Know your eggplants - Part 4

The related Nightshades



Why covering nightshades in an article about eggplants? For several good reasons. Some nightshades are actually consumed like eggplants in some parts of the world. They are in fact called "eggplants" in the native languages of their countries of origin, and for that purpose many have had their fruits improved through breeding and selection. They are nearly or purely wild and retain some resistance to pests, diseases, and climatic conditions. These are increasingly important traits in a world with seriously perturbed weather patterns. Because nightshades are related to the cultivated eggplants they can be used to impart resistance to them. Eggplants in particular are notoriously susceptible to diseases and some pests. This strength building can be achieved via cross-pollination with compatible species or by grafting known cultivars on resistant nightshade rootstock. As a bonus most nightshades are used in some part of the world as medicinal plants so their properties discovered or undiscovered are valuable. If it was not enough, many of the nightshades are rather attractive plants and are sold as ornamentals around the world. Finally because some of those plants are in fact endangered (see for example Solanum viride below) any mention of them is never superfluous. We will only mention a basic few names for all the species below. For comprehensive lists of both botanical Latin and common names please refer to the  MMPND . After looking at many photos of the fruits of all these species with the eyes of a layperson I noted a lot of similarities. The young fruits are either white or pale green and they mature into yellow, orange or red fruits. The plants are very prickly. I hope to get a lot of feedback on identifying the species with more precision but I expect this to be a long term effort. Nightshades can be poisonous so it is vital to know the very cultivar or species that one is dealing with before consuming any part of it whether cooked or raw.


Species on this page:

Solanum aculeatissimum Jacq.
Solanum capsicoides All. (Solanum aculeatissimum sensu Schulz, non Jacq. )
Solanum incanum L. (Solanum melongena L. var.  incanum (L.) Kuntze)
Solanum indicum L.
Solanum insanum L. (Solanum melongena L. var.  insanum Prain)
Solanum lasiocarpum Dunal  (Solanum ferox L. (Terong Asam Group)
Solanum trilobatum L.
Solanum villosum Mill.
Solanum violaceum Ortega
Solanum virginianum L. (Solanum xanthocarpum Schrad. & Wendl.)
Solanum viride Spreng. (Solanum uporo Dunal)

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Solanum aculeatissimum Jacq.

Synonyms : Solanum horridum Salisb.

Straight off we start with a taxonomical controversy. The staff of the National Herbarium of New South Wales at the Royal Botanic Gardens & Domain Trust, Sydney, Australia, list Solanum aculeatissimum Jacq. as a synonym of  Solanum capsicoides All. Many others,  not the least of them the global taxonomic resource for the nightshade family Solanaceae , disagree and point to this error due to the fact that apparently Schulz was not considering the same plant as Jacq. When he named S. aculeatissimum as a synonym of S. capsicoides. This mistake is still repeated today and has lead to a great deal of confusion in the common names, many wrongly attributed to either one species or the other. "Cockroach berry" for example is applied to both species. The correct synonymy is: Solanum aculeatissimum sensu Schulz, non Jacq. = Solanum capsicoides All.  The preferred English name for this species seems to be "Dutch eggplant".  There is a connection, possibly from the many Malay names including the word "terong" (eggplant) in their composition and the association of the Dutch people with Indonesia in the past. Similarly when the Thai lexicographers list Solanum xanthocarpum Schrader & Wendl. as a synonym of Solanum aculeatissimum they probably meant Solanum aculeatissimum sensu Schulz, non Jacq. Again we cannot find confirmation of this synonymy, but certainly as a consequence some of the common names are mixed up a little more. We have not yet come across this but in the PROTA article Nicholson states: " Misidentification of Solanum macrocarpon L. (synonym: Solanum dasyphyllum Schumach. & Thonn.) is a further source of confusion, probably in West Africa in particular". All these confusions probably arise from the fact that all these plants and their fruits look rather similar.
Contrary to Solanum aethiopicum, Solanum aculeatissimum has travelled in the opposite direction, from its native Brazil it was introduced into Africa centuries ago.  Today it is present throughout tropical Africa and Asia.
Due to its resistance to Verticillium wilt (Verticillium dahliae), a deadly disease of eggplants, it can be used as a rootstock for both the common eggplant and the common tomato. In Asia it is used to this end in both fields and hydroponic systems. The resistance to Verticillium wilt can also be passed on to the common eggplant and the Gboma eggplant (Solanum macrocarpon L.) via crossbreeding. The Dutch eggplant will cross with any of these 2 successfully but Nicholson warns that on occasions only sterile seeds will be produced.This nightshade can be propagated from either cuttings or seeds. Top Tropicals  is a possible source of plant material.




Photo courtesy Top Tropicals   reprinted from Solanum aculeatissimum page.





Solanum capsicoides All.

Synonyms : Solanum aculeatissimum sensu Schulz, non Jacq.

This species, also native of Brazil, is fairly widespread in the Caribbean and the fruits are used to make juice. It has also been introduced in tropical Africa but as an ornamental. The preferred name for this plant seems to be " Devil's apple ",  although this is also used to designate other species even with no relation whatsoever with Solanaceae. We understand that this is a yellow-berried species, whilst Solanum aculeatissimum Jacq. is an orange / scarlet / red berried nightshade. Is this correct?
 


 
Reproduced from flickr  with permission of copyright owner Ming I Weng

Leaves               Flowers                  Fruits



Solanum incanum L.

Synonyms : Solanum melongena L. var. incanum (L.) Kuntze

Like Solanum insanum L. it is considered as a possible ancestor of the modern eggplant. Solanum incanum L. is found throughout continental Africa, including South Africa. Its fruits are basically small, bitter and toxic. It grows wild in Madagascar and Mauritius where the fruits are considered edible. It also occurs from the Middle East to India. Selection for larger, less toxic fruits and leaves is taking place in West Africa as well as in the former French colonies, however wide variations in the toxicity of the fruits and leaves make it dangerous to transfer specific uses from one region to another. As is the case with many nightshades it is vital to know the plant one is dealing with, its edible parts, at what stage of development these parts are edible, and how to prepare and cook them.  The fruit and the seed are used in Africa and Asia to curdle milk and to make cheese. In Ethiopia the boiled fruits are used as soap and in the tanning of leather.
Due to its widespread occurrence this species is not in danger of genetic erosion.


 
Reproduced from flickr  with permission of copyright owner Drew Gardner
Flower and leaf 
Reproduced from flickr  with permission of copyright owner Benjamin Shafir
Fruits

 

Solanum indicum L.


Yellow fruit up to 8 mm in diameter.

This is a species too difficult to focus on due to the unreliability of its taxonomy. See   A little taxonomy  "a complex example: Solanum indicum L." Anything that could be said about it could equally apply to the many plants that have been confused with it.
 

Solanum insanum L.

Synonyms :  Solanum melongena L. var. insanum Prain

Closely related to Solanum melongena, perhaps a direct ancestor. Relatively little background is available on this species.


Solanum lasiocarpum Dunal

Synonyms :  Solanum ferox L. (Terong asam Group)

Based on the Malay vernacular and the reported (natives and travelers) strong association of Solanum lasiocarpum with Sarawak, we are guessing that this is Solanum ferox L. (Terong asam Group). The English names for this are either Wild brinjal or Sour brinjal, both being appropriate. Generally speaking Terong asam is wild but occasionally cultivated for its edible fruits in Southeast Asia, New Guinea and Sarawak in particular. The fruits are used in sauces and curries and like most of these (eggplant / nightshade borderline) plants have medicinal uses. There are 1 to 2 fruits per inflorescence on the plants. These round fruits are 2.5 to 3.5 cm in diameter and orange when ripe. 

 




Reproduced with permission from copyright owner Dianne Lim

Green fruit close-up

 

Reproduced with permission from copyright owner Dianne Lim


Green fruits at a Sarawak market

Reproduced with permission from copyright owner Dianne Lim

Ready for cooking 




  Reproduced from  Flickr   with permission from copyright owner XPing

Fruits in various stages of maturity at a market stall in Sarawak 

See  Solanum ferox L. (Terong asam Group) for more details.


Solanum trilobatum L.


This plant grows wild in Thailand and like Solanum ferox would not be considered as an eggplant relative anywhere else but in Thailand where it is consumed like a pea eggplant. Its fruits, of similar size, resemble the pea eggplant, have a bitter taste and vary in colour from white-streaked with green through to yellow-orange to shades of red as they ripen. They are borne on a thorny, climbing herb upon individual stems (rather than in clusters like pea eggplant). This variety is eaten raw with nam prik kapi and is also considered valuable medicinally. No cultivar name has been found anywhere yet.




Reproduced from flickr with permission from copyright owner Arvind Balaraman
Flower


Fruits




Solanum villosum Mill.
This hairy nightshade is thought to come from Eurasia but little is reported about it from this part of the world. In East Africa it is consumed as a green vegetable. The leaves are commonly found in Kenyan and Tanzanian markets in both rural and urban areas.  Manoko, M.L. & van der Weerden report in their PROTA article that it is the most expensive leafy vegetable at the urban market of Arusha in Tanzania. On the other hand in Ethiopia, Kenya, Uganda and Tanzania the ripe fruits are also eaten. There are yellow, orange and red fruited types with edible fruits. This would account for the English name "Red-fruited nightshade" and the French "Morelle jaune" ("Yellow-fruited nightshade"). Some taxonomists have recognised 2 subspecies, later confirmed by Edmonds. The subspecies miniatum is the chosen option for greens due to its smoother foliage. The subspecies villosum has a more hairy leaf. I imagine the same difference than between a traditional turnip leaf and a modern rutabaga leaf. Whether these are two subsp. or two groups of varieties taxonomists of the future will work out, meanwhile it is sufficient to highlight the differences. In Kenya and Tanzania Alpha Seed Company and Kenya Seed Company sell Solanum villosum Mill. seeds.

 

 



subsp. villosum

subsp. villosum

subsp. villosum

 

subsp. miniatum

subsp. miniatum

subsp. miniatum

 




Solanum violaceum Ortega


Here we venture even further out of the eggplant family but into the nightshades. Because we found a mention of something  that could be S. violaceum (referring to the controversy regarding Solanum indicum) in both Nicky's Nurseries (UK) and Baker Creek Heirloom Seeds (USA),  we thought we'd mention this little known species as well. It is described as a 2 meter tall very prickly shrub. Otherwise the descriptions of its fruits is similar to those of Solanum trilobatum. It is known as "Tibbatu" in Sri Lanka (formerly Ceylon) where it is considered as a promising vegetable. On the other hand if its English name "Poison berry" is fine for a medicinal plant it does not inspire confidence as far as food plants go. So it is likely that it should be consumed in its correct stage of fruit development. This may be early or late but should be based on local knowledge. We would urge caution though until more is known about this plant.  No cultivar name has been found anywhere yet. Solanum violaceum has a redeeming feature in its resistance to "Bacterial Wilt", a disease caused by caused by Ralstonia solanacearum. It has been successfully crossed for instance with Solanum aethiopicum L. (Aculeatum Group) in order to increase the resistance of this African eggplant.


 

Solanum virginianum L.
Solanum xanthocarpum Schrader & Wendl.

Surattense nightshade is mostly a medicinal plant much utilised in India but with a poisonous fruit. Like many nightshades it is a potential source of disease resistant material for eggplants.
I am guessing that there are some fruits of this species Yellow berried nightshade in the photo below, I see mostly Kermit looking types, the species of which I still am not sure. If one considers that Solanum xanthocarpum can be a synonym of something else, my title is still incorrect but only partially. The photo is so great however I could not resist the temptation to include it.


Reproduced from flickr with permission from copyright owner Eric Hunt

Not just Solanum xanthocarpum

The above photograph displays some Solanum melongena, Solanum torvum and Solanum xanthocarpum. We can see clearly some plain yellow berries (S. xanthocarpum), and striped yellow larger fruits which are most likely mature "Kermit" types.



Reproduced from Flickr   with permission from copyright owner Tanmay Shende

Flower and prickly leaf close-up

 

Unidentified prickly

 

Unidentified prickly

Unidentified prickly

Unidentified smooth

Unidentified smooth

Variations in fruits of Solanum virginianum L. from different origins at different stages of maturity

 

 

Solanum viride Spreng.

Synonyms : Solanum anthropophagorum Seem.,  Solanum uporo Dunal.


The epithet of the synonym Solanum anthropophagorum Seem. means "Solanum to eat with man" from the days when in Fiji human flesh was wrapped in its leaves, like fish is today, before cooking. It was then an edible green, a medicinal plant from the Polynesian region. Its fruits as can be gathered from some of the vernacular were used as adornments. In its native Fiji and established Cook Islands it was already considered endangered in 2004. Trade Winds Fruit sell the wild form of this plant with smaller round berries. The cultivars such as 'Anthropophagorum' from the Cook Islands and 'Borodina' from Fiji have larger fruits. The former has fruits very much reminiscent of the red jilo.
Reproduced with permission from a rare seed source  Trade Winds Fruit

Wild form



Reproduced from the Cook Islands Biodiversity Database & Website with permission from The Cook Islands Natural Heritage Trust.

Domesticated form

 

References:


Manoko, M.L. & van der Weerden, G.M., 2004. Solanum villosum Mill. [Internet] Record from Protabase. Grubben, G.J.H. & Denton, O.A. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. < http://database.prota.org/search.htm>. Accessed 9 June 2009.

Matu, E.N., 2008. Solanum incanum L. [Internet] Record from Protabase. Schmelzer, G.H. & Gurib-Fakim, A. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. < http://database.prota.org/search.htm>. Accessed 12 June 2009.

McCormack, Gerald (2007) Cook Islands Biodiversity Database, Version 2007.2. Cook Islands Natural Heritage Trust, Rarotonga. Online at http://cookislands.bishopmuseum.org.

Nicholson, M.J., 2008. Solanum aculeatissimum Jacq. [Internet] Record from Protabase. Schmelzer, G.H. & Gurib-Fakim, A. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. < http://database.prota.org/search.htm>. Accessed 9 June 2009.



Compiled by Michel H. Porcher 
Started 02 / 06 / 09
Updated 21 / 06 / 09
Completed: soon!
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