Lindley’s false silverpuffs (Uropappus lindleyi) COSEWIC assessment and status report: chapter 3
Species Information
Name and classification
Scientific name:
Uropappus lindleyi (DC.) Nutt.
Synonyms:
- Microseris lindleyi (DC) A. Gray,
- Calais linearifolia DC.,
- Microseris linearifolia (Nutt.) Schultz-Bip.,
- Uropappus linearifolius Nutt.
Common name:
Lindley’s false silverpuffs, Lindley’s microseris
Family:
Asteraceae, Aster Family
Major plant group:
Eudicot flowering plant
Uropappus lindleyi has been known by a number of names. Peck (1961) treated the plant under the name Uropappus linearifolius Nutt. Elsewhere in the Pacific Northwest, Cronquist (1955) and Chambers (1960) used the name Microseris linearifolia. In recent years, it has been treated either as Microseris lindleyi (Douglas et al. 1998 & 2002, NatureServe Explorer 2003) or as Uropappus lindleyi (Chambers 1993, Kartesz & Meacham 1999). It is presently treated as Uropappus lindleyi in Flora North America. It is the sole species in the monotypic genus Uropappus.The first collection of this species in Canada was recorded on Saturna Island by H. Janszen in 1974.
Morphological description
Uropappus lindleyi is a 10-70 cm tall annual, usually with a simple stem, growing from a slender taproot (Figure 1, Figure 2, Douglas et al. 1998). The 15-30 cm long basal leaves are linear and long-pointed at the tip. They may be entire, or more usually, with linear swept-back lobes. The stem leaves are usually linear, entire and occur on the bottom half of the stems. The flowering stems emerge from the base or from the axils of the stem leaves. The solitary terminal flowering heads have strap-shaped yellow flowers and 15-30 mm long lanceolate involucral bracts. The achenes are slender, 7-17 mm long, blackish and finely ribbed. The pappus consists of 5 linear scales, each terminating in a shorter hair-like bristle arising from a distinct bifid notch in the scale-tip.
Within the range of Uropappus lindleyi in southwestern British Columbia, upon casual examination, this species may be mistaken for many other similar-leaved members with strap-shaped flowers in the tribe Lactuceae. However, a close inspection of the hair-like bristle arising from a distinct bifid notch in the scale-tip of the pappus readily distinguishes this species.
Genetic description
Studies of Microseris genetics have been conducted using plant material from the United States, mostly from California (Pak et al. 2001; Battjes et al. 1994, Price and Bachmann 1975, Jansen et al. 1991a and b, Wallace and Jansen 1990). These studies examined DNA and allozyme variation between species of Microseris. Although Uropappus lindleyi has generally been treated as a member of the genus Microseris, numerous morphological, as well as DNA and allozyme differences, have resulted in several researchers suggesting that this species be reclassified as Uropappus lindleyi (Battjes et al. 1994, Jansen et al. 1991, Wallace and Jansen 1990). It is now treated as Uropappus lindleyi in Flora North America (Chambers 2006).
Figure 1. Illustration of Uropappus lindleyi
- growth form,
- fruitlet with bristly-tipped pappus bracts,
- involucre of bracts that surround a flower head (Line drawing from Douglas et al. 1998, with permission).
Figure 2. Uropappus lindleyi in seed on Galiano Island, British Columbia. A plant with one large, round mature fruiting head is present in centre of photo (Photo by S.J. Smith 2004).
Although genetic variation within Uropappus lindleyi has not yet been examined, Canadian populations may be genetically isolated by the 300 km distance from the main portion of the plants’ range on the eastern side of the Cascades Mountains in Washington State (University of Washington Herbarium Database 2004). Many of the individual Canadian populations may also be isolated from each other by distances of 10-15 km and by water bodies of over 1 km wide.
Designatable units
Only a single designatable unit is recognized for the five localities that all occur within a single ecozone.
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