Maltese Cross is an introduced erect perennial growing 20 to 40 inches high on stout leafy stems that have stiff hair.
Leaves are egg shaped or broadly lance-shaped with one main rib, opposite and entire. The base is rounded, tight to the stem, no stalk.
The inflorescence is a cluster of many flowers rising from the upper pair of leaves. The cluster is very tight with leafy bracts that have fine hair.
Flowers: The brilliant flowers, each no more than an inch wide, sessile, have a green 10-veined tubular calyx that is covered with hair and ends in 5 short sharply pointed triangular lobes. The 5 flower petals in the shape of a Maltese Cross are very deeply cleft with clawed bases. While usually scarlet in color, they can also be white to pink. There are 5 stamens and 5 styles, stamens with red filaments with yellow anthers.
Seeds: Fertile flowers form an ovoid capsule that has the 5 teeth of the calyx at its opening and contains reddish-brown seeds. When the capsule opens at the top seeds are dispersed by action of the wind.
Habitat: As an introduced plant it will usually be found in the wild along roadsides, in waste places, open woodlands and disturbed areas. It therefore tolerates drier soils of various types. As a garden plant, it makes a brilliant display in full sun.
Names: Some references will list this plant as Lychnis chalcedonica L. The genus, Silene, is from the Greek word seilenos and believed to be derived from Silenus who was the foster father of the Greek god Bacchus. Silenus was described as covered with foam, a reference to the white foam frequently found on stems of this genus. Lychnis is Greek for lamp and chalcedonica refers to "of Chalcedon" - an old city in Turkey. The fact that current references use two genus names to refer to the plant indicates a divide among botanists. Flora of North America prefers Silene, some others, such as USDA, will use the genus Lychnis. The author of the plant classification for S. chalcedonica - ‘E.L.H.Krause’ is for Ernst Hans Ludwig Krause (1859-1942) German botanist who published several studies of plants in Germany including Flora von Rostock. His work amended that of - '(L.)' - Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy.
Comparisons: With the flower in the shape of a Maltese Cross, particularly when in scarlet, it is unlikely this plant will be confused with any other, however Royal Catchfly, Silene regia Sims, also has a tubular calyx and scarlet flowers but with different shaped petals. Cardinal Flower in the Lobelia family also has similar colored flowers but of much different shape.
Above: 1st photo - Typical tight flower cluster atop the stem. 2nd photo - Photo from early July 1999, one of the last years the plant grew in the Upland Garden.
Below: 1st photo - The green tubular calyx is 10-veined and is covered with hair and ends in 5 short triangular sharply pointed lobes. 2nd photo - At the base of the inflorescence is a pair of leafy bracts that have fine hair, as does the stem of the cluster and the main plant stem.
Below: 1st photo - Stems are very leafy with the opposite, smooth margined leaves. 2nd photo - Photo from early July 1999, one of the last years the plant grew in the Upland Garden.
Below: Two dense clusters of flowers growing on separate stems. Note the hair on the cluster.
Notes: Eloise Butler's records show that she planted seeds of this species on Sept. 30, 1915 by the Garden entrance and near Old Monarch - the aged white oak, and put in plants in 1916. Martha Crone reported it blooming in 1938 and planting seeds in 1947 and 40 plants in 1948, more seeds in 1953. It was growing in the Upland into the early 2000's, then died out and has not been replanted as it is not a native Minnesota plant. It is not native to North America but has become naturalized across the northern tier of states from Idaho/Montana to the east coast and the lower Canadian Provinces of the same latitudes. It has been reported as naturalized in Minnesota only in St. Louis and Chisago Counties, but the U of M Herbarium notes the plant probably died out and the MN DNR no longer lists the species. Both organizations prefer the Silene genus to the Lychnis genus.
References: Plant characteristics are generally from sources 1A, 32, W2, W3, W7 & W8 plus others as specifically applied. Distribution principally from W1, W2 and 28C. Planting history generally from 1, 4 & 4a. Other sources by specific reference. See Reference List for details.
Identification booklet for most of the flowering forbs and small flowering shrubs of the Eloise Butler Wildflower Garden. Details Here.
Friends of the Wild Flower Garden, Inc. Text and photos are by G. D. Bebeau unless otherwise credited. "www.friendsofthewildflowergarden.org"