Bunchberry is a north temperate circumboreal dogwood; it is widespread, native, low-growing and herbaceous, not shrubby. It begins blooming as early as the beginning of May, but you may spot blooms into July. The plant grows erect but not more than 10 inches high. Only the base of the stem may become woody.
Stems: Stems are green and erect, appearing as an unbranched stem, but it will branch at the top-most stem node, but the branches are so short, you will think it to be unbranched. There are appressed hair on the stems.
Leaves on the stem are scale-like without chlorophyl and only at the top node do they grow as broadly ovate shiny green leaves, opposite but so close together that they appear like a whorl of 6, 2 of the 6 slightly larger, but if a stem does not flower there may be only 4; the smaller leaves grow from axillary buds of the larger leaves. Leaves are very short stalked with appressed hair on the upper side, paler green under, up to 3 inches long and less than 2 inches wide. Leaf bases are wedge-shape and tips are abruptly pointed. Veins curve upward.
The inflorescence is a cluster of 12 to 40 creamy-colored flowers at the top of the stem, surrounded by a set of four whitish or whitish-green colorful bracts.
Individual flowers are perfect, small, 1 to 2 mm wide, 4-parted. The calyx, or hypanthium, is cream colored with appressed hair. Each flower has 4 spreading lance-shaped cream colored petals and 4 sepals of the same color. 4 stamens arise alternate with the petals on long filaments with yellow anthers and a single dark colored pistil with a single style that has a blunt tip. The nectary in the center is sometimes purplish, otherwise cream color. Flowers are protandrous, that is, they are self-sterile and require pollinators as the anthers dispense pollen before the stigma is receptive to pollen.
The pollen release method of Bunchberry is often cited for its speed. The 4 stamen filaments are springy and when the petals reflex backward quickly they release the filaments which spring upward so fast to fling pollen that cameras must record at 10,000 frames per second to capture the release. See this article (pdf).
Fruit: Fertile flowers form a round drupe, up to 1/4 inch diameter, green initially, that turns red at maturity, and usually contains one hard stone seed, which is ovoid, 2.3 to 3.3 mm long, smooth, not ribbed. The pulp is considered edible but not necessarily tasty. Seed germination is tricky - seed must be cold stratified and then subject to alternating cool/warm temperatures. They also need light for germination so must not be completely covered. Planted outdoors in fall they may not germinate until the second year.
Habitat: Bunchberry grows cool moist forests, marshes and bogs. It tolerates a wide range of moisture and soil types. Cool temperatures seem to be the first requirement. It is most likely to be found in slightly to very acidic sites. It grows from a creeping rhizome and slowly spreads forming dense colonies of clones along the rhizome. The longest rhizome found by the U S Forest Service was over 13 feet.
Names: The genus, Cornus, is from the Latin cormu which refers to a 'horn'. Most references believe that name was applied as a reference to the density of the wood of this genus, which also includes the boxwoods. As to the common name, Dogwood is very dense and was once used for loom shuttles and spindles and in old English "Dagwood" referring to woods used in making daggers, skewers, and arrows. The Spindle Tree (Euonymus atropurpureus) is another such species which was referred to by some as “dogwood”. (Ref. #7).
Cornus is also the old Latin name for the cornelian cherry, Cornus mas. The species, canadensis, means 'of Canada', where the plant is found throughout. The author name for the plant classification from 1753 - 'L.' refers to Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy.
Comparisons: There are four Dogwoods in Eloise Butler. All are shrubby plants, listed below, and do not resemble Bunchberry. A closely related species is the Lapland Cornel, C. suecica, which has smaller but more tart berries and the plant is more leafy without the leaves being clustered into a top whorl. It grows only in coastal and northern parts of Canada, in Alaska and in Eurasia.
Above: Bunchberry spreads from a creeping rhizome, creating colonies of plants. Photo - Robert Mohlenbrock, USDA-NRCS Plants Database.
Below: A flowering plant typically has 6 leaves, 2 larger, in a whorl-like arrangement. Fertile flowers produce a red drupe. Photos: Flower - Aaron Carlson, Wisconsin Flora. Drupes - Robert Mohlenbrock, USDA-NRCS Plants Database.
Below: The flower cluster is stalked at the top of the stem; the white bracts fall away after flower mature. In the inset drawing detail of a single flower you see the petals have reflexed allowing the stamen filaments to spring directly upwards. The drawing also shows the scale like leaves on the stem below the whorl. Photos: Plant, Steve Garske, Wisconsin Flora; drawing, 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.
Below: 1st photo - The tubular flowers number from 12 to 40 with a dark pistil and style. Petals are creamy color. 2nd photo - seeds are stones, taking up much of the space in the drupe. Photos: Flower - Merle R. Black, Wisconsin Flora. Seeds - Steve Hurst, USDA-NRCS Plants database.
Notes: Bunchberry Dogwood is indigenous to the Garden area. Eloise Butler noted its presence in her Garden Log on May 28, 1910. She planted the species in 1916, '26, '27 and '31. Martha Crone then planted it in 1933, '34, '46 and '47. It was listed on her 1951 census. The Bunchberry is considered a long-lived plant but in the Garden conditions must have changed and the plants died out. Ken Avery planted the species in 1960 and 1962. He wrote in his annual report to Parks Superintendent Howard Moore in March 1962 "Our experiment with Bunchberry in 1960 was successful and I have ordered a larger number to plant next year." ["next year" being the upcoming season of 1962] He followed up a year later on Jan. 28, 1963 and clarified the issue: "I have continued my policy of reintroducing species that were once growing in the garden but have since disappeared," after which statement Bunchberry appears on his list of species reintroduced. Perhaps the thinning out of the tamaracks in the wetland changed the conditions. They are not mentioned again after this and Ken's successor, Cary George, did not attempt to plant them. Hennepin County where the Garden is located is at the very southern edge of the plants range in Minnesota.
Bunchberry Dogwood is native to all of Minnesota north and east of a line running from Wabasha County in the SE to Page and Norman in NW- basically in the area of the old Big Woods and then into the coniferous forests of the NE. In North America it is found north of a line from Oregon to Iowa to Virginia, covering all of Canada.
There are 6 native dogwoods of the Cornus genus found in Minnesota. The 4 currently found in the Garden are: C. racemosa, Gray Dogwood; C. obliqua, Silky or Pale Dogwood; C. alternifolia, Pagoda Dogwood; and C. sericea, Red-osier Dogwood. Missing are Bunchberry Dogwood, C. canadensis; and Round-leaf Dogwood, C. rugosa, both of which are historical but indigenous to the Garden.
Lore and Uses: Eloise Butler wrote: "A search of bogs and low rich woodlands will be rewarded at this time by the lovely dwarf cornel. What seems like four white petals in this flower are bracts - as the leaves on flower stalks are technically named - and no integral part of the blossom, but grouped about a cluster of small flowers, which develop later into a rounded bunch of bright red berries, toothsome to children, although of cloying sweetness." (1) She added in 1926 "The “bunch” of sweet berries is considered delectable by children, despite a doubtful suspicion of being poisonous. I, myself, have devoured them by handfuls without any ill effect." (2) In her study of the Minnesota Chippewa, Densmore (Ref.#5) notes that the berries were eaten raw. (Ref. #5). Fernald wrote that the berries were insipid and dry whereas those of the more northern species C. suecica, were slightly tart and more palatable.(Ref. #6)
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"