Meiotic chromosome counts from 200 populations of Claytonia
(Montia) perfoliata (sensu lato) reveal a polyploid pillar complex based
on three morphologically different, chemically distinct, and geographically
defined diploids. The basic chromosome number is x=6.
Diploid C. perfoliata Willdenow with linear juvenile leaves and deltoid
mature basal leaves ranges southeastward from...
Claytonia perfoliata is a west-American polyploid complex of
common annuals (x=6). The species is polymorphic; exomorphic
characters are often variable within local populations. In a transect
of the Columbia River Gorge diploids, tetraploids, hexaploids, octoploids,
and decaploids were collected, which varied in shape of basal
and cauline leaves, degree of...
Astragalus diaphanus is a rare plant endemic to the
John Day River drainage of north-central Oregon. This
species has several interesting features, including the
dimorphism of its fruit and its geographical isolation from
the two nearest taxonomically related species, which occur
in Colorado. This study addressed the species' distribution
and...
Phacelia capitata Rruckeberg is a member of the
Phacelia magellanica polyploid complex (species group
Magellanicae), a group of wide-ranging, polymorphic
perennials in western North America related to the South
American P. secunda (= P. magellanica). The purpose of
this project was to determine, to the extent possible, the
interrelationships of...
A cytogeographical study was made of populations of tetraploid
(n=18) and hexaploid (n=27) Achillea millefolium (Compositae-
Anthemideae) from the Pacific Coast states. There is a complex
distributional pattern, involving overlapping ranges, mixed populations,
migration of one form into areas occuplied by the other,
pentaploid hybrids, and septaploid and octoploid plants....
A study was made of the subgenus Genuini of the genus Juncus in the Pacific States, California, Oregon and Washington. Extensive morphological comparisons, geographical distributions, habitat differences and observations of apparent presence or absence of natural hybrids provided the major data sources. Cytological studies were made, but were inconclusive. Eleven...
The Artemisia ludoviciana polyploid complex is a highly polymorphic
assembledge of eight taxa in the Pacific Northwest, with a
chromosome base number of x=9. A cytogenetic analysis of this
complex was carried out to determine the sources of its variation,
the types of polyploidy present, and the genetic processes active...
The goal of the study was to collect data on the ecology and
reproduction of Sophora leachiana in order to help explain the rarity
and restricted range of this species. There are 13 known populations
of S. leachiana, occurring in a 29 by 6.4 km area in the Siskiyou
Mountains...
The Mimulus washingtonensis complex is a group of morphologically similar
species centered in the Pacific Northwest. All are rare, and most are under
consideration for listing as endangered. Morphometric and pollination data were
used in developing a revised taxonomy for the group. Five species and two varieties
are recognized. Mimulus...