Trailliaedoxa gracilis

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Trailliaedoxa gracilis
Systematics
Order : Enzianartige (Gentianales)
Family : Red family (Rubiaceae)
Subfamily : Ixoroideae
Tribe : Trailliaedoxeae
Genre : Trailliaedoxa
Type : Trailliaedoxa gracilis
Scientific name of the  tribe
Trailliaedoxeae
Kainul. & B.Bremer
Scientific name of the  genus
Trailliaedoxa
WWSm. & G.Forrest
Scientific name of the  species
Trailliaedoxa gracilis
WWSm. & G.Forrest

Trailliaedoxa gracilis is the only species of the only genus Trailliaedoxa of the tribe Trailliaedoxeae within the plant family of the red family (Rubiaceae). It occurs only in southwest China .

description

Appearance and leaf

Trailliaedoxa gracilis grows as a mostly deciduous subshrub and reaches heights of usually 20 to 45, rarely up to 60 centimeters. The many, independently upright branches are mostly unreinforced or they can be a little prickly. The somewhat angular or stem-round twigs have an initially tightly curled to finely haired, later balding bark .

At the base of the branches there are usually a pair of reduced, early-falling leaves and a durable stipple. The foliage leaves, which are distributed opposite to one another on the branches or sometimes close together on the compressed stem axes and then appear to be arranged in a whorl , are almost sessile. They do not have domatia . With a length of 5 to 10 millimeters and a width of 3 to 4 millimeters, the simple leaf blades are obovate, elliptical or obverse-lanceolate with a pointed or very short and abruptly truncated blade base and a rounded or blunt upper end. The upper side of the leaf is hairless or sparsely finely haired. The lighter underside of the leaves is hairless or shaggy to curly or stiffly haired, at least along the midrib. The lateral nerves are only indistinctly visible. The two 0.6 to 1 millimeter long, finely hairy and balding stipules can be fused with the petiole and are bilobed, each with a gland on the upper end.

Inflorescence and flower

On the twigs, terminal or paired short shoots appear to be lateral, often nodding, compressed, zymose , umbellate or bundled inflorescences . The inflorescences are 5 to 10 millimeters long and 8 to 10 millimeters in diameter and contain a few to a few (six to twelve) flowers. There can be up to 5 millimeters of inflorescence stems. The inflorescence axes are hairy finely to shaggy. The bracts are usually reduced or sometimes similar to foliage. The flower stalks are 1 to 2 millimeters long.

The hermaphrodite flowers are apparently zygomorphic and five-fold with a double flower envelope . The five sepals are only fused at their base and the balding calyx teeth are 0.8 to 1.5 mm in length, narrow-elliptical or inverted-lanceolate to linear with a pointed upper end. The petals are white, whitish to light yellow or pink. The five petals have a length of 1.8 to 2.5 millimeters and are fused together in a funnel-shaped manner and on the outside sparsely shaggy hairy to balding. The corolla lobes are convolute overlapping in the flower bud and with a length of 1 to 1.5 millimeters elliptical-spatula-shaped with a blunt to rounded upper end. The five stamens rise above the crown. The short stamens are inserted at the throat of the crown. The disc is thick or thickened. The two-chamber ovary contains only one hanging in each chamber ovule . The curved stylus ends with a club-shaped to ellipsoidal scar, which is bilobed on a third to half and protrudes over the crown.

Fruit and seeds

The dry, densely shaggy hairy fissure fruit is 1.5 × 1 millimeter in size and inverted-lanceolate and there are durable sepals. The split fruit breaks down into two ellipsoidal partial fruits that remain closed and each contain a seed. The ellipsoidal seed is medium in size and has a leathery seed coat (testa). There is no endosperm . The embryo is linear-inverted-lanceolate.

Phenology

In China, the flowering period extends from July to August. The fruits ripen in August.

Occurrence

Trailliaedoxa gracilis occurs only in the southwestern Chinese provinces of Sichuan and Yunnan . It thrives on rocks or in thickets on mountain slopes in dry and warm valleys at altitudes of 1400 to 3000 meters.

Systematics

The genus Trailliaedoxa was established in 1917 with the first description of Trailliaedoxa gracilis by William Wright Smith & George Forrest in Notes from the Royal Botanic Garden, Edinburgh , Volume 10, Issue 46, pp. 75-76. The genus name Trailliaedoxa honors the daughter of the British botanist Georg William Triall and wife of George Forrest, who collected the type material with the collection number G. Forrest 10535 in 1913 in Yunnan. The tribe Trailliaedoxeae was described in Kent Kainulainen, Sylvain G. Razafimandimbison & Birgitta Bremer: Phylogenetic relationships and new tribal delimitations in subfamily Ixoroideae (Rubiaceae) , In: Botanical Journal of the Linnean Society , Volume 173, Issue 3, 2013, p. 387– 406 set up.

Trailliaedoxa gracilis is the only way the only genus Trailliaedoxa the tribe Trailliaedoxeae in the subfamily Ixoroideae within the family of the Rubiaceae (Rubiaceae). In which tribe this genus belongs has been controversial since the first description. Molecular genetic studies show that the genus Trailliaedoxa must be in its own tribe and no longer in the tribe Vanguerieae as it was until 2013.

swell

Individual evidence

  1. ↑ a b c d e f Tao Chen, Charlotte M. Taylor: Trailliaedoxa , p. 387 - genus and species - the same text online as the printed work , In: Flora of China Editorial Committee: Wu Zheng-yi, Peter H. Raven & Deyuan Hong (Ed.): Flora of China , Volume 19 - Cucurbitaceae through Valerianaceae, with Annonaceae and Berberidaceae . Science Press and Missouri Botanical Garden Press, Beijing and St. Louis, February 28, 2011, ISBN 978-1-935641-04-9 .
  2. ↑ a b First publication scanned at biodiversitylibrary.org .
  3. ↑ Trailliaedoxa at Tropicos.org. Missouri Botanical Garden, St. Louis, accessed December 28, 2013.
  4. ↑ Umberto Quattrocchi: CRC World Dictionary of Plant Names: Common Names, Scientific Names, Eponyms. Synonyms, and Etymology , CRC Press, 1999, p. 2699 ( limited preview in Google Book Search).
  5. ↑ a b Rafaël Govaerts (Ed.): Trailliaedoxa. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved October 20, 2017.
  6. ↑ Trailliaedoxa in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved December 28, 2013.
  7. ↑ a b Kent Kainulainen, Sylvain G. Razafimandimbison, Birgitta Bremer: Phylogenetic relationships and new tribal delimitations in subfamily Ixoroideae (Rubiaceae). In: Botanical Journal of the Linnean Society . Volume 173, Issue 3, 2013, pp. 387-406, doi : 10.1111 / boj.12038 .

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