Description: This native perennial plant consists of a tuft of basal leaves and one or more flowering culms up to 2½' tall; these culms have alternate leaves and leafy bracts near the inflorescence. The culms are light green, 3-angled toward the base, and glabrous. The leaves are up to 12" long and 1/3" across (or slightly wider); they are light green, glabrous, linear, and scabrous (rough) along the margins. The basal and lower leaves usually arch upward near the base and downward toward their tips.
Each culm terminates in an inflorescence
consisting of 3-8 spikelets of pistillate flowers and a terminal spikelet of
staminate flowers. Each pistillate spikelet is up to 2" long and ½"
across; it has a short cylindrical shape and a bristly appearance because of
the long styles and bracts of the flowers. The perigynia of the flowers are
densely crowded together all around the spikelet. Each perygynium is about 4-5
mm. long and 2 mm. across near the top (where it is widest); it is light green
and obovoid. At the apex, this perigynium is flattened, except for a slender
beak, through which the style of the flower is exerted. Underneath each
perigynium is a narrow linear scale up to 10 mm. long with a long awned tip;
this pistillate scale is much longer than the perigynium. Inside the
perigynium, there is a single obovoid achene about 1.8 mm. long and 1.2 mm.
across; this achene is 3-angled and eventually becomes brown. Each pistillate
flower has a long style that divides into 3 stigmas; this style may be straight
or sinuous (somewhat curly). The pistillate spikelets are sessile to
short-stalked; they are often hidden by the upper leaves and leafy bracts. The
narrow staminate spike is up to 2" long; it becomes brown and withered shortly
after releasing its pollen. The scales of the staminate spike are narrowly
linear. The blooming period occurs during early to mid-summer; some plants will
bloom later in the summer if a disturbance delays their development. The
pistillate spikelets change from green to brown as their achenes mature. The
root system consists of short rhizomes and coarse fibrous roots. Tight bunches
of plants are often formed from the offsets of the rhizomes.
Cultivation: The preference is partial to full sun,
wet to moist conditions, and fertile soil that is loamy or silty. Temporary
flooding is tolerated; this sedge prefers wetter conditions than most others.
It is occasionally attacked by slugs.
Range
& Habitat: Frank's Sedge is occasional to locally common in
southern and central Illinois, while in the northern Illinois it is uncommon or
absent (see
Distribution
Map). Habitats include openings in floodplain woodlands, prairie sloughs,
wet dolomite prairie, fens and seeps, sedge meadows, soggy areas along rivers,
and ditches. This sedge can be found in both disturbed and higher quality
wetlands; sometimes it occurs in great abundance. The spongy perigynia
containing the achenes can float down rivers, spreading this species to new
areas.
Faunal Associations: The
flowers are wind-pollinated and do not rely on insects for cross-pollination.
The caterpillars of various butterflies, skippers, and moths feed on Carex
spp. (see Lepidoptera
Table). Some short-horned grasshoppers and leafhoppers feed on the foliage
of Carex spp. This includes the grasshopper Stethophyma lineatum
and the following leafhoppers: Cosmotettix lineatus, Cosmotettix
luteocephalus, Cosmotettix bierni, and Elymana inornata. The
seeds of Carex spp. are important sources of food to many upland
gamebirds, waterfowl, and songbirds (see
Bird Table). Which kind of
bird is likely to eat the seeds depends on the habitat preferences of the
particular Carex sp.
Photographic
Location: Along a drainage ditch at Judge Webber Park in Urbana,
Illinois. The bristly pistillate spikelets often snag passing debris when this
plant grows in floodplain areas (as it often does).
Comments: This is a rather large and stout sedge
that is fairly easy to identify. It belongs to a small group of Carex
spp. (Sedges) with obovoid perigynia (resembling narrow bell peppers).
These perigynia have long narrow beaks at their apex that give the pistillate
spikelets their bristly appearance. What distinguishes Frank's Sedge from other
members of this group are its linear pistillate scales, which are much longer
than the perigynia. The pistillate scales of other Carex spp. in this
group, viz. Carex squarrosa and Carex typhina, are no longer than
the perigynia. Another difference is the position of the staminate flowers:
Frank's Sedge produces a terminal staminate spikelet that is separate from the
pistillate spikelets, while Carex squarrosa and Carex typhina
always produce staminate flowers underneath the pistillate flowers on the same
spikelets.