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Tall ironweed's inflorescence is a flat-topped panicle arising from the tip of the central stem; it is 6-16" across, open and spreading. There are 10-30 disk florets in a tall ironweed flowerhead. The base of the flowerhead is covered by several series of dark colored, broadly oval appressed bracts (phyllaries), often with fine hairs around their edges. The disk florets have tubular, trumpet-like corollas with five recurved lobes; ray florets are absent. Tall ironweed has a much more "open" composite flowerhead than the other ironweeds in Jackson Park, with the trumpet bases of the disk florets easily visible. The fruits are naked, gray or brown, bullet-shaped seeds with a tuft of both short and long tawny or pale purple hairs. To sort out the Jackson Park ironweeds: (1) if both leaves and stem are densely covered with fine white hairs, the leaves are about 3-4 times longer than wide, and each flowerhead has more than 30 disk florets, it's Missouri ironweed (V. missurica). (2) If both leaves and stems are hairless, there are less than 30 disk florets, and the leaves are narrow (typically a half inch or less; about 6-10+ times longer than wide), it's smooth ironweed (V. fasiculata). (3) If the stems and leaves have only short hairs, there are less than 30 disk florets, and the leaves are about 2" wide and 4-6 times longer than wide, it's tall ironweed (V. gigantea).

Vernonia

Vernonia gigantea

tall ironweed [Blooms: Jul-?]

At the tip of a Missouri ironweed stem, a corymb of composite flowerheads (the inflorescence) is produced. The stems of the inflorescence are also covered in fine white hairs and usually reddish brown in color. Individual flowerheads are magenta and rayless; ray florets are completely absent. Flowerheads contain 32-60 disk florets, each 1/2-3/4" across, which have rounded or broadly angled bracts (phyllaries) with sharp tips, dull green or reddish brown in color, that are layered like fish scales around the base. To sort out the Jackson Park ironweeds: (1) if both leaves and stem are densely covered with fine white hairs, the leaves are about 3-4 times longer than wide, and each flowerhead has more than 30 disk florets, it's Missouri ironweed (V. missurica). (2) If both leaves and stems are hairless, there are less than 30 disk florets, and the leaves are narrow (typically a half inch or less; about 6-10+ times longer than wide), it's smooth ironweed (V. fasiculata). (3) If the stems and leaves have only short hairs, there are less than 30 disk florets, and the leaves are about 2" wide and 4-6 times longer than wide, it's tall ironweed (V. gigantea).

Vernonia

Vernonia missurica

Missouri ironweed [Blooms: Jul-Oct]

In corn speedwell, single flowers 1/8" wide develop at the tips of inflorescences that arise from the axils of the middle and upper leaves; the flowers are nearly sessile. The inflorescence continually elongates, producing new flowers and a series of bracts along its length. The most basal bracts resemble the stem leaf whose axil hosts the inflorescence; the upper bracts are alternate, 3-10 mm long, and narrowly lance-shaped with long hairs fringing the bract margins. Each flower consists of four hairy, green, lance-like sepals/bracts longer than the corolla lobes; a blue to blue-violet corolla with four petal-like lobes, the upper three lobes slightly larger than the lower forth lobe; two stamens with white anthers; and a pistil with a single style. Dark lines (nectar guides) radiate from the throat of the corolla. Each flower only lasts a single day. The fruit is a 1/8" long and wide, tan, heart-shaped seed capsule, somewhat flattened, with two compartments containing 10-30 yellowish, ovoid seeds. There are 16 species of the genus Veronica reported from Illinois. I have only seen three (Veronica arvensis, Veronica polita, and Veronica serpyllifolia) in Jackson Park but, given their minute size and inconspicuousness, it seems likely that more remain to be found.

Veronica

Veronica arvensis

corn speedwell [Blooms: Apr-Jun]

ird's-eye speedwell (Veronica persica) flowers are solitary, arising from the axils of upper leaves on 1/2-3/4" long, hairy pedicels with a leaf-like bract at their bases. Individual flowers are about 8 mm across, consisting of a calyx with four lance-shaped sepals that are fused at their bases and are shorter than the corolla lobes, and a tubular corolla with four lobes ("petals") that are round to oval. The corolla is bluish toward the edges and whitish centrally, with dark blue lines radiating from the center. One of the four lobes is slightly smaller (and whiter) than the other three, so the flower is bilaterally symmetrical. A pistil with a single 2-3 mm long style arises from the center of the flower; two white stamens with dark blue anthers flank the pistil. Fertilized flowers produce a two-lobed fruit nestled in the remnants of the calyx, each lobe containing 5-11 small seeds; the fruit is a laterally compressed heart shaped capsule that is longer than tall with a distinct shallow V-shaped groove where the remnants of the style can be seen.

Veronica

Veronica persica

bird's-eye speedwell [Blooms: May]

Wayside speedwell's flowers are 1/4" across with a green, hairy calyx with four triangular lobes as long as the petals, projecting between them in the spaces between petals; a short corolla with four spreading lobes, three the same size (one on either side, blue to bluish-white with dark blue lines, and the third dark blue with blue-violet lines) and one about half as wide, pale blue or white with light blue lines. The blue lines function as nectar guides. The base of all four lobes is bright white, but the center of the flower is greenish. There are two white stamens with white anthers (backed by a dark blue "U" shape) and a single white pistil emerging from the throat of the corolla. The fruits are heart-shaped capsules with two chambers covered with glandular hairs, each containing 8-12 seeds. The flowers and leaves of wayside speedwell are similar to those of bird's-eye speedwell (Veronica persica), but the calyx lobes of bird's-eye speedwell do not project beyond the petals. There are 16 species of the genus Veronica reported from Illinois. I have only seen three (Veronica arvensis, Veronica polita, and Veronica serpyllifolia) in Jackson Park but, given their minute size and inconspicuousness, it seems likely that more remain to be found.

Veronica

Veronica polita

wayside speedwell [Blooms: Apr-Jun]

Thyme-leafed speedwell's upper stems host clusters (racemes) of flowers 2-7" long; flowers may either be opposite or alternate along the stem. Each flower is 1/8-1/4" across with a short (1/4"), slender petiole; at the base of the petiole is an oblong, hairless, leafy bract also about 1/4" long with smooth margins. (Thus, the flowers effectively arise from leaf axils.) Individual flowers consist of a green calyx with four triangular lobes shorter than the petals; a short corolla with four oval petal-like, lobes (the lowest one smaller than the other three); two stamens with purple or white anthers; and a green ovary with a single style. The lobes (petals) are white or pale blue, usually with dark blue lines radiating from the flower's center on the upper three lobes. The fruit is a laterally flattened, heart-shaped capsule 1/4" across with two chambers and a fringe of glandular hairs. When mature, the chambers split open, releasing 50-72 tiny seeds. There are 16 species of the genus Veronica reported from Illinois. I have only seen three (Veronica arvensis, Veronica polita, and Veronica serpyllifolia) in Jackson Park but, given their minute size and inconspicuousness, it seems likely that more remain to be found.

Veronica

Veronica serpyllifolia

thyme-leafed speedwell [Blooms: Apr-?]

At the top of the Culver's root plant are floral spikes (racemes) up to 10" long covered with small (1/4" long) white, tubular flowers. Individual flowers consist of a short (3 mm long), green calyx with five deep lobes (the lower two lobes longer than the upper three); a tubular corolla with four lobes (the lower two longer than the upper two); two stamens with yellow or reddish brown anthers; and a single style with a tiny stigma. The stamens and stigma protrude well beyond the lip of the flower. The flowers bloom from the base of the floral spike successively towards the tip. The fruit is a 2.5-4.5 mm long ovoid capsule with four apical teeth. The capsules contain 10-30 half millimeter long, ovoid seeds. Culver's root is very popular with a wide diversity of bees.

Veronicastrum

Veronicastrum virginicum

Culver's root [Blooms: Jun-Aug]

Korean spice viburnum's inflorescences are 2.5" diameter umbels of flowers on the tips of new twigs. The flowers are aromatic; the scent is described by the Chicago Botanic Garden as "sweet, rich, and complex with a hint of cloves." The flowers are fragrant for only about two weeks. Individual flowers consist of a tiny (1 mm long), reddish green calyx with five lobes; 8-10 mm long tubular, pale pink to white corollas with five abruptly spreading lobes; five stamens with yellow anthers just inside the throat; and a short (1 mm long), stout style with a knob-like stigma. The corolla is about 1/2" across. Korean spice viburnum flowers are superficially similar to butterfly-bush (Buddleja davidii), which also occurs in Jackson Park, but the latter has a spike-like inflorescence rather than an umbel.

Viburnum

Viburnum carlesii

Korean spice viburnum [Blooms: Apr]

Wayfaring tree flowers occur in flat-topped cymes about 4" across; they are cream-colored with five petals, five stamens with white filaments and tan anthers, and a green ovary with a short (1 mm) style with a large, lobed stigma. The fruit is an oval, flattened drupe, initially red, turning black with maturity, and containing a single seed. They are not toxic but can induce vomiting it eaten when unripe. Wayfaring tree is said to be so named because it grows close to paths (and presumably other natural edges).

Viburnum

Viburnum lantana

wayfaring tree [Blooms: Apr-May]

Nannyberry flowers occur in 2-5" wide, dome-shaped panicles at the tips of young shoots. Individual flowers are 1/4" across, consisting of a light green calyx with five triangular teeth; a creamy white corolla with five oval lobes; five stamens with white filaments and yellow anthers that protrude well past the edges of the corolla lobes; and a light green or yellow pistil with a short style. The fruit is a 6-10 mm long drupe, initially green but turning dark blue-violet when ripe, containing a single seed. Nannyberry is similar to blackhaw (Viburnum prunifolium, also present in Jackson Park) — both have white flowers and blue-black fruits that are drupes — but nannyberry leaves have a long, narrow tip on their leaves in contrast to the rather blunt tips on blackhaw leaves.

Viburnum

Viburnum lentago

nannyberry [Blooms: Apr-May]

In the spring, American cranberry shrubs produce flattened panicles of flowers 2-5" across that bear two types of flowers — around the edges are five-petaled, white flowers about 1" across that are sterile (lacking both pistils and stamens), while in the center of the cluster are five-petaled, cream-colored flowers 1/4" across that are fertile (with both a pistil and five long stamens). By late summer, the flowers are replaced by bright red "cranberries" (actually drupes with a single seed) 1/4-1/2" across that prove very popular with birds (which distribute the seeds) and our local coyotes (whose scat is full of the seeds). After removing the seed, the tart flesh (high in vitamin C) can be eaten raw or cooked. In the fall, the leaves also turn red. Viburnum opulus var. americanum is said to be distinct from Viburnum trilobum (aka, highbush cranberry) by Illinois Wildflowers (www.illinoiswildflowers.info) and Minnesota Wildflowers (www.minnesotawildflowers.info), but plants.usda.gov insists that the latter is a synonym of the former. Worldfloraonline.org only adds to the confusion by insisting that the two names are BOTH junior synonyms of Viburnum opulus. ITIS.gov says that V. opulus is the correct name for the European species (now introduced to the U.S.) and Viburnum opulus var. americanum is the correct name for the American species. The easiest way to distinguish the two forms (if you care to) is to carefully inspect the nectary glands (extrafloral nectaries) on the petioles. In V. opulus americanum, the extrafloral nectaries are oval, with a concave top and a distinct rim; in Viburnum trilobum, the extrafloral nectaries are round in plan view with a convex top and no rim. Although rare in most of Illinois, guelder-rose (V. opulus americanum) is quite common around the lagoons of Jackson Park.

Viburnum

Viburnum opulus

American cranberry [Blooms: Apr-May]

Cymes of flowers arise from the leaf axils of blackhaw; the cymes are heavily branched but are sessile on the leaf axil. Individual flowers are 1/4" across with a 2 mm long calyx tube with five apical lobes that are shorter than the petals; a tubular corolla with five white, rounded lobes (the "petals"); five stamens with white filaments and yellow anthers extending outside the corolla lobes; and a small (less than 1 mm long), cream-colored pistil. The fruit is a fleshy drupe (like a plum or cherry) about 8 mm long containing a single brown nutlet that is flat on one side; the fruit becomes blue-black as it matures. The fruits are edible and popular with birds. Blackhaw is similar to nannyberry (Viburnum lentago, also found in Jackson Park) — both have white flowers and blue-black fruits that are drupes — but nannyberry leaves have a long, narrow tip on their leaves in contrast to the rather blunt tip and reddish petioles on blackhaw leaves. The stamens in blackhaw flowers are slightly shorter than those in nannyberry flowers but the difference is subtle; leaf form and petiole color are better differentiators.

Viburnum

Viburnum prunifolium

blackhaw [Blooms: May-June]

Many of the upper shoots of downy arrowwood end in 1.5-3" wide, dome-shaped panicles of flowers with slightly fuzzy, light green branches. Individual flowers are 1/4" across with a short, light green calyx with five short, broad teeth; a white tubular corolla with five rounded, spreading lobes; five stamens with white filaments and tan anthers that extend outside the corolla; and a single white style. The flowers have an unpleasant odor described by various sources as "rotting flesh." The fruit is a small (1/4-1/2") drupe (a stone fruit like cherries or a plum) 8 mm long and dark blue-violet to black at maturity. Downy arrowwood can be distinguished from other Viburnum spp. by its (1) its small size (less than six feet tall), (2) the relatively few teeth along the leaf margins (5-10 per side), (3) the short (about 1/4") leaf petioles, (4) the small, narrow stipules at the petiole bases, and (5) its flowers' unpleasant odor. The common name derives from the fact that the straight stems of the various arrowwoods was preferred by indigenous Americans for arrow shafts.

Viburnum

Viburnum rafinesquianum

downy arrowwood [Blooms: Aug–Sep]

Wild pansy's flower stalks are long, hairless, and bend like a shepherd's crook just below the base of the flower so the flower axis is approximately horizontal. Individual flowers have five 7-15 mm long, lance-shaped sepals that are longer than the petals and are sharply pointed at their tips; a 4-12 mm long corolla with five white or pale cream-colored petals, a yellow throat with a few dark purple lines, the lateral petals bearded on their upper surface, and a 1-1.5 mm long spur; two stamens not visible externally; and a single style enlarged into a hollow, globose stigma. The fruit is a spherical or ellipsoidal three-valved capsule, 5-10 mm long containing 6-75, 1.5 mm long, brown seeds.

Viola

Viola arvensis

wild pansy [Blooms: Jun-?]

Birdfoot violet (Viola pedata) is a native perennial widely distributed in the eastern half of the U.S. and Canada. The flower stalks (peduncles) arise from the rootstock, reaching heights of only 3-6" tall. The leaves also arise directly from the rootstock, making them formally basal leaves. The flower stalks are green or purple, up to 4" long, each bearing a single flower at its apex. Each flower is 3/4-1.5" across. Visible components include five green sepals; five pale blue-violet to dark purple-violet petals; a tight grouping of orange stamens that pokes out of the throat of the flower; and a short (2 mm long) green style with an oblique, concave area near its tip that is hidden inside the flower. Most violets show some degree of self-fertilization within unopened flowers (cleistogamy) but birdfoot violet does not. Pollination is usually mediated by long-tongued bees and skippers and other small butterflies. Birdfoot violet uses two steps to disperse its seeds. First, the drying 3/8" long seed capsule exerts increasing force on the tiny (~2 mm), copper-colored seeds; at some point, the three segments of the seed capsule split apart and the seeds are explosively ejected (an average of 4.5 feet, but up to 15 feet) "much like a marble squeezed between the fingers" (Beattie and Lyons. 1975. Am. J. Bot. 62:714-722). A stalk-like structure on the seeds (the elaiosome) that is made of a sugary gel encourages ants to pick up the seed (or a clump of seeds) and carry them back to the ants' nests where they germinate. All petals in a flower may be the same color, or the upper two petals may be dark purple-violet while the lower three petals are pale blue-violet. Near the throat of the flower, the base of the lowest petal is white with fine violet nectar guides; this petal extends to form a short spur at the back of the flower. Unlike common violets, there are no white hairs on the lateral petals that occlude the throat of the flower. Birdfoot violet is easily distinguished from the other violets in Jackson Park by the large size of their flowers, the absence of white hairs occluding the throat of the flower, and the deeply lobed leaves.

Viola

Viola pedata

birdfoot violet [Blooms: May]

Yellow violet is a native perennial, the only yellow violet species in Jackson Park (indeed, in all of Illinois). One or more stems arise from an axil of a stem leaf; they are up to 6" tall with a single 3/4" long flower at their tips. Each flower consists of five light green sepals, five yellow petals, five stamens, and a single style; the stamens and style cannot be seen from the exterior. On the lower petal, the flowers have purple lines (nectar guides) and a spur reduced to a small pouch. The two lower, lateral petals have small tufts of hair that obscure the throat of the flower and hide the stamens and style; the two upper, lateral petals are beardless and have only faint lines (nectar guides), if any. The fruit of this species is a bullet-shaped (hairless in the Jackson Park forms) capsule nestled in the calyx with the remnant of the style at its tip, initially green but turning brown as it matures; it ultimately splits along three suture lines to fling the seeds away from the plant.

Viola

Viola pubescens

yellow violet [Blooms: Apr-May]

Common blue violet flowers are 3/4-1" across with the calyx formed from five elongate oval, dark green sepals with a pointed tip, five petals (two upper, two lateral petals with white hairs ("beards") that occlude the throat of the flower, and one lower petal with a white patch and superimposed dark blue lines near the throat). The lower petal has a pouch (the "spur") that extends backwards past the base of the sepals; the spur houses the ovary, single style, and stigma (positioned just behind the petal beards) and, more posteriorly, the nectary. The two stamens surround the ovary and can't be seen without dissecting the flower. Flower color may range from deep violet to white with a purple center, all fading to pale yellow in the center. The fruit is a bullet-shaped capsule 1/4-1/2" long that is nestled in the calyx with the remnant of the style at its tip, initially green but turning brown as it matures; it ultimately splits along three suture lines to fling the approximately 75 seeds, beige or bronze in color, 1.5-2.5 mm long, away from the plant. Much of the reproduction occurs from vegetative clones produced from the rhizomes. Common blue violet prefers light sun or partial shade and a rich soil.

Viola

Viola sororia

common blue violet [Blooms: Apr-May]

Riverbank grape's flowers develop in 5" long, drooping, cylindrical or pyramidal panicles opposite the leaves of new branches (but skipping every third leaf). The flowers are greenish-yellow and are best described as skeletal; they may be either unisexual or (rarely) perfect (both male and female reproductive organs functional). The male and female unisexual flowers usually both occur on the same plant, either in separate or mixed clusters; both male and female flowers are 1/8" across or less, with a minute calyx and five green to yellowish petals that quickly fall off. Male flowers have five very long, pale, erect stamens around a button-like center; female flowers have an ovary with a short style and five short, sterile stamens, often contorted. The fruit are .... grapes — a round berry, 1/4-1/2" across containing 1-4 seeds, initially green but turning blue-black as it matures, often with a white bloom on the skin. You know, grapes. The fruit of riverside grape is often sour until after a frost, then becomes more "sweet/tart" to the tongue. Riverside grape is subject to parasitism by the grape filbert gall midge (Ampelomyia vitiscoryloides), an insect whose larvae produce large, very hairy, conical galls at leaf nodes. This gall midge is restricted to the eastern half of North America; it was first described by Alpheus Spring Packard, Jr. in 1869.

Vitis

Vitis riparia

riverbank grape [Blooms: [May-Jun]