Thimbleweeds. have 5 or 6-part flowers appearing singly atop tall aerial flowering stems, 1 to 3 feet high, the flowers forming an elongated seed head (the "thimble"). Since these can be mistaken for each other, we treat both of them together on this page.
Leaves: The leaves are basal: A. virginiana has 1 to 5 basal leaves on long stalks and that are deeply palmately divided and in addition there is a whorl of 3 smaller stalked leaf-like structures (actually primary bracts) at the base of the inflorescence where the flowering stalks diverge from the stem, and then there are two smaller leaf-like secondary bracts midway to the flower on most of the flower stems and if a flower stem further subdivides, there are a pair of secondary bracts at the division point also. A. cylindrica has 3 to 10 deeply palmately divided basal leaves and a whorl of 3 to 7+ leaf-like primary bracts at the base of the flowering stalks and no secondary bracts on the flower stems. A. cylindrica can show bracts that have deeper cut lobes than A. virginiana. Stems, leaves and flower stalks can have fine hair.
The inflorescence usually consists of 1 to 3+ long stalked solitary flowers in A. virginiana and of 2 to 6 in A. cylindrica. These arise from a common point on the stem above the whorl of primary bracts. Flower stems may themselves divide above the inflorescence base.
Flowers: The flowers have petal like sepals only. A. virginiana usually has 5, that are green, yellow, sometime with reddish tints, but rarely white, with thin hair on the backsides. A. cylindrica has 4 to 6 sepals that are green to whitish with thin silky hair on the backsides. Both species have 50 to 70+ stamens with yellow anthers and the central receptacle of many carpels. In fruit the sepals drop away and the central receptacle elongates into the seed head.
Seeds: A. cylindrica has slightly longer ( 3/4 to 1-3/4 inch) and more cylindrical seed heads than A. virginiana which are 1/2 to 1-1/4 inch and can appear slightly oval. These heads produce dry oblong achenes that are not winged but densely woolly and with a curved beak. Seeds require 60 days of cold stratification for germination.
Winter Interest: Once the flowers have bloomed, the cylindrical shape seed head continues to expand forming the characteristic thimble shape, hence the common name. These heads turn to yellow and then to brown as the season progresses. Due to the stiffness of the stems they will stay upright through the winter winds and snows creating a visual winter interest in the garden landscape. Many of the tough seed heads will not open until spring and then you will see the white cotton ball like fluff with the seeds embedded.
Varieties: See bottom of page.
Habitat: The Thimbleweeds grow in dry to moderate moisture conditions of woods and prairies with full sun to partial sun. Both grow from caudices, rarely with rhizomes and can form clumps.
Names: The origin of the genus Anemone is obscure but is generally applied to what are called windflowers, and is thought by some to be from the Greek anemos, meaning 'wind'. But the studied opinion (see Stern, Ref.#37a, and Ref.#W7) is that consideration must also given to the god Adonis, who in the Greek myth was killed while hunting a boar and from his blood came a red windflower [Anemone coronaria] and the name is a corruption of an old Semitic word for Adonis. The species names virginiana means 'of Virginia', and cylindrica means 'long and round'.
The author names for the plant classification are: 'L.', is for Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy. ‘A.Gray’ is for Asa Gray (1810-1888), American botanist, Professor of Natural History at Harvard and instrumental in unifying plant knowledge of North America and author of Gray’s Manual - Manual of the Botany of the Northern United States, from New England to Wisconsin and South to Ohio and Pennsylvania Inclusive.
Comparison: Before flowering, the leaf structure may confuse with Canada Anemone, Anemone canadensis, but there the flower is white and without the central cone and the the entire plant much shorter.
Above: A cluster of Anemone virginiana and a drawing of Anemone cylindrica. Drawing from Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. 3 vols. Charles Scribner's Sons, New York.
Above and below: Green seed heads of early July. Both of A. cylindrica. 2nd photo below - The stem node with branching leaf whorl and ascending flower stalk of A. cylindrica. All parts hairy.
Below: 1st photo - Older seed heads of mid-August - A. cylindrica. 2nd photo - The more oval head of A. virginiana.
Below: 1st photo - A flower of Thimbleweed, A. cylindrica. 2nd and 3rd photos - Two views of the long-stemmed basal leaf.
Below: Two views of the pair of secondary bracts midway to the flower and above the stem whorl on each separate flower stem of A. virginiana. Plants with multiple flower stems may have this pair of bracts missing on one of the flower stems.
Below: The seed heads as they open the following spring to dispense seeds.
Below: Thimbleweed, A. cylindrica, has palmately divided basal leaves in a whorl of 3 to 10 primary bracts at the base of the flowering stalks. These bracts are more deeply lobed than those of A. virginiana as seen in the next photo below.
Below: A whorl of 3 bracts at the base of the inflorescence of A. virginiana. Note how they are less deeply divided than those of A. cylindrica, shown above.
Notes: Anemone virginiana is indigenous to the Garden area. Eloise Butler catalogued it on Sept. 6, 1907 and Martha Crone planted seeds of it in 1948. A. virginiana is native to Minnesota in most counties except the SW quadrant of the state. Also present but less represented are two other similar species, A. cylindrica and A. riparia. Gardener Cary George reported in the summer of 1987 that he planted A. cylindrica and referenced it as the first time planted in the Garden although Eloise Butler reported planting 2 Anemone cylindrica on Sept. 19, 1918 with plants sourced from Fort Snelling and another on Oct. 6, 1919 from Columbia Heights and Martha Crone planted it in 1945.
Varieties: There are 3 accepted varieties of A. virginiana: var. alba, var. cylindroidea, and var. virginiana. Differences in the anthers and the amount of hair on the back side of the sepals splits var. cylindroidea from the other two. That variety has been reported in northern Minnesota but never collected. The other two varieties are found in Minnesota and differ in the bracts and the achenes. These are not covered here but you can see Flora of North America for details (Ref.#W7).
There are six species of Anemone in the Garden, the two listed here plus the Hepaticas, A. acutiloba and A. americana; Canada Anemone, A. canadensis; and Wood Anemone, A. quinquefolia. Historically Pasque Flower, A. patens was also present.
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"