25 mm in diam.; anthers connivent; filaments usually much less than 1 mm long.

Fruits: Subglobose, 6-12 mm wide, green, orange-brown or blackish at maturity, not enclosed in the calyx.

Ecology: Agricultural weeds also found in waste places, riparian areas and in semi-mesic habitats in many communities in the southwest and CA; 200-8000 ft (50-2500 m); flowering throughout the year.

Distribution: s. U.S. from AL to CA; Mex.; probably native to N. Amer.

Notes: Distinguished by its annual, herbaceous life form to a meter tall, often dark green, broad lance-elliptic leaves, white Solanaceous corollas with yellow anthers and dark blue mature berries. Similar to S. americanum but tends to have larger flowers (diameter of 2-6 mm and <3 mm long in americanum, >3mm long in douglasii) and longer anthers (<1 mm long in americanum >2 mm long in douglasii). In the southwest, these two species are a part of the cosmopolitan -S. nigrum complex-, a group of over 30 species with continuous variation, hybridization, polyploidy and many evolutionary intermediates, often making for difficult classification.

Ethnobotany: Used for food and fodder, or as dyes and their use dates back to the earliest records of written history. They also contain various levels of toxic alkaloids and can be hosts to destructive animals and diseases to crops, being related to other Solanaceous crop plants (Tomatoes, peppers, potatoes etc....).

Synonyms: Solanum nigrum var. douglasii

Editor: FSCoburn, 2014

Etymology: Solanum is Latin for "quieting," in reference to the narcotic properties of some species, douglasii was named for David Douglas, (1799-1834) Scottish botanist who explored the Scottish Highlands, Hawaii and widely across North America collecting many species of plants new to science. Over 80 species are named in his honour.