Polygala verticillata (Whorled Milkwort)

Plant Info
Also known as:
Genus:Polygala
Family:Polygalaceae (Milkwort)
Life cycle:annual
Origin:native
Habitat:part shade, sun; fields, prairies, open woods
Bloom season:July - October
Plant height:4 to 12 inches
Wetland Indicator Status:GP: FACU MW: UPL NCNE: UPL
MN county distribution (click map to enlarge):Minnesota county distribution map
National distribution (click map to enlarge):National distribution map

Pick an image for a larger view. See the glossary for icon descriptions.

Detailed Information

Flower: Flower shape: indistinct Flower shape: irregular Cluster type: spike

[photo of flower cluster] Spike-like raceme, usually densely arranged, up to 2 inches (5 cm) long at the top of the plant and the tips of branching stems. Flowers are white to greenish-white to pinkish, flanked by a pair of spreading, oval to egg-shaped, petal-like sepals, each less than ¼ inch (4 to 5 mm) long, rounded to blunt at the tip and have a conspicuous midvein. Three small petals are fused into a short column in the center, with a fringed, yellowish crest. Flowers bloom from the bottom of the spike up.

Leaves and stem: Leaf attachment: whorl Leaf type: simple

[photo of leaves] Leaves are whorled, usually in 4s or 5s, up to about 1¼ inches (3 cm) long, to ¼ inch (5.5 mm) wide, linear to narrowly lance-elliptic, mostly widest near the middle, toothless, hairless, pointed at the tip, tapering at the base, stalkless or sometimes short-stalked. The lowest leaves may be significantly reduced in size, the largest leaves are usually around mid-stem. Stems are erect, branched, single from the base and hairless.

Fruit: Fruit type: capsule/pod

[photo of developing fruit] Fruit is an elliptic to nearly round, slightly flattened, 2-seeded capsule. Seeds are 1.2 to 2.2 mm long, hairy, with a 2-lobed appendage that is 1/3 to half as long as the seed. Sepals and capsules both drop off at maturity leaving a nub on the stem where the flower stalk was attached.

Notes:

Whorled Milkwort is present in about a third of Minnesota, found in open grasslands and woodland openings. The flower spike is similar to the related Seneca Snakeroot (P. senega) but the latter has alternate leaves and is typically unbranched. It is also very similar to White Milkwort (Polygala alba), which is not present in MN but is just to our west and south on the Great Plains, has more pure white flowers with green centers in clusters up to 3 inches long, mostly alternate leaves, only the lowest 1 or 2 nodes with whorled leaves. There are multiple varieties of P. verticillata, but these are not universally accepted; they are apparently distinguished by the length of the flower stalk and whether leaves are whorled all the way up the stem (excluding the flower clusters). P. vercillata var. isocycla, with nearly stalkless flowers (stalks .3mm or less) with whorls all along the stem is considered the var present in Minnesota.

Native Plant Nurseries, Restoration and Landscaping Services ↓

Map of native plant resources in the upper midwest

  • Morning Sky Greenery - Native Prairie Plants
  • Natural Shore Technologies - Using science to improve land and water
  • Minnesota Native Landscapes - Your Ecological Problem Solvers
  • Spangle Creek Labs - Native orchids, lab propagated
  • Prairie Restorations - Bringing people together with the land

More photos

Photos by Peter M. Dziuk taken in Otter Tail County.

Comments

Have you seen this plant in Minnesota, or have any other comments about it?

Posted by: S. Kimber - Bluestem Prairie SNA in Clay County
on: 2024-07-27 19:05:16

On July 24 saw a fair number hiding in the grass along the northern edge of the Bluestem Trail. This flower is not nearly as showy as its relative Seneca Snakeroot (Polygala senega), which I saw farther south on the same prairie in early June. I have to say, this field guide is pretty amazing. It was the detail about the whorled (as opposed to alternate) leaves, as well as the photographs, that enabled me to identify it and learn its name. Thank you!!

Post a comment

Note: All comments are moderated before posting to keep the spammers out. An email address is required, but will not be posted—it will only be used for information exchange between the 2 of us (if needed) and will never be given to a 3rd party without your express permission.

For info on subjects other than plant identification (gardening, invasive species control, edible plants, etc.), please check the links and invasive species pages for additional resources.



(required)




Note: Comments or information about plants outside of Minnesota and neighboring states may not be posted because I’d like to keep the focus of this web site centered on Minnesota. Thanks for your understanding.