Cyperaceae. This
family usually has 3-angled stems, which is most obvious immediately below the
inflorescence. Some Cyperaceae species have cylindrical stems similar to
grasses. In this case, the spikelets differ from Poaceae in having flowers
mostly helically arranged (grasses have distichous spikelets) and the flowers
differ in lacking glumes and paleas. The perianth may be present in the form of
barbed bristles, which is unique to Cyperaceae. Characteristics of the common
genera are reported below.
1. Eleocharis
palustris. Common spikerush. Rhizomatous
perennials often mat-forming if not bunched, distinguished from other
spikerushes by the combination of its lenticular achenes that bear 2 stigma
branches, stems over
2. Scirpus microcarpus.
Panicled bulrush. A rhizomatous perennial often forming dense stands along with
other wetlands species. This species is distinguished from other bulrushes by
its small spikelets in an open panicle subtended by several leafy bracts, by
rusty or reddish lower leaf sheaths, and by having a lenticular (not 3-angled)
achene. Scirpus is very closely related to Eleocharis and is
distinguished by having more than one spikelet terminate
a flowering stem and flower with an ovary having a thin style.
3. Scirpus validus
(Schoenoplectus tabernaemontani).
Softstem bulrush. A rhizomatous perennial forming extensive and dense stands in
ponds and along ditches. Although with cylindrical stems, note that the
inflorescences, spikelets, and flowers are similar to Scirpus microcarpus.
4. Cyperus esculentus.
Yellow nutgrass. A rhizomatous perennial and often an aggressive colonizer. Cyperus
is the only genus of Cyperaceae in
5. Carex filifolia,
threadleaf sedge. Bunched and mat-forming perennials of typically open dry
sites such as in the sagebrush steppe, the inflorescence is a sessile terminal
spikelet, perigynia surround an elliptical achene. Staminate flowers terminate
the distal end of the spikelet whereas the pistillate flowers are borne towards
the base. Carex with an inflorescence
comprising a single spikelet are usually dry site inhabiting. Carex is
distinguished by monoecious flowers, the pistillate of which produce a
perigynium.
6. Carex hoodii, hood
sedge. Bunched perennials typically of mountain meadow settings, the
inflorescence comprises more than several sessile and tightly clustered
spikelets, the winged perigynia surround an elliptical achene. Each spike
terminates with staminate flowers (note the thin whitish filaments if anthers
are not present) whereas the pistillate flowers are borne below the tip of each
spikelet to its base. Carex with an
inflorescence comprising sessile congested spikelets are usually dry site to
dry meadow inhabiting.
7. Carex paysonis,
payson sedge. Bunched to single-stemmed perennials of subalpine to alpine
meadows, the inflorescence comprises several or more pedicellate spikelets
where the distal-most spikelets bear only staminate flowers and the basal-most
only pistillate flowers. The perigynia surround 3-angled (trigonous) achenes.
The broad dark flower bracts are distinctive of this species and often render
the entire spikelet distinctively black or dark brown in color. Carex with an inflorescence comprising
pedicellate spikelets that are well spaced are usually wet meadow to wet site
inhabiting.
Juncaceae.
The small flowers of Juncaceae have parts in 3’s, unlike other graminoid
families. The fruit is also different from other graminoid families in being a
capsule that splits open along three sutures and spills out three to many
seeds. The seed is the dispersal unit.
8. Juncus balticus.
Baltic rush. A strongly rhizomatous perennial with stems sometime approaching a
meter tall, a colonizer of disturbed open grassy sites at mid elevations.
Juncus produces leaf sheaths with our without well developed leaf blades but in
any case the leaf sheaths are open and the collar, throat, and margins of the
leaf blades are glabrous.
9. Juncus ensifolius.
Swordleaf rush. A rhizomatous perennial common in seeps, along roadsides, etc.,
the laterally flattened leaves (folded flat along the midrib in fresh
condition) and styles that protrude distinctly beyond the tepals are
characteristic of this species.
10. Juncus bufonius.
Toad rush. A bunched annual with stems typically less than 25 cm tall, of moist
meadows, the solitary flowers scattered along the inflorescence rachis is
distinctive of this species. Most Juncus
have flowers congested into heads or at least near the distal branch ends.
11. Luzula parviflora.
Small-flowered woodrush. A single-stemmed perennial of moist mountain meadows.
This species is one of the more common woodrushes and is distinguished from the
others by its open paniculate inflorescence, small flowers, and fairly ample leaves.
Woodrushes differ from rushes in having a fused leaf sheath, long hairs along
the margins of young leaf blades, and only one seed per ovary compartment or
carpel.
Typhaceae.
The inflorescence is a terminal cylindrical spike with pistillate flowers borne
below the staminate ones. The pistillate flower has a perianth of long thin
hairs which serve to disperse the flower and seed.
12. Typha latifolia.
Broadleaf cattail. A tall native perennial forming extensive stands, flowers
are monoecious, the long-stipitate ovary is ultimately dispersed by the
pappus-like perianth. The long styles flare distally into a brownish end. These
style ends from both sterile and fertile pistillate flowers
when packed together render the brownish coloration of the pistillate portion
of the spike. The staminate flowers comprise 2-5 stamens borne from a hair-like
pedicel. Typha latifolia is distinguished from other cattails in this
region by its inflorescence in which the staminate portion is contiguous with
the pistillate portion.