Author: navidcod 
Astragalus macrocephalus Willd.
Hamideh Javadi and Parvin Salehi Shanjani
Natural Resources Gene Bank, Research Institute of Forests and Rangelands, Agricultural Research, Education and Extension Organization, Tehran, Iran.
Uploaded at August 2021
Scientific editors: Valiollah Mozaffarian and Masoumeh Izadpanah
Seed Storage
The storage behavior of this species is orthodox (desiccation-tolerant seeds); dry to 15-20% eRH and store at -20 °C.
Germination requirements
The seeds have physical-physiological dormancy and this is related to seed coat and inhibitors. To remove the seed coat, different methods of scarification can be used (sandpaper, sulfuric acid, hot water, etc.). To break dormancy, stratification with pre-chilling (for 14 days), ultrasonic waves, and hormones (Gibberellic acid 100 ppm) are efficient. The best method for breaking dormancy is rubbing the seeds with sandpaper and moist chilling (14 days at 4 °C). Then germinate under a constant temperature of 20 ºC or alternating temperature 25 ºC (16 hours of light) and 15 ºC (8 hours of dark).
Morphology
Fruit: Pod, ovate, yellowish to light brown with appressed-hairs
Fruit size: Length: 8-10 mm, width: 4-6 mm.
Seed: Cylindrical to reniform, surface glabrous, lustrous, light yellow to pale-brown without brown spots.
Seed size: Length: 4.97-5.62 mm, width: 3.83-4.22 mm in an accession from Khoramabad, Lorestan with 1000 seeds weight 7.7 g, which was collected in 2011 by Mohamadian, Darvishiyan, and Reshno, and the cultivated sample was identified by S. Reza Safavi with accession code 36285.
1000 seed weight: 7.1-8.6 g.
Biological features
Life form: Perennial, herbaceous, erect.
Inflorescence flower type and pollination mechanism: Inflorescence spherical, dense. Flowers hermaphrodite, 5-merous, zygomorphic, calyx tubular or campanulate with dense soft white hairs, corolla yellow to brown, glabrous. Plant monoecious, cross-pollinate. Pollination is carried out by insects and wind.
Time of flowering: May to June
Time of seed ripening: June to July
Seed dispersal methods: The seeds are displaced by the weight
Geographical distribution: Turkey and Iran.
Distribution in Iran: North, North West, West, center. Mazandaran, Azerbaijan, Kordestan, Hamadan, Esfahan, Bakhtiyari and Tehran.
Taxonomy
Family: Papilionaceae
Genus: Astragalus
Species: macrocephalus
Common name: Locoweed
References and Links
Asri, Y. 2012. Range Plants of Iran, Vol. 2: Dicotyledons. Research Institute of Forests and Rangelands Publication, 530 pp.
Baskin, C.C. and Baskin, J.M.1998. Seeds: Ecology, Biogeography, Evolution of Dormancy and Germination. Academic Press, San Diego.
Bewley, J.D. 1997. Seed germination and dormancy. The plant cell, 9: 1055-1066.
Bakhshandeh Faraj-pur, A. 2014. Investigating the possibility of increasing the germination of several species (Astragalus) using various methods of dormancy in order to multiply massive and regenerate rangelands. Master’s thesis, University of Kashan, Faculty of Engineering.
Kožuharova, E. and Firmage, D. 2007. On The Pollination Ecology of Astragalus alopecurus Pallas (Fabaceae) in Bulgaria. Tome, 60(8): 863-870.
Kožuharova, E., Tzvetanova, V. and Firmage, D. 2010. Seed germination and seedling development of two rare Astragalus species (Fabaceae). Phytologia Balcanica, 16 (1): 51-56.
Maassoumi, A.A. 2017. Flora of Iran, No.43: (Papilionaceae: Astragalus I). Research Institute of Forests and Rangelands Publication. p. 60.
Mozaffarian, V. 2012. A Pictorial Dictionary of Botany. Farhange Moaser publisher, 1088 pp.
