Author: navidcod 
Medicago rigidula
Masoumeh Izadpanah, Parvin Salehi Shanjani and Leila Falah Hoseini
Natural Resources Gene Bank, Research Institute of Forests and Rangelands, Agricultural Research, Education and Extension Organization, Tehran, Iran.
Uploaded at August 2021
Scientific editor: Valiullah Mozaffarian
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 of this species are not dormant. Sterilize seeds before placing them on wet germination paper. Place seeds for two weeks in 4 ºC to germinate uniformly. Then germinate under an alternating temperature regime of 15/20 ºC (the higher temperature for 16 hours in light and the lower one for eight hours in dark).
Morphology
Fruit type: Pod
Fruit shape: Straw-colored to dark grey, glabrous, or velvety in appearance due to shorter or longer (many-celled) glandular hairs; cylindrical, discoid or barrel-shaped, hard-walled, spiny or spineless; number of coils 3.5-7, usually not very tightly appressed, turning clockwise; surface of coil with 7-14 radial veins, strongly curved, occasionally S-shape, branching little or anastomosing only on the outer part and merging with a strong lateral vein; a groove, often observable only on unripe pods, lies between the lateral vein and the dorsal suture; the dorsal suture often elevated, giving a convex shape to the edge; spines, if present, 6-13 on each side of the coil, conical at base or with a shallow groove extending halfway up, the longest ones often hooked, inserted at (90)120°-180° to the coil surface.
Seed shape: Mostly reniform, oblong-ovoid, 1-3 seeds in each coil, separated; seed coat smooth, yellow; radicle length less than half the length of the seed.
Fruit size: Diameter: (4.5-) 5-6.8 mm, thickness: (4- ) 6-7 (-8.5) mm
Seed size: Length (2.5-) 3-4 (-4.2) mm, maximum width 1.6-2.1 mm in an accession from Sahneh, Kermanshah with 1000 seed weight 4.5 g, which was collected in 2007 by Borzu Yosefi, and the cultivated sample was identified by Masumeh Izadpanah and Iraj Mehregan with accession number 33006.
1000 seed weight: 2.3-6.2 g
Biological features
Life form: Herbaceous, annual, proumcent to ascending
Inflorescences and flower type and pollination mechanisms: Flowers in axillary pedunculate racemes, hermaphrodite, zygomorphic and asymmetric; corolla (composed of banner: upper large petal, wings: two petals adjacent to the banner, and keel: two bottom petals) yellow, wings shorter than or (very rarely) almost as long as the keel; stamens are always ten in number, and their filaments are fused in a group of nine stamens plus one separate stamen (9+1). Plant monoecious, self-pollinate with 10% cross-pollination, which is carried out by insects.
Time of flowering: March and April in southern provinces; April (rarely March) to September (rarely October) in other provinces
Time of seed ripening: April and May in southern provinces; June (rarely April) to August (rarely October and November) in other provinces
Seed dispersal methods: The seeds are displaced by weight. Pods move by attaching to the wool and hair of animals.
Geographical distribution: Iran, Iraq, Afghanistan. Typus according to Flora Iranica: Illustratio: Medica hirsute echinis rigidioribus, J.BAUHIN&CHERLER, Hist. Pl. 2: 386 (1651); Lectotypus conf. C. C. HEYN (1959)
Distribution in Iran: West, North, East, South. East Azerbaijan, West Azerbaijan, Golestan, Bushehr, Kohgiluyeh and Boyerahmad, Qazvin, Zanjan, Mazandaran, Lorestan, Ilam, Kermanshah, Kordestan, Chaharmahal and Bakhtiari, Kerman, Ardabil, Hamadan, and Khuzestan
Taxonomy
Family: Papilionaceae
Genus: Medicago
Species: rigidula
Common name: Tifton medic
References and Links
Ghahraman, A. Flore of Iran. Research Institute of Forests and Rangelands with University of Tehran Publication. https://floraofiran.net/index.php.
Lesins, K.A. and Lesins, I. 1979. Genus Medicago (Leguminosae): a taxogenetic study. The Hague, Boston, London: Dr W. Junk Publisher, 234 pp.
Small, E. and Brookes, B. 1990. Circumscription of the genus Medicago (Leguminosae) by seed characters. Can. J. Bot. 68: 613-629.
Small, E. and Jomphe, M. 1988. A synopsis of the genus Medicago (Leguminosae). Canadian Journal of Botany, 67: 3260-3294.
Mehregan, I., Rahiminejad, M.R. and Azizian, D. 2002. A taxonomic revision of the genus Medicago L. (Papilionaceae) in Iran. Iranian Journal of Botany, 9: 207-221(In Persian).
Mozaffarian, V. 2012. A Pictorial Dictionary of Botany. Farhange Moaser Publisher, 1088 pp.
Rechinger, K.H. 1984. Flora Iranica 157. Akadmische Druch. U. Verlagsanstalt. Graz.
