Artemisia diffusa (Gintzburger et al., 2003)
Artemisia diffusa (Gintzburger et al., 2003)
Artemisia diffusa H. Krasch. ex P. Pol.
- Russian: Полынь раскидистая - polin' raskidistaja
- Uzbek: Ok-Djusan, Kongur-Dzhuvsan, Keng Shokhli, Shuvokh, Evshan
- Kazakh: Ak-Dzhuvsan
- Turkmen: Evshan
Chromosome number: 2n = 24, 48, 72 (Hamdamov and Noskova 1987).
Description and morphology: Perennial, polymorphic, low shrub (height 30–50 cm). Life span 7–25 years. Stem: pubescent, grey-green, ramified, slender and lignified with short and strong branches at the base ‘caudex’ (4–12 cm in length). Reproductive stems: erect or arch-curved (15–30 cm in height, up to 3 cm wide) and ramified at the upper part. Strong, pivotal root penetrates to depth 1.1–2.5 m. Leaves: sessile (1.5– 2.0 cm long, up to 1 cm wide), 2–3 times pinnatipartite, pointed at the tip. Leaf surface is densely covered with silky hairs of various structures giving leaves a silvery appearance. Flowers: bisexual; inconspicuous, protandrous, pentamerous, pale yellow gathered in groups (3–7) in oviform, sessile capitulum (3–4 mm long), assembled in a wide panicle inflorescence, 5 stamens, accreted by lateral pollen sacs forming a short stamen tube. Anther oval-oblong with a pronounced appendage. Pollen grains striate 3-celled; pollen fertility: 86–92%. Ovary inferior with 2-lobed slightly papillous stigma. Ovule inferior, anatropous, tenui-nucellate, unitegmic ovule. Growth of aboveground organs from end of February-to beginning of June; long summer rest when spring leaves may fall. Vegetation cycle lasts 230–237 days.
Reproduction: Sexual and vegetative. Typical cross-entomophilous plant, but cleistogamy is admitted. Integmic tapetum, polyembryony, somatical apospory, gynodioecy. Flowering: September–October. Fruit maturation: October–November. Fruit: dark brown indehiscent, monospermous achene with membranous pericarp. Seed: small, with erect, large, chlorophytic embryo without endosperm. Seed coat has 3–5 cell layers. Dormancy B1–B3 type. Light sensitive, germinates at 15–20 °C on coarse river sand substrate. Laboratory seed germination ranges from 46% to 94%, while field germination is lower at 5–20%. Special temperature sequences (13/31 °C) after 14 months of storage significantly stimulate germination. Seed viability 2 or more years.
Pastoral importance: One of the best rangeland feeds for all livestock from Morocco (Artemisia herba-alba Asso.) to Central Asia (Artemisia diffusa and other similar Artemisia spp.). Drought and frost-resistant plant valuable for the creation/ or rehabilitation of autumn-winter pastures in arid and semi-desert areas and also for the improvement of degraded lands in clay and gypsum deserts. A limited grazing of Artemisia - Carex plant associations leads to the appearance of Tortula desertorum indicating range senescence and degradation. Provides a valuable fodder bank during the autumn-winter feed gap in areas from North Africa to Central Asia. In early spring, Artemisia is well eaten by cattle because of the high content of carotin (about 100 mg/kg) in young shoots, but care must be exercised with small ruminants (because of the possibility of abortion in spring). Ripe fruits are readily eaten due to a lessening of the strong smell and bitter taste. Annual yield capacity of A. diffusa on natural pastures varies from 0.1 to 0.25 t/ha (Morozova 1946) and 0.48 to 2.54 t/ha on cultivated land. About 1.0–1.5 kg/ha of seed is harvested from natural pastures and up to 6 kg/ha under cultivation. In Uzbekistan, Artemisia diffusa is collected for winter feed. Wood is collected for fuel. Artemisia rangelands are often a prime target for cereal cultivation in low rainfall semi-arid and arid zones inducing desertification. Artemisia is suitable for haymaking, better feed and used after exposure to frost and/or rains in winter when dry and volatile compounds have been leached.
Fodder value: Green leaves and twigs during spring contain (% DM): crude protein 16.9; fibre 15.8; fat 4.5; ash 12.7. At fruit stage (% DM): crude protein 8.0; fat 5.5; ash 6.7; cellulose 45.4. Fodder value is estimated at 18–66 FU and 2.2–7.8 kg digestible protein/100 kg DM.
Habitat: Xero-gypsophyte. Typical plant of the southern Turanian deserts; found on inter-dunes, depressions and on northern slopes of sandy ridges; most abundant on loamy sand, stony and grey-brown soils of plains, foothills and semi-desert areas.
Distribution: Southern and Central Kyzylkum, Kazakhstan, Turkmenistan, South Russia, South and northern part of Turanian lowlands. Other similar ‘white’ Artemisia rangeland from Morocco-Spain to Central Asia. Endemic of Central Asian desert (Butnik et al. 2001a, b).