Elatostema weizhianum, a new species of Urticaceae from Zhejiang, East China

The genus Elatostema (Urticaceae) is most diverse in the limestone regions of southern China. Elatostema weizhianum, a new species from Zhejiang Province, East China, is described and illustrated in the present paper. The phylogenetic analysis revealed that the new species is closely related to E. hypoglaucum but differs in having a triplinerved leaf base, stipules 4–6 mm long and purple-brown maculate, peduncles of staminate inflorescences 5–12 mm long and densely strigose, and achenes ca. 1 mm long, longitudinally 5 - ribbed, and tuberculate.

This new species is morphologically similar to E. grandidentatum but differs in having purple-brown maculate stipules, subsessile pistillate inflorescences borne in pairs axillary, a glabrous receptacle, triangular bracts that are sparsely pubescent dorsally, ovate-orbicular outer bracteoles, oblong-navicular inner bracteoles that are corniculate at the apex and pubescent dorsally and at the margin, inconspicuous, degenerative sepals, and 5 - ribbed and tuberculate achenes.

Based on current observations of the geographic range and population size of the new species, it was assessed as “ EN ” under the IUCN categories and criteria.