Uncarina

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Uncarina
Uncarina grandidieri in the Botanical Garden of Lyon

Uncarina grandidieri in the Botanical Garden of Lyon

Systematics
Nuclear eudicotyledons
Asterids
Euasterids I
Order : Mint family (Lamiales)
Family : Sesame family (Pedaliaceae)
Genre : Uncarina
Scientific name
Uncarina
( Baill. ) Stapf

Uncarina is a genus of plants from the sesame family (Pedaliaceae). The genus name is derived from the Latin uncus for hook and refers to the structure of the fruit.

The genus Uncarina should not be confused with the genus Uncaria Schreber from the red family .

description

Vegetative characteristics

The species occurring in the genus grow as deciduous , smaller trees with only little branched crowns or as hardly branched shrubs . As young plants, no side shoots are usually formed for a long time. The plants reach heights of about 5 to 6 meters, sometimes even higher, and form an underground, turnip-shaped tuber. The trunk and main shoots are smooth and made of soft wood. They are moderately to significantly thickened, especially towards the base and reach a diameter of up to 30 centimeters. The long-stalked and alternately arranged leaves are very variable in shape and size and reach a width of 25 by 25 centimeters. The entire-edged leaves are triangular to pentagonal, deeply lobed and almost fingered to distantly pointed. At the tips of the lobes, yellow water glands ( hydathodes ) are formed, which are occasionally very noticeable. The first leaves at the beginning of the growing season are often much smaller and not so deeply divided. The hair on the leaves is very different. Multicellular, single-row, simple hair and mucous glands with short, almost sedentary or long stems are formed. The four-cell glandular head is often somewhat square or, more rarely, somewhat star-shaped. Furthermore, hair with a very small, one- or four-cell and more or less round head can also be formed.

Flowers of Uncarina grandidieri
White flowers of Uncarina leptocarpa with an atypical hairless corolla tube in the Frankfurt Palm Garden

Inflorescences and flowers

The complex inflorescence is made up of compressed cymes and consists of two to nine individual flowers. Partial inflorescences are seldom reduced to just a single flower and have very small, awl-like bracts . The inflorescences arise slightly above the first axils of the bracts from the current growing season. Occasionally, partial inflorescences with dense clusters of simultaneously open flowers are formed. The flower stalks are often hairy and light green to purple in color.

The relatively large, hermaphrodite flowers have no nectar glands . The flowers are five-fold with a double flower envelope . The five sepals are only fused at their base and the five sepals are linear-lanceolate. The petals are white, purple-pink or yellow in color and have a dark purple, yellowish or white color and sometimes streaky sap marks in the throat. The five petals are fused to a slightly zygomorphic crown. The usually straight, but sometimes also curved, especially with pendulous flowers, corolla tube is relatively long and often hairy. The cylindrical to somewhat funnel-shaped tube is narrowed in the lower part and slightly sagged at the base. The hem is spread out at right angles to the tube. The full-margined corolla lobes are very similar, the lower one is somewhat enlarged. There are four inserted near the base of the corolla tube, fertile stamens do not protrude beyond the corolla tube. A fifth stamen is formed as a short staminodium . The upper ovary forms two compartments with missing or sometimes almost complete partitions. There are five to six ovules per compartment . The long stylus , which does not protrude beyond the corolla tube, ends in a two-lobed scar. There is a nectar discus .

Fruits and seeds

Fruit of Uncarina grandidieri

The stalked capsule fruit is woody and opens later. It is laterally flattened and has an elongated, elliptical to egg-shaped outline in the side view. A distinct beak is often formed at the tip of the fruit, and two different types of spines are formed on the shell. One type is long and flexible and has three to five barbs on each tip. They are in eight longitudinal rows and there are four to nine pieces in each row. At the base, these spines are now and then somewhat widened in the longitudinal direction and sometimes fused to form a conspicuous crest. The other type of spine is not hooked and mostly small and pointed, occasionally only formed as small humps. They are more irregular in longitudinal rows. Sometimes the Velcro fruit has two additional longitudinal wings that protrude from it at right angles. The large and flattened seeds are elongated to triangular in shape. Smaller, more or less wide wings are attached in the middle of the seed coat (winged seeds). The hooked fruits are similar to those of the Harpagophytum species, other sesame plants.

ecology

The anthers do not open to release pollen , the pollen has a pasty consistency, only when the anthers are eaten by a pollinator seeps, the pollen mass oozes out. The pollinators are pollen-eating beetles .

The trampling burdock used to be spread by the extinct elephant birds or by archaeolemurs , today by various hoofed and farm animals.

Systematics and distribution

The genus Uncarina is endemic to the north, west, central south and south in dry, arid bush and forest in Madagascar .

The genus Uncarina was established in 1895 by Otto Stapf . He combined the species Harpagophytum grandidieri , which had already been described by Henri Ernest Baillon in 1887, into the genus newly created by him. The type species is Uncarina grandidieri (Baill.) Stapf .

The following species belong to the genus:

literature

  • H.-D. Ihlenfeldt: Uncarina . In: Urs Eggli (Hrsg.): Succulent lexicon . tape 2 : Dicotyledonous plants (dicotyledons) . Ulmer, Stuttgart 2002, ISBN 3-8001-3915-4 , p. 380 .

Web links

Commons : Uncarina  - collection of images, videos and audio files

Individual evidence

  1. ↑ a b K. Kubitzki, Joachim W. Kadereit: The Families and Generas of Vascular Plants. Vol. VII: Flowering Plants-Dicotyledons: Lamiales , p. 318.
  2. ^ C. Hanson: Pollination of Uncarina. In: Cactus and Succulent Journal. Vol. 69 (6), 1997, p. 305.
  3. ↑ a b Julian P. Hume: Extinct Birds. Second Edition, Helm, 2017, ISBN 978-1-4729-3744-5 , p. 28.
  4. ^ A b Steven M. Goodman, William L. Jungers: Extinct Madagascar. Univ. of Chicago Press, 2014, ISBN 978-0-226-14397-2 , p. 62.
  5. ↑ Engler , Prantl : The natural plant families. 4th part, 3rd section b, Engelmann, 1895, p. 261 ( online )
  6. ^ Bulletin mensuel de la Société linnéenne de Paris. 82, 1887, p. 669 ( online )
  7. ↑ Hans-Dieter Ihlenfeldt: Uncarina ankaranensis (Pedaliaceae), a new species from northwest Madagascar . In: Cacti and other succulents . 55th year (2004), issue 6, p. 148 f.
  8. ↑ In: Schumannia 4: Succulent research in Africa. Succulent Plant Research in Africa p. 83, 2004