The New Zealand Plant Conservation Network

Species

Solanum americanum

Etymology

Solanum: Derivation uncertain - possibly from the Latin word sol, meaning "sun," referring to its status as a plant of the sun. Another possibility is that the root was solare, meaning "to soothe," or solamen, meaning "a comfort," which would refer to the soothing effects of the plant upon ingestion.

Common Name(s)

small-flowered nightshade

Current Conservation Status

2012 - Not Threatened

Conservation status of New Zealand indigenous vascular plants, 2012
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2012 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2009 and replaces all previous NZTCS lists for vascular plants. Authors: Peter J. de Lange, Jeremy R. Rolfe, Paul D. Champion, Shannel P. Courtney, Peter B. Heenan, John W. Barkla, Ewen K. Cameron, David A. Norton and Rodney A. Hitchmough. File size: 792KB

Previous Conservation Status

2009 - Not Threatened
2004 - Not Threatened

Authority

Solanum americanum Mill.

Family

Solanaceae

Flora Category

Vascular - Native

NVS Species Code

SOLNOD

Structural Class

Dicotyledonous Herbs other than Composites

Synonyms

Solanum nodiflorum Jacq.; Solanum nodiflorum subsp. nutans R.J.F.Hend.; S. americanum subsp. nutans ( R.J.F.Hend.) R.J.F.Hend.

Distribution

Indigenous. Kermadec, Three Kings, North, South and Chatham Islands. In the North Island locally common to about the Bay of Plenty and Taranaki scarce otherwise. In the South Island reported from Nelson, Marlborough, North Canterbury and Westland. Uncommon on the Chatham Islands. Abundant on northern offshore islands especially the Kermadec Islands. Present also in Australia, Africa, India, south-east Asia and the Pacific.

Habitat

Usually coastal but also found inland in open forested situations up to about 400 m a.s.l. Occasionally an urban weed. S. americanum is the typical Solanum of northern offshore islands where it grows in great abundance on the richly manured, frequently disturbed ground of petrel colonies, and may on occasion form dense thickets.

Features

Small, annual to perennial bright-green to purple-green herb up to 1 x 1 m but usually much less. All parts glabrous to glabrescent except on occasion on very young growth. Branches and branchlets usually unarmed though sometimes furnished on the flanges with sparse blunt-ended hooks. Petioles to 50 mm long. Cauline leaves 40-100 x 15-55 mm, usually bright green rarelt dark green, ovate, ovate-oblong to lanceolate-ovate, entire or distally coarsely toothed to lobulate, sometimes sinuate; base cuneate, broad-cuneate or attentuate, rarely cordate to truncate; apex more or less acute, sometimes acumininate. Flowers in few-flowered umbels. Peduncles 20 mm long, slender; pedicels up to 5 mm long, more or less pendent, markedly deflexing at fruiting. Calyx < 2 mm long, accrescent; lobes very narrowly elliptic to ovate, reflexed at fruiting. Corolla 5-8 mm diameter, stellate, white, pale mauve, glabrous; lobes triangular. Anthers 1.0-1.5 mm long, yellow. Fruit a berry 5-8 mm diameter, globular, glossy black to purple-black, stone cells present, often copious. Seeds 1.0-2.5 mm long, semi-glossy buff to pale orange-yellow or dark yellow, obovate to broadly obovate, sometimes circular, asymmetric, strongly compressed.

Similar Taxa

Most frequently confused with S. nigrum with which it often grows on the more disturbed northern offshore islands. From S. nigrum, S. americanum differs by its umbellate rather than pseudoumbellate inflorescences, smaller flowers (5-8 cf 8-13 mm diameter), strongly reflexed, narrow calyx lobes in fruiting specimens, smaller anthers (1-1.6 cf. 2-2.7 mm long), and by the presence of stone cells, these being absent in S. nigrum. Both species are chromosomally distinct with S. nigrum having 2n = 72 and S. nodiflorum 2n = 24 chromosomes. Solanum americanum is indeed the correct name for the New Zealand plant ( S. Knapp pers. comm., July 2017) which has been recently (Manoko et al. 2007) though incorrectly, referred back to S. nodiflorum as S. nodiflorum subsp. nutans). The treatment offered here is for this species (there as S. americanum) by Webb et al. (1988) is correct. A third species, S. opacum, is also present in New Zealand, and that species has caused much confusion between S. americanum and S. nigrum because it has deflexed, broad calyx-lobes, dull black or green coloured fruits with stone cells and stamens which are 1.5 mm long - features 'intermediate' between S. americanum and S. nigrum as treated by Webb et al. (1988). However, Webb et al. (1988) state that Solanum opacum is not present in New Zealand which is now known to be incorrect. For differences between S. americanum and S. opacum see the fact sheet of S. opacum.

Flowering

October - April

Flower Colours

Violet / Purple,White

Fruiting

November - June

Propagation Technique

Very weedy and invasive.

Threats

Not Threatened

Chromosome No.

2n = 24

Endemic Taxon

No

Endemic Genus

No

Endemic Family

No

This page last updated on 15 Mar 2018