|
Beach pea flowers, Lathyrus japonicus |
If you've grown sweet peas or garden peas, you'll instantly
recognize their relative growing on the shoreline. Beach peas share the Leguminosae * family resemblance in clusters
of flowers and 'bean' pods.
|
Beach pea pods at
Halibut Point tide line |
Beach peas clamber over anything their tendrils can grasp,
in a modest way. Its ambitious cousin wisteria aims to entwine acres of trees.
|
Wisteria pods high in
a tree |
|
Wisteria japonica flowers |
Wisteria's foliage, flowers and fruit are visibly pea-like.
|
Black locust in bloom,
Robinia pseudo-acacia
|
Black locusts extend the diversity of the legume family to include
tall woody trees on Halibut Point.
It could be said that botanical evolution culminates in the
dicotyledons that contain our most familiar
flowering plants. Among the distinctions that give them a different 'look' from
monocots are the pair (versus single) of embryonic leaves, the netted (versus
parallel) vein pattern in the leaves, and the flower parts in fours or fives
(versus threes). Contrast the
pea family
with grasses and lilies as charted above.
Legumes have always been nutritionally important to mankind.
The pea family includes beans, soybeans, chickpeas, alfalfa and peanuts.
|
American groundnut, Apios americana |
Groundnuts (wild beans or Indian potatoes) produce tubers that
were a staple food for Native Americans, and an important factor in the
survival of the Pilgrims during the first few winters of their settlement. Pound
for pound they contain three times the protein of potatoes, ten times the
calcium, and twice the iron. **
As a member of the legume family the groundnut's ability to supply
its own nitrogen in partnership with
soil bacteria could be a great advantage in comparison to root crops
that require extensive fertilization. But because it has not yet been coaxed
into yielding significantly enough in a single season it has not been
assimilated into modern agriculture.
|
Red and white clover,
Trifolium pratense and T. repens |
|
Palmate hop clover, Trifolium aureum |
Also found at Halibut Point are
two other species of the genus
Trifolium,
Lesser hop clover (
T. dubium) and Pinnate
hop clover (
T. campestre); as well as
members of the genus
Meliolotus,
white-sweet-clover (
M. albus) and
yellow-sweet-clover (
M. officinalis).
Various clovers have been extensively cultivated as livestock
fodder plants, either sown alone or in a mixture with ryegrass to form a staple
crop for silaging. They are also welcome in pastures and meadows as a nectar
source by beekeepers.
|
Rabbit-foot clover, Trifolium arvense |
While not a forage crop, the nitrogen-fixing properties of
rabbit-foot clover enable it to prosper in lean soil locations.
|
Cow vetch, Vicia cracca |
Vetches have made similar contributions to both natural and agricultural
ecologies as clovers, enriching soil, planted as green manure in crop rotation
plans, favored as livestock feed.
Like many legumes they host
rhizobia
bacteria
within structures called
root nodules. These bacteria have the ability
to convert
nitrogen
gas
from the air into a form that is
usable to the plant.
Nitrogen fixation results from a classic
symbiotic relationship beneficial to both organisms.
|
Four-seeded vetch, Vicia tetrasperma |
|
Crown-vetch, Securigera varia |
|
Bird's-foot-trefoil, Lotus corniculatus |
Bird's-foot-trefoil, with many of the same utilitarian qualities as vetch,
presents a startlingly beautiful wildflower in impoverished soils. A
double-flowered variety has been introduced to horticulture.
|
Blue lupine, Lupinus polyphyllus |
Last year, when a presently lawn area in the State Park grew
luxuriantly as a meadow, lupines bloomed in profusion.
Lupine seeds are large and edible enough to have been used
as a food for over 3000 years around the Mediterranean and for as much as 6000
years in the Andean highlands.
The legume family is unrivaled in its combined ornamental
and comestible value to mankind.
_____________________________________
* Most authorities use the name
Fabaceae (from Latin
faba for
'bean') for the pea family. I prefer to retain
Leguminosae, an older name still considered valid, for its reference
to the
fruit of
these plants, which are called
legumes.
** I derived much of
the information in this essay from pertinent Wikipedia articles