W. J. BealBotanical Garden

Of interest this week at Beal...

Scarlet PimpernelAnagallis arvensisFamily: the Primrose family, Primulaceae.Also called Poor-Man’s-Weatherglass, Poison Chickweed, Red Chickweed, Shepherd’s Sundial

This attractive petite (diameter 6mm or 1/4”) flower is that of an introduced weed of sunny lawns and waste places and is found throughout the temperate zone lands of the world. Our specimen (bed 82) exhibits the classic red-orange flowers that give the plant its most common name, scarlet pimpernel. The flowers may also be white in color. A form, with deep blue flowers is variously treated as a subspecies (Anagallis arvensis foemina) or a variety (A. arvensis var. azurea) or as a separate species (Anagallis foemina or A. caerulea).

Other common names, poor-man’s weatherglass and shepherd’s sundial refer to its habit of closing open flowers by late afternoon or whenever cloudy conditions develop. The common name poison chickweed refers to possible confusion with the more common and edible common chickweed, Stellaria media (next page).

Throughout history, this plant has been employed as a medicinal resource for controlling a wide variety of coughing, skin infections, and disorders of the liver

and gall bladder. It has also enjoyed some reputation as a food plant, usually employing leaves or new shoots as a salad or steamed vegetable. However, in today’s world, the presence of notable toxins, especially saponins and cytotoxic cucurbitacins, make this plant too risky for medicinal use and too suspect because of its toxins to be acceptable as a food plant. Exposure to clinical doses can result in tremors and frequent urination. Externally applied, Anagallis arvensis has been used as a wound treatment. In Nepal, the plant is squeezed and the extract used in bathing (http://www.pfaf.org/database/plants.php?Anagallis+arvensis).

Almost all references have the genus Anagallis included within the primrose family, the Primulaceae. However, in 2000, Källersjö, Bergqvist, and Anderberg [American

(Continued from last page) Journal of Botany, Vol. 87(9), 2000] proposed, based upon a suite of morphological and molecular characters, that the genus Anagallis be realigned within the Marlberry or Myrsine family, Myrsinaceae, although its fruit are neither a berry nor a drupe.

Scarlet pimpernel is an introduced weed species, sometimes invasive, of lawns, gardens, and weedy spots and is in no way threatened or endangered. It is found across the United States but is most common among the more temperate eastern seaboard states. In spite of its weedy status, it is an attractive plant, often valued for its flowers. The very striking blue-flowered varieties are occasionally available from commercial sources.

Distinguishing scarlet pimpernel from Common chickweed, Stellaria media.

Anagallis Stellaria

square stems(roll between your fingers) with no fuzz whatever

round stems(roll between your fingers) with a single-file line of fuzz between each node.

always white flowers, 3mm (1/8”) across, five petals slit to look like rabbit ears

usually red flowers, 6mm (1/4”) across, occassionally white, rarely blue, five (or four) petals wide and uncut

In addition, the undersides of Anagallis leaves have conspicuous dark red dots (see photo below and top photo last page), while Stellaria have no such dots (blue-flow-ered Anagallis may have no such dots, but they have bue flowers).