Order 117. PONTEDERIÀCEÆ. (Pickerel-weed Family.)
Aquatic herbs, with perfect more or less irregular flowers from a spathe; the petal-like 6-merous perianth free from the 3-celled ovary; the 3 or 6 mostly unequal or dissimilar stamens inserted in its throat.—Perianth with the 6 divisions colored alike, imbricated in 2 rows in the bud, the whole together sometimes revolute-coiled after flowering, then withering away, or the base thickened-persistent and enclosing the fruit. Anthers introrse. Ovules anatropous. Style 1; stigma 3-lobed or 6-toothed. Fruit a perfectly or incompletely 3-celled many-seeded capsule, or a 1-celled 1-seeded utricle. Embryo slender, in floury albumen.
1. Pontederia. Spike many-flowered. Perianth 2-lipped, its fleshy persistent base enclosing the 1-seeded utricle. Stamens 6.
2. Heteranthera. Spathe 1–few-flowered. Perianth salver-shaped. Stamens 3. Capsule many-seeded.
1. PONTEDÈRIA, L. Pickerel-weed.
Perianth funnel-form, 2-lipped; the 3 upper divisions united to form the 3-lobed upper lip; the 3 lower spreading, and their claws, which form the lower part of the curving tube, more or less separate or separable to the base; after flowering the tube is revolute-coiled from the apex downward, and its fleshy-thickened persistent base encloses the fruit. Stamens 6; the 3 anterior long-exserted; the 3 posterior (often sterile or imperfect) with very short filaments, unequally inserted lower down; anthers versatile, oval, blue. Ovary 3-celled; two of the cells empty, the other with a single suspended ovule. Utricle 1-celled, filled with the single seed.—Stout herbs, growing in shallow water, with thick creeping rootstocks, producing erect long-petioled mostly heart-shaped leaves, and a 1-leaved stem, bearing a spike of violet-blue ephemeral flowers. Root-leaves with a sheathing stipule within the petiole. (Dedicated to Pontedera, Professor at Padua at the beginning of the last century.)
1. P. cordàta, L. Leaves arrow-heart-shaped, blunt, or sometimes triangular-elongated and tapering and scarcely cordate (var. angustifòlia, Torr.); spike dense, from a spathe-like bract; upper lobe of perianth marked with a pair of yellow spots (rarely all white); calyx-tube in fruit crested with 6 toothed ridges.—N. Scotia to Fla., west to Minn. and Tex. July–Sept.
2. HETERANTHÈRA, Ruiz & Pav. Mud-Plantain.
Perianth salver-form with a slender tube; the limb somewhat equally 6-parted, ephemeral. Stamens 3, in the throat, usually unequal; anthers erect. Capsule 1-celled or incompletely 3-celled by intrusion of the placentæ, many-seeded.—Creeping, floating or submerged low herbs, in mud or shallow water, with a 1–few-flowered spathe bursting from the sheathing side or base of a petiole. (Name from ἑτέρα, different, and ἀνθηρά, anther.)
[*] Stamens unequal; 2 posterior filaments with ovate yellow anthers; the other longer, with a larger oblong or sagittate greenish anther; capsule incompletely 3-celled; leaves rounded, long-petioled; creeping or floating plants.