PONTEDERIACEAE

PICKEREL-WEED FAMILY

Elizabeth McClintock

Annual, perennial herb, submersed, emergent, floating, or on wet ground
Leaves simple, alternate or whorled, ± in basal rosette or not; blade linear (especially underwater) to round, sagittate or cordate or not, bases generally sheathing, veins parallel; petioles sometimes inflated or 0 (especially underwater)
Inflorescence: raceme, spike, panicle, or 1-flowered, terminal but often appearing ± axillary, subtended by sheathing bract
Flower bisexual, radial or ± bilateral; perianth lobes generally 6, in 2 series of 3, petal-like; stamens equal or not, attached to perianth tube at various levels, 3, 6, (1, 4), sometimes 3 sterile, modified; ovary superior, 1–3-chambered
Fruit: 1-seeded utricle or many-seeded, loculicidal capsule
Seeds small, longitudinally ribbed or not
Genera in family: ± 6 genera, 30 species: most pantrop, some temp. Some cultivated as orns, some weeds, especially in rice fields
Reference: [Rosatti 1987 J Arnold Arb 68:35–71]

HETERANTHERA

MUD PLANTAIN

Annual, perennial herb, generally submersed, emergent, or on wet ground
Stem ± erect, slender, elongate, ± spreading, rooting at nodes or stout
Leaves alternate, linear, sessile, or ± in basal rosettes, ± ovate, long-petioled
Inflorescence generally 1-flowered
Flower ± radial; perianth salverform, lobes 6; stamens 3, alike or of 2 sizes, shapes, anthers coiling or not; ovary 1-chambered
Fruit: capsule
Seeds many, longitudinally ribbed
Species in genus: ± 12 species: tropical, temp Am, Africa
Etymology: (Greek: different, anther, from unequal anthers of most spp)
. Fls developed underwater generally cleistogamous.

Native

H. dubia (Jacq.) MacMill.

WATER STAR-GRASS

Perennial, generally submersed
Stem often rooting at nodes
Leaf > 15 cm
Flower appearing ± axillary; perianth yellow, tube ± 1.5(–7) cm; stamens 3, alike, anthers coiled
Ecology: Uncommon. Still or moving water
Elevation: < 1500 m.
Bioregional distribution: North Coast, Sacramento Valley, Modoc Plateau
Distribution outside California: widespread N.America, C.America
Vegetatively ± similar to species of Potamogeton , except leaves lack distinct midrib
Horticultural information: Fresh water margins: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24.