TWO NEW SUBSPECIES OF MICROSERIS LACINIATA (ASTERACEAE) FROM THE SISKIYOU MOUNTAINS

摘要

Microseris laciniata subsp. siskiyouensis and subsp. detlingii are. described as endemics of the floristically "central" region of the Siskiyou Mountains of Oregon and adjacent California. These taxa have novel morphological features differentiating them from the related Microseris laciniata subsp. laciniata and subsp. leptosepala also found in this region. The populations are kept separate by allopatry and by adaptation to different edaphic conditions, and thus have different vegetation associations. Intermediate populations occur where pairs of taxa meet and the ecological differences are modified by habitat disturbance.