Rare Species Guide

  Synonyms

Senecio indecorus

  Basis for Listing

Packera indecora (elegant groundsel) is a boreal species endemic to North America. It is seemingly rare in the Upper Great Lakes region and occurs in northeastern Minnesota, where rugged topography and the climate-modifying effects of Lake Superior influence the southerly reaches of the boreal biome (North Shore Highlands and Border Lakes subsections). Packera indecora was first documented from the Grand Marais area of Cook County in July of 1900. Since that time, only seven additional occurrences have been reported in Minnesota. The historic populations have never been relocated, and over the past 50 years P. indecora has only been documented three times, in 1961, 1981, and then not again until 2006. Currently, only one population is known to still occur in Minnesota. This population consists of 3-4 small patches of plants, totaling around 36 individuals, which are scattered along the cool canyon walls and adjacent rocky creek bank of a North Shore stream.

Packera indecora was listed as special concern in Minnesota in 1996. At that time, a more protective status of endangered was considered but delayed pending a more thorough botanical inventory of northeastern Minnesota. Such an inventory was substantially completed by 2013, at which time the rarity of the species was confirmed, and its status was formally changed to endangered.

  Description

Packera indecora is a perennial herb, 30-80 cm (12-32 in.) tall. Basal leaves are petiolate, with ovate to oblong leaf blades and toothed margins. Leaf bases are semi-cordate, truncate to cuneate. Cauline leaves gradually reduce in size distally. Heads number 8-20+, and the branches of the inflorescence are distinctly umbelliform. Florets are golden yellow; ray flowers are absent or few (8-10) and short (< 6.5 mm [0.26 in.]; Voss 1996; Trock 2006). Plants on slopes may become prostrate as they mature, with upward arching upper stems.

There are six other species which occur in Minnesota that are similar to P. indecora, and three of them (P. aurea [golden ragwort], P. paupercula ]balsam ragwort], P. plattensis [prairie ragwort]) are known to occur in the Arrowhead region. Lakela (1965) reported Senecia pauciflorus (elegant groundsel) as occurring on the dry soils of a partly cleared rocky ridge in northern Lake County. This collection has since been determined to be P. indecora. While S. pauciflorus closely resembles P. indecora, it is not known to occur in Minnesota. 

  Habitat

Packera indecora occurs in cool, moist, sandy and gravelly to rocky conditions of northeastern Minnesota. Habitats are often further influenced by the climate modifying effects of Lake Superior and include a streamside, a lakeside, sandstone canyon walls, an old logging dam, and cliff tops. Across its range, P. indecora occurs along streams and in damp meadows and wet woodlands (Trock 2006); in coniferous and mixed, often rocky, woods and openings; and in cedar swamps. It is more often found in rocky and easily drained soils than in permanently wet soils (Voss 1996).

  Biology / Life History

Packera indecora is an herbaceous species that persists as a taprooted perennial. Historic records and recent observations suggest some populations occur in habitats that are subject to disturbance regimes. Annual events, such as spring run-off into North Shore streams may wash away some populations lower on canyon walls, while exposing new substrates for future establishment. The frequency and intensity of these events likely determine the persistence of some populations.

Achenes begin to ripen soon after pollination and, like the seed of many composites, may fall near the plant or get carried some distance by wind and water. Details of germination, longevity of populations, genetic diversity, and other aspects of the life history of Minnesota's P. indecora populations are unknown.

  Conservation / Management

Survey efforts have attempted to relocate some of the historical P. indecora populations in Minnesota, without success. It is uncertain why the historic populations could not be relocated. It may be that the historic populations were small and did not remain viable; that they were lost due to natural or anthropogenic disturbance events; or that, given the immensity of rugged landscapes and poor location information, some populations have simply not been encountered again.

While the species' rugged habitats may seem permanent and indestructible, the highly specialized plants that occur in them and their microhabitats are often vulnerable to human activities. Any activities that would result in the sloughing of substrates or increased erosion, such as recreational rock climbing, logging on adjacent upslope habitats, or the routing of recreational trails along cliff tops could threaten the long-term viability of P. indecora. The invasion of Hieracium aurantiacum (orange hawkweed), an aggressive non-native species, and global climate change are also significant concerns. Watershed protection measures that maintain water quality and natural rates of run-off, erosion, and flow are important to maintaining habitat conditions for this species.

  Best Time to Search

Packera indecora is typically in peak bloom from mid- to late July, though it has been observed flowering from late June to early September. It likely flowers earlier in the warmer inland habitats and later in the cooler habitats directly influenced by Lake Superior.

  Conservation Efforts in Minnesota

Recent survey efforts by the Minnesota Biological Survey in the North Shore Highlands subsection were unsuccessful in finding any populations of P. indecora. However, Minnesota's newest discovered population was subsequently reported by a local botanist. This newly found account emphasizes the contributions that local botanists continue to make towards our understanding and conservation of the flora of Minnesota. A systematic inventory of potential habitat is ongoing and includes portions of Cook, Lake, and St. Louis counties.

The most recent discovery of P. indecora is within the boundary of a State Park, which could potentially provide stewardship and support for protection and conservation actions. That said, even natural areas in state parks can be threatened by recreational activities and nearby developments.

  Authors/Revisions

Welby Smith (MNDNR), 2008 and 2018

(Note: all content ©MNDNR)

  References and Additional Information

Butters, F. K., and E. C. Abbe. 1953. A floristic study of Cook County, northeastern Minnesota. Rhodora 55:21-55.

Lakela, O. 1965. A flora of northeastern Minnesota. University of Minnesota Press, Minneapolis, Minnesota. 541 pp.

Minnesota Department of Natural Resources. 2003. Field guide to the native plant communities of Minnesota: the Laurentian mixed forest province. Ecological Land Classification Program, Minnesota County Biological Survey, and Natural Heritage and Nongame Research Program. Minnesota Department of Natural Resources, St. Paul, Minnesota. 352 pp.

Minnesota Department of Natural Resources, Division of Ecological Resources. 2008. Rare species guide: an online encyclopedia of Minnesota's rare native plants and animals [Web Application]. Minnesota Department of Natural Resources, St. Paul, Minnesota. Accessed 1 July 2009.

Minnesota Department of Natural Resources, Division of Fish and Wildlife. 1995. Statement of need and reasonableness in the matter of proposed amendment of Minnesota Rules, Chapter 6134: endangered and threatened species. Minnesota Department of Natural Resources, St. Paul, Minnesota. 336 pp.

Ownbey, G. B., and T. Morley. 1991. Vascular plants of Minnesota: a checklist and atlas. University of Minnesota Press, Minneapolis. 320 pp.

Penskar, M. R. 2008. Special plant abstract for Senecio indecorus (rayless mountain ragwort). Michigan Natural Features Inventory, Lansing, Michigan. . Accessed 9 November 2009.

Trock, D. K. 2006. Packera. Pages 570-602 in Flora of North America Editorial Committee, editors. Flora of North America north of Mexico. Volume 20. Oxford University Press, New York, New York.

Voss, E. G. 1996. Michigan Flora. Part III: Dicots (Pyrolaceae-Compositae). Cranbrook Institute of Science Bulletin 61 and University of Michigan Herbarium, Ann Arbor, Michigan. 622 pp.