Wild Lupine Lupinus perennis
By permission of the land owner (thank you Mr. McCarthy), Leslie Wood Mummert and I were fortunate to observe a large colony of wild lupine at peak bloom on May 9, 2019, at an undisclosed location in Anne Arundel County, Maryland, in the Patuxent River watershed.
Wild lupine is a native perennial wildflower and is considered Maryland state threatened (S2 – state rare). The plant has been observed in Carroll, Baltimore and Anne Arundel counties on the western shore, and Caroline, Dorchester, Wicomico and Worchester counties on the eastern shore.
The Maryland Biodiversity web-site has documentation of 43 records in the state, mostly coming from the lower eastern shore Wicomico and Worchester counties.
Wild Lupine only produces leaves in the first year of growth. These alternate leaves are palmately compound, with seven to eleven leaflets. Individual leaflets are one to two and a half inches long, and oblanceolate in shape, and with smooth margins.
The flower petals have a pea-like floral structure, consisting of a large upper banner and two wings that project forward to enclose the keel. After the flower blooms for about two to three weeks, the flowers are replaced by elongated seedpods about one and a quarter to two inches long and canescent (grayish white pubescence) like other parts of the plant.
Each seedpod contains about seven seeds, which can be ejected several feet away from the mother plant. The seeds and seed pods are toxic to humans and other animals, as with most lupine plants. The plant is poisonous to livestock and avoided by deer.
It thrives in acidic soil that contains sand or sandy loam, its habitats include sand prairies, openings in sandy woodlands, sandy savannas, edges of sandy woodlands, and stabilized sand dunes. It prefers full or partial sunlight, and some of the habitats it is found in include dominant canopy trees such as pines or oaks – especially black oaks.
The colony that we observed included approximately 300 flowering stems in an area of about 100-feet by 80-feet, on a loamy sand slope with occasional early seral sapling Virginia pine.
Other plant species observed within the flowering block included black locust, black cherry, staghorn sumac, Allegheny blackberry, ebony spleenwort, eastern prickly-pear cactus, striped wintergreen, Venus looking-glass, common mullein, toadflax, red sorrel, downy brome, love grass, field peppergrass, Virginia dwarf-dandelion, Carolina cranesbill and Asiatic bittersweet.
What a treat to see this wild lupine colony at peak flower!
14 years ago, while in the Pocomoke watershed, I observed a small colony of wild lupine.
I took these photos on May 13, 2005 at peak flowering phenology.
The wild lupine plant has a special relationship with the Maryland endangered frosted elfin butterfly. The butterfly’s annual life cycle is largely tied to that of the wild lupine, as being the larval host plant.
I was able to get several photos of the frosted elfin at this location.
The elfin stayed still allowing me to get this close-up photo.