Calligonum polygonoides L. subsp. comosum (L'Hér.) Soskov
C. comosum L’Hér.
Spa.: Arta. Fre.: Calligone chevelu. Ara.: Aurach, arti, arta, lartha, rheda, chuber, chebr, warogat, alshamis, ramo, tape. Tamahaq: Riçu, arreçu, arassu, issaredj, aurech, tarasu, ezul, azal, rezel.
Shrub, hermaphrodite, usually creeping and tufted, up to 2.5 m in height, highly branched from the base. Branches ascending to erect, fasciculate, articulate, tortuous, with smooth white bark, lignified as they age; more slender branches are deciduous and rough, with internodes 2.2-6.8 mm and up to 42 cm in length; old branches have a grey-white and fissured bark. Leaves ephemeral, alternate, sessile, subulate, green and glabrous, smooth, 1.5-5 mm long. Flowers in fascicles of 2-4, rarely solitary, arising at the branch nodes; pedicels articulated, 3-5 mm in length. Perianth composed of 6 tepals, white or pink, with a green thickening in the dorsal side, about 3-5 mm long, persistent and reflexed on the fruit. Stamens 12-15 with purple anthers and filaments concrescent at the base forming a villous disk. Styles 4, 3-4 mm in length, pink, as long as the ovary, stigmas capitate. Fruit an achene, oblong-fusiform, brown, 10-13 × 4-6 mm, ridged, with 4 sides slightly spirally twisted, giving a cross-shaped in cross section. Fruit valleculae wide and ribs narrow. Achenes with 12-18 rows of hairs, free at the base, which give the fruit the appearance of a much larger diameter (12-14 mm).
Flowering:
February to June.
Fruiting:
Between one and two months after flowering, but it is not unusual for a shrub to present both flowers and fruits simultaneously.
Habitat:
Desert sands, at the bottom of dunes, interdune plains, nabkhas and sandy river beds.
Distribution:
Asian and North African deserts. It is the most common taxon for this genus in the northern, central and western Sahara, being very common in almost all dunes, from large ergs in Algeria and Tunisia to the sandy areas that form between the great mountain ranges of central Sahara.
Observations:
C. polygonoides subsp. polygonoides is from western Asia, from Syria to the Sinai Peninsula, in the Mediterranean, reaching to the E up to Armenia and Iran. It differs by having larger leaves (6-10 mm), smaller perianth (c. 3 mm) and shorter achenes (7-8 × 5-6 mm).
Conservation status:
It is a common and widespread species. It is not considered threatened. Currently, it has not been assessed at a global level in the IUCN Red List of Threatened Species. In Tunisia it is included in its List of native species that are rare and threatened with extinction (Order of the Ministry of Agriculture and Water Resources, 19-July-2006).