The Dogbanes are plants with a milky juice, widely branched at the top, with short 5-lobed bell-shaped flowers in clusters.
Spreading Dogbane is a native erect perennial growing to 3 feet high on stems that have many branches and contain a hazardous milky juice. Stems are without hair and color ranges from green to reddish where exposed to sunlight. Sometimes the plant is found sprawling atop other vegetation.
The leaves are opposite, oblong to ovate, with smooth margins, smooth green upper surface, paler underside, and somewhat drooping on the stem. Leaves form a wedge shaped base with a short, often reddish, stalk. (Red color on the stalks and stems is from sun exposure, less exposed parts remain green.) The main vein and lateral veins are prominent and contain the same milky juice as the stems.
The inflorescence is a branched cluster (a cyme) at the tip of the stem and others from the upper leaf axils. Each cluster is subtended by a leaf-like bract.
The flowers resemble a bell with a white to pinkish 1/3 inch long corolla of 5 lobes, whose outer lips recurve outward. These are rounded to pointed at the tips. There are pinkish-red lines inside the corolla. These are nectar guides for insects - the nectaries are deep inside the corolla. The five stamens unite into a cone over the 2 pistils of the two ovaries. Outside the green calyx is shorter than the corolla and has five teeth.
Seed: Fertile flowers produce a pair of long, thin pods and when dry split along one side and release seeds which have white filaments attached for easy transport by air currents.
Habitat: The plant grows from rhizomes and can form colonies from the spreading of the rhizomes. Being a prairie plant it prefers full sun, loamy soil, mesic to dry conditions.
Names: It was the Greek writer of the 1st century, Dioscorides, who provided the Greek name “apokynon” from which comes the generic name Apocynum, and means "away from dog" - referencing the plants toxic nature if eaten by dogs, and thus - 'Dogbane'. The species name is more obscure. Androsaemifolium, is from the Latin 'androsaemum' which was from two original Greek words meaning 'man's blood'. The 'folium' means 'leaves of'. In total this can be said to be a reference of the leaves resembling those of a plant known as 'Tutsan' (Hypericum androsaemum). As to the 'man's blood' part, that plant has a reddish juice but it is also interpreted as the reddish stain you get on your fingers if you crush together the flowers. The author name for the plant classification - 'L.' is for Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy.
Comparisons: A plant with somewhat similar flowers and seed pods, but different growing habit is Prairie Dogbane (Indian Hemp), Apocynum cannabinum, which is taller than Spreading Dogbane.
Above: 1st & 2nd photos - The bell shaped flowers of late June to early July.
Below: 1st photo - The calyx has five pointed lobes 2nd photo - Five stamens unite into a cone around the pistils. 3rd photo - Stems and leaf stalks develop a reddish color from sun exposure.
Below: 1st photo - Seed pods occur in pairs. 2nd photo - Seeds releasing from a typical long seed pods. Pods can also remain over winter and open in the spring.
Notes: Spreading Dogbane is indigenous to the Garden area. Eloise Butler catalogued it on May 31, 1907. Martha Crone planted it in 1946 and sowed seeds in 1949. It is native to Minnesota in most counties except for the SW Quadrant where it is found in only a few areas. It is found throughout North America except for some states of the U.S. in the far south and Nunavut and Labrador in Canada. Their are 4 species of Apocynum listed as native to Minnesota. A. cannabinum, Prairie Dogbane (Indian Hemp); and A. androsaemifolium are the most common. The other two have no current populations listed by the MN-DNR. These are A. sibiricum (which many sources list as a synonym for A. cannabinum) and A x floribundum, a hybrid known as Many-flowered Dogbane.
Lore and Uses: The medicinal part of the plant is the root. The chemicals in the root work on the central nervous system. The plant shares many of the characteristics of it’s cousin Indian Hemp, Apocynum cannabinum. It is an emetic and a cathartic. The main compound is cymarin, a cardiogenic toxin. Other chemicals are apocynin, apocynamarin, and androsin. As such, the plant should never be used as a food in any quantity. Other uses should be by expert use only as the chemicals are major cardiac stimulants - more toxic than the milkweeds, but not quite as powerful as Indian Hemp. In folk medicine the roots were used to cure sore throats, headaches, nosebleeds and irregularities of the heart. See Moore for more details (Ref. #30).
Densmore (Ref. #5) reports numerous uses among the Chippewa. A decoction of root (using one arm length) in very little boiling water, would be used to moisten some cotton and that was stuffed in the nostril to stop a nosebleed. Alternatively, powdered root was put on hot stones, the patient covered his head over the stones and inhaled the vapors to cure headaches. For soreness of the ear, a decoction made with one inch of root was poured into the ear. A very weak decoction of the root was given to infants to drink for common colds.
The outer section of the stem is fibrous and was used to make thread and bow strings. Densmore reports a charm use: Protection against evil influence or “bad medicine” could be gotten by chewing a piece of root.
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"