WILD FLOWERS [189]
of true peas. The partridge pea bears from two to four showy flowers together, each measuring an inch or more across, on a slender pedicel from the axils. It fully expands only four of its five bright yellow petals; they are somewhat unequal in size, the upper ones, with touches of red at the base, as pathfinders, not, however, as nectar-guides, since no sweets are secreted here. Curiously enough, both right and left hand flowers are found upon the same plant; that is to say, the sickle-shaped pistil turns either to the right or the left. One lateral petal, instead of being flexible and spread like the rest, stands so stiffly erect and incurved that it commonly breaks on being bent back. Why? The pistil, it will be noticed, points away from the ten long black anthers. Obviously, then, the flower cannot fertilize itself. Its benefactors are bumblebee females and workers out after pollen. Cup-shaped nectaries ("extra nuptial") are situated on the upper side and near the base of the leaf stalks on these cassia plants, where they can have no direct influence on the fertilization of the blossoms. Apparently, they are free lunch-counters, kept open out of pure charity. Landing upon the long black anthers with pores in their tips to let out the pollen, the bumblebees "seize them between their mandibles, says Professor Robertson, "and stroke them downward with a sort of milking motion. The pollen...falls either directly upon the bee or upon the erect lateral petal which is pressed close against the bee's side. In this way the side of the bee which is next to the incurved petal receives the most pollen.... A bee visiting a left-hand flower receives pollen upon the right side, and then flying to a right-hand flower, strikes the same side against the stigma." When we find circular holes in these petals we may know the leaf-cutter or upholsterer bee (Megachile brevis) has been at work collecting roofs for her nurseries (see Hairy Ruellia). The partridge pea, which has a more westerly range than the sensitive pea's, extends it southward even to Bolivia. Game birds, migrants and rovers, which feed upon the seeds, have of course helped in their wider distribution. The plant blooms from July to September.
WILD or AMERICAN SENNA (Cassia Marylandica) Senna family
Flowers - Yellow, about 3/4 in. broad, numerous, in short axillary clusters on the upper part of plant. Calyx of 5 oblong lobes; 5 petals, 3 forming an upper lip, 2 a lower one; 10 stamens of 3 different kinds; 1 pistil. Stem: 3 to 8 ft. high, little branched. Leaves: Alternate, pinnately compounded of 6 to 10 pairs of oblong leaflets. Fruit: A narrow, flat curving pod, 3 to 4 in. long. Preferred Habitat - Alluvial or moist, rich soil, swamps, roadsides. Flowering Season - July-August. Distribution - New England, westward to Nebraska, south to the Gulf States.
Whoever has seen certain Long Island roadsides bordered with wild senna, the brilliant flower clusters contrasted with the deep green of the beautiful foliage, knows that no effect produced by art along the drives of public park or private garden can match these country lanes in simple charm. Bumblebees, buzzing about the blossoms, may be observed "milking" the anthers just as they do those of the partridge pea. No red spots on any of these petals guide the visitors, as in the previous species, however; for do not the three small, dark stamens, which are reduced to mere scales, answer every purpose as pathfinders here? The stigma, turned sometimes to the right, sometimes to the left, strikes the bee on the side; the senna being what Delpino, the Italian botanist, calls a pleurotribe flower.
While leaves of certain African and East Indian species of senna are most valued for their medicinal properties, those of this plant are largely collected in the Middle and Southern States as a substitute. Caterpillars of several sulphur butterflies, which live exclusively on cassia foliage, appear to feel no evil effects from overdoses.
WILD INDIGO; YELLOW or INDIGO BROOM; HORSEFLY-WEED (Baptisia tinctoria) Pea
WILD or AMERICAN SENNA (Cassia Marylandica) Senna family
Flowers - Yellow, about 3/4 in. broad, numerous, in short axillary clusters on the upper part of plant. Calyx of 5 oblong lobes; 5 petals, 3 forming an upper lip, 2 a lower one; 10 stamens of 3 different kinds; 1 pistil. Stem: 3 to 8 ft. high, little branched. Leaves: Alternate, pinnately compounded of 6 to 10 pairs of oblong leaflets. Fruit: A narrow, flat curving pod, 3 to 4 in. long. Preferred Habitat - Alluvial or moist, rich soil, swamps, roadsides. Flowering Season - July-August. Distribution - New England, westward to Nebraska, south to the Gulf States.
Whoever has seen certain Long Island roadsides bordered with wild senna, the brilliant flower clusters contrasted with the deep green of the beautiful foliage, knows that no effect produced by art along the drives of public park or private garden can match these country lanes in simple charm. Bumblebees, buzzing about the blossoms, may be observed "milking" the anthers just as they do those of the partridge pea. No red spots on any of these petals guide the visitors, as in the previous species, however; for do not the three small, dark stamens, which are reduced to mere scales, answer every purpose as pathfinders here? The stigma, turned sometimes to the right, sometimes to the left, strikes the bee on the side; the senna being what Delpino, the Italian botanist, calls a pleurotribe flower.
While leaves of certain African and East Indian species of senna are most valued for their medicinal properties, those of this plant are largely collected in the Middle and Southern States as a substitute. Caterpillars of several sulphur butterflies, which live exclusively on cassia foliage, appear to feel no evil effects from overdoses.
WILD INDIGO; YELLOW or INDIGO BROOM; HORSEFLY-WEED (Baptisia tinctoria) Pea