// SPECIES PROFILE · EMERGENT AQUATIC PERENNIAL · NATIVE · WETLAND

Pickerelweed

Pontederia cordata

Standing in the shallows at the edge of a pond or slow bayou with its heart-shaped glossy green leaves on long stalks rising clear of the water, Pontederia cordata sends up dense spikes of violet-blue tubular flowers from June through October — one of the longest-blooming native wetland plants in eastern North America. The thick, spreading rhizomes anchor it in the mud of ponds, oxbows, and slow backwaters across NE Oklahoma’s river-bottom country, and the flowers are worked heavily by bumblebees and carpenter bees through the entire growing season.

// QUICK FACTS

Family: Pontederiaceae (pickerelweed family)
Group: Emergent aquatic perennial
Native range: Eastern US including eastern OK
USDA hardiness: Zones 3–10 (Tulsa = 7a/7b)
Mature size: 1–3 ft above water; 2–4 ft including submerged portion
Sun: Full sun (tolerates part shade but blooms less)
Water depth: 0–12 in; thrives in saturated mud to shallow standing water
Soil: Mucky, silty, or clay substrate; very adaptable; pH 5.5–7.5
Bloom time: June–October (peak July–September)
Flower color: Violet-blue, tubular, in dense terminal spikes
Wildlife value: Bumblebees · fish cover · frog habitat · duck & muskrat food
Lifespan: Long-lived perennial; spreads by thick rhizomes
Ecological role: Shallow-water colonizer · aquatic pollinator resource · bank stabilizer

Pickerelweed (Pontederia cordata) — dense spikes of violet-blue tubular flowers rising above heart-shaped glossy leaves at the water's edge — *Pontederia cordata* — violet-blue flower spikes held above heart-shaped emergent leaves. Photo via Wikipedia / Wikimedia Commons.

Identification

[ field key — leaf · flower · rhizome · confusables ]

Leaves & stems

The leaves are the first thing you see: glossy, bright green, arrowhead-to-heart-shaped (cordate to sagittate), 4–8 in long, held on stout, spongy petioles that rise 1–3 ft above the water surface. The leaf bases range from shallowly cordate (heart-shaped) to broadly acute. The erect leaves form a dense stand that shades the water beneath them. Stems and petioles contain aerenchyma — spongy air-channel tissue — that aerates the submerged root system.

Flowers & fruit

A dense terminal spike 3–6 in long, held above the foliage on a stout stalk, bearing dozens of violet-blue, two-lipped tubular flowers each about 1/2 in across. Flowers open in sequence from the bottom of the spike upward over several weeks. Each individual flower lasts only one day. The fruit is a small one-seeded utricle with a corky, toothed outer layer that aids water dispersal. The flower spike is unmistakable in bloom and visible at a distance across a pond.

Rhizomes & root system

The plant anchors itself with thick, horizontal rhizomes buried in the muck of the littoral zone. These rhizomes can spread several feet per year in favorable conditions, forming large interconnected colonies. The fibrous roots extend into the saturated substrate and provide excellent bank stabilization in ponds and slow streams.

Confusables

Arrowhead / duck potato (Sagittaria spp.) also has emergent leaves but its leaves are distinctly arrow-shaped (deeply sagittate), and its flowers are white, three-petaled, and whorled. Arrow arum (Peltandra virginica) has similar arrowhead leaves but produces a greenish spathe-and-spadix flower. Pickerelweed is the only common emergent aquatic in NE Oklahoma that combines heart-shaped leaves with a violet-blue spike of tubular flowers.

Habitat & Range in NE Oklahoma

Pontederia cordata is a plant of shallow, still or slow-moving water across the eastern half of North America, and reaches its western limit in the wetlands of eastern Oklahoma. In NE Oklahoma it is found in the bayous, oxbow lakes, beaver ponds, and sheltered backwater margins of the Arkansas and Verdigris river systems — classic sites include the sloughs of the Neosho Wildlife Area, the quiet coves of Fort Gibson Lake, and the margins of stock ponds in the lower Grand River bottoms.

It prefers water 0–12 in deep over a mucky or fine-sediment substrate, and benefits from seasonal flooding that delivers fresh silt. It is intolerant of heavy wave action or fast current — you will not find it in the main river channel, only in the still backwaters. In garden settings across Tulsa, it can be grown in water garden containers, lined ponds, and rain-garden basins that hold standing water through the growing season.

Ecology & Wildlife Value

[ pollinators · aquatic habitat · waterfowl · fish cover ]

Pollinators

The tubular violet-blue flowers are pollinated primarily by large native bees — bumblebees (Bombus spp.) and carpenter bees (Xylocopa virginica) are the most effective visitors, strong enough to push into the corolla tube to reach the nectar. Smaller bees, syrphid flies, and occasional butterflies also visit. The long June–October bloom window makes pickerelweed an unusually reliable nectar source throughout the growing season.

Aquatic wildlife

The dense stand of stems and leaves provides critical cover and breeding habitat for a wide range of aquatic and semi-aquatic animals. Fish (including juvenile bass, sunfish, and the namesake pickerel) shelter among the stems; frogs and dragonfly nymphs use the emergent stalks as perches and emergence sites. Muskrats and ducks feed on the seeds and rhizomes; the seeds are especially important to wood ducks and mallards in fall and winter.

Container-plant to contain it. In a garden pond, pickerelweed is best planted in a 1–5 gallon submersible fabric pot or plastic nursery pot placed on the pond shelf at the appropriate water depth. This allows you to lift and divide the plant every few years without it colonizing the entire pond margin. In natural mud-bottom ponds it can and will spread aggressively.

Horticulture & Care

[ siting · container planting · winter · pests ]

When to plant

Plant container-grown stock in spring (April–May) after the water has begun to warm, or in early summer (June). The plant establishes fastest in warm water with ample sunlight. Avoid planting in the heat of July–August when plants are stressed by shipping.

Planting & establishment

Sun: full sun (6+ hours) for best flowering. Tolerates part shade but produces fewer flower spikes.
Water depth: 0–12 in above the crown. Plants in saturated mud at the water's edge are as happy as those in 6 in of water.
Soil/substrate: heavy clay-loam or commercial aquatic planting media. Avoid peat-based mixes that float out of the pot.
Container size: 1–5 gallon pot for water gardens. Use a wide, squat pot for stability.
Spacing: 18–24 in apart for a massed margin planting.

Seasonal care

Fertilize: use aquatic plant fertilizer tablets pushed into the container soil once in spring and once in mid-summer.
Divide: lift and divide rhizomes every 2–3 years in spring when the container becomes root-bound.
Winter: cut back frozen or senesced foliage after first hard freeze. In ponds that freeze solid, lower the container to a depth below the ice line (18+ in) or move it to a cool indoor location.
Aggressive spread: in natural-bottom ponds, rhizomes can spread several feet per year. Plant in containers to control spread in designed water features.

Pests & diseases

Essentially pest-free in NE Oklahoma.
Occasional feeding by aquatic leaf beetles (family Chrysomelidae); damage is cosmetic and rarely significant.
No serious disease issues in cultivation.

Propagation

Division of rhizomes in spring is the standard method. Each division should have at least one growing bud and a section of attached root. Seed requires cold-moist stratification and light for germination; sow on the surface of saturated mud in spring. Seed-grown plants may take two years to bloom.

Edible Uses & Ethnobotanical Notes

Pickerelweed has a modest but well-documented record as an edible plant among indigenous peoples of eastern North America. The common name refers to the plant's association with pickerel (pike) fish, which hunt among its stems.

Young leaves and stems: harvested in spring before the plant flowers, these can be boiled or steamed as a green. The flavor is mild, similar to spinach, but the texture can become fibrous as the season progresses.
Seeds: the mature seeds of autumn can be eaten raw as a snack or dried and ground into a nutritious flour by indigenous peoples. They are small but abundant on a mature stand.
Cultural use: documented as a food plant among the Cherokee and other southeastern tribes. The seeds were collected in late summer and fall by shaking the dried spikes into baskets.
Toxicity: no significant toxicity is reported for humans. As with any wild-foraged plant, confirm identification and sample cautiously if you have not eaten it before.

Sources & Further Reading

USDA NRCS PLANTS Database — Pontederia cordata: plants.usda.gov/plant-profile/POCO14
Lady Bird Johnson Wildflower Center — Pontederia cordata: wildflower.org — POCO14
Missouri Botanical Garden Plant Finder — Pontederia cordata.
Oklahoma Biological Survey — county-level distribution of Pontederiaceae in Oklahoma.
Center for Aquatic and Invasive Plants, University of Florida IFAS — Pontederia cordata species profile.
Moerman, D.E. (1998), Native American Ethnobotany, Timber Press — entry for Pontederia cordata.
Wikipedia — Pontederia cordata: en.wikipedia.org/wiki/Pontederia_cordata (CC BY-SA 4.0).

Companion Planting

[ guild · polyculture · cross-layer pairings ]

In a pond margin or water garden, pickerelweed pairs naturally with: arrowhead / duck potato (Sagittaria latifolia), copper iris (Iris fulva), cardinal flower (Lobelia cardinalis), sweet flag (Acorus calamus), buttonbush (Cephalanthus occidentalis), and bald cypress (Taxodium distichum).

Site pickerelweed in the shallow-water shelf zone of a pond or in a dedicated water-garden container where its spread can be managed.