书城公版WILD FLOWERS
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第70章 WHITE AND GREENISH FLOWERS(1)

"The transition from wind-fertilization to insect-fertilization and the first traces of adaptation to insects, could only be due to the influence of quite short-lipped insects with feebly developed color sense.The most primitive flowers are therefore for the most part ******, widely open, regular, devoid of nectar or with their nectar unconcealed and easily accessible, and greenish, white, or yellow in color....Lepidoptera, by the thinness, sometimes by the length, of their tongues, were able to produce special modifications.Through their agency were developed flowers with long and narrow tubes, whose colors and time of opening were in relation to the tastes and habits of their visitors." - Hermann Muller.

"Of all colors, white is the prevailing one; and of white flowers a considerably larger proportion smell sweetly than of any other color, namely, 14.6 per cent; of red only 8.2 per cent are odoriferous.The fact of a large proportion of white flowers smelling sweetly may depend in part on those which are fertilized by moths requiring the double aid of conspicuousness in the dusk and of odor.So great is the economy of Nature, that most flowers which are fertilized by crepuscular or nocturnal insects emit their odor chiefly or exclusively in the evening." - Charles Darwin.

WATER-PLANTAIN

(Alisma Plantago-aquatica) Water-plantain family Flowers - Very small and numerous, white, or pale pink, whorled in bracted clusters forming a large, loose panicle 6 to 15 in.

long on a usually solitary scape 1/2 to 3 ft.high.Calyx of 3sepals corolla of 3 deciduous petals; 6 or more stamens; many carpels in a ring on a small flat receptacle.Leaves: Erect or floating, oblong or ovate, with several ribs, or lance-shaped or grass-like, petioled, all from root.

Perferred Habitat - Shallow water, mud, marshes.

Flowering Season - June-September.

Distribution - North America, Europe, Asia.

Unlike its far more showy, decorative cousin the arrow-head, this wee-blossomed plant, whose misty white panicles rise with compensating generosity the world around, bears only perfect, regular flowers.Twelve infinitesimal drops of nectar, secreted in a fleshy ring around the center, are eagerly sought by flies.

As the anthers point obliquely outward and away from the stigmas, an incoming fly, bearing pollen on his under side, usually alights in the center, and leaves some of the vitalizing dust just where it is most needed.But a "fly starting from a petal,"says Muller, "usually applies its tongue to the nectar-drops one by one, and after each it strokes an anther with its labellae; in so doing it may bring various parts of its body in contact with the anthers.As a rule, however, the parts which come in contact with the anthers are not those which come in contact with the stigmas in the same flower." Any plant that lives in shallow water, which may dry up as summer advances, is under special necessity to produce an extra quantity of cross-fertilized seed to guard against extinction during drought.For the same reason it bears several kinds of leaves adapted to its environment:

broad ones that spread their surfaces to the sunshine, and long grass-like ones to glide through currents of water that would tear those of any other shape.What diversity of leaf-form and structure we meet daily, and yet how very little does the wisest man of science understand of the reasons underlying such marvellous adaptability!

BROAD-LEAVED 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.