Solanum species are distinctive plants in the Potato or Tomato Family, with 'tomato' type flowers that have typical recurved petals and bright yellow stamens, and alternate leaves.
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General:
Annual herb from a taproot; stems branched from the base, decumbent below, short-hairy to nearly smooth, 10-60 cm long.
Leaves:
Basal leaves spoon-shaped, lobed, short-hairy, 2-5 cm long; stem leaves oblong to egg-shaped, deeply lobed, short-stalked, short-hairy, 2-5 cm long, 1-3 cm wide.
Flowers:
Inflorescence of axillary, few-flowered clusters, the flowers on drooping stalks; corolla white, tubular, 5-9 mm wide when expanded, lobed, the lobes spreading to bent back, calyces becoming larger with age, lobed, the lobes unequal and up to 6 mm long at maturity.
Fruits:
Berries, globe-shaped, greenish, 9-14 mm wide; seeds 2.5-3 mm long.
If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.
Illustration Source: The Illustrated Flora of British Columbia
1. Plants climbing or scrambling perennial vines; flowers purple; fruits red.....................Solanum dulcamara
1. Plant annual herbs, not climbing; flowers white or yellow; fruits green or black. 2. Plant spiny; flowers yellow, 2-3 cm wide......................Solanum rostratum 2. Plants not spiny; flowers white or creamy, less than 1 cm wide. 3. Leaves deeply lobed....................................Solanum triflorum 3. Leaves entire, toothed or wavy margined. 4. Calyces 4-6 mm long at maturity, cupping the fruit; stems with spreading hairs.............................Solanum physalifolium 4. Calyces 2-3 mm long at maturity, not cupping the fruit; stems smooth or appressed-hairy...............................Solanum americanum Source: The Illustrated Flora of British Columbia Note that Solanum nigrum (with two subspecies) was added to the BC flora after the publication of the Illustrated Flora, and is not included in this key. It may be confused with Solanum americanum and features overlap, but with good fruiting or flowering material these two species but may be separated as follows: 1. Corollas > 5 mm diameter, anthers 1.5 - 3.0 mm, petals whitish, seeds 1.5 - 2.5 mm, inflorescence raceme-like with an often extended central axis, fruit often dull when mature...................S. nigrum 1. Corollas ca. 4.5 mm diameter, anthers < 1.5 mm, petals whitish to faintly to strongly purple-tinged, seeds 1 -1.5 mm, inflorescence umbel-like with a very short central axis, fruit often shiny when mature.................S. americanum 2. plants subglabrous or often with appressed non-glandular hairs on the stems and leaves...............subsp. nigrum 2. plants villous with spreading glandular multi-celled hairs...........subsp. schultesii Source: Frank Lomer, 2010. |