The diversity of plants used for human food is dazzling--from wheat, apples, and carrots to thyme, bay leaves, and black pepper--but this variety scarcely compares to uncultivated diversity. Today, we give thanks not only for the plant species on our Thanksgiving tables, but also the evolutionary relatives of these species, particularly those found in California. Here are a few fun examples:
Mashed potatoes - Solanum
Green beans - Phaseolus
Bean-producing plants are so special they have their own family. Ok, it's a really big family with over 19,000 species, but that's just how important beans are to the plant diversity of the world. There are over 300 species in the bean family (Fabaceae) native to California, but only one of them is in the same genus as green beans.
The green beans you generally find in soups and casseroles are from the species Phaseolus vulgaris (vulgaris means "common" in Latin). The single native Phaseolus species in California is the slender-stem bean, Phaseolus filiformis. Unlike American nightshade, slender-stem bean is neither common nor widespread in California; only one California specimen has been documented to date! This sand-loving species extends into Arizona, New Mexico, Texas, and Mexico, inhabiting desert washes and producing tiny pink flowers around this time of year. There's little information about whether this species is edible (likely not), but even if it were, we should be mindful of not harming the rare California populations of this species.
Pumpkin pie - Cucurbita
What species do you find on your Thanksgiving table, and do these species have native relatives in your area? Answers to these questions and many more are aided by our knowledge of biodiversity from herbarium specimens.
- genus - scientific name that denotes a rank above species but below family
- habit - the general architecture or form in which a plant grows (e.g., tree, shrub, vine)
- morphology - appearance and appearance-related traits (e.g., leaf shape, color)
- pepo - a type of fleshy fruit with a tough rind, produced by a species of the melon family
- tuber - an underground stem or rhizome that is enlarged and thickened, usually for storage of starch and minerals for the plant
- waif - plant occurring outside of its usual range or circumstances that is not likely to persist