Kingdom: Plantae

Phylum: Magnoliophyta -- flowering plants

Class: Magnoliopsida -- dicots

Order: Gentianales

Family: Apocynaceae -- dogbane

Common Name: spreading dogbane

Species Code: APAN2

Origin: Native to dry, open areas over most of North America.

Rare: no

Form: forb; deciduous, perennial, freely branching, rhizomatous, 20-50 cm tall; milky sap throughout.

Mature height: 8-20 inches

Duration: perennial

Habitat Type: prairie

Wetland Indicator Status: not listed

Leaves: opposite, simple, entire, spreading or drooping, ovate to oblong-lanceolate, 3-7 cm long.

Flowers: borne in terminal and axillary cymes, perfect, pink, campanulate, 5-7 mm long.

Flower color: pink

Bloom: June, July

Bloom starts on: June

Bloom ends on: July

Fruit: follicle, 5-14 cm long, narrow, divergent.

Characteristics:
Apocynum is a highly variable genus and many different species have been proposed.
A. pumilum in St. John 1963, and in Piper & Beattie 1914. Davis (1953) recognized both A. pumilum and A. androsaemifolium as separate species while Hitchcock et al (1969) considered them 2 varieties of A. androsaemifolium.
Reproduces both sexually by seed and vegetatively by rhizomes, although follicle development and seed set is apparently rare on the Palouse.
n=8? (Hitchcock et al 1969).
x=11 (University of British Columbia 2003).
2n=16,22 (Baldwin et al 1994). Insect pollinated.
Flowers are perfect.
Native peoples used the plant fibers for cordage, although it was considered inferior to A. cannabinum for that use. It has been used medicinally but is toxic. Honey derived from the flowers is considered high quality. It can be weedy in cultivated fields.

Sun requirement: full

Soil moisture: mesic

Hazards: Can be weedy in cultivated fields. Toxic to livestock.

Sowing time: fall

Transplant time: spring

Stratification: cold moist

Seed yield: low

Seed harvest: difficult

Seed cleaning: difficult

Planting duration: no information available

Seed shatter: high

Seed size: very small

Seed harvest date: fall

Herbaria: Specimen data and digital resources from The Consortium of Pacific Northwest Herbaria

Alternate Species: pumilum

Propagation:
2 protocols on the Native Plant Network
Hiawatha National Forest, Michigan
University of Kentucky

Other Propagation Information:
Needs 2 months of cold moist stratification in a mesh bag between layer of peat (Hudson & Carlson 1998).
For A. cannabinum, germination is best in light. Piercing the seed coat increases germination (Buhler & Hoffman 1999).
Untreated seeds germinated at 36%. 2 months of cold moist stratification resulted in 56% germination (Greene & Curtis 1950).
Seed stored dry at room temperature germinated without pretreatment. Highest germination was 91% after 9 and 12 months. Germination rate declined to 1% after 60 months (Comes et al 1978). This suggests some afterripening is needed.
Reproduces both sexually by seed and vegetatively by rhizomes, although follicle development and seed set is apparently rare on the Palouse. Probably could be propagated by rhizome cuttings.

Notes:
Apocynum androsaemifolium rarely produces seeds on the Palouse. Attractive plant in flower and the leaves turn bright yellow in fall. It is rhizomatous and could probably be grown from rhizome cuttings. Might be too aggressive for a landscape situation. Perhaps better used in a more wild setting where its aggressive growth could help stabilize a slope (Skinner et al 2005).

References:
Baldwin, B.G., S. Boyd, B.J. Ertter, D.J. Keil, R.W. Patterson, T.J. Rosatti, and D.H. Wilken (eds). 2004. Jepson Online Interchange for California Floristics. University and Jepson Herbaria, University of California, Berkeley, CA. Accessed 7/22/09 online at http://ucjeps.berkeley.edu/interchange.html

Buhler, Douglas D., and Melinda L. Hoffman. 1999. Andersen's Guide to Practical Methods of Propagating Weeds and Other Plants. Weed Science Society of America. Lawrence, Kansas. 248 pp.

Davis, Ray J. 1952. Flora of Idaho. Wm. C. Brown, Dubuque, Iowa. 827 pp.

Fowler, W.B., and A.R. Tiedemann. 1980. Phenological Relationships of Spiraea betulifolia Pall and Apocynum androsaemifolium L. Northwest Science 54:17-25.

Frye, Theodore C., and Eleanor B. Blodgett. 1905. A Contribution to the Life History of Apocynum androsaemifolium. Botanical Gazette 40:49-53.

Greene, H.C., and J.T. Curtis. 1950. Germination Studies of Wisconsin Prairie Plants. American Midland Naturalist 43:186-194.

Hitchcock, C. Leo, Arthur Cronquist, Marion Ownbey, and J.W. Thompson. 1969. Vascular Plants of the Pacific Northwest. University of Washington Press. Seattle, WA. 5 vol.

Hudson, Shelley, and Michael Carlson. 1998. Propagation of Interior British Columbia Native Plants from Seed. British Columbia Ministry of Forests. Online at http://www.for.gov.bc.ca/hfd/pubs/docs/mr/Mr093/Mr093.pdf

Piper, C.V., and R.K. Beattie. 1914. The Flora of Southeastern Washington and Adjacent Idaho. Lancaster, PA: Press of the New Era Printing Company. 296 pp.

Skinner, David M., Paul Warnick, Bill French, and Mary Fauci. 2005. Characteristics and Uses of Native Palouse Forbs in Landscaping. Palouse Prairie Foundation. Accessed 7/22/09 online at http://www.wsu.edu/pmc_nrcs/Docs/Forbs_for_Landscaping.pdf .

St. John, Harold. 1963. Flora of Southeastern Washington and of Adjacent Idaho. 3rd edition. Outdoor Pictures. Escondido, CA.

University of British Columbia. 2003. British Columbia Flora. University of British Columbia Botanical Garden and Centre for Plant Research. Online at http://www.bcflora.org/ Accessed 7/22/09.

Links:
Plant Profile from the USDA PLANTS Database
Species information from the University of Washington Herbarium