GymnocarposprzewalskiiBunge ex Maxim.belongs to Gymnocarpus of Caryophyllaceae, a rare and endangered ancient Mediterranean relict plant, alias ‘a(chǎn)chene caryophyllum’, Perennial deciduous subshrub, 50-100 cm tall.Leaves linear, 5-20 long and 1-1.5 mm wide, sessile, acute apex, contracted base, fleshy, waxy layer on surface, glabrous, no obvious veins.Stipules membranous, scaly.Opposite or alternate leaves.Stems exist in two forms, erect or tortuous, with inflated nodes and multi-branch.The bark of old branches is gray-brown and cracked, young branches red-brown.Hermaphrodite flowers with red and yellow-green colors, petals absent, outer transparent white bracts covered.5 sepals with lanceolate, apex awned, wide transparent membranous margin, covered pubescent.10 stamens, 5 for each of the inner and outer rounds, in which only the inner stamens have anthers, and the outer anthers are aborted, anther ellipsoid, longitudinally dehiscent.Superior ovary, subglobose, 1 ovule; Cymes axillary，composed of 5-15 single flowers, approximate 4 days flowering period for single flower and 30-36 days for population.Achenes persistent.Small, brown and oblong seeds, ca.0.5 mm in diameter, low seed setting rate.Obvious taproot, ca.4 m long, well-developed lateral root with less root hair.Flowering from May to June and fruiting from July to August.

Gymnocarposprzewalskiiis endemic species in China, mainly distributed in Xinjiang, Gansu, Hexi Corridor, central and western Inner Mongolia, Ningxia, Qinghai and other places, which was identified as National first-class key protected plants in 1997.This species has the characteristics of drought, wind erosion and sand burial resistance, salt-alkali and barren tolerance.It is one of the important constructive species in rocky desert areas, and has positive effects on preventing soil desertification and maintaining ecosystem balance in desert areas.Meanwhile, as a rare relict species of the ancient Mediterranean xerophytic flora in the desert region of central Asia, it has very important scientific value for researching the formation, development, climate change of deserts and floristic origin of xerophytes in northwest China.

(GAO Runhong, YANG Haifeng)