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Torrey's rush is 2-3' tall, with robust stems that are deep green, hairless, and circular in cross section; each stem bears 2-5 alternate leaves and 1-3 basal leaves. The central stem branches rapidly at its tip; each branch ends in a spherical flowerhead about 1/2-3/4" across. The lowest flowerhead in the array sits above a very long, thin bract (main image). There may be up to 23 flowerheads in the array. Individual flowerheads are composed of 25-100 florets that each have six stamens, a narrow ellipsoid ovary with a 3-part stigma (center of insert), and six tepals (sepals and petals) in two layers; all tepals are green, bract-like, lance-shaped, and 3-6 mm long. The flowerheads are more bristly than flower-like in appearance. The flowers are wind-pollinated. After fertilization, flowerheads turn brown and look very spikey.

Juncus

Juncus torreyi

Torrey's rush [Blooms: Jul-Aug]

Kochia's greenish-yellow flowers are 4-5 mm across. Perfect flowers have five green, bluntly-triangular sepals that develop wings along their outer face, no petals, five stamens each with two large yellow or pink anthers, and a divided style; pistillate flowers lack the stamens. The flowers are wind-pollinated. The fruit is a flattened, five-lobed, winged capsule nestled in the sepals that contains a solitary seed. ITIS says that the accepted name for this plant is Kochia scoparia; World Flora Online claims the proper binomial is Bassia scoparia.

Kochia

Kochia scoparia

kochia [Blooms: Jul-Aug]

Tulip trees are the tallest native hardwood — one living specimen is 190' tall, the tallest tree east of the Mississippi. (Most tulip trees are in the 80-100' range). Illinois is on the western edge of tulip trees' range, but it is the state tree of Indiana (and Tennessee). Tulip trees have a single trunk and (usually) a pyramidal crown; the bark is gray with whitish furrows. Flowers arise on short stalks in leaf axils. Each flower is bell-shaped, erect, 2-3" across, and ~2.5" tall; there are 9 tepals — 3 pale green sepal-like tepals reflected downward and 6 fleshy petal-like tepals, yellowish-green to green in their upper half with an broad orange stripe below; the very base of the petal is pale yellow-green. In the middle of the flower is a tall (2.5") conical cluster of 60-100 pistils (the receptacle); surrounding the receptacle are 20-50 white stamens with yellow anthers. The fruit is a 1.5" long winged seed (samara) reminiscent of an ash seed; the ovate seed lies at one end of a long, thin wing with a central ridge. The leaves alone are sufficient for a confident identification; in flower or in the fall when the receptacle has produced a crown-like circlet of woody, persistant basal samaras, tulip trees are unmistakable.

Liriodendron

Liriodendron tulipifera

tulip tree [Blooms: June]

White mulberry is species that was introduced (from Asia) in the 1600's in an attempt to established a silkworm industry in North America; it has since escaped cultivation. Individual trees are usually either male (with staminate florets in drooping, whitish to yellow-green catkins 1-1.5" long) or female (with pistillate florets in less obvious green, erect, cylindrical catkins 1.3-3/4" long), but trees that produce both male and female florets are known. Male florets are 1/4" long with a tiny green or yellowish four-lobed calyx, four stamens, and no pistil or petals. (BTW, the pollen is released by mechanically flinging it into the air via the catapult-like stamens. See Taylor et al. 2006. Sex. Plant. Reprod. 19: 19–24.) Female florets are 1/4" long with a tiny green four-lobed calyx, a single, flattened-oval ovary with two diverging white or reddish styles and no stamens or petals. The fruit is a blackberry-like compound drupe that typically changes color from green to white, but some trees have fruit that continues maturation to red and finally to black. (Those producing black fruit are often referred to var. tartarica, but that name is invalid.) White mulberry can be usually be distinguished from black mulberry by the leaves; the underside of white mulberry leaves is invariably hairless and the top surface smooth, but the underside of red mulberry leaves is covered with small hairs and the upper surface is rough. However, white and red mulberry can hybridize, which can confuse matters significantly.

Morus

Morus alba

white mulberry [Blooms: Apr-May]

Hop hornbeam (aka, ironwood) flowers are in the form of catkins, with separate male and female inflorescences. Male (staminate) catkins are 1-2" long, narrowly cylindrical, often occurring in groups of three; male flowers have three stamens. Female (pistillate) catkins are 1/2" long and stubby, occurring singly at the tips of branches; individual flowers consist of a basal, green bract and two red, thread-like styles. The flowers are wind-pollinated. The fruit is 1.5-2.5" long and 3/4-1" wide, superficially similar to the fruit of hops vines (Humulus lupulus), with flattened, spindle-shaped nutlets 5-8 mm long hidden inside yellowish, papery, inflated sacs 1/3-1" long.

Ostrya

Ostrya virginiana

hop hornbeam [Blooms: Apr-May]

Boston ivy is an exotic introduced from Asia; it is a woody vine up to 50' long (with occasional branches) that grows on or over fences, walls, concrete, masonry, and trees. The lower stems are woody and produce small brown rootlets to adhere to surfaces; upper stems are (also) hairless, green to orange-red in color, with branched tendrils that have adhesive pads at their tips. Leaves are alternate, 6" long and across exclusive of the long, slender petioles, palmately tri-lobed with undulating or crenate margins. Cymes of flowers lacking a distinct central axis arise from the leaf axils; the cymes are 4" in both dimensions. Individual flowers are 1/4" across; they have five yellowish-green petals, five stamens with yellow anthers, and a single style. Fertilized flowers produce berries 3/8" across. When mature the berries are dark blue with a whitish bloom, usually hidden beneath the leaves; the flower stalks are yellow- or brownish-green or a dull orange-red.

Parthenocissus

Parthenocissus tricuspidata

Boston ivy [Blooms: ??]

Woodbine is a woody vine that usually uses trees as a substrate; the vine can be as much as 60' long. The stem is initially green and hairless; as it matures it becomes woody and develops a reddish- or grey-brown color. The leaves are alternate, palmately compound, usually with five (rarely 4 or 7) leaflets that are about 5" long and 2.5" wide with coarse marginal teeth, shiny-green when young but getting duller with age; the compound leaf has a slender 6-8" long petiole. Three- to six-inch-long clusters of 10-75 flowers arise from the main vines opposite the leaves; the clusters have two main branches and multiply-branched flower stalks with no clear central stem. Individual flowers are inconspicuous, 1/4" across with five yellowish green petals with narrow margins perpendicular to the plane of the petal and a pointed, curled tip; the petals are initially spreading but later become reflected backwards. In the center of the flower are five pale red stamens with creamy white or purple anthers, a reddish ovary, and a single white, stubby, conical style. The fruits are round blue-black berries 3/8" across that are reminiscent of grapes in a cluster with red, branched flower stalks; each berry contains four seeds. Woodbine has palmate leaves with five leaflets, very similar to Virginia creeper (Parthenocissus quinquefolia), but lacks the distinctive aerial roots "bearded" with short tendrils that are present in Virginia creeper. Opposite the base of the leaf petiole on the stem, woodbine produces a thin filament that branches 2-3 times, anchoring the vine by twining around objects. In Virginia creeper, the equivalent filaments are stouter, branch up to 10 times, and end in robust, egg-shaped pads that attach to the substrate. The inflorescence of woodbine lacks a central axis; the inflorescence of Virginia has a distinct central axis. Wikipedia (https://en.wikipedia.org/wiki/Parthenocissus_inserta) lists other differences between the two species. Illinois Wildflowers, USDA Plants, and and World Flora Online consider the two species to be one; Minnesota Wildflowers considers them to be separate and distinct. Flora of North America indicates the correct scientific name for woodbine is Parthenocissus vitacea (not P. inserta), as does ITIS and MissouriPlants.com, implying that woodbine and Virginia creeper are distinct species. Both woodbine and Virginia creeper have 40 chromosomes. Lu et al.'s (2012, 2023) molecular and morphological analyses indicate that woodbine and Virginia creeper are very closely related but are distinct species, and I'll consider that to be correct here.

Parthenocissus

Parthenocissus vitacea

woodbine [Blooms: ??]

Hoptree (a.k.a., wafer ash) is a large shrub with a rounded, irregular crown and (usually) a robust central trunk up to 6" across. Hoptree may produce single-sex (male or female) or bisexual (male and female organs both present) flowers on the same tree. Individual flowers are about 1/4" across, regardless of gender. Perfect (bisexual) flowers have 4-5 greenish sepals, 4-5 narrow, creamy white petals, 4-5 stamens with hairy white bases and yellow anthers, and a single, flattened green pistil. Male flowers are more or less identical but lack the pistil; female flowers are more or less identical but lack the stamens. The fruits are single seeds 1-1.5" long with a broad, flattened, papery wing extending almost all the way around the seed.

Ptelea

Ptelea trifoliata

hoptree [Blooms: May-Jun]

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]

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: ??]

On black snakeroot, one to five 1/2" wide globoid umbels (flower clusters) arise from the tips of the upper stems. Each umbel is packed with 20-60 tiny flowers and their flower stalks (pedicels). In each umbel, 1-3 flowers are "perfect" (with both male and female organs) and the rest are staminate (stamens only). In addition to the male stamens, the perfect flowers have two long, cylindrical styles (emerging from a hidden ovary) that arch and recurve from the middle of the flower; the styles are much longer than the hooked bristles on the ovary. Both staminate and perfect flowers have a minute (<1 mm) green calyx with five rounded teeth, five dull yellow to greenish-yellow, heart-shaped petals (tip of the heart towards the center of the flower), and five protruding stamens <3 mm long with obvious yellow (or brown) anthers. The fruit is a 1/4" long round to cylindrical bur covered with short, hooked bristles; the remains of the styles often persist. The bur splits to release the two seeds inside.

Sanicula

Sanicula odorata

black snakeroot [Blooms: May-Jun]