_Sagittaria latifolia (S. variabilis)_
_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 grass-like; 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, “O 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.
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 arrow-head, 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.