Cow udder plant
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Cow udder plant ( Solanum mammosum ) |
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The cow udder plant , teat-shaped nightshade or nipple plant ( Solanum mammosum ) is a species of plant from the subgenus Leptostemonum of the genus of nightshade ( Solanum ). It grows in tropical areas, its original home is in northern South America and possibly also on the Caribbean islands . Because of its unusually shaped fruits, it is occasionally grown as an ornamental plant.
description
Vegetative characteristics
The cow udder plant is a 0.5 to 2 m high shrub , the stem of which branches just above the base and often blooms while it is still herbaceous. The green or purple-tinted stem axis has a diameter of up to 4 cm at the base and a rotating cross-section. The reinforcement of the shoot consists of a few to many, pointed, straight or mostly curved spines , which are usually longer than 5 mm and can be up to 20 mm long. The base of the spines is greatly enlarged and depressed, it can be up to 10 mm long. The spines are covered with fine, stalked-glandular, and simple, but shorter hair than on the shoot. The plants are rarely unarmed. The sympodial units have two leaves , which are usually opposite.
The leaves are simple; when they are opposite one of the two is about twice the size of the other; the larger leaves are 8 to 17 × 9 to 20 cm in size. The leaves are almost round and relatively thin. The base of the leaf is heart-shaped, the tip of the leaf sharply pointed. The leaf margin is lobed from a quarter to half and divides the leaf into mostly two pairs of leaf lobes, the lobes themselves are additionally provided with pointed, triangular lobes or coarse teeth. Both the top and bottom of the leaf and the leaf stalks are covered with straight, protruding spines. The largest spines are on the petioles and the main veins of the leaves, these are 0.5 to 2.5 cm long, the base is up to 0.5 mm wide. There are only very fine spines on the weaker veins. The petioles of the larger leaves are 5 to 12 cm long.
Both the stem and the leaves are covered with trichomes . On the one hand, there are simple, three- to five-cell, translucent trichomes on the stem and leaves, which are 2 to 3.2 mm long on the stem and 1.4 to 1.8 mm long on the leaves. Furthermore, there are glandular trichomes that are about 0.2 mm long on the stem axis and 0.2 to 0.5 mm on the leaves. The hairiness of the leaf stalks resembles that of the stem axis. On the underside of the leaf there are also three- to seven-rayed star-shaped trichomes, the lower rays of which are 0.15 to 0.6 mm long and approximately at a 45 ° angle. The middle ray is elongated, usually three-celled and 1.2 to 2.2 mm long.
Inflorescences and flowers
The sessile inflorescences are outside of the leaf axils ( concealment ), are unbranched and consist of two to ten flowers. The buds are initially light purple, during growth they initially take on a very distinctly cone-like shape that extends from the center to the tip of the bud. The plants are Andromonözisch , since of the flowers of an inflorescence mostly only the lowest one is hermaphroditic, the other flowers are purely male fertile. Only occasionally two, in exceptional cases up to five fruits per inflorescence are formed. The hairiness of the inflorescence axes resembles that of the trunk. The inflorescence axes are unreinforced or covered with a few, small, straight, needle-shaped spines that are shorter than 5 mm. Inflorescence stalks are not formed. The main axis of the inflorescence is up to 2 cm long, the flower stalks are 10 to 20 mm long during the flowering phase, those of the fertile flowers soon bend back.
The flowers have a 5 to 8 mm long calyx , the tube 1 to 1.5 mm and the calyx tips 3 to 5.3 mm long. The calyx is 1 to 2 mm wide at the base, narrowly lanceolate, almost linear in shape. It is covered with two- to five-cell, simple, translucent hair of up to 2.5 mm in length and significantly shorter one- to two-cell hair of around 1.2 to 1.6 mm in length. It is unreinforced or has a few needle-shaped spines less than 5 mm in length. The blue-purple crown has a diameter of 1 to 2 cm and is star-shaped. The petals are relatively thin, the corolla tube is 3 to 4 mm long, the corolla lobes are narrow triangular and have a size of 13 to 15 × 2 to 3 mm. The outside of the crown is protruding finely haired, the trichomes are three- to six-cell, simple, translucent hairs 0.8 to 3.2 mm in length, as well as glandular hairs with one to two-cell heads and a length of up to 0.4 mm .
The stamens have relatively strong stamens with a length of 1 to 1.2 mm. The anthers are 8 to 12.5 mm long, at the base 2 to 2.2 wide. The tips are narrowed and slightly curved. The pollen is released through small pores at the top of the anthers. The ovary is covered with fine, stalked glands that are about 0.05 mm long. In sterile flowers is a rudimentary stylus with a length of about 1.2 to 2.0 mm is formed, fertile pen have a length of 12 mm and 0.5 mm wide. They are about 2.2 mm beyond the anthers. The suddenly widening scar is 0.8 mm wide and 0.4 mm long, head-shaped and slightly bilobed. The literature cited does not provide any information on the type of pollinator.
Fruits and seeds
The flower stalks are extended to 15 to 30 mm when the fruit is ripe, and bend around the axis of the shoot, so that the fruit is almost vertical and almost perched on the shoot. The calyx initially enlarges, so that it has a size of 10 × 4 mm at the base, later shrinks and usually falls off the ripe or aging fruit irregularly.
The fruits are berries with a diameter of 3.5 to 5.5 cm, sometimes they are spherical or indented-spherical, usually the fruit narrows to a cylindrical, pointed "nipple" with a size of up to 2 × 2.5 cm. Including this nipple at the tip, the fruit is then 4 to 8 cm long. This makes the fruit one of the largest fruits within the nightshade genus. Often at the base five (or rarely less, up to only one) cylindrical or egg-shaped appendages with a diameter of up to 2 mm and a length of up to 3 cm are formed. These appendages arise from initially whitish, finger-like appendages that arise from the ovary before flowering and stand between the stamens. However, they are only formed after the stamens and pistil are relatively wide, the first approaches can be seen when the bud is 2.5 to 3.0 mm long. Shortly before flowering, a pin-like structure is formed on the tips of these appendages, which, however, wither and fall off after the actual carpel has been pollinated. The remaining part of the appendages continue to enlarge with the formation of the rest of the fruit, and they bend back more and more, but this can vary greatly. When the fruit is ripe, the "nipples" are bent back between 10 ° and 150 °.
After pollination , the unripe fruits are initially whitish yellow-green, but take on a darker green as they develop. Ripe fruits, including the "nipples", are bright yellow or orange-yellow, with age they become darker and dull orange to brown. Ripe fruits can remain on the plant for a long time under ideal conditions. The exocarp is shiny, tough and hairless, the mesocarp is spongy, white and about 7 mm thick. From the initially two-chambered ovary, a single-chambered berry develops through the dissolution of the upper axial placentation. This creates a cavity about 2.5 cm in diameter in which the seeds are embedded in a slightly greenish pulp . These are 3 to 3.5 × 4 to 4.5 mm in size, 1 mm thick, almost circular, flat, yellowish brown or brown. The surface is fine and almost smooth. After about three months, the fruit begins to dry up, regardless of whether the fruit is still on the plant or not. The seeds are fertile for about six months.
Other specifications
The number of chromosomes in the cow udder plant is what is known within the nightshade genus ( Solanum ) only from the closely related Solanum platense . The fruits of the plant in particular are poisonous. Various steroid alkaloids have been detected in the plant , the most important stereoid alkaloids include solasodine , β- solamargin and solamargin. While the solasodine content made up 0.2 to 1.2% of the dry matter in the investigations of the fruits, no stereoid alkaloids could be found in the leaves. In addition, the sapogenin diosgenin and phytosterols were detected in the fruits .
Distribution and locations
The species is restricted to tropical areas only, it is native to northern South America and possibly to the Caribbean islands . It is often found on the Caribbean islands, in Central America between southern Mexico to Panama and in an arc that extends from northwestern Bolivia around the Amazon basin to Guyana . The species is rarely and sporadically to be found in the Amazon basin and on the east coast of Brazil . In some other areas it is occasionally found as an introduced plant, but quite rarely in Africa, more often in the area of the East Indies .
The cow udder plant grows as part of the ruderal flora on pastureland, at roadsides, rubbish dumps and on cultivated land. The species prefers a warm tropical climate with at least occasional heavy rainfall. It can usually be found between sea level and altitudes of up to 100 m, but it can also grow at altitudes of up to 1800 m. Blossoms and fruits are formed all year round without a trend being discernible.
It is believed that the species spread early on to the American continent through people who recognized the toxicity of the fruit and made use of it. Since the plant grows well in garbage dumps and similar locations, it has been able to spread widely as a crop follower. Whether the evolutionary formation of the “nipples” took place before or after this spread cannot be said with any certainty.
Systematics
The species Solanum mammosum is classified in the subgenus Leptostemonum of the genus nightshade ( Solanum ). In the various systematic classifications of the subgenus, the species is classified relatively similarly by different authors, for example Rachel Levin et al. (2006) classified in the Acanthophora section , which roughly corresponds to the Solanum mammosum group by Michael Whalen (1984). In the cladistic representation of the subgenus by Michael Nee (1991, 1999), the species is classified in the Acanthophora clade. Within this clade, the species is adjacent to Solanum palinacanthum .
use
Due to the conspicuous fruits, cow udder plants are occasionally grown as ornamental plants . Among other things, there was also a selection of plants that are less heavily armed with spines.
Guatemalan men who returned to Esquipulas from traditional pilgrimages each January often wore strands of Tillandsia usneoides with the bright yellow fruits of the cow udder plant woven into them. This tradition can be traced back to an ancient Indian fertility ritual. According to reports from Peru, the plants are cultivated in order to use the poisonous fruits as rat poison . In Venezuela, the fruits are said to have been used against cockroaches and as a poison to catch fish , medical applications have been reported from Honduras (against colds) and from Panama (against maggot infestations).
Individual evidence
- ↑ a b c d e f g h PBI Solanum: Solanum mammosum , online, accessed November 5, 2007.
- ^ A b Robert H. Miller: Morphological Study of Solanum mammosum and its mammiform Fruit. In: Botanical Gazette , Volume 130, Number 4, 1969. Pages 230-237.
- ^ 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.
- ↑ G. Indrayanto et al .: Solanum mammosum L. (Terong Susu): In Vitro Culture and the Production of Steroidal Alkaloids and Other Secondary Metabolities . In: YPS Bajaj (editor): Medicinal and Aromatic Plants X , Springer Verlag, Berlin, Heidelberg, 1998, ISBN 978-3-540-62727-2 . Pages 394-414.
- ↑ a b Michael Nee: Patterns in biogeography in Solanum, section Acanthophora . In: JG Hawkes, RN Lester & AD Skelding (Eds.): The Biology and Taxonomy of the Solanaceae . Academic Press, London, 1979. ISBN 978-0-12-333150-2 . Pages 569-580.
- ^ Paul C. Standley and Steyermark: Tillandsia usenoides. In: Flora of Guatemala , Field Museum of Natural History, Botanical Series, Volume 24, Part I, 1958. Pages 468-469.
- ^ J. Francis Macbride: Solanum mammosum. In: Flora of Peru , Field Museum of Natural History, Botanical Series, Volume XIII, Part VB, Number 1, 1962. Pages 255-256.
