Rare Plant Profile – Nodding Umbrella-plant, Eriogonum cernuum[1]
Nodding umbrella-plant (Eriogonum cernuum Nutt) is an annual herb in the Polygonaceae (Buckwheat) Family[2]. It grows 10-40 cm tall and has freely branching stems, usually divided in 3s near the base and in 2s on the upper parts[3]. Leaves are round to oval shaped, 1-2 cm wide, usually greenish in colour and densely white-woolly underneath and slightly woolly on upper surfaces. Nodding umbrella-plant is named for its nodding flower clusters which bend sharply downward in open, freely branched clusters[4]. It grows in coarse-grained sandy to gravelly soils in badlands, dry valley rims and slopes, and on active sand dunes[5].
In Canada, nodding umbrella-plant is found in the grasslands of Alberta and Saskatchewan[6]. It is listed as N3, or Vulnerable, in Canada and S3, or Vulnerable, in Alberta[7]. The total population in Alberta is estimated to be less than 10,000 plants[8]. One of the main threats is due to habitat loss because of conversion and dune stabilization. As sand dunes stabilize, some populations will likely be crowded out by other plant species as disturbed or exposed lands progress through the stages of succession[9].
Nodding umbrella-plant is an important source of nectar for several species of native bumble bee (Bombus spp)[10]. In Alberta this includes Bombus bifarius (two-form bumble bee), B. flavifrons (bumble bee), B. huntii (Hunt’s bumble bee) and others[11],[12].
[1] https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.141988/Eriogonum_cernuum
[2] Kershaw, L.; Gould, J.; Johnson, D.; Lancaster, J. 2001. Rare vascular plants of Alberta. Univ. Alberta Press, Edmonton, Alberta and Nat. Resour. Can., Can. For. Serv., North. For. Cent., Edmonton, Alberta
[3] Ibid.
[4] Ibid.
[5] Ibid.
[6] http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=250060213
[7] https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.141988/Eriogonum_cernuum
[8] Kershaw, L.; Gould, J.; Johnson, D.; Lancaster, J. 2001. Rare vascular plants of Alberta. Univ. Alberta Press, Edmonton, Alberta and Nat. Resour. Can., Can. For. Serv., North. For. Cent., Edmonton, Alberta
[9] Ibid.
[10] http://fieldguide.mt.gov/speciesDetail.aspx?elcode=PDPGN08110
[11] Ibid.