Summer Briefs: Apios americana and Portulaca oleracea

Apios americana – Groundnut

Summer is the peak season for flowering vines in North Carolina.   Best known are the many species of brightly colored morning glories, and the beautiful passion flowers and butterfly peas.   Although it is quite common, Groundnut is one of the lesser known summer flowering vines.   It generally grows along the margins of rivers, streams and lakes, often draped over shrubby vegetation.  Its common name gives no hint of its flowers, and is based on the underground tubers the plant produces – tubers which are high in protein and nutrients, and were commonly eaten by Native Americans and early settlers.

Usually only the outside of the flowers, with their odd, pink shades of color, are visible.

Apios americana Groundnut Flowers

Apios americana
Groundnut
Flowers

Approaching the flowers is often difficult due to their location near the water’s edge.   And the flowers themselves only open fully for a few hours a day.  But if all goes well, the unusual form and deep, rich colors of the open flower can be observed.

Apios americana Groundnut Flower Close Up

Apios americana
Groundnut
Flower Close Up

Groundnut is a member of the pea and bean family, the Fabaceae.  It differs from most of its relatives in having five to seven leaflets rather than three.  This makes distinguishing the vine from its relatives easy, even when the flowers are not present.  Below a leaf with five leaflets and the bean-like pod of the fruit can be seen.

Apios americana Ground Nut Pod and Leaflets

Apios americana
Ground Nut
Pod and Leaflets

Portulaca oleracea– Common Purslane

Portulaca oleracea, which is the largest wild portulaca in North Carolina, is usually considered an exotic weed, but there is some evidence for nativity, at least in part of its range.  It is considered common and widespread in North Carolina, but is strangely absent from Wake and  surrounding counties on distribution maps.  The photos in this article, however, are from Wake County.    The succulent leaves are flat, smooth and glossy.  This portulaca can be found growing in gardens, disturbed soils, sandy soils, and, in this case, a stony water mitigation area.  The typical plant form is shown below.

Portulaca oleracea Common Purslane Plant Form

Portulaca oleracea
Common Purslane
Plant Form

Portulaca oleracea is a very late summer annual that grows and blooms quickly.  Its yellow flowers only open in full sun, and sometimes don’t open completely even then, as seen below.  It is easy to identify when blooming, as it is the only portulaca in North Carolina that has flat leaves and yellow flowers.

Portulaca oleracea Common Purslane Flowers

Portulaca oleracea
Common Purslane
Flowers

Growth radiates from a central taproot; the stems do not root at the nodes.   The prostrate growth habit can create mats that form a large circle up to two feet across.  But in this case, the huge mat pictured below actually measured three and one-half feet across. It was the largest plant in the mitigation area.

Portulaca oleracea Common Purslane Plant Form

Portulaca oleracea
Common Purslane
Plant Form

Although Portulaca oleracea is known to be drought resistant, the huge size of the plant pictured above did not serve it well.  Above average rainfall through late June and July aided rapid growth .  But the plant did not survive an extended period of extreme heat and drought in August.

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