Solanum americanum Mill., Gard. dict. ed. 8: Solanum no. 5. 1768;
(Solanum americanum, solanum nigrum & Solanum villosum– 5 images.)
Although The Plant List treats S. nigrum and S. americanum as synonyms, seeing so many errors in this database I prefer to follow GRIN and eFlora of China, wherever available, since both treat them distinct with following differences
S. americanum: Flowers less than 5 mm across; anthers 1-1.5 mm long; berries 6-7 mm in diam, shining black; fruiting calyx reflexed; seeds 1-1.5 mm long
S. nigrum: Flowers 7-10 mm across, anthers 2-3 mm long; berries 7-9 mm in diam, dull black; fruiting calyx appressed or slightly deflexed; seeds 1.7-2.5 mm long
Solanum americanum, commonly known as American nightshade or Glossy nightshade is a herbaceous flowering plant of wide though uncertain native range. The certain native range encompasses the tropics and subtropics of the Americas, Melanesia, New Guinea, and Australia.
The plant is widely naturalised around the Tropical Pacific and Indian Oceans, including Hawaiʻi, Indochina, Madagascar and Africa, possibly via anthropogenic introduction in these locales.
Solanum americanum is one of the most widespread and morphologically variable species belonging to the section Solanum. It can be confused with other black nightshade species in the Solanum nigrum complex.
Solanum americanum grows up to 1–1.5 metres (39–59 in) tall and is an annual or short-lived perennial. The leaves are alternate on the branch, and vary greatly in size, up to 10 centimetres (3.9 in) long and 7 centimetres (2.8 in) broad, with a 4-centimetre (1.6 in) petiole and a coarsely wavy or toothed margin. The flowers are about 1 cm diameter, white or occasionally light purple, with yellow stamens. The fruit is a shiny black berry 5–10 millimetres (0.20–0.39 in) diameter, containing numerous small seeds.
Solanum americanum is a variable taxon. It is considered by some botanists to be more than one species, and others recognise subspecies. Some botanists have suggested that Solanum americanum’ may be conspecific with the European nightshade, S. nigrum. 
The ripe fruit is cooked into jams and preserves, or eaten raw. In Africa, South America, New Guinea and Oceania the young green shoots of Solanum americanum are cooked and eaten as greens, after boiling in water. The cooking water used for boiling the leaves is discarded as it contains the soluble alkaloids. In Kenya, Cameroon and Papua New Guinea the leaves are sold as a leaf vegetable in the markets. The leaves are used in a West Indian stew, and it is known as branched Kalaloo. In Mauritius it is cultivated and eaten as a pot-herb and used in bouillon. Experts warn that care should be taken since numerous toxins are reported with levels varying with local conditions and varieties.
(From Wikipedia on 19.7.14)
Solanum americanum: S. americanum Miller, The Gardeners Dictionary, Ed. 8, art. Solanum no. 5, 1768
syn: Solanum nigrum L.; S. humile Lam.
For a long time S. americanum and S. nigrum were treated at distinct species, former characterised by smaller flowers (less than 5 mm across), smaller anthers (1-1.5 mm long) smaller (6-7 mm) shining black berries, and latter by larger flowers (6-9 mm across), longer anthers (2-3 mm) and larger (7-9 mm) dull black, purple or yellowish-green berries. Both species are distinct from S. villosum in inflorescence with usually more than 6 flowers, longer peduncles (1.5-3 cm in fruit).
Solanum nigrum complex: Solanum nigrum complex is one of the most confused group of species with at
least 3 species expected in India: S. americanum, S. nigrum and S. villosum (especially the glabresecent form of it sometimes called S. miniatum, but now synonym). There are number of uploads in our database, which need to be sorted out.
These three species can be differentiated as under:
The following upload by you had clearly shining black berries and longer peduncled matching S. americanum but perhaps flower size (diam), anther length and berry size should help in confirming identification. I would request you to kindly explore these features if you are able to find this plant in your area. efi thread
– The plant is not there at present. It might erupt after monsoon. From what I remember the description matches with the key number 4a(Very small flowers etc.) i.e. S.americanum
efloraofindia:”For Id 08102011MR4’’ wild white flower Pune: Date/Time-Oct 2011
Location- Place, Altitude, GPS-Pune
Solanum americanum may be
Why not Solanum nigrum?
Both are synonym
Oh I am so happy to know this.
Jan2015sk10 – Solanum 3 species comparision : 1 post by 1 author. Attachments (5)
Pictures were taken today from same place, these three species growing here as weeds. Earlier I thought we had only two, no S. americanum Mill., but the eFI and FoC KEY tells me otherwise.
Jan2015sk05 – Solanum americanum Miller? : 4 posts by 3 authors. Attachments (5)
1 ft wild herb photographed today (15.1.15)
yes seems to be Solanum americanum
Solanaceae Fortnight: Feb2015sk01/18: Solanum americanum Mill. : 3 posts by 2 authors. Attachments (2)
I was looking forward to this fortnight. Thanks to … My earlier upload of this species.
This small wild herb is common here
Solanaceae Fortnight: Solanum americanum from Agastamuni, Uttarakhand-GSFEB20/22 : 1 post by 1 author. Attachments (4).
Solanum americanum Miller, Gard. Dict., ed. 8. no. 5. 1768.
Annual herb differing from Solanum nigrum in 3-10 flowered cymes, less than 5 mm across, smaller anthers barely 1-1.5 mm long, shining black berries 5-7 mm in diam; pedicels and peduncle erecto-patent and strongly reflexed calyx lobes
Photographed from Agastamuni in Uttarakhand.
Solanaceae Week: Solanum americanum PKFEB06/06 : 2 posts by 2 authors. Attachments (1).
Solanaceae Fortnight:Pune:: Solanum americanum ::SMPFEB 2/2 : 1 post by 1 author. 4 images.
Growing as a weed in Pune
Solanaceae Fortnight:: Solanum americanum Mill.-NS Feb 37/37 : 2 posts by 2 authors. Attachments (7)
This is a frequent herb, flowering and fruiting in December till March in north Indian plains. Clearly distinct from one more of the same genus blooming at the same time (Solanum villosum Mill.) in having green stems, smaller, pinkish flowers and shining black-coloured berries.. edges of stem bear very small spines..
This should not be confused with Solanum nigrum L. which flowers in summers and monsoons, bears larger number of fruits per peduncle, dull berries and large fruiting calyx .
I am attaching the pics of all the three taxa in consecutive messages, your views are requested..
Solanaceae Fortnight: Solanum americanum Mill from Assam KD 08, FEB ’15 : 3 posts by 3 authors. Attachments (3)
Attached images are Solanum americanum Mill from Assam.
Yes, thanks …
Yes …, nice photographs.
Solanum nigrum FOR VALIDATION :: Vythiri, Wayanad :: 15 NOV 19 : 7 posts by 4 authors. 2 images.
Date: November 15, 2019 … Altitude: about 700 m (2,300 ft) asl
¿ Solanum nigrum ?
I will go with S. villosum …
and the parasite: cuscuta fibrils
Thanks very much … for the ID. Will update my notes.
Pl. check if it matches as per differences between closer species given at Solanum villosum
Thanks … The leaves are not dentate sinuate as much as expected for S. villosum. The posted plant has leaves with almost entire margin.
The flowers are tiny – less than 5 mm across, thus making me think of Solanum americanum.
…, please let me know if I am mistaking; or missing some characteristic leading to S. villosum.
Hope we get validating comments.
12 very high resolution images.
Location: Kathmandu, Nepal
Date: 07 December 2020
Altitude: 1400 m.
Botanical Name: Solanum nigrum:
State: j and k
Seems to be correct. Black fruit. Another red variety fruit is also seen in Mysore in wild.
I think it will be Solanum americanum as the fruiting calyx is reflexed as per keys and details herein.
Thanks … for the final ID.
Is this Solanum nigrum??: 2 high res. images.
It will be Solanum americanum, as the fruiting calyx is reflexed, provided ripe fruits are black.