书城公版WILD FLOWERS
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第31章 FROM BLUE TO PURPLE FLOWERS(29)

Americana), waves long, slender wands studded with blue or sometimes whitish flowers high above the ground of moist thickets and woods throughout the eastern half of this country, but rarely near the sea.Doubtless the salt air, which intensifies the color of so many flowers, would brighten its rather slatey blue.The corolla, which is flat, round, about an inch across, and deeply cleft into five pointed petals, has the effect of a miniature pinwheel in motion.Mature flowers have the style elongated, bent downward, then curved upward, that the stigmas may certainly be in the way of the visiting insect pollen-laden from an earlier bloomer, and be cross-fertilized.The larger bees, its benefactors, which visit it for nectar, touch only the upper side of the style, on which they must alight; but the anthers waste pollen by shedding it on all sides.No insect can take shelter from rain or pass the night in this flower, as he frequently does in its more hospitable relative, the harebell.English gardeners, more appreciative than our own of our native flora, frequently utilize this charming plant in their rockwork, increasing their stock by a division of the dense, leafy rosettes.

VENUS' LOOKING-GLASS; CLASPING BELLFLOWER(Legouzia perfoliata; Specularia perfoliata of Gray)Bellflower family Flowers - Violet blue, from 1/2 to 3/4 in.across; solitary or 2or 3 together, seated, in axils of upper leaves.Calyx lobes varying from 3 to 5 in earlier and later flowers, acute, rigid;corolla a 5-spoked wheel; 5 stamens; pistil with 3 stigmas.Stem:

6 in.to 2 ft.long, hairy, densely leafy, slender, weak.Leaves:

Round, clasped about stem by heart-shaped base.

Preferred Habitat - Sterile waste places, dry woods.

Flowering Season - May-September.

Distribution - From British Columbia, Oregon, and Mexico, east to Atlantic Ocean.

At the top of a gradually lengthened and apparently overburdened leafy stalk, weakly leaning upon surrounding vegetation, a few perfect blossoms spread their violet wheels, while below them insignificant earlier flowers, which, although they have never opened, nor reared their heads above the hollows of the little shell-like leaves where they lie secluded, have, nevertheless, been producing seed without imported pollen while their showy sisters slept.But the later blooms, by attracting insects, set cross-fertilized seed to counteract any evil tendencies that might weaken the species if it depended upon self-fertilization only.When the European Venus' looking-glass used to be cultivated in gardens here, our grandmothers tell us it was altogether too prolific, crowding out of existence its less fruitful, but more lovely, neighbors.

The SMALL VENUS' LOOKING-GLASS (L.biflora), of similar habit to the preceding, but with egg-shaped or oblong leaves seated on, not clasping, its smooth and very slender stem, grows in the South and westward to California.

GREAT LOBELIA; BLUE CARDINAL-FLOWER

(Lobelia syphilitica) Bellflower family Flowers - Bright blue, touched with white, fading to pale blue, about 1 in.long, borne on tall, erect, leafy spike.Calyx 5-parted, the lobes sharply cut, hairy.Corolla tubular, open to base on one side, 2-lipped, irregularly 5-lobed, the petals pronounced at maturity only.Stamens 5, united by their hairy anthers into a tube around the style; larger anthers smooth.

Stem: 1 to 3 ft.high, stout, ******, leafy, slightly hairy.

Leaves: Alternate, oblong, tapering, pointed, irregularly toothed, 2 to 6 in.long, 1/2 to 2 in.wide.

Preferred Habitat - Moist or wet soil; beside streams.

Flowering Season - July-October Distribution - Ontario and northern United States west to Dakota, south to Kansas and Georgia.

To the evolutionist, ever on the lookout for connecting links, the lobelias form an interesting group, because their corolla, slit down the upper side and somewhat flattened, shows the beginning of the tendency toward the strap or ray flowers that are nearly confined to the composites of much later development, of course, than tubular single blossoms.Next to massing their flowers in showy heads, as the composites do, the lobelias have the almost equally advantageous plan of crowding theirs along a stem so as to make a conspicuous advertisement to attract the passing bee and to offer him the special inducement of numerous feeding places close together.

The handsome GREAT LOBELIA, constantly and invidiously compared with its gorgeous sister the cardinal flower, suffers unfairly.

When asked what his favorite color was, Eugene Field replied:

"Why, I like any color at all so long as it's red!" Most men, at least, agree with him, and certainly hummingbirds do; our scarcity of red flowers being due, we must believe, to the scarcity of hummingbirds, which chiefly fertilize them.But how bees love the blue blossoms!

There are many cases where the pistil of a flower necessarily comes in contact with its own pollen, yet fertilization does not take place, however improbable this may appear.Most orchids, for example, are not susceptible to their own pollen.It would seem as if our lobelia, in elevating its stigma through the ring formed by the united anthers, must come in contact with some of the pollen they have previously discharged from their tips, not only on the bumblebee that shakes it out of them when he jars the flower, but also within the tube.But when the anthers are mature, the two lobes of the still immature stigma are pressed together, and cannot be fertilized.Nevertheless, the hairy tips of some of the anthers brush off the pollen grains that may have lodged on the stigma as it passes through the ring in its ascent, thus ****** surety doubly sure.Only after the stigma projects beyond the ring of anthers does it expand its lobes, which are now ready to receive pollen brought from another later flower by the incoming bumblebee to which it is adapted.