Scirpus tabernaemontanii (Scirpus lacustris ssp. validus) softstem bulrush; tule; American great bulrush

Family: Cyperaceae
Wetland Indictor Status: OBL


General Species Description

Softstem bulrush is an extremely tall (to 2 m), olive green/grey, leafless plant with round stems. The stems are easily crushed. It is usually found in large colonies in marshy areas. The multiple flower spikelets are terminal with an erect involucral bract and usually have a short stalk. The spikelets are a light reddish brown, compact, and slightly less than 1 cm long.


Leaves

There are no leaves, just a basal sheath.


Inflorescence/Flowers

The inflorescence of the softstem bulrush is a medium sized group of spikelets at the tip of the long stalk. The single, green, involucral bract appears to be an extension of the stem about 2-10 cm long, not as long as the inflorescence. Each spikelet is reminiscent of a tiny pine cone. They are light to medium brown with a slightly reddish hue. Reddish stripes may be visible on the scales. The achene is just visible above the scales. The stalks of the inflorescence droop slightly. The spikelets may be attached directly to the stalks, but are usually joined to the stalks by a short stem which branches off the main stalk. Each spikelet appears slightly hairy, but not wooly as in wooly sedge (Scirpus atrocinctus).


Fruits

The achenes of soft stemmed bulrush are egg shaped with the narrow end pointing down. The tip is not pointed. There are usually more than 5 bristles around the achene that are approximatley the same length as the achene.


Habitat

Softstem bulrush is found in marshes and at the muddy edges of ponds, lakes, and streams at low elevations. It is often found near coastal areas as it tolerates salty and alkaline conditions. It may be found with hardstem bulrush (Scirpus acutus) with which it may hybridize as well as other plants which enjoy muddy, marshy areas. It usually grows in large colonies, but occassionally a solitary plant may be found.


Range

It is found throughout the temperate climates of North America. It is fairly common in Oregon. Large stands of it may be found in the slough areas of the Columbia River Gorge.


Similar Species

Softstem bulrush is most commonly confused with hardstem bulrush (Scirpus acutus). Hardstem bulrush, unlike softstem bulrush, has a hard stem (obviously). However these plants sometimes hybridize and you may find a plant that is somewhere between soft and hard stemmed. The stems of hardstem bulrush are also taller and wider. Also in hardstem bulrush the achenes are completely hidden by the scales. The scales are grayish white with a reddish midrib and more strongly notched at the tip. Another species that interbreeds with softstem bulrush is threesquare tule (Scirpus triqueter). It was recently found in the Columbia River basin where it is now quite common. It's distinguishing feature is that the stem is strongly triangular and not quite as tall as softstem bulrush. Again, since it hybridizes you may find a plant which is somewhat triangular, a mix of the two species. Softstem bulrush could be briefly confused with woolly sedge (Scirpus atrocinctus) but the stem of the softstem bulrush has no leaves and the flowering head is not so woolly.


Ecological Value

The stems are used by wildlife as nesting material. The achenes are a favorite food of water birds.


Human Value

The stems are excellent for basketweaving as they are very long and remain flexible when dried. It is easily transplanted and can be used for naturalizing a manmade pond, or to aid in the restoration of a wetland.


References

A Field Guide to the Common Wetland Plants of Western Washington & Northwestern Oregon, edited by Sarah Spear Cooke, Seattle Audobon Society, 1997 -- Flora of the Pacific Northwest, Hitchcock and Cronquist, University of Washington Press, 1974


This page was created by: Rose Wingenbach, August 1998


Return to Northwest Oregon Wetland Plants Project