SPREADING DOGBANE; FLY-TRAP DOGBANE; HONEY-BLOOM; BITTER-ROOT
(Apocynum androsaemifolium) Dogbane family
Flowers - Delicate pink, veined with a deeper shade, fragrant, bell-shaped, about 1/3 in. across, borne in loose terminal cymes. Calyx 5-parted; corolla of 5 spreading, recurved lobes united into a tube; within the tube 5 tiny, triangular appendages alternate with stamens; the arrow-shaped anthers united around the stigma and slightly adhering to it. Stem: 1 to 4 ft. high, with forking, spreading, leafy branches. Leaves: Opposite, entire-edged, broadly oval, narrow at base, paler, and more or less hairy below. Fruit: Two pods about 4 in. long. Preferred Habitat - Fields, thickets, beside roads, lanes, and walls. Flowering Season - June-July. Distribution - Northern part of British Possessions south to Georgia, westward to Nebraska.
Everywhere at the North we come across this interesting, rather shrubby plant, with its pretty but inconspicuous little rose-veined bells suggesting pink lilies-of-the-valley. Now that we have learned to read the faces of flowers, as it were, we instantly suspect by the color, fragrance, pathfinders, and structure that these are artful wilers, intent on gaining ends of their own through their insect admirers. What are they up to?
Let us watch. Bees, flies, moths, and butterflies, especially the latter, hover near. Alighting, the butterfly visitor unrolls his long tongue and inserts it where the five pink veins tell him to, for five nectar-bearing glands stand in a ring around the base of the pistil. Now, as he withdraws his slender tongue through one of the V-shaped cavities that make a circle of traps, he may count himself lucky to escape with no heavier toll imposed than pollen cemented to it. This granular dust he is required to rub off against the stigma of the next flower entered. Some bees, too, have been taken with the dogbane's pollen cemented to their tongues. But suppose a fly call upon this innocent-looking blossom? His short tongue, as well as the butterfly's, is guided into one of the V-shaped cavities after he has sipped; but, getting wedged between the trap's horny teeth, the poor little victim is held a prisoner there until he slowly dies of starvation in sight of plenty. This is the penalty he must pay for trespassing on the butterfly's preserves! The dogbane, which is perfectly adapted to the butterfly, and dependent upon it for help in producing fertile seed, ruthlessly destroys all poachers that are not big or strong enough to jerk away from its vise-like grasp. One often sees small flies and even moths dead and dangling by the tongue from the wicked little charmers. If the flower assimilated their dead bodies as the pitcher plant, for example, does those of its victims, the fly's fate would seem less cruel. To be killed by slow torture and dangled like a scarecrow simply for pilfering a drop of nectar is surely an execution of justice medieval in its severity.
In July the most splendid of our native beetles, the green dandy (Eumolpus auratus) fastens itself to the dogbane's foliage in numbers until often the leaves appear to be studded with these brilliant little jewels. "It is not easy," says William Hamilton Gibson, "to describe its burnished hue, which is either shimmering green, or peacock blue, or purplish-green, or refulgent ruby, according to the position in which it rests." But it is not golden, as its specific name would imply. It confines itself exclusively to the dogbane. To prevent capture, it has a trick of drawing up its legs and rolling off into the grass its body so cleverly matches.
>From the silky coma on which the small seeds float away from long pods to found new colonies, from the opposite leaves, milky juice, and certain structural resemblances in the flowers, one might guess this plant belonged to the milkweed tribe. Formerly it was so classed; and although the botanists have now removed its family one step away, the milkweed butterflies, especially the Monarch (Anosia plexippus), ignoring the arbitrary dividing line of man, still includes the dogbane on its visiting list. We know that this plant derived its name from the fact that it was considered poisonous to dogs; and we also know that all the tribe of milkweed butterflies are provided with protective secretions which are distasteful to birds and predaceous insects, enjoying their immunity from attack, it is thought, from the acrid, poisonous character of the foliage on which the caterpillars feed.
COMMON MIIKWEED or SILKWEED
(Asclepias Syriaca; A. cornuti of Gray) Milkweed family
Flowers - Dull pale greenish purple pink, or brownish pink, borne on pedicels, in many flowered, broad umbels. Calyx inferior, 5-parted; corolla deeply 5-cleft, the segments turned backward. Above them an erect, 5-parted crown, each part called a hood, containing a nectary, and with a tooth on either side, and an incurved horn projecting from within. Behind the crown the short, stout stamens, united by their filaments in a tube, are inserted on the corolla. Broad anthers united around a thick column of pistils terminating in a large, sticky, 5-angled disk. The anther sacs tipped with a winged membrane; a waxy, pear-shaped pollen-mass in each sac connected with the stigma in pairs or fours by a dark gland, and suspended by a stalk like a pair of saddle-bags. Stem: Stout, leafy, usually unbranched, 3 to 5 ft. high, juice milky. Leaves: Opposite, oblong, entire-edged smooth above, hairy below, 4 to 9 in. long. Fruit: 2 thick, warty pods, usually only one filled with compressed seeds attached to tufts of silky, white, fluffy hairs. Preferred Habitat - Fields and waste places, roadsides. Flowering Season - June-September Distribution - New Brunswick, far westward and southward to North Carolina and Kansas.
After the orchids, no flowers show greater executive ability, none have adopted more ingenious methods of compelling insects to work for them than the milkweeds. Wonderfully have they perfected their mechanism in every part until no member of the family even attempts to fertilize itself; hence their triumphal, vigorous march around the earth, the tribe numbering over nineteen hundred species located chiefly in those tropical and warm, temperate regions that teem with insect life.
Commonest of all with us is this rank weed, which possesses the dignity of a rubber plant. Much more attractive to human eyes, at least, than the dull, pale, brownish-pink umbels of flowers are its exquisite silky seed-tufts. But not so with insects. Knowing that the slightly fragrant blossoms are rich in nectar, bees, wasps, flies, beetles, and butterflies come to feast. Now, the visitor finding his alighting place slippery, his feet claw about in all directions to secure a hold, just as it was planned they should for in his struggles some of his feet must get caught in the fine little clefts at the base of the flower. His efforts to extricate his foot only draw it into a slot at the end of which lies a little dark-brown body. In a newly opened flower five of these little bodies may be seen between the horns of the crown, at equal distances around it. This tiny brown excrescence is hard and horny, with a notch in its face. It is continuous with and forms the end of the slot in which the visitor's foot is caught. Into this he must draw his foot or claw, and finding it rather tightly held, must give a vigorous jerk to get it free. Attached to either side of the little horny piece is a flattened yellow pollen-mass, and so away he flies with a pair of these pollinia, that look like tiny saddle-bags, dangling from his feet. One might think that such rough handling as many insects must submit to from flowers would discourage them from making any more visits; but the desire for food is a mighty passion. While the insect is flying off to another blossom, the stalk to which the saddlebags are attached twists until it brings them together, that, when his feet get caught in other slots, they may be in the position to get broken off in his struggles for freedom precisely where they will fertilize the stigmatic chambers. Now the visitor flies away with the stalks alone sticking to his claws. Bumblebees and hive-bees have been caught with a dozen pollen-masses dangling from a single foot. Outrageous imposition!