Hi Gang,
Take a bite out of a wild onion bulb or try chomping on a wild potato
tuber and you'll know that geophytes can taste awful or actually be
poisonous. Likely, one reason underground plant parts can be toxic or vile
is because they have evolved chemical defenses to ward off insects and
hungry vertebrates.
Although any part of a plant can produce chemicals that deter herbivory,
the underground parts seem like special cases. Underground storage organs
are rich repositories of food, and such is a bonanza for animals. Why
bother eating a leaf when a tuber provides far more nourishment in the form
of complex carbohydrates.
Some plants actually give off chemicals that are not nasty-tasting or
poisonous but which mimic alarm chemicals emitted by insects--the thinking
is that insects sense the chemicals and move to apparently safer locations.
Some plants give off chemicals that inhibit the growth of other species.
Extracts from the bulbs of wild garlic (Allium ursinum) inhibit seed
germination and seedling growth of various plant species. Perhaps such
inhibitory activity is useful in the ongoing competition for soil water,
nutrients, and light.
Though plants have various abilities that evolved independent of humans,
we humans have learned out to exploit the copious chemical synthesizing
ability of plants, including geophytes. Extracts from Crinum jagus are
purported to protect against snake venom. A recent scientific paper
describes how C. jagus extracts, when injected into mice, appear to protect
the animals from snake venom. In particular, protection from carpet viper
venom (Echis ocellatus), a snake found in West Africa, was claimed.
Cordially,
Joe
Conroe, TX
Rain last night, 70s this week, frost on the weekend upcoming
LINK: Saw-scaled viper (carpet viper) info
http://elsevier-international.com/journals/…
CITATION: Ode and Asuzu. 2006. The anti-snake venom activities of
methanolic extract of the bulb of Crinum jagus (Amaryllidaceae). Toxicon.
48:331-342.
http://tinyurl.com/ycbtor/