Setchellanthus caeruleus
| Setchellanthus caeruleus | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name of the family | ||||||||||||
| Setchellanthaceae | ||||||||||||
| Polecat | ||||||||||||
| Scientific name of the genus | ||||||||||||
| Setchellanthus | ||||||||||||
| Brandegee | ||||||||||||
| Scientific name of the species | ||||||||||||
| Setchellanthus caeruleus | ||||||||||||
| Brandegee |
Setchellanthus caeruleus is the only species of the genus Setchellanthus , which in turn forms the monogeneric plant family of the Setchellanthaceae . This is assigned to the order of the cruciferous (Brassicales).
description
Setchellanthus caeruleus forms 0.3 to 1.2 m high shrubs . The vegetative habitus is not characterized by any special features. The small leaves have no stipules and are arc annoying. The plant has unicellular T-shaped hairs on a broad epidermal base . There are no myrosin producing cells.
The large axillary flowers are blue and give off a pungent odor. The flower is sixfold (hexameric), in rare cases five or sevenfold and has a double flower envelope . The sepals are fused and the calyx is unevenly split, which can be seen as a typical feature of the Setchellanthus flower. The petals are nailed, so they taper towards the base of the petals. The androeceum is numerous and centrifugally arranged in five to seven groups on a straight axis. The pollen is tricolated and therefore has three openings. The gynoeceum consists of three intergrown carpels . There is a briefly trained gynophore. On the short stylus , the scars are almost head-shaped. Setchellanthus has an axial placentation with 10-14 ovules per carpel in two rows.
A capsule with seven columns is formed as the fruit . The number of seeds can vary considerably. In the literature, figures from one to fifty seeds per fruit are given. Setchellanthus caeruleus fruits are elongated, the length specifications range from 1–5 cm to 5.1–10 cm in length. They are relatively resilient, with a simple, short-haired surface.
The seed length varies between 5 and 25 mm. An aril is missing from the brown-colored seeds . The seed coat is soft, uneven and wrinkled. An endosperm is present, but sometimes only poorly developed (single-celled endosperm). The embryo is usually fully developed. The number of chromosomes is unknown.
distribution
Setchellanthus caeruleus occurs only in two places in central Mexico , including in the province of Oaxaca .
Systematics
The family was first described at the beginning of the 20th century by the American botanist Townshend Stith Brandegee . In 1909 he also described the genus Setchellanthus and the only species Setchellanthus caeruleus . The family and species were systematically re-recorded through polecat .
Setchellanthus caeruleus was previously assigned to the caper family (Capparaceae). According to current phylogenetic studies (especially Karol et al. 1999), the species was removed from there and transferred to its own monogeneric family, the Setchellanthaceae. This shows great similarities to the Limnanthaceae .
Individual evidence
- ↑ USDA website ( Memento of the original from May 6, 2009 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.
- ^ Germplasm Resources Information Network (GRIN)
- ^ First described in: University of California Publications in Botany 3: 378. 1909.
- ↑ Description in: Taxon 48: 260. May 17, 1999.
literature
Much of the information in this article has been obtained from the following sources:
- Description of the Setchellanthaceae on the APG website. Query: July 19, 2007
Further literature:
- HH Polecat : Setchellanthaceae (Capparales), a new family for a relictual, glucosinulate-producing endemic of the Mexican deserts . In: Taxon . tape 48 , 1999, pp. 257-275 .
- KG Karol et al .: Nucleotide sequence of rbcL and phylogenetic relationships of Setchellanthus caeruleus (Setchellanthaceae) . In: Taxon . tape 48 , 1999, pp. 303-315 .
- H. Tobe, S. Carlquist, HH Iltis: Reproductive anatomy and relationships of Setchellanthus caeruleus (Setchellanthaceae) . In: Taxon . tape 48 , 1999, pp. 277-283 .
- AS Tomb: Pollen morphology and relationships of Setchellanthus caeruleus (Setchellanthaceae) . In: Taxon . tape 48 , 1999, pp. 285-288 .
Web links
- Agricultural Research Service - USDA, entry Setchellanthaceae