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Gray's sedge is the most easily identifiable sedge in Jackson Park — the large, pistillate (female) spikelet (reminiscent of the head of a medieval mace) is unmistakable. Fertile culms of Gray's sedge may reach up to 3' tall, but most plants don't exceed 2.5'. The culms are triangular in section ("three-angled"), light green and unbranched, with a few alternate, dark green leaves (each 5-14" long and 4-10 mm wide) along its length. The leaves have a deep groove along their midline and, usually, secondary folds on either side, producing a V- or W-shaped cross section in the leaves. Fertile culms produce an Inflorescence at their apex consisting of one or more globoid (mace-like) pistillate spikelets (1-1.5' diameter spiky clusters of perigynia that radiate in all directions) and a single staminate spikelet up to 2.5" long and 1-4 mm wide. Each pistillate spikelet has a 3-10" long leaf at its base. Each perigynum in the pistillate spikelets is quite large (12-18 mm long, 4-8 mm wide), an elongate teardrop (lanceolate) shape, with stigmas emerging from the pointed end. The staminate spikelet is at the tip of the culm on the end of a short pedicle, usually yellow-brown in color. The male and female spikelets are labeled; the long, tan-colored anthers (male) and white stigmas (female) are clearly visible in this image.

Carex

Carex grayi

Gray's sedge [Blooms: May-Jul]

Fertile culms of wood gray sedge produce a terminal inflorescence 6-8" long bearing 2-4 pistillate (female) spikelets and a single staminate (male) spikelet 3/4" long attached beside the topmost pistillate spikelet. Pistillate spikelets are 1-1.5" long and 5 mm across on 3.5 cm long pedicels with a 3-6" long, leaflike bract at their base; there are 5-15 female perigynia in each pistillate spikelet. The perigynia are 4-5.5 mm long, smooth ovoids that are quite inflated, tapering to a blunt tip and base, with easily visible lines ("nerves" - see insert) that run from one end of the perigynum to the other. At the base of each perigynium is a pistillate scale about the same length as the perigynium, narrowing drastically at the free end to a sharp needle ("awn" - see insert). Immature perigynia are green, turning brown with maturity. Wood gray sedge can't be confused with any other sedge that occurs in Jackson Park.

Carex

Carex grisea

wood gray sedge [Blooms: May-Jun]

Fertile culms of porcupine sedge produce an inflorescence at their tips with a single, terminal staminate spikelet and 2-4 pistillate spikelets below balancing on or hanging from thin pedicels. The staminate spikelet is paralleled along its length by a bristly bract; both are up to 2" long. Pistillate spikelets are 0.75-2.5" long and 1/2" across, roughly cylindrical in outline, and packed with widely spreading, inflated perigynia 5-8 mm long and about 2 mm across whose sharp tips give rise to the common name; at their base, the perigynia have a leaf-like bract 4-6" long and 3-4 mm across. The lowest pistillate spikelet has the longest (up to 12") bract. Porcupine sedge is commonly found near the shorelines around the Jackson Park lagoons. Of all the Jackson Park sedges, porcupine sedge is most similar to cyperus sedge (C. pseudocyperus) but has stubbier pistillate spikelets.

Carex

Carex hystericina

porcupine sedge [Blooms: May-Jul]

Troublesome sedge is superficially similar to crested sedge (C. cristatella) but with fewer, less spiky spikelets, and with perigynia less crowded. Two to five (rarely six) spikelets are crowded along an inflorescence at the tip of the culm, each 6-15 mm long and 5-10 mm wide. The perigynia are rounded at tip and base, tapering distally to a blunt point, each with a darker green, winged margin and a lighter center. Staminate (male) perigynia are relatively few and located at the base of the spikelets; most of the perigynia are pistillate (female). At the base of the lowermost spikelet is a thin, bristle-like, usually short bract. The left side of the image shows a young inflorescence; the right side shows a mature inflorescence post-fertilization.

Carex

Carex molesta

troublesome sedge [Blooms: May-Jun]

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-?]

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]

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]