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Wikipedia / Scirpus

Scirpus is a genus of grass-like species in the sedge family Cyperaceae many with the common names club-rush, wood club-rush or bulrush. They mostly inhabit wetlands and damp locations.

Description

Scirpus are rhizomatous perennial herbs, with 3-angled stems and flat grass-like leaves. The flowers are in clusters of small spikelets, often brown or greenish brown. Some species (e.g. S. lacustris) can reach a height of , while S. sylvaticus is about and others, such as S. supinus, are much smaller, only reaching tall.

Taxonomy

The taxonomy of the genus is complex, and under review by botanists. Recent studies by taxonomists of the Cyperaceae have resulted in the creation of several new genera, including the genera Schoenoplectus and Bolboschoenus; others (including Blysmus, Isolepis, Nomochloa, and Scirpoides) have also been used. At one point this genus held almost 300 species, but many of the species once assigned to it have now been reassigned, and it now holds an estimated 120 species.

Selected species

  1. (This list is incomplete, and may include some species now assigned to other genera.)

  2. Scirpus ancistrochaetus northeastern bulrush

  3. Scirpus atrocinctus black-girdle bulrush

  4. Scirpus atrovirens woolgrass bulrush

  5. Scirpus bicolor

  6. Scirpus campestris salt marsh bulrush

  7. Scirpus cespitosus deergrass, synonymous with Trichophorum cespitosum

  8. Scirpus congdonii Congdon's bulrush

  9. Scirpus cyperinus - woolgrass/cottongrass bulrush

  10. Scirpus diffusus

  11. Scirpus divaricatus spreading bulrush

  12. Scirpus expansus Woodland beakrush

  13. Scirpus flaccidifolius reclining bulrush

  14. Scirpus fluitans floating club-rush

  15. Scirpus fluviatilis - river bulrush

  16. Scirpus georgianus Georgia bulrush

  17. Scirpus grossus Greater club-rush, Giant bulrush

  18. Scirpus hattorianus - mosquito bulrush

  19. Scirpus lineatus drooping bulrush

  20. Scirpus longii Long's bulrush

  21. Scirpus mariqueter

  22. Scirpus microcarpus small-fruit bulrush

  23. Scirpus mucronatus

  24. Scirpus nevadensis Nevada bulrush

  25. Scirpus olneyi Olney bulrush, synonymous with Schoenoplectus americanus

  26. Scirpus pacificus Pacific Coast bulrush

  27. Scirpus pallidus pale bulrush

  28. Scirpus paludosus salt marsh bulrush

  29. Scirpus pedicellatus stalked bulrush

  30. Scirpus pendulus pendulous bulrush

  31. Scirpus polyphyllus leafy bulrush

  32. Scirpus pumilus dwarf deergrass

  33. Scirpus pungens sharp club-rush

  34. Scirpus radicans

  35. Scirpus robustus salt marsh bulrush

  36. Scirpus supinus dwarf club-rush

  37. Scirpus sylvaticus wood club-rush

  38. Scirpus triqueter triangular club-rush

  39. Selected species in a broader view of the genus

  40. Bolboschoenus maritimus sea club-rush

  41. Isolepis cernua slender club-rush

  42. Isolepis setacea bristle club-rush

  43. Schoenoplectus acutus tule

  44. Schoenoplectus hudsonianus alpine deergrass

  45. Schoenoplectus lacustris common club-rush

  46. Schoenoplectus tabernaemontani

  47. Scirpoides holoschoenus round-headed club-rush

Fossil record

Several hundred fossil fruits of Scirpus ragozinii have been described from middle Miocene strata of the Fasterholt area near Silkeborg in Central Jutland, Denmark. Thirty-five fossil fruits of the extant Scirpus sylvaticus have been extracted from borehole samples of the Middle Miocene fresh water deposits in Nowy Sacz Basin, West Carpathians, Poland.

Distribution and habitat

The genus has a nearly cosmopolitan distribution, found on every continent except Africa and Antarctica.

Many species are common in wetlands and can produce dense stands of vegetation, along rivers, in coastal deltas and in ponds and potholes. Although flooding is the most important factor affecting its distribution, drought, ice scour, grazing, fire and salinity also affect its abundance. It can survive unfavourable conditions like prolonged flooding, or drought, as buried seeds.

Ecology

Scirpus species are used as food plants by the larvae of some Lepidoptera species, including Chedra microstigma and Scirpophaga nivella. They provide habitat for other wildlife.

Scirpus plants play a vital role in wetland ecosystems by stabilizing soil and reducing erosion. Their dense root systems help filter water and improve its quality.

Uses

Scirpus species are often planted to inhibit soil erosion. They are also used in some herbal remedies; the plant's rhizomes are collected in the autumn and winter and dried in the sun before use.

References

Sources

  • Muntz, Philip A. A California Flora. Berkeley, CA: University of California Press, 1973, copyright 1959

  • Muntz, Philip A. A California Flora: Supplement. Berkeley, CA: University of California Press, 1976 (Scirpus lacutris, validus, glaucus, p.183))