WILD FLOWERS [152]
the deep-hidden sweets. How pleasant the way is made for such insects as a flower must needs encourage! For these the perennial wild potato vine keeps open house far later in the day than its annual relatives. Professor Robertson says it is dependent mainly upon two bees, Entechnia taurea and Xenoglossa ipomoeae, the latter its namesake.
One has to dig deep to find the huge, fleshy, potato-like root from which the vine derived its name of man-of-the-earth. Such a storehouse of juices is surely necessary in the dry soil where the wild potato lives.
Happily, the COMMON MORNING-GLORY (I. purpurea) - the Convolvulus major of seedsmen's catalogues - has so commonly escaped from cultivation in the eastern half of the United States and Canada as now to deserve counting among our wild flowers, albeit South America is its true home. Surely no description of this commonest of all garden climbers is needed; everyone has an opportunity to watch how the bees cross-fertilize it.
The vine has a special interest because of Darwin's illuminating experiments upon it when he planted six self-fertilized seeds and six seeds fertilized with the pollen brought from flowers on a different vine, on opposite sides of the same pot. Vines produced by the former reached an average height of five feet four inches, whereas the cross-pollenized seed sent its stems up two feet higher, and produced very many more flowers. If so marked a benefit from imported pollen may be observed in a single generation, is it any wonder that ambitious plants employ every sort of ingenious device to compel insects to bring them pollen from distant flowers of the same species? How punctually the MOON-FLOWER (I. grandiflora), next of kin to the morning-glory, opens its immense, pure white, sweet-scented flowers at night to attract night-flying moths, because their long tongues, which only can drain the nectar, may not be withdrawn until they are dusted with vitalizing powder for export to some waiting sister.
GRONOVIUS' or COMMON DODDER; STRANGLE-WEED; LOVE VINE; ANGEL'S HAIR (Cuscuta gronovii) Dodder family
Flowers - Dull white, minute, numerous, in dense clusters. Calyx inferior, greenish white, 5-parted; corolla bell-shaped, the 5 lobes spreading, 5 fringed scales within; 5 stamens, each inserted on corolla throat above a scale; 2 slender styles. Stem: Bright orange yellow, thread-like, twining high, leafless. Preferred Habitat - Moist soil, meadows, ditches, beside streams. Flowering Season - July-September. Distribution - Nova Scotia and Manitoba, south to the Gulf States.
Like tangled yellow yarn wound spirally about the herbage and shrubbery in moist thickets, the dodder grows, its beautiful bright threads plentifully studded with small flowers tightly bunched. Try to loosen its hold on the support it is climbing up, and the secret of its guilt is out at once; for no honest vine is this, but a parasite, a degenerate of the lowest type, with numerous sharp suckers (haustoria) penetrating the bark of its victim, and spreading in the softer tissues beneath to steal all their nourishment. So firmly are these suckers attached, that the golden thread-like stem will break before they can be torn from their hold.
Not a leaf now remains on the vine to tell of virtue in its remote ancestors; the absence of green matter (chlorophyll) testifies to dishonest methods of gaining a living (see Indian pipe); not even a root is left after the seedling is old enough to twine about its hard-working, respectable neighbors. Starting out in life with apparently the best intentions, suddenly the tender young twiner develops an appetite for strong drink and murder combined, such as would terrify any budding criminal in Five Points or Seven Dials! No sooner has it laid hold of its victim and tapped it, than the now useless root and lower portion wither away, leaving the dodder in mid-air, without any connection with the soil below, but abundantly nourished with juices already stored up, and even assimilated, at its host's expense. By rapidly lengthening the cells on
One has to dig deep to find the huge, fleshy, potato-like root from which the vine derived its name of man-of-the-earth. Such a storehouse of juices is surely necessary in the dry soil where the wild potato lives.
Happily, the COMMON MORNING-GLORY (I. purpurea) - the Convolvulus major of seedsmen's catalogues - has so commonly escaped from cultivation in the eastern half of the United States and Canada as now to deserve counting among our wild flowers, albeit South America is its true home. Surely no description of this commonest of all garden climbers is needed; everyone has an opportunity to watch how the bees cross-fertilize it.
The vine has a special interest because of Darwin's illuminating experiments upon it when he planted six self-fertilized seeds and six seeds fertilized with the pollen brought from flowers on a different vine, on opposite sides of the same pot. Vines produced by the former reached an average height of five feet four inches, whereas the cross-pollenized seed sent its stems up two feet higher, and produced very many more flowers. If so marked a benefit from imported pollen may be observed in a single generation, is it any wonder that ambitious plants employ every sort of ingenious device to compel insects to bring them pollen from distant flowers of the same species? How punctually the MOON-FLOWER (I. grandiflora), next of kin to the morning-glory, opens its immense, pure white, sweet-scented flowers at night to attract night-flying moths, because their long tongues, which only can drain the nectar, may not be withdrawn until they are dusted with vitalizing powder for export to some waiting sister.
GRONOVIUS' or COMMON DODDER; STRANGLE-WEED; LOVE VINE; ANGEL'S HAIR (Cuscuta gronovii) Dodder family
Flowers - Dull white, minute, numerous, in dense clusters. Calyx inferior, greenish white, 5-parted; corolla bell-shaped, the 5 lobes spreading, 5 fringed scales within; 5 stamens, each inserted on corolla throat above a scale; 2 slender styles. Stem: Bright orange yellow, thread-like, twining high, leafless. Preferred Habitat - Moist soil, meadows, ditches, beside streams. Flowering Season - July-September. Distribution - Nova Scotia and Manitoba, south to the Gulf States.
Like tangled yellow yarn wound spirally about the herbage and shrubbery in moist thickets, the dodder grows, its beautiful bright threads plentifully studded with small flowers tightly bunched. Try to loosen its hold on the support it is climbing up, and the secret of its guilt is out at once; for no honest vine is this, but a parasite, a degenerate of the lowest type, with numerous sharp suckers (haustoria) penetrating the bark of its victim, and spreading in the softer tissues beneath to steal all their nourishment. So firmly are these suckers attached, that the golden thread-like stem will break before they can be torn from their hold.
Not a leaf now remains on the vine to tell of virtue in its remote ancestors; the absence of green matter (chlorophyll) testifies to dishonest methods of gaining a living (see Indian pipe); not even a root is left after the seedling is old enough to twine about its hard-working, respectable neighbors. Starting out in life with apparently the best intentions, suddenly the tender young twiner develops an appetite for strong drink and murder combined, such as would terrify any budding criminal in Five Points or Seven Dials! No sooner has it laid hold of its victim and tapped it, than the now useless root and lower portion wither away, leaving the dodder in mid-air, without any connection with the soil below, but abundantly nourished with juices already stored up, and even assimilated, at its host's expense. By rapidly lengthening the cells on