BC Conservation Data Centre: Species Summary
Cyperus subsquarrosus
small-flowered lipocarpha
| Scientific Name: | Cyperus subsquarrosus (Muhl.) Bauters | ||||||||||
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| Scientific Name Synonyms: |
Hemicarpha micrantha
Lipocarpha micrantha Scirpus micranthus |
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| English Name: | small-flowered lipocarpha | ||||||||||
| Classification / Taxonomy | |||||||||||
| Scientific Name - Concept Reference: | Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR. | ||||||||||
| Classification Level: | Species | ||||||||||
| Taxonomy Comments: | Formerly tracked in B.C. as HEMICARPHA MICRANTHA. | ||||||||||
| Species Group: | Vascular Plant | ||||||||||
| Species Code: | LIPOMIC | ||||||||||
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| Conservation Status / Legal Designation | |||||||||||
| Global Status: | G5 (Jul 2024) | ||||||||||
| Provincial Status: | S1 (Apr 2019) | ||||||||||
| BC List: | Red | ||||||||||
| Provincial FRPA list: | |||||||||||
| Provincial Wildlife Act: | |||||||||||
| COSEWIC Status: | Endangered (Nov 2002) | ||||||||||
| SARA Schedule: | 1 - Endangered (Jan 2005) | ||||||||||
| General Status Canada: | 1 - At Risk (2010) | ||||||||||
| Ecology & Life History | |||||||||||
| General Description: | |||||||||||
| Technical Description: | Culms: slender, 2-10 (-20) cm tall, usually recurved toward the northern limits of the species. Leaves: similar to the filiform involucre bracts, up to 10 cm long and 0.5 mm wide, slightly resembling the stems. Spike: mostly 1-3 per stem, ovoid, 2-6 mm long. Involucre: with a single leaf. Scales of spikelets: numerous, spirally imbricate, 1-2 mm long, firm, oblong or narrowly obovate, mucronate, slightly reticulated with many close rows of crowded low papillae, outer scales may be awned, inner scales hyaline, usually minute, frequently absent. Flowers: perfect, perianth absent, bristles none. Style: 2 cleft, not enlarged. Stamen: one. Achene: 0.5-0.7 mm long, cylindric to compressed, becoming irridescent brown at maturity. | ||||||||||
| Diagnostic Characteristics: | Inner scale much shorter than the achene, bristle like, bifid, or lacking; achene cylindric, irridescent brown when mature; scales of spikelet spirally imbricate; base of style not enlarged. | ||||||||||
| Subspecies Comments: | None. | ||||||||||
| Identification Comments: | Lipocarpha micrantha is a very small sedge, but it is quite distinctive and easy to identify under a microscope. | ||||||||||
| Similar Species: | No species can be confused with Lipocarpha micrantha provided a microscope is used for identification purposes. Smith et al. (2002) indicate that L. micrantha is readily distinguished from C. squarrosus by the shape of the flower head: Cyperus flowers occur on two-sided spikes, while Lipocarpha flowers occur in a dense cone-shaped head. In the field, however, L. micrantha may be confused with Cyperus squarrosus, although flower head shape should make separation relatively easy. | ||||||||||
| Provincial Reproduction Comments: | As with other shoreline and aquatic species, Lipocarpha micrantha likely depends upon its seed bank, and numbers fluctuate from year to year along with annual variations in water levels. Dormancy for at least two years is reported (Smith et al., in press), and may occur for many years (Smith et al. 2002). | ||||||||||
| Provincial Ecology Comments: | In B.C., Lipocarpha micrantha has been found only on moist sandy beaches and back beaches (moist to wet interdunal swales), but it is possible that it may also occur along creek banks, and in damp patches and wet meadows that are not directly associated with lakes or rivers. Key habitat components seem to be wetland or temporary wetland conditions with fluctuating water table levels, sandy substrates with low organic matter, and low levels of competition. | ||||||||||
| Habitats: (Type / Subtype / Dependence) |
Other Unique Habitats / Beach / Facultative - frequent use
Riparian / Riparian Forest / Facultative - frequent use Riparian / Riparian Shrub / Facultative - frequent use Wetland / Bog / Facultative - frequent use Wetland / Fen / Facultative - frequent use Wetland / Marsh / Facultative - frequent use Wetland / Swamp / Facultative - frequent use |
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| Global Habitat Comments: | Lipocarpha micrantha occurs in emergent shorelines, riverbank drawdown zones, freshwater tidal shores, and other moist sandy areas (FNA 2002, Weakley and the Southeastern Flora Team 2024). | ||||||||||
| Provincial Habitat Comments: | Lipocarpha micrantha is found on moist sandy beaches and back beaches (dune swales and meadows) that are protected from wave action and are tied to fluctuating lake levels (Smith et al. 2002). The species is reported as being intolerant of competition and organic sediment (Smith et al. 2002). In other regions, it is reported to be associated with the sandy borders of streams and ponds (Maine Department of Conservation 2004). | ||||||||||
| Provincial Phenology: (1st half of month/ 2nd half of month) |
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| Provincial Phenology Comments: | In B.C., Lipocarpha micrantha appears to flower in late summer and may be submerged until late in the season. Smith et al. (in press) indicate that the species germinates in late summer when water levels drop, and that flowering and fruiting occur in August and September. | ||||||||||
| Elevation (m) (min / max): | Provincial: 280 / 340 | ||||||||||
| Known Pests: | |||||||||||
| Pollen Vector: | |||||||||||
| Pollinator: | |||||||||||
| Dispersal: | |||||||||||
| Provincial Inventory | |||||||||||
| Inventory Priority: | |||||||||||
| Ownership of occurrences (Known locations): | Mixed private/government | ||||||||||
| Inventory Need: | There is definite need for detailed inventory for Lipocarpha micrantha. Because the species is extremely small and occurs in dune swales and other damp patches that are associated with fluctuating lake levels, it may be overlooked and may be more abundant in some years than in others. It may also be found on sites that are not associated with lakes, streams, or ponds. Wet meadows of any sort that have low organic matter and a sandy substrate should be searched for this species. | ||||||||||
| Inventory Comments: | The coverage and intensity of preceding inventory work for Lipocarpha micrantha is unknown. Given the possibility that the species may occur in wet meadows and damp patches as well as in sites such as dune swales that are associated with lakes and ponds, additional inventory is warranted. Furthermore, given that the species occurs in the Lake of the Woods area in northern Ontario, it may also occur farther north in B.C. than has yet been reported. Maps highlighting potential (sandy) lakeshore habitat could be developed and used to direct inventory efforts, but the identification of habitats such as wet meadows would be problematic; therefore, the maps would have to be supplemented by local ecological knowledge. | ||||||||||
| Economic Attributes | |||||||||||
| Provincial Economic Comments: | None. | ||||||||||
| Distribution | |||||||||||
| Endemic: | N | ||||||||||
| Global Range Comment: | Lipocarpha micrantha occurs in North America from British Columbia, Canada south to California, United States east to Floria, and north to Québec (FNA 2002). It also occurs in Mexico, the West Indies, Central America, South America, and Africa. Range extent was estimated to be over 48 million square kilometers using herbarium specimens and photo-based observations documented between 1993 and 2024 (GBIF 2024, iNaturalist 2024, SEINet 2024). | ||||||||||
| Disjunct, more common elsewhere: | Y | ||||||||||
| Peripheral, major distribution elsewhere: | Y | ||||||||||
| Authors / Contributors | |||||||||||
| Global Information Author: | ISAAC, J., rev. N. Ventrella (2024) | ||||||||||
| Last Updated: | Jul 04, 2024 | ||||||||||
| Provincial Information Author: | Brian Klinkenberg and Rose Klinkenberg | ||||||||||
| Last Updated: | |||||||||||
| Last Literature Search: | |||||||||||
| References and Related Literature | |||||||||||
B.C. Ministry of Environment. Recovery Planning in BC. B.C. Minist. Environ. Victoria, BC. |
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Britton, N. L. and A. Brown. 1913. An Illustrated Flora of the Northern United States and Canada. 3 vol. Dover Publications, Inc., N. Y. 2052 pp. |
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Douglas, G.W., D. Meidinger, and J. Penny. 2002. Rare Native Vascular Plants of British Columbia, 2nd ed. B.C. Conserv. Data Centre, Terrestrial Inf. Branch, Victoria. 358pp. |
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Douglas, G.W., D. Meidinger, and J. Pojar, eds. 2001. Illustrated Flora of British Columbia, Vol. 6, Monocotyledons (Acoraceae through Najadaceae). B.C. Minist. Environ., Lands and Parks, and B.C. Minist. For., Victoria, BC. 361pp. |
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Fassett, Norman C. 1940. A Manual of Aquatic Plants. McGraw- Hill Book Company, New York, New York. 382 p. |
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Fernald, M.L. 1950 Gray's Manual of Botany, 8th ed. American Book Company, New York. 1632 pp. |
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Flora of North America Editorial Committee (FNA). 2002b. Flora of North America north of Mexico. Vol. 23. Magnoliophyta: Commelinidae (in part): Cyperaceae. Oxford Univ. Press, New York. xxiv + 608 pp. |
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Friesner, R.C. 1941. The genus Solidago in West Virginia. Castanea 6:53-75. |
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Gleason, H.A., and A. Cronquist. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. New York Botanical Garden, Bronx, New York. 910 pp. |
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Godfrey, R.K., and J.W. Wooten. 1979. Aquatic and wetland plants of southeastern United States: Monocotyledons. Univ. Georgia Press, Athens. 712 pp. |
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McCance, R.M., Jr., and J.F. Burns, eds. 1984. Ohio endangered and threatened vascular plants: Abstracts of state-listed taxa. Division Natural Areas and Preserves, Ohio Dept. Natural Resources, Columbus. 635 pp. |
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Radford, A.E., H.E. Ahles, and C.R. Bell. 1968. Manual of the vascular flora of the Carolinas. Univ. North Carolina Press, Chapel Hill, NC. 1183 pp. |
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Sabourin, A. et al. 1992. Status Report on Small-flowered Lipocarpha, Lipocarpha micrantha, in Canada. Unpubl. rep. submitted to the Comm. on the Status of Endangered Wildl. in Can. Ottawa. 33pp. |
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Smith, T.W. et al. 2001. Update COSEWIC Status Report on Small-flowered Lipocarpha, Lipocarpha micrantha, in Canada. Unpubl. Rep. submitted to the Comm. on the Status of Endangered Wildl. in Can. Ottawa. 23pp. |
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Svenson, H.K. 1957. Vol. 18 (part 9): 508-509 in North American Flora. |
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Voss, E.G. 1972. Michigan flora: A guide to the identification and occurrence of the native and naturalized seed-plants of the state. Part I. Gymnosperms and monocots. Cranbrook Institute of Science and Univ. Michigan Herbarium. Ann Arbor. 488 pp. |
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Weakley, A.S., and Southeastern Flora Team. 2023. Flora of the southeastern United States. Edition of April 14, 2023. University of North Carolina Herbarium (NCU), North Carolina Botanical Garden, University of North Carolina, Chapel Hill. 2105 pp. |
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Please visit the website Conservation Status Ranks for definitions of the data fields used in this summary report.
Suggested Citation:
B.C. Conservation Data Centre. 2024. Species Summary: Cyperus subsquarrosus. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jun 4, 2026).