Showing 37–54 of 580 results

Filters
Thmbleweed flowers are borne on long (1-2') stalks; each flower is about 3/4" across with 5 pointed white petals-like sepals that often remain partially closed; the green pistillate cone in the center of the flower is about twice as long as it is wide (i.e., a tall gumdrop) ~20% of the flower diameter. A. canadensis may also have pointed petals, but the cone in the center of the flower is hemispherical (a short gumdrop). Thimbleweed (A. cylindrica) is best distinguished from tall anemone (A. virginiana) by the shape of the leaflets — A. cylindrica has leaflets with a wedge-shaped base with the lobes radiating out from the base, while A. virginiana has a rounded leaflet base with toothed distal margins.

Anemone

Anemone cylindrica

thimbleweed [Blooms: Jun-Jul]

Wood anemone produces slender green, hairy stems that bear either alternate leaves or (more typically) a whorl of three compound leaves at the apex of the stem; the 5 cm tall flower stalk arises from the center of the whorl. The flower stalks each bear a single white (sometimes pink) flower 1" across with 4-9 petal-like sepals and 30-60 stamens with white anthers surrounding numerous simple pistils.

Anemone

Anemone quinquefolia

wood anemone [Blooms: Apr–May]

Tall anemones have leaves on long petioles (like A. cylindrica). The petals (actually, sepals) of the flowers are pointed (like A. cylindrica); the pistillate cone in the center of the flower is approximately hemispherical and >1/3" across, about 20% of flower diameter. Thimbleweed (A. cylindrica) is best distinguished from tall anemone (A. virginiana) by the shape of the leaflets — A. cylindrica has leaflets with a wedge-shaped base with the lobes radiating out from the base while A. virginiana has a rounded leaflet base with toothed distal margins.

Anemone

Anemone virginiana

tall anemone [Blooms: Jun–Jul]

Field pussytoes flowerheads are either pistillate (female) or staminate (male), both about 8 mm long, both looking like a compact tuft of white hairs. The very similar plantain-leafed pussytoes (A. plantaginifolia) looks much the same but has basal leaves with three main veins (best viewed from the underside) rather than one.

Antennaria

Antennaria neglecta

field pussytoes [Blooms: Apr-May]

Male and female flowers of Parlin's pussytoes occur on separate plants as clusters of 4-12+ flowerheads on a stalk; colonies of male plants are often well separated from colonies of female plants. (Colonies form from extensive, horizontal stolons that arch upward at their tips.) Female flowerheads are 1/3-3/4" long and look like miniature shaving brushes — the reddish or purple-tinged thread-like styles protrude from the top of the flowerhead. Each flowerhead is surrounded by bracts (phyllaries) that are green and leaf-like at their base, thinning to a translucent white, petal-like tip. Individual florets are 4-7 mm long (up to about 1/4"); the phyllaries are 7-13 mm long (up to 1/2"). Male flowerheads are less furry than the female flowerheads, consisting of scaly, white male florets 3.5-5 mm long with a brown column of stamens protruding from the center of each floret. The phyllaries on the male flowerheads are 6-9 mm long. The fruits are 1-2 mm long brown seeds with a tuft of 5-8 mm long white hairs to help loft them into the wind. Parlin's pussytoes is one of the host plants for the larvae of the American painted lady butterfly (Vanessa virginiensis). Some reproductively isolated populations (2N chromosome numbers of 56, 70, 84, and 112 all exist in the wild) apparently lack male plants altogether and reproduce by gynoecy (like several cultivated vegetables). Missouri Wildflowers seems to deny that A. plantaginifolia is a distinct species from A. parlinii, but both Antennaria plantaginifolia and Antennaria parlinii are recognized by ITIS.gov and the USDA Plants database. Note that both Parlin's pussytoes and plantain-leafed pussytoes have at least three veins on the basal leaves so may be easily confused in the field. The basal leaves of plantain-leafed pussytoes are often hairier than those of Parlin's pussytoes, which are thus greener, but the best way to distinguish the two species is by the larger size of the flowers and seeds of Parlin's pussytoes.

Antennaria

Antennaria parlinii

Parlin's pussytoes [Blooms: Apr]

Plantain-leafed pussytoes is a short (6" tall) plant. The basal leaves are 2" wide and 3.5" long, spoon-shaped with long petioles, grayish green, with 3-5 conspicuous main veins; the lower surface is densely covered with appressed hairs and is shiny white. Individual plantain-leafed pussytoe plants bear either male or female flowers exclusively. Flowerheads are short (<1/2" long) and composed exclusively of white disc florets surrounded by a layer of phyllaries; female florets are fluffy white from the profusion of styles (looking a bit like Q-Tips) while male florets show tubular, brownish anthers. Asexual reproduction may produce colonies of exclusively male or female plants. The similar field pussytoes has basal leaves with only a single (rather than 3-5) main veins.

Antennaria

Antennaria plantaginifolia

plaintain-leafed pussytoes [Blooms: Apr-May]

The main stems and some of the lateral branches of dogbane produce panicles of flowers 1-3" across on their tips; the central flowers in the cluster open first. Individual flowers are tiny — 2-3 mm across and 3-5 mm long, bell-shaped, with a fluted edge produced by the 5 white pointed petals. The stamens are shorter than the petals and curve toward the center of the flower, forming a cone over the ovoid stigma.

Apocynum

Apocynum cannabinum

common dogbane [Blooms: Jun-Aug]

Spectacular and unmistakable red and yellow, columbine's bell-like flowers hang aperture down from an arching flower stalk; the four elongate, parallel spurs point up while the stamens and style emerge from the bottom of the flower. This is the only columbine native to Illinois.

Aquilegia

Aquilegia canadensis

red columbine [Blooms: Apr-Jun]

An ornate pink flower with multiple levels of petals above a central core of projecting yellow stamens. This variant of Aquilegia vulgaris ("stellata" commercially called 'Nora Barlow') is a genetic variant that produces multiple stacked flowers (like the difference between a wild rose and commercial roses).

Aquilegia

Aquilegia vulgaris

common columbine [Blooms:May-Jun]

Japanese angelica tree may be mistaken for the (native) devil's walking stick, Aralia spinosa. However, the Japanese angelica tree (A. elata) has shorter (although quite substantial) compound leaves, sessile leaflets directly attached to the petiolule, a smaller inflorescence (about 2' tall rather than over 3'), and shorter, less intimidating spines on the trunk. Leaf venation (best viewed from the underside) is the best way to differentiate the two. In devil's walking stick, the pinnate leaf vein tips curve to form a sub-marginal vein parallel to the leaf margin. In the Japanese angelica tree, the leaf veins extend all the way to the margins of the leaf.

Aralia

Aralia elata

Japanese angelica tree [Blooms: Jul/Aug–?]

Spikenard is superficially similar to devil's walking stick (Aralia spinosa) but lacks the spiny leaves and stem of the latter. Both produce a terminal inflorescence of flowers (20+ ft. up). Unlike devil's walking stick, the flowers of spikenard are perfect; i.e., they have both male (stamens) and female (a stigma) parts. In this photo, both flower buds and flowers with prominent stamens are apparent.

Aralia

Aralia racemosa

spikenard [Blooms: Jul-Aug]

A small, somewhat shrubby tree up to 25' tall, although half that height is more common in Jackson Park (which is near the northern limit of its range). Devil's walking stick produces a terminal inflorescence of flowers (20+ ft. up). Flowers are small (1/4" long), white and are produced in umbels at the top of the tree. Devil's walking stick has flowers that are either male (bearing stamens) or female (bearing styles). The male flowers of devil's walking stick have prominent stamens and five white, triangular petals; the female flowers (shown here) look like rounded green buds with five stout styles emerging from the distal end.

Aralia

Aralia spinosa

devil's walking stick [Blooms: Aug-Sep]

Burdock has thistle-like, composite flowers with lavender to purple (rarely, white) disc florets but no ray florets; the surrounding bracts are green and strongly hooked.

Arctium

Arctium minus

burdock [Blooms: Jul-Oct]

Bearberry produces small clusters of 2-15 flowers from the tips of the previous year's twigs. Individual flowers are urn- or bell-shaped with a constricted opening ringed by five short lobes, 1/2" long and wide; they have a five-lobed flattened calyx, a white or pink corolla, 10 stamens, and a single style none of which protrude outside the corolla. The flower pedicels are about 1/4" long, red and have a narrow bract at their base. The fruit is a spherical drupe 1/4-1/2" across, initially whitish green but red at maturity.

Arctostaphylos

Arctostaphylos uva-ursi

bearberry [Blooms: April]

Two thyme-leaved sandwort flowers, with leaves clearly visible on the stem on the left of the image. Easily overlooked as just another chickweed, thyme-leafed sandwort's petals are not deeply notched like chickweeds. The stems are 6-10" tall, erect or sprawling, dark purple, and covered with fine hairs. Tiny (4 mm) white flowers on 1/4" pedicels with backward-pointing hairs; flowers have five pointed, white, oblong petals; five hairy green sepals longer than the petals; ten white stamens with magenta anthers; a green central ovary; and three white styles. An exotic from Europe that prefers disturbed areas with minimal other vegetation.

Arenaria

Arenaria serpyllifolia

thyme-leaved sandwort [Blooms: Apr-Jun]

Jack-in-the-pulpit is iconic and unmistakable wildflower. Plants are 1-2' tall; they don't flower until at least 3 years old. Each plant has a single upright stalk (a.k.a., the peduncle) that produces the inflorescence; the stalk develops directly from an underground storage organ, the corm. The inflorescences are light green to reddish green, often with reddish-brown stripes. The outermost spathe wraps loosely around the robust, cylindrical spadix; the top of the spathe bends 90° to form a hood (the "pulpit") over the spadix ("Jack"). The top half of the spadix produces volatile compounds that attract small insects, especially fungus gnats; the insects carry the pollen between plants. The bottom half of the spadix bears highly reduced florets. Both male and female florets lack petals; male florets consist of four stamens while female florets consist only of a stigma attached directly to the top of the ovary. Each plant typically has EITHER male or female florets located on the bottom half of the spadix; a single plant usually produces only one sex of florets in a given season, but plants switch between male and female multiple times during their ~20 year lifespan (they are "sequential hermaphrodites").

Arisaema

Arisaema triphyllum

Jack-in-the-pulpit [Blooms: Apr-Jun]

Flowerheads of pale Indian plantain. These plants can be to 9' tall and commonly reach 6+ feet; the stem is pale green to purple with a whitish cast. The flat-topped apical flowerhead is shaped like an inverted pyramid made up of small (1/8x3/8") tubular, cream-colored flowers with five disc florets surrounded by five bracts.

Arnoglossum

Arnoglossum atriplicifolium

pale Indian-plantain [Blooms: Jun-Aug]

Prairie Indian plantain flowerheads are tubular, 3/16" x 3/8", greenish white to reddish white, with five disc florets surrounded by five bracts with white keels (which distinguishes them from pale Indian plantain flowerheads).

Arnoglossum

Arnoglossum plantagineum

prairie Indian-plantain [Blooms: Jun-Jul]