BROADLEAVED ARROWHEAD





(Sagittaria latifolia; S. variabilis of Gray) Water-plantain

family



Flowers - White, 1 to 1 1/2 in. wide, in 3-bracted whorls of 3,

borne near the summit of a leafless scape 4 in. to 4 ft. tall.

Calyx of 3 sepals corolla of 3 rounded, spreading petals. Stamens

and pistils numerous, the former yellow in upper flowers usually

absent or imperfect in lower pistillate flowers. Leaves:

Exceedingly variable; those under water usually long and

grasslike; upper ones sharply arrow-shaped or blunt and broad,

spongy or leathery, on long petioles.

Preferred Habitat - Shallow water and mud.

Flowering Season - July-September.

Distribution - From Mexico northward throughout our area to the

circumpolar regions.



Wading into shallow water or standing on some muddy shore, like a

heron, this striking plant, so often found in that bird's haunts,

is quite as decorative in a picture, and, happily, far more

approachable in life. Indeed, one of the comforts of botany as

compared with bird study is that we may get close enough to the

flowers to observe their last detail, whereas the bird we have

followed laboriously over hill and dale, through briers and

swamps, darts away beyond the range of field-glasses with

tantalizing swiftness.



While no single plant is yet thoroughly known to scientists, in

spite of the years of study devoted by specialists to separate

groups, no plant remains wholly meaningless. When Keppler

discovered the majestic order of movement of the heavenly bodies,

he exclaimed, "Oh God, I think Thy thoughts after Thee!" - the

expression of a discipleship every reverent soul must be

conscious of in penetrating, be it ever so little a way, into the

inner meaning of the humblest wayside weed.



Fragile, delicate, pure white, golden-centered flowers of the

arrowhead, usually clustered about the top of the scape,

naturally are the first to attract the attention whether of man

or insect. Below these, dull green, unattractive collections of

pistils, which by courtesy only may be called flowers, also form

little groups of three. Like the Quakers at meeting, the male and

female arrowhead flowers are separated, often on distinct plants.

Of course the insect visitors - bees and flies chiefly - alight

on the showy staminate blossoms first, and transfer pollen from

them to the dull pistillate ones later, as it was intended they

should, to prevent self-fertilization. How endless are the

devices of the flowers to guard against this evil and to compel

insects to cross-pollinate them! The most minute detail of the

mechanism involved, which the microscope reveals, only increases

our interest and wonder.



Any plant which elects to grow in shallow water must be

amphibious; it must be able to breathe beneath the surface as the

fish do, and also be adapted to thrive without those parts that

correspond to gills; for ponds and streams have an unpleasant way

of drying up in summer, leaving it stranded on the shore. This

accounts in part for the variable leaves on the arrowhead, those

underneath the water being long and ribbon-like, to bring the

greatest possible area into contact with the air with which the

water is charged. Broad leaves would be torn to shreds by the

current through which grass-like blades glide harmlessly; but

when this plant grows on shore, having no longer use for its

lower ribbons, it loses them, and expands only broad arrow-shaped

surfaces to the sunny air, leaves to be supplied with carbonic

acid to assimilate, and sunshine to turn off the oxygen and store

up the carbon into their system.





BRIDEWEED BROADLEAVED KALMIA facebooktwittergoogle_plusredditpinterestlinkedinmail

Feedback