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Palm sedge fertile culms tend to have fewer leaves (5-10) restricted to the lower half of the culm while infertile culms produce more leaves (8-12+) along their entire length. Fertile culms generate a narrow (5-9 cm long, 1 cm across) inflorescence at their tips bearing 5-12 partially overlapping, stalkless spikelets. Spikelets are 2 cm long, 3-4 mm across prolate spheroids (spindle-shaped); staminate (male) florets are restricted to approximately the bottom quarter of the spikelet while pistillate (female) florets cover the rest of the spikelet. Each spikelet rests on a scale-like bract, only obvious on the lowest spikelet. Perigynia are very large compared to most sedges — 6-8 mm long and about 2 mm across; protruding from the tips of the perigynia are either slender, white styles or pale yellow or white, cylindrical anthers.

Carex

Carex muskingumensis

palm sedge [Blooms: Jun-Jul]

Fertile culms produce a 4-12" long inflorescence at their tip whose central stalk (rachis) is also triangular. Near the tip of the rachis are 1-3 pistillate (male) spikelets 1/2-1.25" long, light green, turning brown with maturity. Below are 2-3 pistillate (female) spikelets each with a leaf-like bract immediately below; the bracts increase in size beneath lower pistillate spikes. The staminate spikelets are usually about 1-3" above the pistillate spikelets, but occasionally appear to grow out of a pistillate spikelet (right). Pistillate spikelets (left) are cylindrical, up to 1.5" long, densely packed with quite hairy, chubby-triangular, perigynia (each 2.5-4" long and about half as wide), and their accompanying bristly bracts. The plants are wind pollinated. Wooly sedge is unusual in its very hairy perigynia; no other Jackson Park sedge has this character.

Carex

Carex pellita

woolly sedge [Blooms: Apr-May]

Cyperus sedge's fertile culms develop an inflorescence at their tips 1.5-6" long consisting of a single staminate spikelet up to 3" long and 2-6 pistillate spikelets 3" long and 9-12 mm across. The pistillate spikelets are initially erect but later droop (especially the lowest pistillate spike, which has the longest pedicle). At the base of each pistillate spike's pedicle is a leaf-like bract up to 20" long. Perigynia of the pistillate spikes are oriented perpendicular to the axis of the cylindrical spikelet, 3.5-6 mm long and 1-2 mm wide, not inflated, lance-shaped with two strong 1 mm long teeth at their tips. (Insert) - Three fuzzy stigmas protrude from the tips of the perigynia.

Carex

Carex pseudocyperus

cyperus sedge [Blooms: Jun-Jul]

A fertile culm of star sedge (right). Most culms are fertile, generating an apical inflorescence 1.5-3" long with 3-8 spikelets more closely spaced the higher their position on the inflorescence. Spikelets consist of 1-9 perigynia, 3 mm long and 1.5 mm wide, each initially erect, but later rotating so they point in all directions. (Thus, the species name "radiata.") At the base of each spikelet is a needle-like, long, narrow bract. The bracts are longer the further the spike is from the tip of the inflorescence; the bract beneath the most basal spikelet may be as long as the entire inflorescence. The male florets (lower left image; note the club-like anthers) occur above (more distal than) the female florets in the spikelet; the latter have a pair of 1 mm long styles protruding from their tips (upper left image; the fuzzy stigmas are beginning to wither in this image).

Carex

Carex radiata

star sedge [Blooms: May-?]

Rosy sedge (Carex rosea) is a native perennial sedge that typically grows 8-12" tall but individual culms may get as long as three feet. Culms are three sided ("three square"), 1.6-2.2 mm wide basally, tapering to 0.5-0.9 mm distally; the upper parts of the culm are rough textured. Spikes are stalkless and occur in a cluster at the tip of the culm up to 2.75" long. The cluster is composed of 4-8 small spikelets, crowded at the tip of the spike but well separated lower in the spike. Individual spikes consist of staminate (male) florets at the tip and pistillate (female) florets at the base, the individual florets radiating in all directions from the center of the spike. At the base of each spike is a bristle-like bract; the lowest bract in the cluster may be more leaf-like and may overtop the terminal spike. The staminate florets have anthers 0.8-1.3 mm long. The pistillate spikes produce fruit in late spring or early summer that consists of clusters of seeds (achenes) 1.6-2.2mm long and 1.1-1.6 mm wide. The pistillate scales are 1.3-2.75 mm long. The perigynia are 2.6-4 mm long and 1.1-1.8 mm wide, green to yellowish brown at maturity, lance-shaped in outline and flattened on the back; they taper to a short beak with minute teeth along the edges and two larger teeth at the tip. The styles often persist in the fruit with the two twisted stigmas protruding. Each cluster of seeds is wrapped in a casing (perigynium) and subtended by an egg-shaped to nearly round pistillate scale, translucent white with a green midrib, blunt or pointed at the tip but lacking an awn. You're unlikely to confuse rosy sedge with any of the other local sedges except the star sedge (Carex radiata) which also has culms that are triangular in section and, late in the development of the inflorescence, also has a "starburst" pattern of spikelets radiating in all directions. Star sedge has narrower (<2 mm) leaves than rosy sedge (3 mm) and star sedge has straight styles while rosy sedge has styles that curl through three turns; the styles in both species are red (assuming the styles are in their prime when you see them). Compare photos of the two species before deciding on an identification.

Carex

Carex rosea

rosy sedge [Blooms: May-Jun]

Fertile culms produce an apical inflorescence up to 12" long bearing 1-3 staminate (male) spikelets 1-2 cm long with 3 anthers and 2-5 pistillate (female) spikelets 1.5-3 cm long. The pistillate spikelets are roughly cylindrical overall with 10-30 perigynia 4-7 mm long radiating in all directions from the axis; each perigynium has an inflated, nearly-spherical base and a long, tapering, sharp distal beak.

Carex

Carex sprengelii

longbeaked sedge [Blooms: Apr-May]

Two prickly sedge inflorescences photographed about a month apart. Fertile culms bear an apical inflorescence from 2-4" long bearing several short spikelets with a distinctly spikey appearance; the spikelets are initially light green (left image) but turn gold (right image) to brown as they mature. Each spikelet has a needle-like bract at its base (longest in the lowermost spikelet); the spikelet has a few staminate (male) perigynia apically but the majority of the perigynia are pistillate.

Carex

Carex stipata

prickly sedge [Blooms: May-Jun]

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]

At the apex of the blue cohosh stem is a floral panicle 1-3" long bearing 5-30 flowers. Individual flowers (insert) are about 1/3" (8 mm) across with six petal-like yellow-green sepals, and six stamens with yellow anthers in a ring around a central green ovary and style. The petals have been reduced to six green lobes at the base of the stamens, between the sepals.

Caulophyllum

Caulophyllum thalictroides

blue cohosh [Blooms: Apr-May]

American bittersweet side branches occasionally produce panicles of flowers (up to 6" long) at their tips. Male flowers are about 1/4" wide with five light green petals with jagged or undulate margins, five green sepals, and five stamens with yellow anthers and a narrow style rudiment.

Celastrus

Celastrus scandens

American bittersweet [Blooms: Jun-Jul]

Common hackberry flowers may be staminate (male), pistillate (female), or perfect (both), all on the same tree. Flowers are about 1/4" across and bloom before the leaves open, often high in the tree (thus, I have no pictures yet). All flowers are wind-pollinated, yellowish-green with 4-6 spreading sepals joined at their bases; there are no petals. Male flowers have 4-5 stamens with green or yellow-brown anthers; female flowers have a green ovary with a large two-part, densely fuzzy style like an umbrella beneath the ovary. Perfect flowers have both.

Celtis

Celtis occidentalis

common hackberry [Blooms: Apr-May]

Sandburs are no one's friend. They are a form of grass with light green culms, round in section, up to 2.5' long; they are mostly covered by the sheaths of the alternate leaves. Each culm and upper branches (if any) terminate in a 4" long (3/4" across) raceme of 4-20 spiky burs. Each 1/4" diameter bur (excluding the spines) consists of 2-3 spikelets, each containing a fertile flower recognizable only by the stamens or styles protruding from the tip of the spikelets. The flowers are wind pollinated. This is the only sandbur in Illinois, so identification is easy (if not always painless).

Cenchrus

Cenchrus longispinus

sandbur [Blooms: Aug-?]

Lamb's quarters produces inconspicuous star-shaped, yellow-green flowers, <1/8" across, sessile on flower stalks in round, tight clusters; the flowers have no petals, five stamens with yellow anthers, and a single divided style at the tip of a round, green ovary, all cupped in a five-lobed, mealy-white, calyx. The flowers are wind-pollinated and can aggravate hay fever symptoms.

Chenopodium

Chenopodium album

lamb's quarters [Blooms: Jul-Sep]

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]

Winged pigweed flowers are whitish-green, sessile, and 1/16" across; the flowers have five inward-curving sepals that cover the ovaries, five stamens, and a flattened ovary with 2-3 styles. Flowers may contain only a pistil or both a pistil and stamens; if the latter, the creamy-yellow anthers are prominent.

Cycloloma

Cycloloma atriplicifolium

winged pigweed [Blooms: Jul-Aug]

Broad-leaved helleborine's inflorescence is a 4-12" long raceme with 15-50 flowers, all on one side of the flower stalk. Individual flowers are 1/2-3/4" wide. The petals are greenish-purple with the lower petal forming a pale red bowl; behind the petals, the three sepals are pale green with purple stripes. (The sepals are as long as the petals, as are the bracts below the flowers' stalks.) The fruit is a hairy capsule ~1/2" long, and egg-shaped. Broad-leaved helleborine prefers woodlands.

Epipactis

Epipactis helleborine

broad-leaved helleborine [Blooms: Jul]