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triped squill is another early spring wildflower native to western Asia and the Caucasus; it tends to grow in clumps of plants 4-6" across. There are (only) two dark green, basal, hairless leaves up to 6" long and ~1/2" wide that widen towards their tips; the margins are smooth. A cluster (raceme) of 3-6 flowers are present on a stalk ("scape") 4-8" tall; overall, the cluster and scape resemble the related wild hyacinths. Each flower has six white tepals with a medial blue stripe. The filaments of the six stamens are flattened and fused together to form a white central, lobed, hollow cone that surrounds the style; the anthers are yellow and lie just inside the tip of the cone. This plant is one of the earliest to bloom in the spring in Jackson Park, but goes dormant in the late spring, basically biding its time until the next year. It prefers moist, well-drained soils.

Puschkinia

Puschkinia scilloides

striped squill [Blooms: Mar-Apr]

Slender mountain-mint flowers occur in small terminal clusters at the tips of the upper stems with distinctive very long, narrow bracts with spine-like tips just beneath the clusters; the bracts are densely covered with short, curled hairs on the blade and longer, bristly hairs along the margins. Individual flowers are tubular, white with scattered purple dots, and about 1/4" long; there is a calyx that is divided several slender green lobes. The corolla is divided into two parts, an upper lip and a lower lip that is divided into three lobes. The four stamens and two styles are also white, but the anthers are purple. The styles have a bifurcated stigma. Slender mountain mint is very similar to Virginia mountain mint (Pycnanthemum virginianum), but several characters make it straightforward to distinguish them. Leaves on slender mountain mints are always less than 1/4" wide and the stems are hairless; Virginia mountain mint will have the larger leaves more than 1/4" wide and has lines of white hairs on the stems. Slender mountain blooms earlier than Virginian mountain mint, but the blooming period of the two species overlaps. All parts of slender mountain mint give off a strong mint-like odor when crushed, but please restrain yourself from excessive foliage-crushing — it's not polite.

Pycnanthemum

Pycnanthemum tenuifolium

slender mountain-mint [Blooms: Jun-Aug]

Virginia mountain-mint flower heads are 3/4-1" across with up to 50 flowers; only a few flowers open at any one time. The flowers are hairy on the outer surfaces, white to light purple in color. Individual flowers are 1/4" across, tubular, and two-lipped; the lower lip is three-lobed with purple spots; four stamens with purple anthers emerge from the lower tube. There are two styles with deeply-notched tips that extend well beyond the edges of the lips of the corolla. The calyx that cups the flower is hairy, light green and has five triangular teeth.

Pycnanthemum

Pycnanthemum virginianum

Virginia mountain-mint [Blooms: Jul-Aug]

Small-flowered buttercup is a native species that has flowers similar to several other buttercups but is distinguished by its broad range of leaf shapes — other buttercups don't have this wide a variety of leaf shapes on a single plant. The flowers are stalked in groups of one to three on the end of the stems. Each flower is 1/4" across with five lance-shaped or triangular petals that are shorter than the sepals. There are five broadly rounded sepals, a ring of 5-10+ stamens with yellow anthers, and a central mound of green carpels, each with a pistil. After fertilization, the carpels enlarge and the central mound elongates until it is ovoid; the fruits (achenes) are shiny and have small beaks.

Ranunculus

Ranunculus abortivus

small-flowered buttercup [Blooms: Apr-May]

In Japanese knotweed, axils of the upper leaves produce slender, fuzzy spikes 2-4" long, covered with white or greenish flowers; more than one spike can arise from an axil. The flowers arise in groups of 3-6 from papery sheaths on the spikes. Individual flowers are sessile, about 8 mm long, with a funnel-shaped calyx, five petal-like sepals with wings on their outer faces, no petals, 6-8 stamens, and a tripartite stigma on top of a bullet-shaped green ovary. The fruit is a single shiny, black, three-angled seed with three broad, whitish, wings. Japanese knotweed is a highly aggressive invasive, luckily uncommon in Jackson Park. I know of three places in Jackson Park where it grows (it is a perennial); the Park District has eradicated it in one of these locations.

Reynoutria

Reynoutria japonica

Japanese knotweed [Blooms: Aug-Sep]

Jetbead flowers are solitary, arising on the tips of the green twigs. Flowers are elevated on 1/4-1/2" long stalks. There are four green sepals at the base of the flower, each with a bractlet half the length of the sepals that is located below the intersection of each pair of sepals. Four white, nearly circular petals alternate in position with the sepals. A greenish hypanthium covers the center of the flower with a four-lobed ridge marking its edges. Numerous (30-60) stamens with white filaments and yellow anthers, usually in four distinct clusters, lie inside the ridge; the stamens surround four pistils, each with a single style and a circular, terminal stigma. After fertilization, 1-4 fruits develop in the center of the flower that turn shiny black at maturity (the "jetbead"); the seeds remain attached to the persistant sepals until late in the fall and may persist through the winter.

Rhodotypos

Rhodotypos scandens

jetbead [Blooms: Apr-May]

Missouri gooseberry produces groups (racemes or corymbs) of 1-3 flowers on a horizontal flower stalk near some leaf petioles; the 1/4-1/2" long flower pedicels droop downward, so the axis of the flower is vertical. An egg-shaped, sessile bract is present at the base of each flower stalk. Missouri gooseberry flowers are easy to overlook because they don't comport with one's usual idea of "flowers" — they are very elongate, as if viewed in a fun house mirror. The flowers have a very narrow, white or greenish-white, tubular calyx with 4-5 oblong, spreading or reflected sepal lobes as long as the calyx; five short, erect petals extending from the calyx; and 4-5 stamens that double the vertical length of the flower. Hidden inside, at the base of the calyx, is a smooth ovary topped by a single pistil with one style; only the style is visible externally, sometimes extending past the stamens during flowering. After fertilization, the flower parts wither and the ovary expands into a smooth, globular berry 6-12 mm in diameter containing numerous tiny seeds; the berry is initially green, turning dull red or dull purple when ripe. If you see a gooseberry in Jackson Park with a prickly surface on the fruit (looking like a miniature, green medieval mace), it is prickly gooseberry, Ribes cynosbati, which also has lobed leaves. I have yet to see prickly gooseberry in Jackson Park, but it is known to occur in northern Illinois.

Ribes

Ribes missouriense

Missouri gooseberry [Blooms: Apr-May]

The inflorescence of black locust is a drooping raceme (flower spike) 4-7" long, with a pale green central stalk (rachis) and petiole, covered in 3/4-1" long, pea-like flowers. Each flower consists of a white or light green tubular calyx with five triangular teeth, densely covered with short hairs, and five white petals — a vertical banner with a yellow spot at its base, two lateral petals forming a keel, and two more wings enclosing the keel. The stamens (with orange anthers) and a single style are hidden within the keel. The fruit is a drooping, green seedpod 2-4' long at maturity, when it is dark brown and laterally flattened, containing from 3-10, quarter-inch-long seeds. Black locust produces a hardwood that is extremely resistant to rot and was prized by boat and bridge builders, especially as a source for trenails. (A dowel used to join two pieces of wood by driving it through a slightly undersized hole bored through the pieces; see Eric Sloane, "A Reverence for Wood," p. 37.)

Robinia

Robinia pseudoacacia

black locust [Blooms: May-Jun]

Multiflora rose's flowering stalks produce abundant white flowers in panicles of up to 30 flowers — in full bloom, a multiflora rose shrub can be breathtaking. Individual flowers are about 1" across, each with five green sepals covered with glandular hairs, five oval white petals, a ring of 35-100+ stamens with bright yellow or orange anthers, and a greenish central column of styles with yellow stigmas. (The only other local species with a stylar column is climbing wild rose, Rosa setigera.) The fruit are 1/4" diameter typical rose hips, hairless, orange-red or red when mature; the sepal remnants are shed before maturity. There are at least two large multiflora rose shrubs on Wooded Island.

Rosa

Rosa multiflora

multiflora rose [Blooms: May-Jun]

Common blackberry canes produce leaves and actively grow in their first year (primocanes); in their second year, they switch to producing flowers and fruit (floricanes). Second-year canes produce cylindrical racemes (up to 8.5' long) on the tips of short lateral shoots, longer than wide, with about a dozen flowers; the peduncles and pedicels of the raceme are covered with conspicuous glandular-tipped hairs. Each flower is 1-2" wide, has five green, pointed, triangular sepals with a tail-like extension, densely covered with glandular and non-glandular hairs; five white, rounded, wrinkled petals; 20-100 creamy stamens with white or yellow anthers; and a green cluster of numerous (100+) slender styles. After fertilization, the central cluster of styles enlarges to form a typical blackberry (drupe) 3/4" long and a bit less than half as wide, initially white or green but turning red-black when mature. The fruit is popular with most birds and mammals (including humans), who subsequently disperse the seeds.

Rubus

Rubus allegheniensis

common blackberry [Blooms: May-June]

Young, densely-hairy, stems of common dewberry terminate in single flowers or corymbs of 2-3 (rarely five) flowers. Individual flowers are 1-1.25" across consisting of five green, lance-shaped, hairy and glandular-hairy sepals with a thin, narrow "tail" at the tip; five white, wrinkled petals longer than the sepals; numerous (20-100) stamens; and a cluster of 5-150 green carpels with their club-shaped styles in the center of the flower. Floral stems may also arise from the axils of leaves. The fruits are pretty typical compound drupes (aggregate fruit like blackberries) 1/2-3/4" across, usually tightly attached to the receptacle with relatively few drupelets (10-40 of the smaller sections of the fruit); ripe fruit are dark red to black and shiny (not pruinose).

Rubus

Rubus flagellaris

common dewberry [Blooms: May-Jun]

Second-year canes of Pennsylvania blackberry produce 2-4" (across) corymbs of flowers on the tips of short lateral shoots. Each flower is about one inch wide, has five green, largely hairless, lance-shaped sepals much shorter than the petals with a thin "tail" on their tips; five white, oblong, wrinkled petals, widest about a third of the way from the distal tip; 20-100 creamy stamens with white or yellow anthers; and a light green cluster of numerous (100+) styles. Lance-like stipules or large leafy bracts flank the base of the flower pedicel, the latter often partially hiding the flower. After fertilization, the central cluster of styles enlarges to form a typical blackberry (drupe) 3/4" long, initially white or green but turning black when mature. The fruit is popular with most birds and mammals (including humans), who subsequently disperse the seeds.

Rubus

Rubus pensilvanicus

Pennsylvania blackberry [Blooms: May-Jun]

Common arrowhead's flowering stalks are about as tall as the leaves, either angular or round in section. Branches of the inflorescence end in 2-5 whorls of 2-3 flowers; the terminal branch bears 3-9 whorls of 2-3 flowers. Beneath each whorl 2-3, 1/8-1/3" long, boat-shaped, green floral bracts unite. Male (staminate) flowers have 25-30 yellow stamens while female (pistillate) flowers have a central green sphere of carpels; the male flowers are located above the female flowers in each raceme. Perfect flowers (both male and female organs present) do occur but are rare. Individual flowers are about 1-1.5" across with three oval, green sepals and three rounded, white petals about twice the length of the sepals. Male flowers have 7-30 yellow stamens in the center of the flower; female flowers instead have a bur-like green cluster of hundreds of carpels and their spike-like pistils (which have terminal or lateral styles). The pistils form a dense spiral on the surface of the central green mass. After fertilization, the female flowers lose their petals and transform into a bur-like, brown fruit about 3/4" across when mature; the spikes on the bur are individual seeds (achenes) that have a large, fang-like projection at right angles to the main axis of the seed.

Sagittaria

Sagittaria latifolia

common arrowhead [Blooms: Aug – Sep]

Upper branches of elderberry end in flat to domed panicles of flowers 3-10" across. Individual flowers are about 1/4" across, with a green, cup-shaped calyx, a creamy white corolla with five petal-like lobes, five long, spreading stamens with white anthers, and a creamy white hemispherical ovary with 3-5 short styles; flowers occur in umbel-like panicles 10" across made of dozens of flowers. The fruits are <1/4" wide spherical drupes in starburst-like sprays, dark purple to black when mature. The flower stalks are light green, turning purplish as the fruit ripens. The raw fruit is sweet with a slightly bitter or astringent aftertaste but may induce nausea or diarrhea if eaten in more than small quantities. The fruit is widely used in a variety of herbal supplements (as infusions and extracts), jam, and herbal wine. Note that all parts of the plant including the sap (except the flesh of the fruit) contain toxic cyanide-producing glycosides; berries should be cooked before consumption.

Sambucus

Sambucus nigra

elderberry [Blooms: May-Jul]

Bloodroot flowers are 1.5-3" across with 8-16 (typically 8) bright white petals, numerous stamens with golden yellow anthers, and an oval, green pistil with a pale yellow, two-lobed stigma at its tip. Two light green sepals are present in the floral bud but they drop off as soon as the flower begins to open. After fertilization, the ovary expands into a spindle-shaped seed capsule about 1" long, yellow when mature, that splits to release the seeds. The seeds are disbursed by ants that are attracted by the white, fleshy appendage (an elaiosome) on the bright red seed. The red sap is highly toxic, both externally and internally — it inhibits the cellular Na+/K+ ATPase enzyme and kills the cells. Avoid getting the sap on your skin and certainly avoid getting it in your eyes or on mucous membranes.

Sanguinaria

Sanguinaria canadensis

bloodroot [Blooms: Mar-Apr]

The tips of the upper stems of Canadian black snakeroot give rise to umbels 2.5" across of greenish white flowers; each umbel usually consists of 1-4 umbellets, each with 2-3 pistillate flowers or perfect flowers and 2-6 staminate flowers. In perfect flowers, the pistils develop (and are deployed) before the stamens develop; the pistillate stage persists for much longer. Each flower has a green calyx with five lance-like lobes slightly longer than the five greenish-white petals. Male and perfect flowers add five stamens with white anthers and lack the series of hooked spines of the pistillate flowers. Female and perfect flowers have ovaries densely covered with distinctive, neatly stacked series of long, hooked bristles arrayed perpendicular to the axis of the flower. The fruit is round, 3-5 mm long, covered in rows of those same hooked bristles; it splits on maturity to release the two seeds.

Sanicula

Sanicula canadensis

Canadian black snakeroot [Blooms: Jun-Jul]

Soapwort produces clusters of 3/4-1" flowers from the tips of terminal stems and branches. Individual flowers have a 1" long, green or reddish, sometimes hairy, cylindrical calyx; a corolla with five spreading (later reflexed), pink to white, oblong petals/lobes with a notched tip; 10 white stamens with pale yellow anthers that protrude from the throat of the flower; and a similarly protruding, divided white style. The calyx persists as an inflated seed capsule filled with 15-75 tiny dark brown, kidney-shaped seeds. Soapwort might be mistaken for a phlox, but the stamens and style in phlox are always hidden in the calyx tube, never protruding as in soapwort, and soapwort has leaves with three obvious longitudinal veins. Soapwort contains saponins in both the foliage and (especially) the seeds that make a frothy soap-like lather when boiled (and were once used as a soap substitute), but caution is recommended — the saponins are toxic. Herbivores generally avoid this plant.

Saponaria

Saponaria officinalis

soapwort [Blooms: Jun-Jul]

Mad-dog skullcap flower racemes may arise at the tips of the stems or from the axils of leaves. Each raceme is up to 6" long, containing 6-7 pairs of flowers; each flower has a short, basal leafy bract. Flowers are up to 8 mm long with a short, slender pedicel, a light green tubular calyx with two shallow lobes (the upper lobe with a dish-like projection), and a pale blue, lavender, or white, densely hairy, tubular corolla 5-8 mm long with a short, hood-like, upper lip and a slightly flared, three-lobed lower lip. Hidden inside the upper lip of the corolla are four stamens and a single bifurcated style. After fertilization, the calyx swells into a green capsule with includes the dish-like projection mentioned above, giving the capsule a unique appearance; inside is a cluster of four nutlets. The mouth of the calyx is visible as a thin slit beneath the projection.

Scutellaria

Scutellaria lateriflora

mad-dog skullcap [Blooms: Jul-Aug]