Ludwigia linearis

narrow-leaf primrose-willow, narrowleaf primrosewillow, narrowleaf primrose-willow
Family

Onagraceae

Leaf Arrangement

alternate

Leaf Attachment

sessile

Leaf Margin

entire

Leaf Type

simple

Leaf Shape

linear, lanceolate

Growth Form

forb

Flower Color

yellow

Flower Petals

4

Flower Month

June - September

Height (meters)

0.4 - 1.0

Milky Sap

No

Armed/Unarmed

Unarmed

Origin

native

Lifespan

perennial

Growing Season

Warm season


Wetland Class

OBL

Wetland Coefficient of Conservatism

5

Prairie Coefficient of Conservatism

7

Field Characters

Calyx segments (sepals) 4 and triangular. Similar to Lythrum alatum var. lanceolatum when sterile, both having mostly alternate leaves, but they may be distinguished by the size and shape of their leaves. The leaves of Ludwigia are linear to narrowly elliptical, 2.5 cm long and 1.5-5 mm wide. Those of Lythrum alatum are elliptic to elliptic-lanceolate, 5.5 cm long and 10 mm wide. The leaves of Lythrum lineare are also narrow (4 mm wide) but unlike Ludwigia linearis and Lythrum alatum its leaves are mostly opposite. Lythrum lineare - opposite leaves, 4 mm wide Lythrum alatum - alternate leaves, 10-14 mm wide Ludwigia linearis - alternate leaves, 5 mm wide Capsule obtusely quadrangular, 6-8 mm long.

Cultural Information

Seeds average approximately 38,000,000/lb.

Natural History

Found occasionally in wet places, especially in pine flatwoods and prairies of Louisiana and southeast Texas.

Habitat

Wet soil, muddy shores, and shallow waters, wet places, and pine woods, savannahs, ditches and bogs.