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Blunt broom sedge (Carex tribuloides) is a native perennial that ranges across the eastern half of the U.S. It is classified as "Secure" in Illinois although it is not very common in Jackson Park. The culms of blunt broom sedge range from 1.5-3 feet long, erect or (more often) ascending. In tufts of blunt broom sedge, both sterile and fertile culms appear; both are light green, hairless, and triangular ("3-angled") in cross section. Fertile culms carry a 2.5" long inflorescence at their tips consisting of 5-15 partly overlapping or slightly separated spikelets. In contrast to the usual pattern in sedges, the spikelets of blunt broom sedges bear male (staminate) florets at their bases and female (pistillate) florets distally, the latter with two protruding stigmas. Individual spikelets are stalkless, 6-12 mm long, ovoid, and markedly prickly due to the long beaks of the ascending perigynia (which are 3-5 mm long and 1.25-1.75 mm across, flattened, and lance-shaped). The spikelets are cone-shaped in outline, tapered at their base and rounded at their tips. Immature spikelets are light green; mature spikelets are light brown. The lowest spikelet in an inflorescence has a 1/2-3/4" long, needle-like bract at its base; the next higher spikelet may also have a (shorter) bract at its base. The florets are wind pollinated. Blunt broom sedge prefers moist to wet conditions in light shade to full sun, favoring habitats like wet meadows, floodplain forests, pond margins, and swamps.

Carex

Carex tribuloides

blunt broom sedge [Blooms: May-Jun]

Brown fox sedge fertile culms apically bear a 2-5" long, 15 mm wide inflorescence (bottom) with numerous spikelets variably spaced along the axis. All spikelets have staminate (male) flowers apically and pistillate flowers below with a bristle-like bract at their bases; the lowest bract is the longest (up to 2"). Perigynia (top) are 2-3 mm long and 1.5 mm across, tapering to a toothed beak; pistillate scales as long as the perigynia with terminal awns add to the bristly appearance.

Carex

Carex vulpinoidea

brown fox sedge [Blooms: May-Jul]

Pecan trees have separate male and female flowers on the same tree. The staminate (male) catkins droop from short spurs on the twigs; they typically develop in groups of three and are about 4-6" long with numerous staminate florets along the catkin. Individual staminate florets have a three lobed bractlet arising from their base that shelter the 4-6 stamens that hang beneath it; the middle lobe is the longer of the three lobes. The pistillate (female) spikes develop at the tips of a subset of the twigs, each spike bearing 3-10 greenish, pistillate florets; the florets are 1/4" long and 1/8" across. Each pistillate floret contains a short, tubular calyx, four bractlets of unequal sizes, and a pistil with two feathery stigmas. Each bractlet has four erect to spreading, lance-shaped lobes. The pistillate florets are wind pollinated. Fertilized florets transform into 2-6 greenish fruits (nuts in a husk) in a cluster, each with four short wings; when mature, the ovoid fruits are about 2" long and 1" across, brown or black in color; the husks partially divide into four segments along the wings, releasing the nut. Pecan is typically a bottomland tree that lives in river valleys but can grow in any rich, moist, well-drained soil. The leaves of black walnut and pecan have a similar number of leaflets in their odd-pinnate leaves, but the fruits are completely different. According to the Arnold Arboretum at Harvard, pecan trees (Carya illinoinensis) can live for over 300 years. For some reason, Carya illinoinensis is the state tree of ...... Texas.

Carya

Carya illinoinensis

pecan [Blooms: Jun-Aug]

American hazelnut flowers. The male inflorescence is a cylindrical catkin that appears in the fall on the most recent year's twigs and then overwinters; in the spring, the catkin elongates (to 2-4" long) and the male flowers (consisting of two tiny bracts and four stamens) open to release their pollen. The female inflorescence looks like a small bud protected by bracts that is located at the branch tip or in leaf axils; it contains several pistillate flowers seen only as red styles/stigmas protruding from the tip of the "bud."

Corylus

Corylus americana

American hazelnut [Blooms: Mar-Apr]

Shining flatsedge is an attractive plant up to 10" tall with sprawling culms up to 8" long, triangular in section. The flower spike (inflorescence) has 2-7 strikingly laterally-flattened spikelets 1/4-1/2" long; each spikelet has 8-18 reddish-brown floral scales arranged in two opposing rows, each covering a floret consisting of 2-3 stamens, an ovary, and a split style which may protrude 1-2 mm beyond the scales. The plant is wind pollinated.

Cyperus

Cyperus bipartitus

shining flatsedge [Blooms: Aug-Sep]

Yellow nut sedge flower spikes are 2-3" long with spikelets sticking out at 90° to the axis and 90° to each other around the axis (producing four somewhat irregular rows down the axis). The axis itself is flattened with narrow wings. Individual spikelets are 1/2-3/4" long, yellow- or golden-brown, flattened, with from10-30, 2-3 mm long scales, each covering a floret. Each floret has a white, tripartite style with curly ends (the stigmas) and three stamens with yellowish-brown anthers; the flowers are wind pollinated.

Cyperus

Cyperus esculentus

yellow nut sedge [Blooms: Aug-?]

Rusty flatsedge produces an umbel comprised of 3-6 floral stalks 1-4" long bearing clusters of 2-4 floral spikes. (Visually, this looks much like the branch of a fir tree.) Individual spikes are 1/2-1.5" long with individual needle-like spikelets 1/2-1" long pointing in all directions (like a bottle brush). Each spikelet has 8-25 scales sheltering perfect florets (i.e., both three stamens and a tripartite style are present). Spikelets are initially yellow- or whitish green, becoming reddish-brown at maturity. (Thus the "rusty" name.)

Cyperus

Cyperus odoratus

rusty flatsedge [Blooms: Aug-Sep]

in common spike-rush, at the tip of the culm is a single spike, elongate-ovoid with a sharply pointed tip, up to about 1" long; 30-100 florets ( each with three stamens bearing dark yellow anthers and a split style) are spirally arranged around the spikelet, each protected by a pointed scale 3-5 mm long. The scales have a green to straw-colored midrib, reddish- or orange-brown flanks, and a translucent edge. The two lowest scales in the spike lack flowers. The lowest scale wraps less than 3/4 of the base; it is mostly green bordered by a brown band and a translucent, rounded edge and is more leathery than other scales.

Eleocharis

Eleocharis palustris

common spike-rush [Blooms: May-Jul]

Lyme grass flower spikes are 5-14" long, initially blue-green or silvery but turning beige when mature. There are typically one pair of spikelets per node on the spike. The spikelets are 1/2-1" long, containing 2-5 (typically 3) florets; each floret contains two bottlebrush-like styles and 1-3 stamens, each typically with a single yellow anther. Like all grasses, Lyme grass is wind pollinated. Lyme grass is very similar to the native American dune grass (Leymus mollis) but the latter is greener and is finely hairy under the spike. Lyme grass has become established in sandy habitats around the Great Lakes and (curiously) along the coast of Greenland.

Leymus

Leymus arenarius

Lyme grass [Blooms: May-Jun]

Reed canary-grass is a very widespread species (the native range is circumboreal in the Northern Hemisphere) that is listed as "vulnerable" in Illinois. It is a wetland grass that reaches heights of 3-5 feet; plants tend to be widely spaced on Jackson Park although they are known to produce clonal colonies elsewhere. The leaves are flat, alternate, and evenly spaced along the culm. The leaf blades reach up to 12 long and 3/4" across; they are green or blue-gray and hairless with continuous (but rough-textured) margins. The leaf base is much wider than the culm (stem) which it clasps tightly; the leaf sheaths look like an extension of the leaf in both color and appearance. When reproductive (early-midsummer), the culms produce a narrowly-pyramidal panicle up to 10" long and 2-3" across of spikelets that bear the florets. Spikelets are initially green but fade over time to a light tan color. The stem and leaves all turn a diagnostic light tan during the late fall and winter; the leaves mostly remain attached.

Phalaris

Phalaris arundinacea

reed canary-grass [Blooms: May-?]

At the tip of the culm, dark green bulrush produces an inflorescence comprised of one to three (rarely four or five) compound umbels of spikelets; beneath the inflorescence are 3+ leafy bracts (similar to the leaves) that are up to 1' long and 1/2" wide. At least one of the bracts is always longer than the inflorescence. The umbels generate 1/4-4" long, straight branches in all directions that terminate in umbelletes of 5-20 spikelets that rest on slender, leafy bractlets; the spikelets may be sessile or may rest on 1/2" long branchlets. The branches and branchlets are green, straight, and stiff. Spikelets are less than 1/4" long (3-6 mm), ovoid or egg-shaped, yellowish green initially but darkening to brown or black later; the spikelets are an assemblage of numerous spirally arranged, overlapping scales and their florets. The florets each have a single subtending scale, three stamens, and an ovary with a tripartite style; they are wind pollinated. Bulblets may form on one or more branches and sprout late in the season. The umbels may be visually dense and complex and take some study to sort out.

Scirpus

Scirpus atrovirens

dark green bulrush [Blooms: May-Jul]