Megapterium Species, Missouri Evening Primrose, Ozark Sundrops

Megapterium missouriensis

Family: Onagraceae (on-uh-GRAY-see-ee) (Info)
Genus: Megapterium
Species: missouriensis (miss-oor-ee-EN-sis) (Info)
Synonym:Oenothera missouriensis



Foliage Color:

Unknown - Tell us

Bloom Characteristics:

This plant is attractive to bees, butterflies and/or birds

Water Requirements:

Drought-tolerant; suitable for xeriscaping

Average Water Needs; Water regularly; do not overwater

Where to Grow:

Unknown - Tell us


12-18 in. (30-45 cm)


15-18 in. (38-45 cm)


USDA Zone 4a: to -34.4 C (-30 F)

USDA Zone 4b: to -31.6 C (-25 F)

USDA Zone 5a: to -28.8 C (-20 F)

USDA Zone 5b: to -26.1 C (-15 F)

USDA Zone 6a: to -23.3 C (-10 F)

USDA Zone 6b: to -20.5 C (-5 F)

USDA Zone 7a: to -17.7 C (0 F)

USDA Zone 7b: to -14.9 C (5 F)

USDA Zone 8a: to -12.2 C (10 F)

USDA Zone 8b: to -9.4 C (15 F)

Sun Exposure:

Full Sun


Unknown - Tell us

Bloom Color:

Bright Yellow

Bloom Time:

Late Spring/Early Summer



Other details:

May be a noxious weed or invasive

Soil pH requirements:

Unknown - Tell us

Patent Information:


Propagation Methods:

By dividing the rootball

From seed; direct sow outdoors in fall

Seed Collecting:

Allow pods to dry on plant; break open to collect seeds


This plant has been said to grow in the following regions:

, (2 reports)

Arab, Alabama

Anchorage, Alaska

East Richmond Heights, California

Hemet, California

Perris, California

San Jose, California

Englewood, Colorado

Wethersfield, Connecticut

Villa Rica, Georgia

Anna, Illinois

Peoria, Illinois

Washington, Illinois

Waukegan, Illinois

Demotte, Indiana

Kalona, Iowa

Radcliffe, Iowa

Ewing, Kentucky

Flemingsburg, Kentucky

Durham, Maine

West Friendship, Maryland

Attleboro, Massachusetts

Billerica, Massachusetts

Dracut, Massachusetts

Swansea, Massachusetts

Dearborn Heights, Michigan

Minneapolis, Minnesota

Maben, Mississippi

Conway, Missouri

Goodman, Missouri

Elkhorn, Nebraska

Reno, Nevada

Munsonville, New Hampshire

Red Bank, New Jersey

Trenton, New Jersey

Buffalo, New York

Cortland, New York

Himrod, New York

Ithaca, New York

Graham, North Carolina

High Point, North Carolina

Tuxedo, North Carolina

Vass, North Carolina

Winston Salem, North Carolina

Zirconia, North Carolina

Hillsboro, North Dakota

Wilton, North Dakota

Akron, Ohio

Baltimore, Ohio

Chillicothe, Ohio

Oak Hill, Ohio

Bartlesville, Oklahoma

Phoenixville, Pennsylvania

Wilkes Barre, Pennsylvania

Wakefield, Rhode Island

Columbia, South Carolina

Rock Hill, South Carolina

Williamston, South Carolina

Knoxville, Tennessee

Murfreesboro, Tennessee

Garland, Texas

Ogden, Utah

Salt Lake City, Utah

East Barre, Vermont

Lexington, Virginia

Auburn, Washington

Great Cacapon, West Virginia

Orma, West Virginia

White Sulphur Springs, West Virginia

Milwaukee, Wisconsin

New Richmond, Wisconsin

South Milwaukee, Wisconsin

show all

Gardeners' Notes:


On Apr 20, 2015, SChloe40 from Savannah, GA wrote:

I love this plant! In Illinois it attracts the green bee fly. Beautiful


On Oct 10, 2013, weedsfree from Magna, UT (Zone 7a) wrote:

I don't have any problems with this spreading by seed. I have a hard time germinating them as well. My plants that I have had for several years just get bigger each year. The first couple of years I had them, the seed pods were tiny with sand like seeds. now the pods are very large with normal sized seeds for this plant. Blooms all summer long here right to mid to late September.


On Jul 14, 2010, BarbyJo from Baltimore, OH wrote:

Love this plant!
HATE the Japanese Beetles that eat the leaves to bare skeletons by the end of June.


On May 26, 2010, braun06 from Peoria Heights, IL (Zone 5b) wrote:

This is a cool native perennial. Aside from flowering it has dark green shiny leaves. Its very tough too. It self seeds easily.


On Mar 19, 2010, AndyMissy from Williamston, SC wrote:

LOVE this shrub! Upstate S.C. I get a 3'-4' x 3'-4' shrub, it stays upright and well confined, self seeds......blooms late May to frost. Interesting to everyone, the sunset "popping" open of these blooms entertains young and old alike! Dead head daily for best results. Attracts butterflies, luna moths and bumblebee moth.....Summer fun! Tough and resistant! Light Licorice scented. I drop seeds and this plant takes off.


On Mar 21, 2009, dellrose from The Ozarks, MO (Zone 5b) wrote:

My neighbor gave me a small volunteer that had come up in her yard and I planted it in my newly made lasagna garden early last spring. It got about 4 feet tall and 5 feet wide and had tons of beautiful yellow blooms for several weeks. It also attracted the Hummingbird Moths at night which were fun to watch. This year I have several volunteers and plan on moving them to different areas of the yard in small lasagna beds and see if they get as big as the one did last year.


On Aug 3, 2008, Sneirish from Swansea, MA (Zone 6b) wrote:

I started mine from seed in pots last summer, chosen by chance (it was one of the few perennial seed packets left in the store in July). The seedlings were planted in September in a small raised bed with some Oenothera Lemon Drops (much smaller flowers) and a shrub rose. They have done extremely well returning this spring and in bloom since June. I love the flowers - they look so delicate and almost translucent.


On Dec 27, 2007, JedS from Shawnee Mission, KS wrote:

Even if you live in Missouri, don't venture to plant this in poor draining, rich clay soil, as I did, unless it's for a nobler cause. Even though I amended the soil with sand, it flops and stays that way with the onset of the early Spring rains. Nevertheless, I have retained the plants because I love its early Spring blooming lemon yellow flowers, and more importantly the fact that I wanted to attract more of the stately, giant green with red accent colored Luna Moths in my garden near the eastern Kansas / western Missouri border. Fortunately, I've been successful in attracting more of these magnificent creatures that pollinate this plant in the evening. All's well that end's well.


On Jun 19, 2007, mem2bam from Chillicothe, OH wrote:

Love this plant. Have had it several years doesn't seem to invasive to me. I have it surounded by small river rock & the plastic? weed barrier, around it with mulch on top. Stays in about a 2 1/2 ft. area.


On Nov 15, 2006, AnniesAnnuals from Richmond, CA wrote:

Here in zone !0a ( SanFrancisco Bay Area) , Oenothera missouriensis blooms all Summer long with deadheading . Its a tough and showy groundcover and with a sidedress of compost blooms like crazy . Real nice spreading over a rock wall . I fell in love with it while visiting Arizona and never thought it would winter over here in our frost free zone. Mine is now 3 years old and not behaving invasively. I cut it back severely in November.


On Jun 25, 2006, prettyred from Seaside Heights, NJ wrote:

This plant does produce a few new seedlings each year, but they are a welcome (and limited) spreader in the front of the border. And the little plants that sprout are very easy to move. The bright, cool lemon yellow is a nice contrast to the more golden coreopsis that takes over my garden this time of year. Sundrop flowers from late May through the end of June, with a few flowers blooming throughout the summer.


On Jul 28, 2005, LarryDavid from Salt Lake City, UT (Zone 5b) wrote:

Great xeriscape plant. The flowers are fun, but the seed pods are intriguing.


On Oct 26, 2004, lmelling from Ithaca, NY (Zone 5b) wrote:

Although these little guys do tend to be aggressive, the color and their toughness in the right area makes them worth having!

I'm in zone 5, and because I was told in advance that they were possibly invasive, I planted them in an area where I wouldn't have to worry. I have an area at the top of my pond that seems to resist cultivation - no matter how hard I try, the weeds tend to take over every year during the summer and I've not had a good track record with other species I planted there - it's in full sun and moist to wet all summer due to drainage from the woods. The sundrops love it! They've now traveled from their spot above the pond, down through the rocks to the rim of the pond and put on a wonderful show for a few weeks each summer. For me, they're definitely an... read more


On Aug 3, 2003, leisurlee from East Barre, VT (Zone 4a) wrote:

It adds interesting foliage, and it's gorgeous during it's early bloom time. When it stops blooming, it's just sort of blah.


On Jun 25, 2002, Lindy wrote:

The flower blooms from is a perennial. does well in drought areas.