Convolvulus divaricatus (Gintzburger et al., 2003)

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Suaeda salsa
Gintzburger et al., Rangelands in Uzbekistan, 2003
Convolvulus divaricatus (Gintzburger et al., 2003)
Convolvulus hamadae
Convolvulus divaricatus
Convolvulus divaricatus collected for silkworms near Shafirkhan (Bukhara)
Convolvulus divaricatus

Convolvulus divaricatus Rgl. et Schmalh.

Local name:

  • Russian: Вьюнок растопыренный, партек - v'junok rastopyrennyj, partek
  • Turkmen: Ak-kert
  • Uzbek: Partek

Chromosome number: n = 11 (Darlington and Wylie 1955; Grant 1982); 2n = 20, 40 (Baquar et al. 1965; Fedorov 1969).

Description and morphology: Perennial shrub (height 30–90 cm), greyish, woolly, small hemispherical. Pivotal woody root (to depth 2–8 m or more). Stem: strongly branched, prostrate (trailing) from base, decumbent or ascending, densely pubescent mixed with long hairs. Leaves: alternate, small, almost sessile, reduced to scale, highly pubescent with glandular hairs; rarely lobed or pinnately lobed with serrate margin. Lower leaves – linear-lanceolate or oblong; upper – sessile, apex obtuse to acute, oviform-lanceolate, rounded or attenuate at base. Flowers: bisexual; actinomorphic, large, funnel-shaped campanulate, yellowish or pinkwhite, pentamerous, assembled in a terminal dichasium by 1 or 2–3 clusters. Perianth compound, 5 oviform-lanceolate, densely villous sepals and 5-lobed corolla (10–15 mm long) with accreted petals, bell, funnel-shaped, tubular or folded; 5 stamens attached to corolla tube base with well differentiated nectarium. Anthers ovoid-lengthened, opening introrse by longitudinal cracks. Pollen grain 2-celled, 3 pores. Style with 2 linear cylindrical stigmas. Ovary superior with 1–2, rarely 4, anatropous, unitegmic, tenui-nucellulate ovules.

Reproduction: Sexual. Entomophilous. Flowering: May–June. Fruit maturation: September–October. Fruit: capsule, sometimes opening with a false crack. Seed: incurvate embryo with folding cotyledons, surrounded by hard cartilaginous layer of endosperm. Seed coat water impermeable. Dormancy Af type. Germination low. Scarification and long-term stratification (5 °C and 29–30 °C) for 1.5– 2.0 months or longer result in 55–85% germination. Treatment with concentrated sulphuric acid (30 minutes) and/or soaking in boiling water significantly increase germination.

Pastoral importance: Well grazed by camels, sheep and goats in winter and early spring until summer; but not eaten from middle of summer until autumn. One of the best rangelands, Convolvulus divaricatus is considered to be the best pasture for Karakul sheep in autumn and winter after the first rains. Expected yield is low at 0.005–0.02 t/ha.

Fodder value: Vegetative growth (% DM): ash 10; protein 14; fat 2.9; cellulose 40; nitrogenfree extract 33. Green parts contain alkaloids.

Economic interest: Currently harvested to feed silkworm in the Shafirkhan region near Bukhara. As a medicinal plant it is used as a treatment for constipation and urological disease. It is sometimes used for fixing mobile sand and small dunes.

Habitat: Psammo-xerophyte. Occurs on sandy flats or gypseous soil.

Distribution: Kyzylkum, Ustyurt, southern part of Middle Asia; rarely Iran and Mongolia.