Panarctic Flora

360702-03 The Delphinium brachycentrum aggregate D. brachycentrum, D. chamissonis

Geography: Asian (NE) - amphi-Beringian.

Notes: Yurtsev: The three allopatric taxa Delphinium brachycentrum subsp. brachycentrum, subsp. maydellianum, and D. chamissonis are each distinctly different and uniform, and D. chamissonis is the correct name for the amphi-Beringian plant. Delphinium chamissonis differs from D. brachycentrum subsp. brachycentrum (restricted to Kamtchatka) in being a low, slender plant with few flowers and fewer cauline leaves, deep dissection of leaf blades (with terminal segments not much longer than lateral ones), leaf lower surface pubescent only along veins (not throughout), sepals oblong-ovate (not lanceolate, long-attenuate) and subacute to subobtuse, and bracteoles not opposite, remote from the flower base.

Delphinium brachycentrum subsp. maydellianum is, in some aspects, intermediate between D. chamissonis and D. brachycentrum subsp. brachycentrum. It differs from D. chamissonis in a greater number of leaves and flowers and more dissected leaves, from D. brachycentrum subsp. brachycentrum in leaf lower surface pubescent only along the veins, terminal segments not much protruding, pedicel and bracteole structure as in D. chamissonis, and sepals not long-attenuate. Subspecies maydellianum occupies gaps in the range of D. chamissonis in the northern Koryak Mountains, the Anadyr River area, and at the isthmus of Chukchi Peninsula. Subspecies maydellianum may have arisen from hybridization between D. brachycentrum subsp. brachycentrum and D. chamissonis but is morphologically uniform.