Solanum subg. Leptostemonum

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Solanum subg. Leptostemonum
Solanum pyracanthon

Solanum pyracanthon

Systematics
Asterids
Euasterids I
Order : Nightshade (Solanales)
Family : Nightshade family (Solanaceae)
Genre : Nightshade ( solanum )
Subgenus : Solanum subg. Leptostemonum
Scientific name
Solanum subg. Leptostemonum
( Dunal ) Bitter

Solanum subg. Leptostemonum is one of seven subgenus of the genus of nightshade ( Solanum ), into which about 350 to 450 species are classified. This makes it the second largest subgenus, about a third of all nightshade species belong to it. A special characteristic of the subgenus is the formation of spines that can be on the stem axis, on the leaves and / or on the calyx. The star-shaped trichomes , which can be found on almost all vegetative parts, and the pointed anthers are also typical. The subgenus includes cultivated and food plants such as the aubergine ( Solanum melongena ), but also invasive weeds such as Solanum viarum .

description

Vegetative characteristics

The species of the subgenus Leptostemonum are in most cases up to 1 m high shrubs or perennial herbs, only in rare cases are they climbing plants , short-lived plants ( ephemeral plants ) or up to 20 m high trees with a trunk diameter of up to 30 cm. Many species form adventitious roots . Almost all species of the subgenus are studded with spines. These have a broad base, are bent back, needle-like or awl-shaped. Also typical is the hair with star-shaped trichomes , which can be sessile or stalked, are sometimes sea urchin-like and relatively often glandular. The leaves are entire, lobed, roughly toothed or pinnately fissured, and often covered with spines. Within the Androceras section , the longest leaves can be found with a length of up to 30 cm.

Inflorescences and flowers

Lulo flowers ( Solanum quitoense ).

The zymous inflorescences are either branching with a few flowers, or non-branching with one to two, three to five or six to twelve (in rare cases up to 50) flowers each . The flowers are mostly radial symmetry , only in a few cases zygomorphic . The flower size is very variable within the suborder. There are species whose inflorescences are completely bisexual, but also many Andromonözischen representatives, in which the outer flowers of an inflorescence are purely male. Androdioceia occurs in some species , then there are hermaphrodite and purely male plants. The calyx is often covered with star-shaped trichomes or spines on the outside, heavily lobed and usually continues to grow while the fruit is ripe. The corolla is wheel-shaped or star-shaped, (6) 10 to 20 (25) mm in size, weakly or heavily lobed, mostly white, blue, lavender or purple, more rarely yellow or greenish in color. In some species the crown is zygomorphic. The stamens often appear in different lengths, the anthers are free, but are partially inclined to each other. The stamens attach to the back of the anthers (dorsifix anthers). The size of the stamens is between (4) 7 and 9 (10) mm. The tip of the anthers is usually elongated, and there are also two small pores that open where the pollen can escape. The stamens are significantly shorter than the anthers. The ends of the stamens are clearly separated from each other. The pen is busy cylindrical or pfriemförmig and hairless or with glandular trichomes. If different stylus lengths occur within an inflorescence, the lower one or two flowers are usually provided with a longer stylus and are fertile, whereas the other, functionally male flowers have a shorter stylus.

Fruits and seeds

Solanum carolinense fruits .
Seeds of Solanum rostratum .

The fruits are dry, fleshy or slimy filled, rarely woody berries . Except for Solanum tudununggae and Solanum vansittartense, the fruits do not crack . There are different ways of enlarging the calyx, so that the fruits can be partly uncovered, on the other hand almost completely covered by the calyx. When the fruit is ripe, the calyx is usually 0.5 to 1 (1.5) cm or 1 to 3 cm in diameter, with Solanum lycocarpum 12 cm and more, with cultivars of the aubergine ( Solanum melongena ) up to 15 to 20 × 5 × 15 cm can be achieved. In the fruits there are usually 100 to 400 seeds , in individual cases only (1) 5 to 25 (50), in the fruits of the cultivars of the aubergine there can be up to 15,000 seeds. The species with the fewest seeds within the nightshade genus is Solanum tenuissimum with usually only one or two, rarely three seeds. The pale yellow, light or dark brown, black or straw-colored seeds are lenticular to kidney-shaped, the surface is finely pitted to slightly reticulate, occasionally winged with a 1 to 1.2 mm wide wing. The size of the seeds is (1.5) 2 to 4 (5) mm. The endosperm has a honeycomb-like shape.

Chromosome number and karyotype

Almost all examined species of the subgenus, like almost all other representatives of the genus, have a base chromosome number of . Only known exceptions are the types mammosum Solanum and Solanum platense with . From Solanum elaeagnifolium a polyploid series with and is known.

So far, only a few species of the subgenus have been examined karyotypically, but the results suggest that morphological differences between the species are partly associated with changed chromosome structures. Overall, the chromosomes are very small; in 13 South American species examined, the average size ranges from 1.33 to 2.93 µm. However, they are still twice to five times as large as the chromosomes of the remaining subgenus of the nightshade, only the section Cyphomandropsis has chromosomes that are on average 3 to 14 µm larger. The two species with have larger chromosomes than the other examined species .

Occurrence and locations

The species of the subgenus Leptostemonum are distributed worldwide in the tropics and subtropics , a few species are also found in temperate climates . The largest center of diversity is South America with around 180 species, followed by Australia and Indonesia with around 100 species and Africa with around 80 species. There are also some species in Madagascar , in Central and North America and in southern Asia .

Within the South American diversity center, the subgenus is particularly well represented in Brazil with a total of 110 species represented. Of these, 58 species (i.e. 13% of the total number of species in the subgenus) are endemic there. The south-eastern coastal region of the country is particularly rich in species with 64 species, 20 of which are endemic there.

The species of the subgenus occur in a variety of vegetation types and often show a strong adaptation to moist, dry or particularly hot locations.

Systematics

The internal system of the sub-genus has not yet been sufficiently clarified and is presented in different ways through different works. William D'Arcy divided the section into 22 sections in his 1973 work , Whalen named 33 species groups without taxonomic rank in 1984 and Michael Nee limited the division to ten sections. A phylogenetic examination of the subgenus showed a division into ten clades , some of which correspond to sections or species groups described earlier, six of the 112 species examined could not be classified into one of the ten clades. The Aculeigerum section or the species group around Solanum wendlandii , as well as the Nemorense section (species group Solanum nemorense ), which was assigned to the subgenus Leptostemonum in the classical systematics , are no longer included in the subgenus according to more recent phylogenetic studies, but are placed in its vicinity.







Old world clade


   

Elaeagnifolium clade



   


Micracantha clade


   

Torva clade



   

Carolinense clade




   

Bahamense clade



   


Acanthophora clade


   

Lasiocarpa clade



   

Androceras / Crinitum clade




   

Robustum clade



According to the cladogram

  1. The Robustum clade contains species from the species groups named by whales around Solanum erythrotrichum (for example Solanum accrescens and Solanum robustum ), around Solanum polytrichum (for example Solanum stagnale ) and species that were previously assigned to the Acanthophora section (for example Solanum agrarium and Solanum stenandrum ), as well as the species Solanum microphyllum, which is endemic to the Caribbean islands
  2. The Lasiocarpa clade contains all the species that were united by whales in the Solanum quitoense group, which also includes the Lasiocarpa section . In addition to Solanum quitoense , Solanum candidum , Solanum hyporhodium , Solanum lasiocarpum , Solanum felinum , Solanum pseudolulo , Solanum repandum and Solanum vestissimum belong to this clade.
  3. The Acanthophora clade contains most of the species that Whalen referred to as the Solanum mammosum group, except for the species in the Acanthophora section , which were assigned to the Robustum clade.
  4. The Androceras / Crinitum clade, which is only moderately supported by the test results, contains the species of the Solanum rostratum group (in addition to S. rostratrum, for example, Solanum citrullifolium ), the Solanum crinitum group (besides S. crinitum, for example Solanum lycocarpum ) and the previously unordered Mexican Species Solanum mitlense .
  5. The torva clade contains all of the species studied that were designated by whales as the Solanum torvum group.
  6. The Carolinense clade is formed by the species Solanum carolinense , Solanum comptum and Solanum conditum , the latter two species were assigned to the Solanum multispinum clade by whales, while S. carolinense remained unorganized .
  7. Solanum bahamense and Solanum drymophilum form the Bahamense clade and were also jointly assigned to the S. bahamense groupby whales.
  8. The Micracantha clade contains the species Solanum jamaicense , Solanum aturense and Solanum adhaerens , the latter two of which were classified by whales in the Solanum lanceifolium group and the former was not assigned.
  9. The Elaeagnifolium clade contains Solanum elaeagnifolium , Solanum hindsianum, and Solanum tridynamum , all of which were assigned to the Solanum vespertilio group by whales .
  10. The Old World clade contains all species of the subgenus that are believed to have originated in the Old World, with the exception of some species of the Lasiocarpa and Acanthophora clade, which were probably introduced into areas of the South Pacific and Africa relatively recently . This clade includes various species cultivated as aubergines, for example Solanum melongena , Solanum macrocarpon and Solanum aethiopicum , but also the sodom apple ( Solanum linnaeanum ) and related species such as Solanum incanum .

The species Solanum campechiense , Solanum sisymbriifolium , Solanum polygamum , Solanum hieronymi , Solanum multispinum and Solanum crotonoides could not be classified in one of the ten clades. A list of other species can be found in the nightshade system .

Botanical history

A division of the genus of nightshade ( Solanum ) into species with and without spines has existed at least since the description of the genus by Carl von Linné in his work Species Plantarum of 1753. Since then, the rank and extent of the group of prickly nightshades has changed again and again . In 1852, Michel Félix Dunal presented a morphologically based classification of the nightshade genus and first described the Leptostemonum as a taxonomic group with the status of a section . He further subdivided these into three subsections with the names Euleptostemonum , Torvaria and Asterotrichotum . The name he chose is derived from the Greek leptos for thin and stemos for standing vertically and refers to the vertically standing spines. With the revision of the genus by Georg Bitter in 1919, which is based on similar morphological features as the classification of Dunals, the rank of a subgenus was assigned to the Leptostemonum . However, the works of Bitter, who died in 1927, had never reached completeness, so that his subdivision of the genre was never complete. The work of Almut Seithe, who in 1962 presented another system divided into only two sub-genres, was largely based on the work of Bitter. In contrast to previous work, hair was chosen as a fundamental distinguishing feature in their system. The taxon Leptostemonum does not appear in this system, most of the species from Dunal's section Leptostemonum are placed in Seithe's subgenus Stellatipilum . Even in the revision of the genus by Siegfried Danert from 1970, Leptostemonum does not appear, he built on the Seithes system, but expanded it with the help of features such as the branching scheme of the stem axis. It was not until William D'Arcy in 1973 and the other revisions of the genus mentioned under "Systematics" that Leptostemonum was again listed as a taxon within the nightshade.

Importance to humans

food

Eggplant fruit ( Solanum melongena )

Some of the species in the subgenus Leptostemonum are used as food by humans. These include above all some species from the Melongena section , above all the aubergine ( Solanum melongena ), but also Solanum macrocarpon and Solanum aethiopicum . The world production of aubergines in 2006 was 31.9 million tons.

Other species are also used as food on a smaller scale. The lulo ( Solanum quitoense ) comes from the Andes and its fruits, like those of some related species (for example Solanum pectinatum or Solanum vestissimum ), are eaten as fruit. The fruits of the species Solanum sessiliflorum , which also belongs to this group, are also used as fruit, but there have been reports of other, more unusual uses: the seeds, which are ground to powder, are said to be used by the Taiwanese Indians to soothe irritation in the mouth caused by chewing coca .

In Australia , some species of the subgenus that grow in arid areas are used by the Aborigines . The most widespread is the use of Solanum centrale , the fruits of which are harvested after they have dried on the plant and resemble raisins . The fruits are then made into a paste with water, which is either eaten immediately or dried in large round plates. The fruits of the species Solanum chippendalei, which is also widespread in Australia, are skewered on a stick and dried, the bitter placenta and black seeds are removed before eating and the remaining fruit is also made into a paste. Various possible uses are documented for around 20 other species, some of the fruits are eaten without further processing, some after several processing steps.

weed

Cleared Solanum viarum plants are collected in a hole in the ground to be burned.

Due to the high adaptability to different locations and the protection against predators through the spiked reinforcement, some species of the subgenus are considered invasive weeds . Solanum viarum , a species native to South America , was first documented in Florida in 1988 and has since spread across the southeastern United States . The threat posed by the plant consists in competition with other plant species and the restriction of forage plants to pasture areas, the poisoning of livestock by the solasodine contained in the plant and the spread of various bacteria that use the plant as a host. Bacteria such as Ralstonia solanacearum are also used as a countermeasure against the infestation, as well as manual removal and chemical control with herbicides .

The originally native to America Art Solanum elaeagnifolium has from the early 1970s outside their original distribution space in the more northern areas of the US, but also in Australia , Egypt , Greece , India , Israel , Zimbabwe , Sicily , South Africa , Morocco and Spain spread . Solanum rostratum , actually native to Mexico and the USA , has also been found in Russia and Australia for some time . These species as well as Solanum sisymbriifolium and Solanum carolinense are also considered to be invasive weeds.

Ornamental plants

Solanum atropurpureum in the Jena Botanical Garden .

The species of the subgenus Leptostemonum are only of limited importance as ornamental plants . There are ornamental forms of the aubergine ( Solanum melongena ), which are offered as an egg tree. Solanum mammosum , which is known as the cow udder plant because of its peculiarly shaped fruits , is also offered less frequently.

Because of its impressive spines, the often bright purple shoots and the relatively simple care, the species Solanum atropurpureum has long been shown in European botanical gardens.

Danger

To a large extent, there is no information available on the endangerment of the species of the subgenus Leptostemonum . The assigned the subgenus kind Solanum drymophilum ( Puerto Rico ) is in the Red List of Threatened Species of IUCN as " critically endangered (CR) classified", the kind Solanum asteropilodes ( Ecuador ) counts as " vulnerable (VU) ".

Some Australian species are protected by the Queensland Nature Conservation Act of 1992. The list of species from 2000 lists Solanum papaverifolium as " endangered ", Solanum carduiforme and Solanum dunalianum as " vulnerable ", and Solanum dimorphispinum , Solanum hamulosum , Solanum multiglochidiatum and Solanum sporadotrichum as " rare ". For these and other Australian species, the aim is to be included in the IUCN Red List. For example, for Solanum angustum , Solanum graniticum, classification as " endangered " and for Solanum lythrocarpum , Solanum dumicola , Solanum dryanderense , Solanum francisii and Solanum eminens as " vulnerable " are recommended.

swell

  1. ↑ a b c d e f g Armando T. Hunziker: The Genera of Solanaceae . ARG Gantner Verlag KG, Ruggell, Liechtenstein 2001. ISBN 3-904144-77-4 .
  2. ↑ PBI Solanum: Solanum tenuissimum , online, accessed September 29, 2007.
  3. ^ A b c F. Chiarini and G. Bernardello: Karyotype Studies in South American Species of Solanum subgen. Leptostemonum (Solanaceae) In: Plant Biology , Volume 8, 2006. Pages 483-493.
  4. ^ A b Maria de Fatima Agra: Diversity and Distribution of Solanum subg. Leptostemonum in Brazil In: DM Spooner et al. (Ed.): Solanaceae VI: Genomics Meets Biodiversity , ISHS Acta Horticulturae 745, June 2007. ISBN 978-9066054271 . Pages 31-42.
  5. ↑ a b c Rachel Levin, Nicole Myers, Lynn Bohs: Phylogenetic Relationship among the “Spiny Solanums ” (Solanum subgenus Leptostemonum, Solanaceae). In: American Journal of Botany , Volume 93, Number 1, 2006. Pages 157-169.
  6. ↑ Lynn Bohs: Major Clades in Solanum based on ndhF Sequence Data. In: Solanaceae: William G. D'Arcy Memorial V. Hollowell et al. (Editors). Monographs in Systematic Botany from the Missouri Botanical Garden. 2005. Pages 27-49.
  7. ↑ Almut Seithe: Hair types as taxonomic characters in Solanum. In: The biology and taxonomy of the Solanaceae . Academic Press, London, 1979. Pages 307-319.
  8. ^ Siegfried Danert: Infrageerische Taxa der Genus Solanum L. In: Genetic Resources and Crop Evolution . Volume 18, Number 1, December 1970. Pages 253-297. doi : 10.1007 / BF02095597
  9. ↑ Source: faostat , accessed on September 24, 2007
  10. ^ Office of International Affairs (ed.): Lost Crops of the Incas: Little-Known Plants of the Andes with Promise for Worldwide Cultivation , National Academy Press, 1989. Pages 267-275.
  11. ↑ PBI Solanum: Solanum sessiliflorum , Online, accessed September 29, 2007.
  12. ↑ Nicolas Peterson: Aboriginal uses of Australian Solanaceae. In: The biology and taxonomy of the Solanaceae . Academic Press, London, 1979. Pages 171-189.
  13. ↑ Invasive.org: Tropical Soda Apple , online, accessed September 25, 2007.
  14. ↑ USDA Forest Service: Weed of the Week - Tropical Soda Apple, Solanum viarum (PDF; 227 kB) , WOW 03-08-05.
  15. ↑ Solanum elaegnifolium ( Memento of the original from September 23, 2006 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. at the Washington State Noxious Weed Control Board.  @1@ 2Template: Webachiv / IABot / www.nwcb.wa.gov
  16. ↑ PBI Solanum: Solanum rostratum , online, accessed September 30, 2007.
  17. ↑ PBI Solanum: Solanum atropurpureum , Online, accessed September 29, 2007.
  18. ^ World Conservation Monitoring Center 1998. Solanum drymophilum . In: 2007 IUCN Red List of Threatened Species . IUCN 2007, accessed September 24, 2007.
  19. ^ World Conservation Monitoring Center 1998. Solanum asteropilodes . In: 2007 IUCN Red List of Threatened Species . IUCN 2007, accessed September 24, 2007.
  20. ↑ Queensland Subordinate Legislation: Nature Conservation and other Legislation Amendment Regulation (No. 1) 2000 (PDF; 122 kB) , addition to the Queensland Nature Conservation Act , 1992.
  21. ^ PBI Solanum: Solanum angustum , Online, accessed September 26, 2007.
  22. ↑ PBI Solanum: Solanum graniticum , online, accessed September 30, 2007.
  23. ^ PBI Solanum: Solanum lythrocarpum , Online, accessed September 30, 2007.
  24. ↑ PBI Solanum: Solanum dumicola , Online, accessed September 30, 2007.
  25. ↑ PBI Solanum: Solanum dryanderense , online, accessed September 30, 2007.
  26. ↑ PBI Solanum: Solanum francisii , online, accessed September 30, 2007.
  27. ^ PBI Solanum: Solanum eminens , Online, accessed September 30, 2007.

Web links

Commons : Solanum subg. Leptostemonum  - album with pictures, videos and audio files
This version was added to the list of articles worth reading on October 28, 2007 .