Haloxylon aphyllum (Gintzburger et al., 2003)
Haloxylon aphyllum (Gintzburger et al., 2003)
Haloxylon aphyllum (Minkw.) Iljin
- Russian: Саксаул черный, саксаул солончаковый, саксаул безлистный - saksaul černyj, saksaul solončakovyj, saksaul bezlistnyj
- Uzbek: Kora saksovul
- Turkmen: Kora-sazak
- Kazakh: Sokseul
Chromosome number: 2n = 18, 22 (Baquar et al. 1966; Fedorov 1969).
Description and morphology: ‘Black Saxaoul’. Tree-like (height 4–10 m), aphylous, stem succulent, strongly ramified. Life span 50–90 years. Deep pivotal root system penetrating to depth 9–16 m within 5–6 years. Trunk: 20–40 cm in diameter, thick, rough, with dark grey bark. Stem: articulate, dark green, cylindrical, jointed, trailing. Leaves: opposite, connate, scale-like or rudimentary small lumpy bud. Bracteoles 2 larger than perianth segments, hulled, slightly toothed on margin. Perianth segments 5, membranous, free or connate at base. Flowers: bisexual; inconspicuous, antipetalous, solitary, axillary to scale-like leaves; 5 stamens, filaments connate at base on a hypogenous disc; anthers oblong-elongated without appendage. Pollen grains 3-celled, multiporate. Ovary superior. Styles 2–3, short, thick; stigmas filiform, up to 2–3 times longer than column. Ovule anaamphitropous, crassi-nucellate, bitegmic.
Reproduction: Sexual. Typical wind-pollinated plant. Possible seeding and transplanting from cuttings. Seed production not every year. Apomixis and parthenocarpy. Flowering: April–May. Fruit maturation: October–beginning of November. Fruit: monospermous, indehiscent nut-like, developing horizontal wings near middle. Wings orbicular or wedge-shape at base, horizontal (7–12 mm) with rough edges on perimeter, fine venation. Tepal lobes orbicular form a noticeable adpressed column on upper side. Seed: horizontal, orbicular, light brown, smooth, with a thin fruiting body, large spiral embryo (15–20 mm), chlorophytic with poor endosperm. Seed coat two-layered with intermediate cuticle. Dormancy A2–B1 type. Viable seed: 76–92%. Germination: 40–88% (20–25 °C). Seed longevity 8–9 months. Seed stratification (2–4 °C) for 1–2 months increases germination.
Pastoral importance: One of the most important range plants in Middle and Central Asia to northern China. Young vegetative stems, leaves and fruits are a valuable feed for all livestock nearly all year round. In autumn and winter the fruits and annual shoots have the best value; shepherds consider the fruits to be a highly calorific forage. Extensively used for the creation of long-term pastures, for range restoration and/or improvement, in tugaï communities on sandy soils, takyr, salt-marshes (solonchakalkaline soils), also appropriate for sand-dune fixation and creation of a wind belt. Expected yield in Artemisia Karnabchol steppe varies from 0.8–3.0 t/ha on highly fertile soils (Taninchka, Gombasa wells) to 0.3–1.4 t/ha on infertile ones; 0.6–0.8 t/ha in the Kyzylkum. Seed production yields 0.05–0.3 t/ha at 5– 6 years. Trees planted in 1960–70 for range improvement, now intensively used by local populations as much needed fuelwood.
Fodder value: Changes from spring to winter (% DM): crude protein 8.3–12.0, up to 20 in fruits; fat 1.4–2.1; cellulose 14–33; ash 14–38; nitrogen-free extract 30–40. Fodder value is evaluated to be 29–53 FU with 3.7 kg digestible protein/100 kg DM. A valuable source of fuelwood the plant contains more ash then H. persicum.
Habitat: Xero-psammo-halophyte; phreatophyte. Common in inter-dune depressions, on sand dunes and sandy soils with various levels of salt, as well as in valleys and river beds with a high water table, sometimes saline; on layers of salty clay; also on grey-brown soils, margins of takyr forming open forest. Largely used in plantations (Karnabchol, Nuratau region).
Economic interest: Fodder, useful for sandfixing, soil-improving, fuel, coal-making (up to 40%). Local people extract acetone, alcohol and vinegar from the wood. Ash of green younger branches (‘ichkara’) is widely use for dyeing wool dark brown. Large living collection of some 50–60 accessions of Middle and Central Asian species in the arboretum of the Papanay Karakul Sheep Station in Nuratau province. There is an urgent need for reforestation and establishment of new plantations using ‘Saxaoul’ for the future of local populations in remote desert areas.
Distribution: Middle Asia, Iran, Afghanistan, north-western China (Turfan-Xinjiang province, Minqin Research Station in Ghanzu province). Introduced for sand-dune fixation and on gypsum soils in North Africa (southern Tunisia and Libya) and Near East (Marragha Station, Aleppo province, Syria).