Black nightshade is an introduced Eurasian species that is now found in North America in several Canadian provinces (AB, BC, MB, NF, NS, ON, QC) and some coastal US states ((AK, AL, CA, DC, FL, HI, MA, MD, ME, NH, NY, OR, SC, VA, WA) (USDA 2010). In British Columbia, it is reported from disturbed sites in the southwestern corner of the province where it has been collected on the mainland (Vancouver, Port Coquitlam, Delta), Bowen Island, and Vancouver Island (southeast of Qualicum Beach).
Solanum species are a distinctive genus of plants with 'tomato' type flowers with typical recurved petals and bright yellow stamens. In black nightshade, petals are white to whitish, leaves have wavy or large-toothed edge and are alternate on the stems, fruits are black to black-purple. Plants are perennial, sometimes annual, with an overall dark greenish or purple green colour. This is considered a poisonous species in the (Canadian Poisonous Plant Information System (2010)). |
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. |