Lathrocasis

Lathrocasis is a monotypic genus of an annual endemic to the western United States.  It occurs in open areas including gravelly slopes, sagebrush scrub, and pinyon pine-juniper woodlands and rarely into aspen-conifer zones at elevations from 1525-3000 m.

Phylogeny

Lathrocasis is sister to a clade comprised of Allophyllum, Collomia, Gilia, and Navarretia (Johnson et al. 2008).  However, support for this relationship is weak (66 percent parsimony bootstrap and 0.92 posterior probability).  Unpublished analyses including more taxa and more genes continue to indicate an uncertain relationship at this node.  This difficulty may be in part due to the fact that Lathrocasis is on a long branch with many putatively homoplasious substitutions (Johnson and Weese 2000).

Biogeography

Lathrocasis occurs in both the Great Basin and Rocky Mountains in the northwestern North America in the US states of California, Colorado, Idaho, Montanta, Nevada, Oregon, Utah, Washington, and Wyoming as well as in British Columbia, Canada.

Lathrocasis_ggReproduction

Lathrocasis appears to be autogamous (Grant and Grant 1965, Johnson and Weese 2000) as the anthers and stigma mature at the same time, the anthers make contact with the stigma, and the flowers are only open for one day.

Taxonomy

  1. Lathrocasis tenerrima (A. Gray) L.A. Johnson

References

Johnson, L. A. and T. L. Weese. 2000. Morphological and molecular characterization, geographic distribution, and relationships of Lathrocasis tenerrima (Polemoniaceae). Western North American Naturalist  60:355-373.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s