Trifolium polymorphum
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Trifolium polymorphum |
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Trifolium polymorphum is a species of the genus clover ( Trifolium ). It is assigned to the Lotoidea section , where it is the only type of the monotypical subsection Oxalioidea .
description
Trifolium polymorphum is a perennial , herbaceous plant . The stem axis is isolated or densely hairy and prostrate. It forms stolons that branch out at the internodes .
The leaves sit on long, slender stems that are several times longer than the pinna. The leaves are dreifedrig, the individual pinna between 0.5 and 1.8 inches long and 0.5 to 1.5 inches wide. The blades are heart-shaped with a deeply notched tip. The venature emerges clearly. The leaf margin is whole or irregular, very finely serrated. The stipules are ovate to lanceolate, tapering to a point and paper-like.
The inflorescences are stalked and spherical. They measure 1 to 2.5 centimeters in diameter. 1 to 8 individual flowers together can also grow directly from leaf axils on the stolons. The single flowers have a slender stalk. The calyx is between 3 and 5 millimeters long and hairy. The calyx teeth are just as long or up to 50% longer than the calyx tube. They are narrow, triangular, or sickle-shaped. The crown is 0.8 to 1.5 inches long and pink in color. The flag is longer than the shuttle and the wing. Flowers directly on the axilla (on the stolons) often do not open at all, here the flag includes the boat and wings.
The legumes are about three times longer than the calyx and almost spherical. Each pod bears two or three seeds . The seeds are between 1.1 and 1.5 millimeters in size and brown in color.
The number of chromosomes is 2n = 16. Some lines are also polyploid with 2n = 32 chromosomes.
distribution
Trifolium polymorphum is native to the open prairie, especially on sandy soil. The distribution area includes Chile , parts of Argentina , Peru , Uruguay , Paraguay and parts of Brazil as well as East Texas and West Louisiana in the United States .
ecology
Trifolium polymorphum is cross- pollinating , but the flowers on the stolons are self-pollinating .
The mechanism of propagation is unique for clover. The species forms two different fruits. The upper inflorescences produce light fruits that are carried away by the wind, while the lower inflorescences curve downward and deposit the seeds on the ground. This combination of topochory and telechory is called amphicarpy .
Systematics
Trifolium polymorphum is a very variable species. The individuals from South America are usually hairier than those from North America. There are also significant differences in the size of the leaves and flowers. Even so, no safe subspecies have been described.
literature
- Michael Zohary, David Heller: The Genus Trifolium . The Israel Academy of Sciences and Humanities , Jerusalem 1984, ISBN 978-965-208-056-1 , pp. 208 .
- John M. Gillett, Norman L. Taylor, M. Gillett: The World of Clovers . Iowa State University Press , Ames 2001, ISBN 978-0-8138-2986-9 , pp. 319 f .