Sealy
Description
Dracocephalum wallichii is a Himalayan dragonhead recorded from India, China (Xizang), Nepal and Bhutan, with GBIF holding around 175 occurrences across the high eastern and central ranges. It is a plant of the alpine zone, growing on open stony slopes, gravelly meadows, scree and grassy banks typically between about 3500 and 4500 m. The photographed material from the Chele-La in western Bhutan at 3800 m, flowering in July, is characteristic: at this high pass the species blooms in the brief summer window after snowmelt, exploiting well-drained, sunny ground among the alpine turf and rock where competition from taller vegetation is limited.
It is a perennial herb with a woody rootstock giving rise to several erect or ascending quadrangular stems. The leaves are opposite, oblong to narrowly ovate, the margin crenate to incised, and often somewhat aromatic, as is general in the genus. The inflorescence is a dense, head-like to interrupted terminal spike of verticillasters subtended by conspicuous, often spine-toothed and ciliate floral bracts that are a notable feature of the species. Each flower has a tubular, two-lipped calyx and a strongly two-lipped corolla coloured blue to violet-purple, the hooded upper lip arching over the four didynamous stamens and the lower lip spreading and three-lobed as a landing platform for bees. The fruit comprises four smooth nutlets enclosed in the persistent calyx.
The species was described by Sealy and honours Nathaniel Wallich, an early collector of Himalayan plants. Dracocephalum is a genus of the temperate northern hemisphere centred on central Asia, well represented in alpine and steppe habitats; D. wallichii is one of its few truly Himalayan-alpine members and is distinguished by its bracteal armature and dense spike. Pollinated chiefly by bumblebees, it is a typical short-season alpine perennial, and being widespread in remote high terrain it is of no immediate conservation concern.
Author: Sealy · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Annotated Checklist of the Flowering Plants of Nepal, Budantsev revision of the genus Dracocephalum