Showing 73–90 of 109 results

Filtered (5)
Duckweed is a tiny, floating flowering plant (one of the smallest in the group) that is present on the lagoons and Columbia Basin from May through October. The flower is highly reduced — about 1 mm across consisting of a cup-shaped scale, a pair of tiny stamens, and a single pistil; I have never observed it. (The flowers are rarely produced — most reproduction is vegetative.) The combination leaf and stem is oval, 2-5 mm long and 1.5-3.5 mm across with a single rootlet up to 2 cm long dangling from the underside. Unless you have a good magnifying glass or microscope, further detail will not be useful.

Lemna

Lemna minor

duckweed [Blooms: ?]

In grape honeysuckle, a short flowering stalk emerges from the tip of the stem where it emerges from the terminal pair of leaves; 2-5 whorls of flowers develop along this flowering stalk. Each flower is about 1" long. It consists of an egg-shaped, swollen, dark green ovary; a pale yellow to orange-yellow, two-lipped corolla that fades with age to orange or red; five stamens with yellow anthers; and a single style with a dome-shaped stigma. There are no hairs on the flowers. Both the stamens and the style protrude from the corolla. The ovary of fertilized flowers produces berries which are initially green but, at maturity, become globoid, orange-red to red, and about 1/4-1/2" long. Grape honeysuckle is the only honeysuckle (native or exotic) in Jackson Park that is a woody vine; it is distinctive and should be easy to recognize.

Lonicera

Lonicera reticulata

grape honeysuckle [Blooms: Jun]

American bugleweed flowers form in whorls of the axils of the middle and upper leaves. Individual flowers are 1/8" across, white with pinkish-purple spots, with a calyx about as long as floral tube with five teeth; the distal end of the short tubular corolla has five sharply-pointed, narrowly-triangular lobes. The two stamens with purple anthers and single style project well outside the mouth of the corolla. The fruits are four, flat-topped nutlets that form in the cup of the calyx. The deep, narrow lobes of the lower leaves are a characteristic of this species; they are not present in the other Lycopus species in Jackson Park.

Lycopus

Lycopus americanus

American bugleweed [Blooms: Jul-Sep]

Northern bugleweed can be up to 2.5' tall; the stem is unbranched, square in section, and light green. The leaves are opposite, 1.5-4" long and a third as wide, elliptical in outline with 5-9 coarse, sharply-pointed marginal teeth on each side of the leaf. Each pair of opposite leaves is oriented at 90° to the pairs above and below. The flowers occur in whorls in the axils of the middle and upper leaves. Individual flowers are about 1/8" long. They have a light green, very short (1 mm) calyx with 4-5 triangular teeth; a white, tubular corolla with four (or five) lobes, the uppermost notched at the tip or sometimes in two parts; two stamens with purple anthers extending just out of the corolla tube; and a style with a bifurcated tip. The fruit is four nutlets with a bumpy upper surface and a depressed center, cupped in the calyx.

Lycopus

Lycopus uniflorus

northern bugleweed [Blooms: Jul-Aug]

Fringed loosestrife is a native wildflower unrelated to the much-maligned (exotic) purple loosestrife. Flowers arise from the axils of the middle and upper leaves, held on slender, flexible pedicels up to 3" long so that the flowers commonly nod. Individual flowers are about 1" across; they have a green calyx with lance-shaped teeth behind a corolla with a reddish center and five yellow, petal-like lobes with a narrow yellow filament coming off the midline apex of most of the lobes. The five stamens have robust, tan-colored anthers and a simple white style with a tiny apical green stigma. The fruit is a shiny, green spherical capsule held cupped in the calyx. Fringed loosestrife prefers wet habitats near water or on moist hillsides.

Lysimachia

Lysimachia ciliata

fringed loosestrife [Blooms: Jun-Jul]

Winged loosestrife is a native species that has a central stem up to 3' tall, much more modest that its notorious cousin, purple loosestrife. The stem is four-sided, narrowly winged, and largely hairless; wings run along the stem but are interrupted at the leaf nodes. The inflorescence is a spike up to 1.5' long; the flowers develop singly or in pairs from the axils of bracts on the inflorescence. Each flower is pale lavender or purple and smaller than the flowers of purple loosestrife (1/4-1/2") but otherwise superficially similar — pale purple or lavender, six wrinkled petals with a medial purple stripe, six stamens. The light green, narrow calyx is about as long as the petals, has six (not five) lance-shaped teeth, and bold longitudinal stripes. The style may or may not protrude from the corolla — the flowers are distylous so the styles may either lie just inside the flower throat or protrude well outside; the style has a fuzzy, green, globular stigma. The fruit is a capsule that develops in the remnants of the calyx. Winged loosestrife prefers wet soils and is a less showy plant than purple loosestrife, but it is a native plant that plays nicely with its neighbors.

Lythrum

Lythrum alatum

winged loosestrife [Blooms: Jun-Aug]

Purple loosestrife plants are 2-5' tall. The stems branch frequently, are square in section or ridged, and are very hairy except where the stem is woody. The very showy flower spikes can be up to 20" long. Individual flowers are 1/2-1" wide that are sessile or on very short stalks; there are 5-7 (usually six) purple, wrinkled petals with a dark purple line near their base. (Imagine purple crepe paper.) The long tubular calyx is yellow-green, ridged, and hairy, with five long, narrow teeth at the distal end. Purple loosestrife is "tristylous" — it exhibits three discrete flower morphs that differ in the relative lengths of the stamens and style. Each plant bears flowers of only a single morph. Each morph has two different lengths of stamens — pistil short, stamens long AND stamens intermediate in length; pistil intermediate in length, stamens short AND long; and pistil long, stamens short AND intermediate in length. Tristyly presumably minimizes self-fertilization. Purple loosestrife is a very aggressive, invasive species which crowds out other species. Another invasive which is also called purple loosestrife, Lythrum virgatum, has similar flowers but the leaves narrow towards their base. (L. virgatum is not known to occur — yet — in Illinois.) Do not confuse purple loosestrife with the native winged loosestrife (Lythrum alatum) which has winged stems, smaller flowers (1/2"), hairless foliage, and solitary flowers in leaf axils. It's not as striking a plant as purple loosestrife, but it plays better with its neighbors.

Lythrum

Lythrum salicaria

purple loosestrife [Blooms: Jun-Sep]

Water chickweed (aka, giant chickweed) is an exotic from Europe; it resembles a much-enlarged enlarged (potentially 1-2.5' tall vs. a few inches although the stalk sprawls) version of our common chickweeds. Flowers may occur as singletons arising from the leaf axils or clusters of a few flowers at the end of the stems. Each flower is 1/2" across; it has five fuzzy, green, oval sepals slightly shorter than the petals; five white, deeply-cleft petals that look like ten; 10 stamens with white anthers; and a green ovary with five short, arching styles. The stems and the 1" long pedicels of the flowers are both very fuzzy. The fruit is an ovoid seed capsule nestled in the persistant sepals which hangs down from the pedicel when ripe; it could easily be mistaken for a bud if you didn't notice it was pointed down.

Myosoton

Myosoton aquaticum

water chickweed [Blooms: May-Jun]

Spatterdock is an archaic-looking water lily, and for good reason — the genus is at least 50 million years old. Single flowers are borne on the tips of stout pedicels. The buds are enclosed in three green outer sepals which reveal three underlying yellow sepals when the flower opens. An open flower is 1-3" in diameter with the opening 40-50% of that total. The yellow petals have been reduced to oblong scale-like structures inside the flower below the stamens. The large, mushroom-shaped pistil takes up most of the center of the flower the stigmatic disc visually dominating. The very numerous, oblong, truncate, ribbon-like stamens lie immediately below the large, flattened disc-like stigma; they look nothing like the delicate stamens common in most flowers. The fruit is flask-shaped, constricted below the pistil, boldly ribbed and green on the globular body; the remnant of the stigmatic disc is red-rimmed.

Nuphar

Nuphar advena

spatterdock [Blooms: Jun-Sep]

Fragrant water lily flower stalks, like the leaves, develop directly from the rhizomes. Flowers are 3-6" across; they have four greenish-white sepals that rest on the water's surface; 15-40 brilliant white (occasionally pink) petals in multiple series; 35-120 stamens with bright yellow anthers distributed around the inner circumference of tthe flower; and a central stigmatic disc on the floor of the flower at the base of the stamens. Flowers open and close daily. The fruit is 1-2" long and globoid; its stalk bends downward so the fruit develops underwater. After the tiny seeds (~1/16-1/8") are released, they float for some time, dispersed by wind and water currents, then sink to the bottom of the water body where they germinate.

Nymphaea

Nymphaea odorata

fragrant water-lily [Blooms: May-Aug]

Eastern prickly pear is the commonest of three prickly pears native to Illinois, all quite rare. Eastern prickly pear can grow to be as much as 2' tall but Jackson Park specimens rarely exceed 6". Flowers are 2-3" across consisting of numerous yellow, satiny tepals, the innermost layer with reddish-orange highlights towards the tepals bases, 50-1500 stamens with pale yellow anthers, and a single style topped with a ring of six fleshy, white stigmas. Each flower lasts a single day. Fruits are initially green but turn reddish-brown when mature; they are 1-2" long, less than 1" in diameter, and concave on the top.

Opuntia

Opuntia humifusa

Eastern prickly-pear [Blooms: Jun-Jul]

Sweet mock-orange inflorescences are racemes with 5-7 fragrant flowers; the most basal pair of flowers arise directly from the leaf axils. Individual flowers are 1-1.5" across, have four triangular green sepals, four brilliant white petals, 20-50 white stamens with orange anthers, and four white styles with yellow-orange stigmas. The styles are closely appressed proximally, separate distally.

Philadelphus

Philadelphus coronarius

sweet mock-orange [Blooms: May-Jun]

Cleft phlox flowers are supported by 1" pedicels, are 3/4" across, white or pale violet, with a tubular corolla that flares into five petal-like lobes that are each deeply cleft at their tips; the throat is very narrow. A three-lobed stigma and the orange anthers of the stamens lie just within the opening to the throat of the flower. Cleft phlox is endemic to the Midwest. The cleft petal lobes distinguish cleft phlox from all other Phlox species.

Phlox

Phlox bifida

cleft phlox [Blooms: Apr-?]

Woodland phlox is a 1-1.5' tall plant with a fuzzy to hairy stem, light green or reddish brown in color. Leaves are opposite (or sometimes in a three-leaf whorl), sessile or clasping the stem, three times longer than wide, lance-shaped with smooth margins, and fuzzy to hairy overall with short hairs around the margins. The flowers are 1" across, pale blue-violet, lavender, or (rarely) white, and with a long, narrow tubular throat that abruptly flares into five petal-like, spoon-shaped lobes. The calyx is green or reddish-green, hairy, with five long, narrow teeth almost half the length of the flower, spreading near their tips. The five stamens and style are hidden within the throat. Woodland phlox has relatively broader leaves than other Phlox species and has a more intense blue-violet (and less pink) color.

Phlox

Phlox divaricata

woodland phlox [Blooms: Apr-May]

Smooth phlox is a 1-2' tall plant with an unbranched, hairless stem topped with a slightly domed cluster of 3-20 pink or lavender flowers. Each flower is about 3/4" across and has a long, tubular throat that abruptly flares into five petal-like lobes; each lobe is wedge-shaped and overlaps the next lobe clockwise. The calyx (also hairless) consists of five triangular segments that taper rapidly to sharp points; the calyx is <1/3 the length of the corolla tube. The five stamens and single style with a three-part stigma either lie within the corolla tube or are just visible in the throat. After fertilization, a narrow seed capsule filled with numerous seeds fills the persistant calyx. Smooth phlox prefers moist to wet habitats. Smooth phlox flowers resemble prairie phlox (P. bifida) but the latter species is quite hairy on the stems, leaves, and the exterior of the flower (the calyx); smooth phlox is hairless. Checking the hairiness (or lack thereof) of the calyx is the quickest way to tell prairie phlox from smooth phlox.

Phlox

Phlox glaberrima interior

smooth phlox [Blooms: Jun-Aug]

Prairie phlox is a compact, single-stemmed, plant 1/2-1.75' tall with (typically) a dome-shaped cluster of flowers at the apex. Individual flowers are 1/2-3/4" across, pink or lavender (rarely white); the corolla is tubular with five wedge-shaped, petal-like lobes often with darker markings (nectar guides) near the throat; the corolla is hairy on all external surfaces. The throat is very narrow; the five stamens with yellow anthers are recessed but just visible. The very short, tubular, hairy calyx base is green, with five long, narrow teeth that extend parallel to the narrow throat (also hairy) of the corolla. The fruit is oval and shorter than the calyx (in which it develops); when ripe, the capsule splits explosively, flinging the seeds in all directions. The species name ("pilosa") means "hairy" in Latin, and this species is indeed hairy on almost every surface. Prairie phlox flowers resemble smooth phlox (P. glaberrima) and, to a lesser extent, woodland phlox (P. divaricata), but the former species is quite hairy on the stems, leaves, and the exterior of the flower (the calyx); smooth phlox is hairless. Checking the hairiness (or lack thereof) of the calyx is the quickest way to tell prairie phlox from smooth phlox; checking the hairiness of the exterior of the corolla tube will distinguish woodland phlox (hairless) from prairie phlox (hairy).

Phlox

Phlox pilosa

prairie phlox [Blooms: Apr-Jun]

Mayapple produces a single, hairless stem that branches no more than once; each stem thus has either a single leaf (infertile stems) or two leaves (fertile stems). Fertile stems produce a solitary nodding flower, 2-3" across, that is hidden beneath the leaves where the two leaves branch on the stem. The flowers contain 6-9 brilliant white petals and a ring of 12-18 tan stamens with large, banana-shaped anthers, all surrounding a surprisingly large, yellow ovary topped with a button of a stigmata. The fruit is a large (1.5" long), ellipsoidal berry, yellow when ripe. All parts of the plant are poisonous including the green fruit, but the ripe (yellow) fruit is edible (in small quantities).

Podophyllum

Podophyllum peltatum

mayapple [Blooms: Apr-May]

Lesser celadine flowers arise singly from the axils of the upper leaves or on the ends of stems. Individual flowers are about 1" across with three light green sepals half the length of the petals, 7-12 yellow, oblong petals, and a ring of about 30 (yellow) stamens around a central group of about 15-20 (greenish) pistils. This species rarely produces fruit, instead reproducing asexually. The alternative name "Ficaria verna" is occasionally used for lesser celadine, but that name is now considered invalid.

Ranunculus

Ranunculus ficaria

lesser celadine [Blooms: Apr-May]