This native plant should not be confused with Lythrum salicaria (Purple Loosestrife). The latter is an aggressive Eurasian plant that invades wetlands and forms dense stands that exclude other species. It was introduced to the United States as an ornamental plant. As compared to the native plant, Purple Loosestrife has wingless stems, a larger size, and slender willow-like leaves that often have hairs.

This native perennial plant is up to 3' tall, branching occasionally from the lower half of the central stem. This central stem is strongly winged and hairless. The leaves are alternate in the upper half of the central stem and opposite from each other in the lower half; they are usually alternate in the smaller side stems. The leaves are up to 4" long and 2" across, becoming gradually smaller as they ascend the stems. They are hairless, cordate or lanceolate, and have smooth margins. The inflorescence consists of a tall narrow spike up to 1½' long. One or two flowers appear from the axils of small leaves, which are crowded together along the spike. Each flower is about ½" across or slightly larger, and is lavender or purple. It has six lobes that flare outward from a tubular calyx; each lobe has a fine line of darker purple that leads to the throat of the flower. There are 6 stamens and a pistil that may, or may not, be exerted from the flower. The calyx is green or purple, with six triangular teeth. The blooming period occurs from mid- to late summer, and lasts about 1-2 months. There is no floral scent. The root system consists of a taproot with rhizomes. The tiny seeds can be carried a considerable distance by wind or water.

Lythrum alatum Pursh:
Canada (North America)
Mexico (Mesoamerica)
United States (North America)
Caribbean (Caribbean)

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: New England west to Wyoming and Colorado, south to Kansas and Oklahoma (Great Plains Flora Association 1986).

Winged Loosestrife is widely distributed in Illinois, but occurs only occasionally in any specific locale (see Distribution Map). Habitats include moist black soil prairies, marshes, fens, borders of lakes, areas along rivers and drainage ditches, and low-lying ground along railroads. This plant has trouble competing against dense stands of the taller wetland grasses.

Winged Loosestrife is widely distributed in Illinois, but occurs only occasionally in any specific locale (see Distribution Map). Habitats include moist black soil prairies, marshes, fens, borders of lakes, areas along rivers and drainage ditches, and low-lying ground along railroads. This plant has trouble competing against dense stands of the taller wetland grasses.

Lythrum alatum (Winged Loosestrife)
(Bees collect pollen or seek nectar; Syrphid flies feed on pollen & are non-pollinating, otherwise they suck nectar; other insects suck nectar; one observation is from Grundel & Pavlovic as indicated below, otherwise the observations are from Robertson)

Bees (long-tongued)
Apidae (Apinae): Apis mellifera sn fq; Apidae (Bombini): Bombus griseocallis sn, Bombus impatiens sn cp fq; Anthophoridae (Ceratinini): Ceratina dupla dupla sn; Anthophoridae (Epeolini): Epeolus bifasciatus sn, Triepeolus concavus sn, Triepeolus lunatus concolor sn; Anthophoridae (Eucerini): Florilegus condigna sn, Melissodes bimaculata bimaculata sn, Melissodes coloradensis sn, Melissodes communis sn, Melissodes comptoides sn cp fq, Melissodes tepaneca sn cp, Svastra atripes atripes sn, Svastra obliqua obliqua sn, Synhalonia speciosa sn; Megachilidae (Coelioxini): Coelioxys modesta sn, Coelioxys octodentata sn fq; Megachilidae (Megachilini): Megachile brevis brevis sn cp fq, Megachile campanulae campanulae sn, Megachile inimica sayi sn, Megachile mendica sn, Megachile petulans sn; Megachilidae (Osmiini): Hoplitis pilosifrons sn

Bees (short-tongued)
Halictidae (Halictinae): Agapostemon sericea sn fq, Agapostemon virescens sn, Augochlorella striata sn, Halictus confusus sn, Halictus ligatus sn cp, Lasioglossum versatus sn cp; Andrenidae (Panurginae): Calliopsis andreniformis sn cp

Wasps
Sphecidae (Sphecinae): Ammophila nigricans fq, Ammophila procera, Prionyx atrata

Flies
Syrphidae: Eristalis stipator sn, Helophilus latifrons fp np, Tropidia mamillata fp np; Bombyliidae: Exoprosopa fasciata sn fq, Exoprosopa fascipennis sn, Exoprosopa meigenii sn, Systoechus vulgaris sn; Tachinidae: Archytas analis sn

Butterflies
Nymphalidae: Chlosyne nycteis, Vanessa cardui; Lycaenidae: Lycaeides melissa samuelis (GP), Lycaena hyllus; Pieridae: Colias philodice, Eurema lisa, Pieris rapae, Pontia protodice fq

Skippers
Hesperiidae: Ancyloxypha numitor, Pholisora catullus, Polites peckius fq, Polites themistocles

Many kinds of insects visit the flowers, including various long-tongued bees, Green Metallic bees, bee flies, butterflies, and skippers. Among the long-tongued bees, are such visitors as honeybees, bumblebees, Epeoline Cuckoo bees, Miner bees, and large Leaf-Cutting bees. Sometimes Syrphid flies feed on the pollen, but they are non-pollinating. The seeds are too small to be of any interest to birds; little information is available about this plant's status as a food source to mammalian herbivores.

Canada

Rounded National Status Rank: N3 - Vulnerable

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

The preference is full sun and wet to moist conditions. The soil should be poorly drained and high in organic matter. Foliar disease is not troublesome. Winged Loosestrife is easier to grow from transplants, as the tiny seedlings are highly vulnerable to the effect of summer heat and drought. Mature plants may appear ragged towards the end of the blooming season, or flop over from lack of support.