Cuscuta australis

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Cuscuta australis
Southern silk (Cuscuta australis)

Southern silk ( Cuscuta australis )

Systematics
Asterids
Euasterids I
Order : Nightshade (Solanales)
Family : Bindweed family (Convolvulaceae)
Genre : Silk ( cuscuta )
Type : Cuscuta australis
Scientific name
Cuscuta australis
R.Br.

The Southern silk ( Cuscuta australis ) is a plant from the genus silk in the family of wind plants (Convolvulaceae). This parasitic plant is widespread in Eurasia and Africa .

description

Habit and flowers

Vegetative characteristics

Cuscuta australis is a mostly annual , rarely perennial herbaceous plant . Their stems are moderately thick, greenish-yellow to orange in color.

Generative characteristics

The flowers are on short peduncles in compact clusters. The flowers are about 2 millimeters in size, four or five-fold and often glandular. The chalice is bell-shaped and about as long as the corolla tube . The calyx lobes are ovate to circular, blunt and do not overlap. The crown is bell-shaped, with blunt or almost pointed, upright or protruding corolla lobes. The corolla lobes are somewhat shorter or longer than the corolla tube. The anthers protrude from the flower envelope. The scales at the base of the corolla tube are usually shorter than the corolla tube, have two columns and have a few fringes, or they have receded into teeth at the base of the corolla tube. The stylus is shorter than the spherical ovary .

The capsule fruits are spherical to indented spherical with a diameter of 3.5 to 4 millimeters and a large opening between the styluses. The faded crown remains at the base of the capsule. The seeds are 1.5 millimeters long.

The number of chromosomes is 2n = 56 or approx. 28.

ecology

In Cuscuta australis usually is a therophytes . Like all representatives of the genus silk, it is a holoparasitic plant species. It is particularly parasitic on species of the genera Polygonum or Xanthium .

Systematics and distribution

The first publication of Cuscuta australis was in 1810 by Robert Brown . Synonyms for Cuscuta australis R.Br. are: Cuscuta obtusiflora var. australis (R.Br.) Engelm. , Grammica australis (R.Br.) Hadac & Chrtek , Grammica scandens subsp. australis (R.Br.) Holub .

Cuscuta australis is common in Eurasia and Africa . It is a neophyte in Central Europe .

By Cuscuta australis there are several varieties that are often treated in European literature as a subspecies:

  • Cuscuta australis R.Br. var. australis (Syn .: Cuscuta millettii Hook. & Arn. , Cuscuta obtusiflora var. cordofana Engelm. , Cuscuta grassii Delponte , Cuscuta hygrophilae H.Pearson , Cuscuta kawakamii Hayata , Cuscuta nuda Pilg. , Cuscuta cordofana (Engelm.) Yunck. , Cuscuta scandens var. Bidentis (Berthold) Kerguélen ): It is common in the Old World .
  • Knotweed silk ( Cuscuta australis var. Cesatiana (Bertol.) Yunck .; Syn .: Cuscuta australis subsp. Cesatiana (Bertol.) Maire , Cuscuta cesatiana Bertol. , Cuscuta obtusiflora var. Cesatiana (Bertol.) Engelm. , Grammica scandens subsp . cesatiana (Bertol.) Holub , Cuscuta scandens subsp. cesatiana (Bertol.) Soó , Grammica cesatiana (Bertol.) Chrtek , Cuscuta polygonorum Ces. nom. illeg., Cuscuta australis var. glandulosa (Engelm.) Maire ): She is coming from southern Europe and southern central Europe to India.
  • Cuscuta australis var. Tineoi (Insenga) Yunck. (Syn .: Cuscuta australis subsp. Tineoi (Insenga) Feinbrun , Cuscuta tineoi Insenga , Grammica australis subsp. Tineoi (Insenga) Dostál , Cuscuta breviflora Vis. , Cuscuta aurantiaca Req. Ex Bertol. , Cassutha chrysocoma Des Moul. , Cuscuta chrysocoma Welw . ex Des Moul. , Grammica chrysocoma (Welw. ex Des Moul.) Des Moul. , Cuscuta rogowitschiana Trautv. , Cuscuta obtusiflora var. breviflora (Vis.) Engelm. , Cuscuta bidentis Berthiot , Grammica bidentis (Berthiot) Royer , Cuscuta obtiflora var. bidentis (Berthiot) Rouy ): It occurs from Central and Southern Europe to the western Himalayas.

swell

Individual evidence

  1. ↑ data sheet at PROTA = Plant Resources of Tropical Africa .
  2. ↑ a b c d Naomi Feinbrun: Cuscuta. In: TG Tutin, VH Heywood, NA Burges, DM Moore, DH Valentine, SM Walters, DA Webb (eds.): Flora Europaea . Volume 3: Diapensiaceae to Myoporaceae . Cambridge University Press, Cambridge 1972, ISBN 0-521-08489-X , pp. 75 (English, limited preview in Google Book search).
  3. ↑ Cuscuta australis at Tropicos.org. In: IPCN Chromosome Reports . Missouri Botanical Garden, St. Louis
  4. ^ Erich Oberdorfer : Plant-sociological excursion flora for Germany and neighboring areas . With the collaboration of Angelika Schwabe and Theo Müller. 8th, heavily revised and expanded edition. Eugen Ulmer, Stuttgart (Hohenheim) 2001, ISBN 3-8001-3131-5 , pp.  774 .
  5. ↑ a b c d e f Rafaël Govaerts (Ed.): Cuscuta australis. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved February 3, 2016.

Web links

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