Taxonomic revision of the Dracocephalum fruticulosum group Lamiaceae

This study presents a taxonomic revision of the Dracocephalum fruticulosum group based on field investigation, specimen comparison, and literature research. Four taxa are currently recognised within this group, namely D. fruticulosum, D. psammophilum, D. linearifolium var. linearifolium, D. linearifolium var. etokense. In this paper, the D. fruticulosum group in Flora Reipublicae Popularis Sinicae, Flora Intramongolica and Flora of China is further revised, and D. linearifolium var. linearifolium and D. linearifolium var. etokense are here treated as synonyms for D. psammophilum.

The distinguishing features between D. fruticulosum and D. psammophilum lie in the number of leaf veins, the characteristics of glands and glandular pits on abaxial surface of leaf, and the presence or absence of spiny tips at the apex of the blades in the lower stem, rather than differences in leaf shape, leaf margin features (toothed or spiny), or calyx morphology. Based on available specimens and field surveys, it is concluded that D. fruticulosum is currently not occurring in China.