Genus of the Week

Week of Apr. 13-19

This week's genus:

Lathyrus

The genus Lathyrus displays several of the commonly known characteristics of the Leguminosae family, including typical pea flowers and tendrils at the terminal ends of the stems. While some species in this genus have edible seeds/pods, many are considered poisonous: lathyrism is a medical term used to describe the disease caused by eating peas or chick peas. This disease has been observed in both humans and animals, and includes symptoms such as cramps and "deformity". Those who are wise enough not to eat these species can be satisfied with admiring their beauty as well as their symbiotic relationship with nitrogen-fixing bacteria.

Here are a few links to images and descriptions of different Lathyrus species:

• The International Legume Database and Information Service (ILDIS) has compiled images and information for more than a dozen Lathyrus species. This is a great web site.
• The Canadian Poisonous Plants Information System has data for both L. odoratus (Sweet Pea), which can cause osteolathyrism, and L. sativus (Chick Pea), which can cause neurolathyrism.
• Botanik online, a German site, has images of herbarium specimens of L. vernus and L. sylvestris.
• The Internet Garden has a section specifically devoted to Peter Grayson, the "guru of Lathyrus cultivation" (their words, not mine). There is a link from there to an interesting history that he has written about the Sweet Pea.
• Click here to learn more about lectin, a protein that has been isolated from L. ochrus.
• The Singletary Pea (L. hirsutis) is susceptible to a number of plant pathogens. This site lists some of them.
• The California Native Plant Society's web site has information about L. biflorus (Two-flowered Pea), including a photo and literature references.
• Molecular biologists may be interesting in visiting this page, which has an abstract from a presentation given at the International Plant Genome Conference (Plant Genome IV) concerning molecular markers for several Legume species.
• Another interesting site for molecular biologists is the CoolGenes site, a searchable genome database for several Legumes, including, of course, Lathyrus species. (Note: as of 10/14/03, the CoolGenes database is offline. The link now takes you to the UK CropNet site, which mirrors many of the genetic databases, and has a link for CoolGenes that may on day be operational.)

1. Forey, Pamela. Wild Flowers of North America. New York, Gallery Books: 1991.
2. Heywood, V.H., ed. Flowering Plants of the World. New York, Oxford University Press: 1993.
3. Neiring, William A. and Nancy C. Olmstead., eds. The Audubon Society Field Guide to North American Wildflowers, Eastern Region. Alfred A. Knopf, New York: 1979.