Anthocercis

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Anthocercis
Anthocercis viscosa

Anthocercis viscosa

Systematics
Nuclear eudicotyledons
Asterids
Euasterids I
Order : Nightshade (Solanales)
Family : Nightshade family (Solanaceae)
Genre : Anthocercis
Scientific name
Anthocercis
Labill.

Anthocercis is a genus ofplantsfromthe nightshade family (Solanaceae) endemic to southwest Australia . The flowers are particularly noticeable because of the long, narrow corolla lobes , from which the botanical genus name is derived.

description

Vegetative characteristics

The Anthocercis species are shrubs with a height of up to three meters, but rarely only up to 60 cm high. The plants are hairless or hairy, sometimes tomentose. The trichomes are simple and glandular, branched trichomes are rare. The sometimes thick and leathery leaves are narrowly elliptical to inversely ovate, ovate or linear, more rarely spatulate or elliptical. They are sessile or provided with a petiole of up to 3 mm in length; the leaf blade varies between 2 and 80 mm in length and between 0.5 and 35 mm in width. The leaf margin is entire, finely serrated or finely notched with saw teeth.

Inflorescences and flowers

The fully developed flowers are in zymose , racemose or panicle-shaped inflorescences , only rarely they are individually. The five-part, radially symmetrical calyx is (1.5) 3 to 8 (15) mm long, the individual calyx lobes are slightly longer or shorter than the calyx tube. The petals are differently colored, mainly white to creamy-white or yellow to yellow-green. The inside of the corolla tube has dark purple or green stripes. The five-part crown is completely or almost radially symmetrical and (7) 12 to 20 (40) mm long. The long and narrow corolla lobes can be a little shorter, a little or a lot longer than the corolla tube.

The mostly four stamens are near the base of the corolla tube alternating with the petals and do not protrude beyond the corolla tube. They occur in two different lengths within a flower, or are each almost the same length. Occasionally a fifth sterile stamen called staminodium occurs. The stamens are irregularly lobed, the 1 to 1.5 mm long anthers are inclined to each other or stand free. They consist of two counters that are either free-standing or at least separated in the lower half. They jump up longitudinally with a crack pointing outwards and release groups of pollen or individual pollen grains. The upper gynoeceum consists of two fused carpels. The ovary is twofold. The placentation is central angled. There are (three) 10 to 50 anatropic to hemianatropic ovules per compartment, i.e. the micropyle are bent by up to 180 ° and can almost lie against the funiculus . The stylus has a head-shaped or slightly bilobed scar .

Fruits and seeds

The fruits are septum cleft - capsules cracking open . They are pear-shaped or narrow to broadly ovate, have a length of (3) 5 to 7 (14) mm and contain 4 to 15, in rare cases only one or up to 100 seeds . The capsules consist of either two forked or four pointed chambers. The seeds are (1.4) 1.6 to 2.3 mm long, the long and thin embryo lies almost straight in the endosperm .

Chromosome number

The base chromosome number is , with the majority of species being tetraploid .

Occurrence

The genus is endemic to the temperate areas of southwestern Australia , with the distribution center in western Australia and only a few species in southern Australia. The species are adapted to moderately moist to dry soils.

Systematics

External system

In the systematics of the nightshade family (Solanaceae), the genus Anthocercis is mostly classified in the tribe Anthocercideae of the subfamily Nicotianoideae , especially according to phylogenomic data (comparison of homologous DNA sequences) in the subfamily Anthocercidoideae (after Hunziker ) has been considered. The same seven genera with 31 species are classified into the respective taxa by all of the authors, which are predominantly endemic in Australia, only the species Duboisia myoporides can also be found in New Caledonia .

Both morphological , phytochemical and molecular genetic studies indicate that the tribes are monophyletic. Only the classification of the genus Symonanthus has not been fully clarified, it is partly placed close to the genus Tobacco ( Nicotiana ) ( Nicotiana forms the sister group of the Anthocercideae and together with these forms the subfamily Nicotianoideae). Common morphological features are, for example, the calyx that does not grow any further after flowering, the more or less radial symmetry flowers and the outwardly popping (extrorsen) anthers.

Within the tribe, Anthocercis possibly forms the sister group of the other genera, with the exception of Symonanthus .

Main distribution area of ​​the genus. (The occurrences in South Australia are not shown.)
Anthocercis littorea

Internal system

Ten species are distinguished within the genus:

ingredients

Various tropane alkaloids , which occur in the form of tigloyl esters , have been detected in all species of the genus . Some types contain hyoscyamine or scopolamine and derivatives thereof. The littorin detected in Anthocercis littorea was also found in the roots of Brugmansia sanguinea .

etymology

The name of the genus is derived from the Greek words άνθος anthos "flower, blossom" and κερκίς kerkis "weaver shuttle", originally for a narrow rod to which the weft is attached during weaving, and refers to the narrow corolla tips.

Botanical history

The genus was first described in 1806 by Jacques Labillardière with the species Anthocercis littorea , without assigning it to a family. The first assignment to the nightshade family was made in 1810 by Robert Brown , who also described other species and the genus Duboisia . In 1838 George Don assigned both genera to the tribe Anthocercideae within the nightshade family (Solanaceae). Since the genera Anthocercis and Duboisia develop four stamens in two different lengths, they were assigned to the figwort family (Scrophulariaceae) through two works by George Bentham in 1846 and 1869, and he continued to place the genus Anthotroche among the nightshade family. John Miers proposed a family Atropaceae in 1849, which continued to contain the genus Anthotroche in a tribe Duboiseae in addition to Anthocercis and Duboisia . He saw this family between the nightshade family and the figwort family and stated that it might be subordinate to one of the two families as the subfamily Atropineae. In the systematics of the nightshade family, which was established in 1891 by Richard Wettstein , the genera Anthocercis , Duboisia and Anthotroche are again assigned to the nightshade family, but there the tribe Salpiglossideae. Charles Baehni added the Anthocercis back to the tribe Anthocercideae in 1946, but also assigned four species to the genus, which later turned out to be unrelated. The most extensive taxonomic studies of recent times come from Laurence Haegi , who in 1981 also described the related genera Crenidium and Grammosolen .

Danger

According to the Australian " Environment Protection and Biodiversity Conservation Act " from 1999, the species Anthocercis gracilis is considered "endangered" ( vulnerable ) . In the Red List of Threatened Species of IUCN currently (as of 2016) will be performed no species of the genus.

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  1. ↑ a b c d e f g Armando T. Hunziker: The Genera of Solanaceae. ARG Gantner Verlag KG, Ruggell, Liechtenstein 2001, ISBN 3-904144-77-4 .
  2. ↑ a b c d Anthocercis in: Western Australian Herbarium. FloraBase - The Western Australian Flora. Department of Environment and Conservation, 1998-. Retrieved October 5, 2007.
  3. ↑ RG Olmstead et al .: Phylogeny and Provisional Classification of the Solanaceae Based on Chloroplast DNA (PDF file; 128 kB). In: M. Nee, DE Symon, JP Jessup and JG Hawkes (Eds.): Solanaceae IV, Advances in Biology and Utilization. Royal Botanic Gardens, Kew. 1999. pp. 111-137.
  4. ^ A b c Richard G. Olmstead, Lynn Bohs, Hala Abdel Migid, Eugenio Santiago-Valentin, Vicente F. Garcia, Sarah M. Collier (2008): A molecular phylogeny of the Solanaceae. Taxon 57 (4): 1159-1181. doi: 10.1002 / tax.574010
  5. ^ William D'Arcy: The classification of the Solanaceae. In: The biology and taxonomy of the Solanaceae. Academic Press, London 1979, pp. 3-47.
  6. ↑ a b Vicente F. Garcia and Richard G. Olmstead: Phylogenetics of Tribe Anthocercideae (Solanaceae) Based on ndhF and trnL / F Sequence Data (PDF file; 255 kB). In: Systematic Botany. Volume 28, Number 3, 2003. pp. 609-615.
  7. ^ A b Laurence Haegi: Australian Genera of the Solanaceae . In: The biology and taxonomy of the Solanaceae . Academic Press, London 1979, pp. 121-124.
  8. ^ John Miers: Observations upon several genera hitherto placed in Solanaceae and upon others intermediate between that family and the Scrophulariaceae. In: The Annals and Magazin of Natural History . Second Series, Volume III, Number 15, 1849. pp. 161-182.
  9. ↑ EPBC Act List of Threatened Flora . Department of the Environment and Water Resources. Online, accessed October 5, 2007.

Web links

Commons : Anthocercis  - album with pictures, videos and audio files
This version was added to the list of articles worth reading on October 14, 2007 .