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Upright prairie coneflower (aka, "Mexican hat") is a 1-3' tall plant native to North America but an exotic in Illinois; it looks like English plantain (Plantago lanceolata) dressed up for a party. The stems are green and longitudinally ridged; they bear alternate, pinnatifid leaves with 5-11 elongate, narrow lobes. The upper stems produce flower stalks (peduncles) 2-12" long, minutely grooved, and lacking leaves; the peduncles are very "wire-like." The flowerheads are 1.5-3" long cylinders composed of numerous brown or purplish disk florets that bloom from the bottom of the cylinder to the top; at the base of the cylinder are 4-12 ray florets with drooping, 1/2-1.5" long, oblong petals with notched tips that are yellow, maroon, or yellow with basal maroon patches (the "party skirt"). This plant is unmistakable when in bloom. The imaged flower was photographed in Bobolink Meadow in July, 2010; I have not seen a specimen since.

Ratibida

Ratibida columnifera

upright prairie coneflower [Blooms: Jul]

Grey-headed coneflower's composite flowerheads sit individually on the tips of long, thin, ridged stalks; they have up to 15 drooping, 2" long, yellow ray florets and a central 3/4" tall gumball- or egg-shaped cone of 100-200 disc florets. The ray florets are sterile; the disc florets have both stamens (5) and styles (1). Beneath the flowerhead are two series of long, narrowly-triangular bracts. The disc florets mature progressively from the bottom of the cone to the top; immature disc florets are light green or grey, mature disc florets are brown, giving the portion of the cone they cover a fuzzy appearance. (Thus the analogy implicit in the common name to a grey, bald pate peeking through a head of brown, fuzzy hair.) After fertilization, the cone becomes a mass of small (2-4 mm long), brown seeds (achenes) that are devoid of a tuft of hairs.

Ratibida

Ratibida pinnata

grey-headed coneflower [Blooms: Jun-Oct]

In buckthorn, umbels of flowers arise from leaf axils. Flowers on a single plant may be perfect (both male and female organs present), but more commonly the flowers are dioecious with either all male (staminate) or all female (pistillate) flowers found on any given plant. Individual flowers are 1/4" across. They have four greenish-yellow, triangular, spreading sepals that together form a calyx and four petals that can't be easily seen without magnification; the "petals" in the flowers are actually sepals. Male flowers have four greenish stamens with cream-colored anthers; female flowers have a single style that has a tip divided into four branches. After fertilization, female (or perfect) flowers produce a shiny black, 1/4" wide, cherry-like fruit containing 3-4 seeds. Birds can eat the fruit without ill effects, but in humans the fruit produces stomach cramps and acts as a strong laxative (as indicated by the species name, "cathartica").

Rhamnus

Rhamnus cathartica

buckthorn [Blooms: May-Jun]

Fragrant sumac is a native shrub that grows 2-8' tall. One-inch-long spikes of closely-packed flowers arise from leaf axils. Individual flowers are 1/8" long, tubular but less than twice as long as wide, with five greenish-yellow petals and a calyx of five short sepals fused at their bases; flowers are either perfect (with both male and female organs) or unisexual (either stamens only or pistils only). (If unisexual, all flowers on one plant are the same sex.) Male flowers have five stamens with yellow-orange anthers but no pistil; female flowers have a pistil with a Y-shaped tip but no stamens. After fertilization, the flowers are replaced by fruits 1/4-3/8" in diameter, roughly spherical, deep red, and exuberantly hairy; it contains a single stone (a seed with a hard coat). Fragrant sumac blooms before either smooth sumac or staghorn sumac and its fruit matures earlier.

Rhus

Rhus aromatica

fragrant sumac [Blooms: Apr-May]

Smooth sumac is dioecious — each plant produces only either male (staminate) or female (pistillate) flowers. Individual flowers are about 1/4" across with a green calyx with five teeth and a whitish green or yellowish green corolla with five spreading petals. The lobes and teeth range from lance-shaped to oval. Male flowers also have five stamens with large yellow anthers and style rudiments; female flowers have an ovary with three closely-packed, stout styles in the center and sometimes with rudiments of stamens. On female plants, after fertilization, the flowers are replaced with about 5 mm wide drupes containing a single straw-yellow stony seed. The fruits are initially green and densely covered with short hairs, turning an intense, deep red when mature.

Rhus

Rhus glabra

smooth sumac [Blooms: May-Jul]

In staghorn sumac, some upper stems bear clusters (panicles) of flowers that are up to 12" long and 6" across; pistillate (female) inflorescences (see below) tend to be more densely packed with flowers and smaller than the staminate (male) inflorescences. Individual flowers are 1/8-1/4" across with a five-lobed calyx, each lobe about as long as (and alternating with) the petals, and five spreading, oblong petals; both calyx and petals are yellowish-green. Staghorn sumac has a complicated sex life. Some plants have both perfect flowers (with both male and female organs) and unisexual flowers (male or female but not both) on the same individual. Other plants have flowers of only one sex (either male or female but not both). Female flowers have a central pistil with an orange-yellow, three-part stigma; male flowers have five stamens with large, bright yellow anthers. The fruits are very fuzzy, berry-like drupes about 1/4" across, deep red when ripe, each with a single seed. The velvety branches and fuzzy fruit distinguish this plant from other sumacs. A citrus-y summer drink can be made from an infusion of the fruits soaked in hot water for a few hours; just be sure to filter the infusion through a fine filter (coffee filters are good) as the hairs covering the fruit can irritate the throat. Add some sugar or honey to taste. The binomial "Rhus hirta" is occasionally used for staghorn sumac, but ITIS is clear that the accepted name is Rhus typhina.

Rhus

Rhus typhina

staghorn sumac [Blooms: May-Jul]

The tips of some short, lateral shoots of wild black currant produce clusters (racemes) of 6-15 flowers that are suspended by short pedicels from a central, drooping stalk 1-3" long. At the base of each pedicel is a 3/8" long yellowish bract. Individual flowers are 1/2" long, bell-shaped with a short tubular calyx with (1) five spreading, oblong, greenish-white apical lobes (sepals), (2) five squared-off whitish petals emerging from the tubular calyx and forming a ring-shaped wall, (3) five stamens, shorter than the petals, with cream-colored anthers, and (4) a green ovary with two styles that are fused except at their tips. The fruit consists of 3/8" wide, shiny berries, initially green, black when fully ripe, containing lots of tiny seeds. The berries are edible when cooked and have been used to make pies, jelly, or wines (if you can get to them before the birds do). Note that commercial black currants are derived from the European version of this species (Ribes nigrum), not Ribes americanum.

Ribes

Ribes americanum

wild black currant [Blooms: Apr-May]

Golden currant produces one- to three-inch-long clusters (racemes) of 5-18 drooping flowers from the leaf axils. Individual flowers are 3/4" long and across; the joined sepals are yellowish-green and tubular basally but abruptly flare into five bright golden-yellow, rectangular lobes with rounded tips. The petals are short (2-3 mm), rectangular structures that surround the throat of the corolla; they may be yellow or orange but are usually red or red-tipped. Between the petals are five stamens that extend to the tips of the petals, bearing white anthers; the styles are light green, fused to just below the stigmas, and protrude beyond the petals. The fruit is a small (1/4-3/8") edible berry with lots of seeds; fruit color is initially green but ranges from golden yellow to black when mature. Unlike gooseberries, this plant lacks spines and prickles; its large yellow flowers are distinctive. Golden currant is native to North America and was once very popular as an ornamental plant (and fruit for jams and jellies); it has probably escaped cultivation numerous times.

Ribes

Ribes aureum

golden currant [Blooms: Apr-May]

The upper stems of marsh yellow-cress end in one or more 2-8" long racemes of flowers; racemes may also develop from leaf axils. Flowers in bloom are restricted to the tip of the raceme; cylindrical seedpods (siliques) oriented perpendicular to the stem decorate the lower regions of the raceme. Individual flowers are tiny (about 3 mm long) with four greenish-yellow oblong sepals, four yellow spatulate petals, 4-6 stamens with yellow or light brown anthers, and a stout style with a two-lobed stigma. After fertilization, 3-10 mm long, dumbbell-shaped, hairless, green siliques containing two rows of tiny seeds develop. The siliques bear the remnant of the style on one end and 1/2" long pedicels on the other.

Rorippa

Rorippa palustris

marsh yellow-cress [Blooms: Jun-Aug]

Black-eyed susan flowerheads are 2-3" across; they have two series (outer longer than inner) of numerous slender, sharply-pointed, green bracts beneath the flowerhead, each densely covered with long, stiff hairs; 8-20 (usually less than 12) yellow-orange, sterile ray florets (rarely with a maroon patch near the base of the petal); and 250 to over 500 dark purplish-brown disk florets, each with slender, sharply pointed styles. The fruit consists of numerous four-sided brown or black seeds that remain embedded in the remnants of the disc flowers (a gumdrop shaped, brown mass).

Rudbeckia

Rudbeckia hirta

black-eyed susan [Blooms: Jun-Oct]

Cutleaf coneflower (aka, green-headed coneflower) is an imposing tallgrass prairie plant, 3-8' tall, that can form dense stands. The composite flowerheads are 2-3" across. Eight to fifteen light green, oblong bracts lie beneath a central globe-like, light green to yellow cone surrounded by 6-12 yellow, drooping, sterile ray florets. The disk florets have yellow to yellowish green corollas and a protruding bifurcated stigma; the stamens are yellow, fused to the base of the corolla, with deep purple anthers attached around the styles side-by-side. Immature disk florets are green (thus the alternative common name); mature disk florets produce a spikey appearance. The disk florets mature from the bottom of the cone to the top, lending a pincushion-like appearance to the cone.

Rudbeckia

Rudbeckia laciniata

cutleaf coneflower [Blooms: Jul-Sep]

Sweet coneflower flowerheads are 2-3.5" across, occurring as single blooms on the tips of stems or branches. A flowerhead is comprised of numerous 1/2" long medium green, lance-shaped phyllaries, downy with short hairs; 10-20 bright yellow, oblong, sterile ray florets with a tiny notch at their tips; and a deep brown hemisphere of 200-400 disk florets (the central disc). The disk florets have a tubular, dark reddish-purple corolla; bifurcated stigmas that have sharp tips; with the purplish-brown anthers adhering side by side around the deep purple styles. Sweet coneflower is distinctive among the Jackson Park coneflowers with its chocolate brown disk and bright yellow, elongate-oval petals with a shallow notch at their tips.

Rudbeckia

Rudbeckia subtomentosa

sweet coneflower [Blooms: Jul-Aug]

Brown-eyed susan is a native bushy plant that branches at the leaf axils and produces prodigious numbers of small flowers, up to 5' tall. The stems are deep reddish brown and covered with long white hairs. The leaves are alternate, twice as long as wide, lance-shaped, up to 4" long and covered by short, stiff hairs that give it a rough texture. Some lower leaves are three-lobed, sometimes deeply, and halberd- or trident-shaped. Upper stems terminate in one or two flowerheads, 1-2" across. Each flowerhead has an underlying inner and outer series of eight (total) green bracts with hairs along the margins; 6-13 golden-yellow, sterile ray florets, often with a small notch in the tips of the oval petals; and a central cone of 150 to over 300 purplish-brown, cylindrical disc florets with five stamens and short, blunt, bifurcated stigma. If in doubt, brown-eyed susan tends to be taller than black-eyed susan, with fewer petals (6-13 vs. 8-20) and smaller flowers.

Rudbeckia

Rudbeckia triloba

brown-eyed susan [Blooms: Jun-Sep]

Weeping willow is an exotic, probably originally bred in Asia or Europe. It is not very cold tolerant, so most "weeping willows" growing north of Kentucky or Virginia are actually hybrids. The aesthetically delightful "weeping" forms with yellow branches (the "golden" variety) are most likely a hybrid of Salix babylonica and Salix alba. There are separate male and female inflorescences in the form of catkins; each tree only produces one sex of catkins. The male catkins are 1-2" long and have no petals — only a series of stamens with white filaments and large (usually yellow) anthers. The female catkins are smaller (1" or less) and less showy with a series of green floral bracts that look like a series of awnings over 2-4 styles with flat stigmas; after fertilization they produce a green to brown capsule that releases cottony seeds.

Salix

Salix babylonica

weeping willow [Blooms: Apr]

Missouri River willow is dioecious — male and female florets (in the form of spike-like catkins) occur on separate plants. Catkins arise on one-year-old branches at about the same time as the leaves begin to emerge. Male catkins may be 1/2-2" long; each floret has two stamens with yellow anthers on their tips. Female catkins range from 3/4-2.5" long; the florets are yellowish-green and vase- or flask-shaped with an inflated base and a long beak that has a single protruding style. Both male and female catkins have a very small brown or bicolored bract at their bases that is covered with long, white hairs. After fertilization, female florets elongate as the catkin also elongates; the fruit is a yellowish to reddish green, hairless capsule, generally pear-shaped with a long beak. On maturity, the capsule splits to release seeds with long, attached, cottony hairs.

Salix

Salix eriocephala

Missouri River willow [Blooms: Apr]

Prairie willow is dioecious — plants produce either all male or all female inflorescences in the form of short catkins produced from one-year-old branches before the leaves emerge; a tiny black or bicolored bract covered in long, dense white hairs is present at the base of both male and female catkins. The florets lack both sepals and petals but both have a basal, hairy bract (regardless of sex). Male catkins are 1/4-1.25" long, elongating as they mature. Initially the male catkins are silvery (from long hairs) but become yellow or reddish from the numerous anthers. Individual male florets consist of a hairy, basal bract and a pair of stamens with cylindrical anthers initially purple, turning yellow, red, or orange. Female catkins are 1/2-3" long, also elongating as they mature. Individual female florets consist of the hairy bract and a hairy green ovary 4-8 mm long with an elongate beak densely covered with wooly hairs; a pair of stigmas protrude from the tip. After fertilization, the female florets transform into 1/4-1/2" long capsules, light brown at maturity, that split in two to release seeds surrounded by long, cottony hairs.

Salix

Salix humilis

prairie willow [Blooms: Apr-May]

Narrowleaf willow is dioecious — plants produce either all male or all female inflorescences (catkins) with the florets (male or female) spiraling around the catkin axis in a pseudo-whorl. Catkins are produced on one-year-old branches at the same time the leaves emerge. Male catkins are cylindrical, 3/4-2" long; they may be either erect or lean to one side but generally are ascending. Female catkins are also cylindrical, 1.5-3" long, initially green but turning light brown on maturity; they are usually terminal spikes on the new season's growth. Individual male florets consist of a single yellow, silky-hairy, oblong bract (quickly shed) and a pair of stamens with bright yellow anthers; the lower parts of the filaments are also covered by silky hairs. Individual female florets also have an oblong, basal bract that is shed; above that is a 1 mm long slender stalk supporting a bottle-shaped ovary 5-9 mm long with a pair of flat stigmas at its apex that appear to be four. After fertilization, the catkin elongates, and the ovary develops into a capsule that splits longitudinally to release the seeds when they are mature.

Salix

Salix interior

narrowleaf willow [Blooms: Apr-Jul]

Black willow is dioecious — plants produce either all male or all female inflorescences (catkins) on one-year-old branches; the catkins emerge with the leaves. Male catkins are 1-3" long, cylindrical, yellow to greenish-white, and usually curved. Female catkins are greenish are 1-3" long, elongating as they mature. Both male and female florets are numerous and arranged in pseudo whorls around the axis of their respective catkins; neither has either sepals or petals. Individual male florets have 3-6 stamens with yellow, globose anthers and a pale yellow, oval basal bract shorter than the stamens. Individual female florets also have a pale yellow, oval basal bract; a hairless, flask-shaped pistil 3-5 mm long is elevated above the bract on a 0.5-1.5 mm long (short!) pedicel and has a single style and a pair of stigmas at its tip. After fertilization, a capsule enlarges, finally splitting longitudinally to release the seeds with their attached cottony hairs.

Salix

Salix nigra

black willow [Blooms: ??]