Bupleurum triradiatum subsp. arcticum (Regel) Hult.
 
FamilyUmbelliferae — APG family: Apiaceae
SynonymsBupleurum angulosus Cham. & Schlecht., Bupleurum ranunculoides var. arcticum Regel, Bupleurum americanum Coult. & Rose.
Common namethoroughwax
DescriptionStems from short, simple or many-headed caudex, simple or branched; basal leaves linear-lanceolate, acute or somewhat acute; stem leaves oblong-lanceolate to rarely ovate-lanceolate, sessile, more or less clasping; umbel with 2-9 rays; in- volucre with 2-6 leafy bracts; involucels of foliaceous, bright-yellow bractlets; umbels compact; petals yellow, often blotched with purple; fruit dark brown, broadly oblong, more or less winged.
EcologyMeadows, dry, stony slopes, in McKinley Park to at least 1,200 meters. B. triradiatum described from Lake Baikal, subsp. arcticum from Kotzebue Sound.
Taxonomy
notes
Alpine specimens are small, with few rays in the umbel; the lowland specimens are branched, up to 70 cm tall, with up to 9 rays. Broken line on circumpolar map indicates range of subsp. triraditum.
Hultén's Flora About

This is a digital representation of Eric Hultén’s ‘Flora of Alaska and Neighboring Territories: A Manual of the Vascular Plants’, which was published by Stanford University Press in 1968. The book was digitized by C. Webb (at UAMN) as part of the Flora of Alaska project, with funding by the US NSF (Grant 1759964 to Ickert-Bond & Webb), and with permission of Stanford University Press. Data and images © 1968 Board of Trustees of the Leland Stanford Jr. Univ. Usage licence: Creative Commons BY-NC-SA 4.0. NB: You may find OCR errors; please refer to the hard-copy if in doubt.