Showing 271–288 of 580 results

Filtered (50)
Purple dead-nettle's whorls of flowers occur in the leaf axils and at the tip of the stem. Flowers are about 1/2" long with a short, five-lobed green calyx and a tubular, purplish pink to white corolla with an upper and lower lip; the lower lip is divided into two lobes, often white with purple spots. There are four short stamens with brown anthers positioned beneath the upper lip and a single style with a two-lobed stigma. The closely-related henbit (Lamium amplexicaule) has much longer tubular flowers and leaves that are sessile or clasp the stem rather than being borne on petioles. The "dead-nettle" name comes from a resemblance of the leaves to some nettles, but the lack of stinging hairs (thus, a dead nettle).

Lamium

Lamium purpureum

purple dead-nettle [Blooms: Apr-?]

Wood nettle plants may be either monoecious (separate male and female flowers on the same plants) or unisexual (only male or only female flowers). Male flowers are produced from branching cymes 4" long that arise from the leaf axils; female flower are produced from branching cymes, also 4" long, localized near the apex of the stem. Male flowers are small (1/8" across), consisting of five narrow, greenish-white sepals and five stamens; there are no petals but there is a vestigial pistil. Female flowers are about the same size (1/8" across) with four green sepals (two larger, two smaller) that look like tiny leaves with undulating edges and an ovary with a long, white, vertically-oriented J-shaped style that tapers to a point. The female flowers are wind-pollinated. The fruit is circular in outline but very flattened, green turning black with maturation, on a short winged stalk; the remains of the style are attached at the free end of the fruit.

Laportea

Laportea canadensis

wood nettle [Blooms: Aug-Sep]

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: ?]

Motherwort is a naturalized exotic from Eurasia with stems up to 5' tall (more commonly 3-4'); branches occur near apex, if they are present at all. The flowers are sessile; they occur in whorls just above a pair of opposite leaves in the upper half of the plant, almost completely covering the stem. Individual flowers are about 3/8" long, two-lipped and VERY hairy on the outer surfaces with profuse long, white hairs; the upper lip is reflected backwards and unlobed, while the lower lip is divided into three lobes. The lips are white or light pink with purple spots on the lower lip and purple mottling on the upper lip. Four stamens with purple anthers protrude about half way up the upper lip; there s a single style with a two-lobed stigma that is located between the two longest stamens. The stubby, tubular calyx has five very sharp lobes/spines lending a touch of danger to the flowers; after fertilization, the calyx holds four nutlets, each containing a single seed. Motherwort was introduced from Europe (where it was previously introduced from Asia) primarily as a medicinal herb; it is now considered invasive. Motherwort could possibly be confused with field mint (Mentha arvensis) but field mint lacks the distinctive three- or five-lobed angular-cleft leaves of motherwort and has boldly-protruding stamens that are lacking in motherwort.

Leonurus

Leonurus cardiaca

motherwort [Blooms: Jun-Aug]

Field peppergrass tems produce racemes of flowers near their apex; flowers near the top of the raceme are the youngest with older flowers (and later seed pods) further down the inflorescence. The flowers have a calyx of green or purple-green, lance-like sepals, four white, spoon-shaped petals, six stamens, and a single style. The fruits are flattened pods oval in outline with the remnants of the style protruding from a notch in the end (rather like field pennycress, Thlaspi arvense); each seedpod contains two seeds. This is an easy plant to overlook if only because it look like the weed that it is.

Lepidium

Lepidium campestre

field peppergrass [Blooms: May-?]

Peppergrass (aka, Virginia pepperweed) is a weedy, 1.5' tall, rather bushy plant. The flower spikes (racemes) are 2-4" long with tiny (<1/8") white apical flowers forming a larger inflorescence. The flowers have four oblong green or tan sepals with a white edge, half the length of the petals, alternating with four white, triangular petals. There are two stamens with yellow anthers and a stubby (0.2 mm tall) style on a green ovary. Below the flowers, the flower spike is covered with 1/8" wide seedpods on (relatively) long stalks, reminiscent of a bottlebrush; the seedpods are oval with an apical notch (much like half-sized versions of field pennycress (Thlaspi arvense) seedpods) containing two seeds. This species is native to the U.S. The stubby cylindrical inflorescences are and the triangular petals alternating with shorter sepals are diagnostic and distinguish pepper grass from field peppergrass (Lepidium campestre).

Lepidium

Lepidium virginicum

peppergrass [Blooms: Oct-Nov]

Round-headed bush-clover present stout, tall (2-5') green columns in the middle of open habitats. The stem is unbranched below the midpoint (except at the inflorescences), round in section, grooved, and densely covered in white hairs. At the apex of the main stem and on some of the side stems are slightly elongated balls of flowers 3-5" long and half as wide with numerous clover-like white flowers nearly hidden among leafy bracts; brown flowerheads and stalks may persist through winter. Each clover-like flower is about 1/4" wide and 1/2" long with five petals, one large vertical upper petal ("standard") and two perpendicular side petals ("wings") are visible; the other two petals (forming the keel) are hidden from view by the wings. There are ten stamens, all but one with their filaments fused together, and a single style with a small stigma. The petals are white with a patch of reddish-purple near the junction of the three visible petals. The fruit is a fuzzy pod less than 1/4" long containing a single seed. Round-headed bush-clover is a perennial with a tap root that may go down two meters into the soil.

Lespedeza

Lespedeza capitata

round-headed bush-clover [Blooms: Aug-Sep]

Violet bush-clover produces racemes or sparsely branched panicles of 3-8 flowers from the tips of stems or axils of middle or upper leaves; the inflorescences are borne on long peduncles that extend above/beyond the leaves. Individual flowers are 6-10 mm long and pea-like; they include a light green calyx with five teeth that is half the length of the flower; five whitish purple to purple petals (one upright banner with a basal patch of rosy purple; two lower, outer wings shorter than the keel; and two lower, inner petals that make up the keel); 10 stamens; and a pistil with a single style. Both the stamens and style are usually hidden within the keel. Fertilized flowers produce small green, single-seeded seedpods that lack sticky hairs (unlike the much-larger tick-trefoils); at maturity, the seedpods are 4-7 mm long and dark brown.

Lespedeza

Lespedeza frutescens

violet bush-clover [Blooms: Aug-Sep]

Ox-eye daisy is an aggressive plant that was introduced to the U.S. in the 19th century and is now thoroughly naturalized. Flowerheads occur singly at the apex of the stem on a long flower stalk. The flowerheads are about 1.5-2" across with 15-35 brilliant white, oblong ray florets and 120-200 yellow disc florets in a central, flattened disc about 3/4" across. The ray florets are fertile (they bear pistils with a split stigma) while the disc florets have both pistils and stamens. The disc florets are tubular with five tiny lobes at the apex, five stamens, and a single style with a bifurcated tip. The underside of the flower has numerous bracts in 2-4 layers; the bracts are green with purple to brown edges that outline each bract.

Leucanthemum

Leucanthemum vulgare

ox-eye daisy [Blooms: May-Jul]

Despite its common name, summer snowflake starts blooming in the spring (late April), not the summer. It is an introduced species, native to Europe and west Asia, similar in appearance to snowdrops (Galanthus nivalis) but larger. The leaves are exclusively basal, up to 12" long and an inch wide, flattened, arching, dark green, sheathing the base of the stems which may be the same length but are usually shorter than the leaves. The flowers dangle from the tips of hollow flower scapes in groups of 2-5, subtended by a single green, sword-shaped, spathe-like bract. Each flower has three sepals and three petals (white, pointed, with a yellowish-green spot near their tips), six stamens with orange anthers, and a single style with a green tip and a tiny stigma. Summer snowflake is toxic if ingested (like many lilies).

Leucojum

Leucojum aestivum

summer snowflake [Blooms: Apr-May]

Lyme grass flower spikes are 5-14" long, initially blue-green or silvery but turning beige when mature. There are typically one pair of spikelets per node on the spike. The spikelets are 1/2-1" long, containing 2-5 (typically 3) florets; each floret contains two bottlebrush-like styles and 1-3 stamens, each typically with a single yellow anther. Like all grasses, Lyme grass is wind pollinated. Lyme grass is very similar to the native American dune grass (Leymus mollis) but the latter is greener and is finely hairy under the spike. Lyme grass has become established in sandy habitats around the Great Lakes and (curiously) along the coast of Greenland.

Leymus

Leymus arenarius

Lyme grass [Blooms: May-Jun]

Rough blazing star's floral spike grows directly from the stem 6-18" long, with composite flowerheads along its length. Very early buds may appear as white, miniature cabbage-like structures, with purple highlights. Flowerheads open from the apex and proceed in a wave towards the base of the inflorescence. Flowerheads are about 1" across and usually stalkless. They are composed entirely of 25-40 disc florets (no ray florets), each with a tubular pinkish-purple corolla with five sharply-pointed apical lobes; a very long divided style emerges from the center of the corolla and the five brown anthers are inserted side by side around the base of the style. The exterior of the flowerhead is covered with 4-5 overlapping series of green or purple-tinged broadly rounded bracts whose edges are rolled in and rough with series of distinct, tiny teeth. Rocky Mountain blazing star's bracts look very similar to rough blazing star's, but the flowerheads of rough blazing star are essentially sessile (flower stalk no more than 1/4" long) while the flowerheads of Rocky Mountain blazing star have significant stalks, most commonly 1/2-1" long (as long as the flowerhead). The Jackson Park blazing stars bloom in the order cylindrical, prairie, rough, marsh, and Rocky Mountain; in relative abundance, rough is the most common, followed by cylindrical, prairie, marsh, and Rocky Mountain. Quick key to the Jackson Park blazing stars: bracts covering base of the flowerhead are (1) sharply pointed (-> cylindrical), (2) recurved away from flower, flaring (-> prairie), (3) tip round, closely appressed (-> marsh), (4) margins with tiny teeth, rolled under (-> rough if flower stalk is very short, Rocky Mountain if flower stalk about same length as flowerhead).

Liatris

Liatris aspera

rough blazing-star [Blooms: Aug-Sept]

Cylindrical blazing star is a more open plant than the other Jackson Park blazing stars, with the flowerheads relatively widely spaced along the 2-4" long racemes that are perched atop a 1-1.5' tall, unbranched stem. The showy flowerheads are pink or purplish-pink, about 1/2-3/4" in diameter, sessile or held on up to 3/4" stalks, with 15-25 disk flowers and no ray flowers; the base of the flowerheads is covered with 5-7 layers of scale-like, overlapping bracts with a sharp tip that together form a slim cylinder ~3/4" long and 1/3" diameter. The disk florets are tubular with five recurved triangular flaps at their apex; a pinkish white style, surrounded at its base by the five closely-packed yellowish-brown anthers and divided distally into two long filaments. Cylindrical blazing star appears to prefer dryer, well drained soils. The Jackson Park blazing stars bloom in the order cylindrical, prairie, rough, marsh, and Rocky Mountain; in relative abundance, rough is the most common, followed by cylindrical, prairie, marsh, and Rocky Mountain blazing stars. Quick key to the Jackson Park blazing stars: bracts covering base of the flowerhead are (1) sharply pointed (-> cylindrical), (2) recurved away from flower, flaring (-> prairie), (3) tip round, closely appressed (-> marsh), (4) margins with tiny teeth, rolled under (-> rough if flower stalk is very short, Rocky Mountain if flower stalk about same length as flowerhead).

Liatris

Liatris cylindracea

cylindrical blazing-star [Blooms: Jul-Aug]

Rocky Mountain blazing star (aka, northern plains blazing star) is the least common of the blazing stars in Jackson Park. Flowerheads lack ray florets but have 30-100 disc florets. Rocky Mountain blazing star flowerheads most closely resemble those of rough blazing star in that the bracts covering the base of the flowers in both have their edges rolled under with toothed edges, but the bracts in Rocky Mountain blazing star tend to flatten with age. The best way to distinguish the two species is by the length of the flowerhead's stalk —  the flowerheads of rough blazing star are essentially stalkless (stalks 1/4" long max) while those of Rocky Mountain blazing star are typically 1/2-1" long or longer, often the same size or longer than the flowerhead itself. Illinois is on the eastern edge of Rocky Mountain blazing star's range, so it's a fairly rare sight here. Quick key to the Jackson Park blazing stars: bracts covering base of the flowerhead are (1) sharply pointed (-> cylindrical), (2) recurved away from flower, flaring (-> prairie), (3) tip round, closely appressed (-> marsh), (4) margins with tiny teeth, rolled under (-> rough if flower stalk is very short, Rocky Mountain if flower stalk about same length as flowerhead).

Liatris

Liatris ligulistylis

Rocky Mountain blazing-star [Blooms: Aug-Sep]

Prairie blazing star's stem ends in a spike of composite, purple flowerheads 1/4-1/2" across; pinkish-red bracts cover the underside of the flowerheads, tapering to a fine tip that dramatically curls away from the flowerhead (like the scales on a dry pine cone). (No other blazing stars have such recurved bracts.) Each flowerhead has 5-10 disc florets that are tubular, 7-10 mm long, with five lobes at the apex forming a prominent star shape. A hairy, divided style protrudes well beyond the apex of the corolla; the base of the style is surrounded by the 3 mm long, reddish-brown anthers of the five stamens. Prairie blazing stars prefer well-watered areas. The Jackson Park blazing stars bloom in the order cylindrical, prairie, rough, marsh, and Rocky Mountain; in relative abundance, rough is the most common, followed by cylindrical, prairie, marsh, and Rocky Mountain. Quick key to the Jackson Park blazing stars: bracts covering base of the flowerhead are (1) sharply pointed (-> cylindrical), (2) recurved away from flower, flaring (-> prairie), (3) tip round, closely appressed (-> marsh), (4) margins with tiny teeth, rolled under (-> rough if flower stalk is very short, Rocky Mountain if flower stalk about same length as flowerhead).

Liatris

Liatris pycnostachya

prairie blazing-star [Blooms: Jul-Aug]

Savanna blazing-star's inflorescence is a long (up to 24"), narrow raceme of 10-40 flowerheads blooming in order from the tip of the inflorescence downwards. Each flowerhead has a 1/2-3.5" long, ascending stalk (peduncle); flowerheads are usually solitary on the peduncle. A sessile, leafy bract resembling the leaves occurs at the base of each peduncle. The central stalk of the inflorescences and the peduncle are fuzzy with short, white hairs. Each flowerhead is 1-2" across; they have 20-80 disk florets and no ray florets. The disk florets are tubular with five narrow, spreading lobes. The styles are bifurcated and extend well beyond the corolla of the disk florets, giving the flowerheads a shaggy aspect. There are five stamens hidden within the throat of the disk floret; the black anthers are visible, appressed to the body of the style. Surrounding the base of the flowerhead are scale-like bracts (phyllaries) in 4-6 overlapping series; they are slightly spreading and angled upwards but are neither appressed nor recurved. Individual phyllaries are oval or egg-shaped with short hairs protruding from their margins; they are often dark purple when the flowerhead is blooming. The fruit is a cylindrical, black seed with a tuft of white hairs about twice as long as the seed on one end. Preferred habitats are sandy savannas. Skippers and monarch butterflies seem particularly fond of savanna blazing-star. Savanna blazing-star might be confused with the much more common rough blazing star (Liatris aspera), but the latter always has appressed phyllaries with toothed, incurved edges, in contrast to savanna blazing-star's spreading, flat phyllaries and a much shorter stalk beneath the flowerhead than is present in savanna blazing-star. NatureServe Explorer (https://explorer.natureserve.org) rejects the name "Liatris scariosa" in favor of "Liatris novae-angliae" but ITIS (www.itis.gov)rejects the latter, as does the USDA Plants website(https://plants.usda.gov/). Here we will follow the latter two sources.

Liatris

Liatris scariosa

savanna blazing-star [Blooms: Aug]

Marsh blazing star flower spikes are 4-18" long extensions of the main stem, crowded with pinkish-purple flowerheads facing in all directions. Individual flowerheads are about 8 mm across; ray florets are absent and the 4-10 disc florets dominate. The corolla of a disc floret is tubular with five lance-shaped apical lobes; the divided style extends well outside the tubular corolla, surrounded at its base by five tightly packed stamens. The base of the flowerhead is covered with overlapping, flattened, elongate-oval bracts with rounded tips. Marsh blazing star is similar to prairie blazing star in appearance, but the bracts of prairie blazing star are highly recurved (like the scales on a dry pine cone). Quick key to the Jackson Park blazing stars: bracts covering base of the flowerhead are (1) sharply pointed (-> cylindrical), (2) recurved away from flower, flaring (-> prairie), (3) tip round, closely appressed (-> marsh), (4) margins with tiny teeth, rolled under (-> rough if flower stalk is very short, Rocky Mountain if flower stalk about same length as flowerhead).

Liatris

Liatris spicata

marsh blazing-star [Blooms: Aug]

Michigan lily is a moderately tall (up to 4.5'), slender, graceful plant. The flowers are 2-3" wide, dangling from 4-8" long stalks shaped like a shepherd's crook. The six tepals are yellow-orange to orange-red with purplish-brown spots scattered across their surface; the tips of the tepals are strongly recurved so the tips almost touch the base of the flower. There are six stamens with greenish-white filaments and large (1/2" long), reddish-brown anthers; a robust, yellowish-white style with a large 3-lobed, orange-red stigma. The 1.5" long seedpods are six-lobed, egg-shaped, and internally divided into three compartments. The Illinois Wildflowers website (www.illinoiswildflowers.info/) says that Michigan lily is "uncommon" but it is widespread on Wooded island and the west shore of West Lagoon in Jackson Park. Michigan lilies are easily distinguished from day lilies (Hemerocallis fulva) by the abundant spots on the tepals of the former, the tepals recurved so that they nearly touch the flower base, and the presence of stem leaves deployed in whorls along the stem.

Lilium

Lilium michiganense

Michigan lily [Blooms: Jun-Jul]