Morphological variation in the rare Idaho endemic, Lepidium papilliferum (Brassicaceae) and segregation of Owyhee County populations as a new variety of Lepidium montanum

Call Number:

URL:

Keywords:

Abstract:

Lepidium papilliferum (L.F. Hend.) Nelson & Macbr. (Brassicaceae) is a rare annual or biennial endemic to southwestern Idaho and listed as threatened by U.S. Fish and Wildlife Service under the Endangered Species Act. It comprises three main metapopulations: the Jarbidge, Boise Foothills (BF), and Snake River Plains (SRP) populations. This study investigates morphological relationships among these populations of L. papilliferum and the closely related Lepidium montanum Nutt. var. montanum, to determine if there is sufficient evidence to taxonomically segregate the Jarbidge populations currently considered L. papilliferum from the other L. papilliferum populations. We measured 22 morphological characteristics on 61 herbarium specimens and conducted a Principal Components Analysis to assess the range of variability for these characters across the full range of L. papilliferum populations in southwestern Idaho. Jarbidge and SRP (including BF) populations were distinguishable by the first three principal component axes, which represented 56.4% of the variation among sampled populations. Six morphological characters (relating mainly to trichomes and leaf division) differed significantly between Jarbidge and SRP L. papilliferum populations. The Jarbidge populations are morphologically and geographically distinct from the others and can be supported as a distinct variety — L. montanum var. owyheense Barbour & Mansfield, var. nov. The absence of papillae on the filaments of Jarbidge plants supports closer affinity to L. montanum than to L. papilliferum. Current genetic data support the current taxonomy and this proposed taxonomy equally-- with L. montanum as paraphyletic and L. papilliferum as monophyletic in both cases.

Notes:

Reference Code: A22MAN01IDUS <br>

Full Citation: Mansfield, D.H. and L. Barbour. 2022. Morphological variation in the rare Idaho endemic, Lepidium papilliferum (Brassicaceae) and segregation of Owyhee County populations as a new variety of Lepidium montanum. Phytoneuron 2022-46: 1–20. Published 17 October 2022. ISSN 2153 733X <br>

Location: ELECTRONIC FILE - BOTANY: PLANT SPECIES: Lepidium papilliferum <br>

Keywords: Lepidium papilliferum, Lepidium montanum var. owyheense, Lepidium montanum var. montanum, Lepidium philonitrum, Snake River Plains, Boise Foothills, Jarbidge, population <br>