Grabowskia
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Grabowskia obtusa in the Argentine national park Talampaya |
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| Grabowskia | ||||||||||||
| Schltdl. |
Grabowskia is a plant genus of the family of the nightshade family (Solanaceae). The four species belonging to the genus are common in America . The generic epithet honors the German botanist and pharmacist Heinrich Emanuel Grabowski (1792–1842).
description
Vegetative characteristics
Grabowskia species are usually 1.5 to 2.5 m high shrubs , occasionally they are only up to 0.5 m high. Small trees with a height of up to 5 m and a trunk base diameter of up to 40 cm are rare . They grow upright and branched, the stems are armed with thorns . Young twigs are smooth and somewhat shiny, dark mahogany to blackish in color. They crack with age.
The leaf blades are thick, their shape ranges from inverted ovate or inverted ovoid to elliptical to broadly elliptical. At the tip they can be rounded or blunt, the base is pointed and descending on the petiole. The leaves are hairless or hairy only with glandular trichomes with a short stem and a multicellular head and later balding. They can be bluish or greenish-bluish in color and are usually 15 to 28 (rarely 8 to 40) mm long and 20 to 25 (rarely 14 to 35) mm wide. The exception is Grabowskia megalosperma with very narrow leaves.
Inflorescences and flowers
The flowers can be fragrant or unscented. They stand individually or in zymotic groups of two to twelve pieces. The flower stalks are 5 to 8 mm long and thus about as long as the calyx . This is cup-shaped, radially symmetrical, five-lobed or five-lobed and always shorter than the corolla tube. The crown is slightly zygomorphic , 8 to 12 (rarely up to 15) mm long. It is white-yellowish or greenish, or white-purple or purple in color. The veins are usually green, brown or dark purple in color. The corolla tube is conical or almost cylindrical and 1.5 to 2.5 times longer than the calyx lobes. These are wider than long, eyelet, bent back or provided with a bent edge.
The stamens and pistils protrude beyond the bracts . The stamens are of the same shape and set about the lower third of the corolla tube or something above or below it. The stamens are longer than the anthers and hairy on the lower half. The anthers attached to the back (dorsally) are 2.1 to 3.1 (rarely 1.9 to 3.5) mm long, the counters are almost completely free from each other on the lower half. The pollen grains are trizonocolporate and medium-sized with a size of about 25.3 µm. The ovary has two compartments , each carpel is single-chambered at the base and two-chambered in the upper 2/3 by a transverse partition. Each of the resulting chambers contains two ovules , the upper ones being larger than the lower ones. The scar is disc-shaped, indented and is located on a slightly inverted friem-shaped stylus .
Fruits and seeds
The fruits are inverted egg-shaped or almost spherical and yellow, orange-yellow or bluish black in color. They are partially surrounded by the non-enlarging calyx. They contain two elongated cores with a rounded tip and a three-toothed base. Each kernel contains a single upright seed , only occasionally two seeds are formed, then the upper one is significantly larger than the lower one.
distribution
The species occur in a disjoint area in America, with Grabowskia boerhaviifolia having the greatest distribution: It occurs in Mexico, the Galapagos Islands , Peru , Chile , Bolivia and western Argentina . The other species occur in Argentina and neighboring countries.
Systematics
Internal system
Four or more species are distinguished within the genus:
- Grabowskia ameghinoi Speg.
- Grabowskia boerhaviifolia (Lf) Schltdl.
- Grabowskia duplicata Arnott
- Grabowskia geniculata Fernald
- Grabowskia glauca I. M. Johnst.
- Grabowskia megalosperma Speg.
- Grabowskia obtusa Arnott
- Grabowskia schizocalyx Dammer
- Grabowskia sodiroi bitter
- Grabowskia spegazinii Dusén
Type species is Grabowskia boerhaviifolia .
External system
The genus Grabowskia is classified within the systematics of the nightshade family together with the genera buckthorn ( Lycium ) and Phrodus in the tribe Lycieae. Phylogenetic studies of the tribe showed that the tribe is monophyletic , but that the two genera Phrodus and Grabowskia are placed within the goat thorns. Phrodus is a sister clade to almost all species of the genus Lycium . Exceptions are some species that are characterized by stone bodies in the fruits, mostly white, pendulous, relatively large flowers with calyx tips longer than the calyx tubes and flat, often blue-green leaves. The genus Grabowskia is a sister clade to this latter group of Lycium species.
supporting documents
literature
- Armando T. Hunziker: The Genera of Solanaceae , ARG Gantner Verlag KG, Ruggell, Liechtenstein 2001, ISBN 3-904144-77-4 .
Individual evidence
- ↑ Lotte Burkhardt: Directory of eponymous plant names . Extended Edition. Botanic Garden and Botanical Museum Berlin, Free University Berlin Berlin 2018. [1]
- ^ D. Gledhill: The Name of Plants . Cambridge University Press. 2008: p. 183 ( online )
- ↑ Rachel A. Levin and Jill S. Miller, Relationships within tribe Lycieae (Solanaceae): paraphyly of Lycium and multiple origins of gender dimorphism . In: American Journal of Botany , Volume 92, 2005. Pages 2044-2053.
