The Anglestem Primrose-willow, Ludwigia leptocarpa

The primrose-willows, which are sometimes called water-willows, are common and widespread along the lake shores, ponds, and wetlands of the Coastal Plain and Piedmont of North Carolina.   They are members of the Evening Primrose family, the Onagraceae, and are usually found as erect and well branched, small to medium sized shrubs.  One of the largest of these is Ludwigia leptocarpa, the Anglestem Primrose-willow.  Pictured below is a single plant of L. leptocarpa standing alone, followed by a group of plants forming a small hedge along the shore of a lake.

Ludwigia leptocarpa Anglestem Primrose-willow Shrub

Ludwigia leptocarpa
Anglestem Primrose-willow
Shrub

Ludwigia leptocarpa Anglestem Primrose-willow Hedge of Shrubs

Ludwigia leptocarpa
Anglestem Primrose-willow
Hedge of Shrubs

L. leptocarpa has noticeably elongated floral tubes, a distinctive characteristic that distinguishes it from all of its close relatives.  In fact, another common name for this plant is Longpod Primrose-willow.  The photo below shows the long floral tube of a flower bud, a flower, and a flower that has just lost its petals.  Notice the extreme pubescence seen on the stems and floral tubes, another characteristic which distinguishes it from its near relatives, whose stems are smooth.

Ludwigia leptocarpa Anglestem Primrose-willow Floral Tubes

Ludwigia leptocarpa
Anglestem Primrose-willow
Floral Tubes

As the flowers age, the floral tubes turn red, making them more visible from a distance.

Ludwigia leptocarpa Anglestem Primrose-willow Red Floral Tubes

Ludwigia leptocarpa
Anglestem Primrose-willow
Red Floral Tubes

The developing seedpods retain the distinctive elongation.

Ludwigia leptocarpa Anglestem Primrose-willow Seedpod

Ludwigia leptocarpa
Anglestem Primrose-willow
Seedpod

L. leptocarpa has a sharply angled stem which is the source of the  common name Anglestem Primrose-willow.  See below.  Notice also the  heavy pubescence.

Ludwigia leptocarpa Anglestem Primrose-willow Angled Stem

Ludwigia leptocarpa
Anglestem Primrose-willow
Angled Stem

L. leptocarpa has flowers with 5 to 7 petals and sepals, while its closest relatives have 4- petaled flowers.

Ludwigia leptocarpa Anglestem Primrose-willow Flower

Ludwigia leptocarpa
Anglestem Primrose-willow
Flower

Ludwigia leptocarpa Anglestem Primrose-willow Flower

Ludwigia leptocarpa
Anglestem Primrose-willow
Flower

The bright yellow flowers of L. leptocarpa do somewhat resemble the flowers of Evening Primroses (Oenothera biennis), and are the source of part of the common name.  Their shrubby early growth and narrow, lanceolate leaves also resemble young willows.  Although most of the Ludwigia genus are herbaceous, Ludwigia alternifolia  (Seedbox) has woody stems, which resemble young willows even more.  Thus the shrubby members of the Ludwigia genus  came to be known collectively as Primrose-willows.

Herb Amyx

 

Advertisements
This entry was posted in Uncategorized and tagged , , , , , , , , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s