Wildflowers of the Midwest

WHITE FLOWERS

Justicia americana

Acanthaceae

water willow

Shallow and/or quiet water in streams, rivers, lakes. Summer.

An erect perennial, unbranched, glabrous, 1½–2½ ft. tall, colonial. Leaves opposite, usually sessile, linear-lanceolate, 3–6 in. long × ⅓–1 in. wide. Flowers irregular, ¾–1 in. wide, tubular, 2-lipped, the upper with a notched tip, the lower with 3 spreading lobes, the larger middle one with dark purple markings, occurring in compact heads on upright axillary stalks. Water willow is a common host of dodder (Cuscuta). Contrary to what its common name suggests, this species is not a true willow (Salix). IA, IL, IN, MI, MO, OH. Occurs primarily in the lower Midwest. Common. SN

Yucca flaccida

Agavaceae

Adam’s needle

Cemeteries, roadsides, fields, old homesites, sand prairies. Summer.

A semi-woody perennial greater than 5 ft. tall. Leaves evergreen, several in a basal rosette, linear to narrowly lanceolate and somewhat flexible with sharp tips, margins frayed into curling fibrous strands, 1½–2½ ft. long × 1–3 in. wide. Flowers regular, 2–3 in. long, bell-shaped and nodding, bearing 6 thick and fleshy tepals, numerous on a terminal, spreading, and densely hairy panicle. Fruit a thick, cylindrical capsule. Our only native yucca, soapweed yucca (Y. glauca), reaches its easternmost natural range in western IA and southern MO. IL, IN, MI, MO, OH, WI. Introduced from farther south. Scattered in the Midwest. DT

Alisma subcordatum

Alismataceae

common water plantain

Mudflats, swamps, marshes, lake and pond edges, ditches. Summer.

A glabrous perennial 1–2 ft. tall. Leaves basal, petiolate, ovate to somewhat subcordate, 5–12 in. long × 1–6 in. wide, petioles commonly longer than the blades. Flowers (inset, left) regular, about ⅛ in. wide, with 3 petals and sepals about ¹/₁₆ in. long, floral array highly branched with numerous flowers. The similar large-flowered water plantain (A. triviale) is more common in the northern part of our region; its flowers are larger, about ¼ in. wide, with petals longer than sepals (inset, right). IA, IL, IN, MI, MN, MO, OH, WI. Common and widespread throughout. MAH/SN

Echinodorus berteroi

Alismataceae

upright burhead

Marshes, ponds, wet open areas. Summer, fall.

An upright annual or perennial to 2 ⅓ ft. tall. Leaves basal, long-petiolate, rounded to cordate at base, entire, glabrous, to 6 in. long and wide. Flowers regular, to ½ inch wide, with 3 sepals and 3 petals, in whorls along branches, creating open, conical arrangements along stem. Fruit forms bur-like heads. Creeping burhead (E. cordifolius) has stems that arch or creep along the ground and root at their tips. May be confused with Alisma or Sagittaria. IA, IL, IN, MO, OH, WI. Mostly in southern portion of the Tallgrass Prairie, with few occurrences in the Ozark Highlands and Eastern Forests. SN

Sagittaria calycina

Alismataceae

hooded arrowhead

Mudflats, especially along rivers and oxbow ponds. Summer.

An erect to lax glabrous annual, 6–24 in. tall. Leaves all basal, the petioles long and often rather spongy, blades sagittate with 2 spreading lower lobes, up to 1 ft. long and about as wide. Flowers regular, up to 1 in. wide, with 3 petals and 3 sepals, the latter closely appressed to fruiting head, on thick downwardly curving pedicels. Inflorescence erect, consisting of 3–10 whorls. Fruit an achene with beak projecting horizontally. Syn. S. montevidensis. IA, IL, IN, MI, MN, MO, OH, WI. Occurs mostly in the lower Midwest. SN

Sagittaria cuneata

Alismataceae

arumleaf arrowhead

Marshes, mudflats, lakes, streams. Summer, fall.

A glabrous perennial to 2 ft. tall, monoecious. Leaves basal, entire, variable, those on submerged plants ribbon-like, also with long-petiolate floating sagittate leaves (or lacking basal lobes), when emergent with short-lobed sagittate leaves (sometimes unlobed) to 8 in. long × 4 in. wide, on stout petioles to 1 ft. long. Flowers regular, to 1 in. wide, male (above) and female (below), with 3 spreading petals, stalked, in whorls of 3 in terminal inflorescence to 8 in. long. Fruit an achene with minute erect beak (see inset), numerous in globular heads. IA, IL, IN, MI, MN, OH, WI. More frequent northward, scattered southward. SN

Sagittaria graminea

Alismataceae

grass-leaved arrowhead

Marshes, shores, lakes. Summer, fall.

A glabrous perennial to 3 ft. tall, monoecious. Leaves basal, entire, variable, those of submerged plants in rosettes, stiff and sessile with parallel margins, when emergent with parallel margins or narrowly ovate, to 7 in. long × 1½ in. wide, on petioles to 7 in. long. Flowers regular, to 1 in. wide, male (above) and female (below), with 3 spreading petals, stalked, in whorls of 3 in terminal inflorescence to 8 in. long. Fruit an achene, broader above middle, with minute erect beak on one side, numerous in globular heads. Crested arrowhead (S. cristata) is more northern and has slightly longer beaks on fruit. IA, IL, IN, MI, MN, MO, OH, WI. Scattered. SN

Sagittaria latifolia

Alismataceae

common arrowhead

Marshes, shallow portions of lakes and ponds, swamps, streams, ditches. Summer.

An erect, glabrous, usually monoecious perennial, tuberous, 1–3 ft. tall. Leaves basal, long-petiolate, blades variable but usually sagittate with 2 spreading lower lobes, up to 1 ft. long × 6 in. wide. Flowers regular, 1–1½ in. wide, with 3 petals and 3 sepals, the latter reflexed in fruit, on slender pedicels, in 2–10 whorls on flowering stem. Leafy bracts below each whorl are ¼–⅓ in. long and boat-shaped. Fruit an achene with a horizontal beak (see inset). In shortbeak arrowhead (S. brevirostra), the bracts are ⅓–⅔ in. long and long-tapering. IA, IL, IN, MI, MN, MO, OH, WI. Common, possibly in every county. SN

Sagittaria rigida

Alismataceae

stiff arrowhead, sessilefruit arrowhead

Marshes, lakes, ponds, rivers. Summer, fall.

A glabrous perennial to 3 ft. tall, monoecious. Leaves basal, entire, variable, those on submerged plants in rosettes, stiff and sessile with parallel margins, when emergent with parallel margins or more often ovate, rarely sagittate with small basal lobes, to 6 in. long × 4 in. wide, on long petioles. Flowers regular, to 1 in. wide, stalked male (above) and sessile female (below), with 3 spreading petals, in whorls of 3 in terminal inflorescence to 6 in. long. Fruit an achene, broader above middle, with ascending beak on one side, numerous in sessile globular heads. IA, IL, IN, MI, MN, MO, OH, WI. Scattered, more frequent westward. PD

Allium burdickii

Alliaceae

narrow-leaved wild leek

Dry-mesic and mesic upland woods. Summer.

A glabrous perennial herb from a bulb, commonly occurring in clumps, 6–8 in. tall. Leaves mostly present only in spring, flat, narrowly lanceolate, pale green throughout, 4–10 in. long × 1–2 in. wide, gradually tapering to the ground without a distinct leaf stalk (see inset). Has onion smell. Flowers regular, about ⅛–¼ in. long, somewhat bell-shaped with 6 tepals. Inflorescence of 10–20 flowers in an umbel atop an 8-in.-tall leafless stalk. Leaves of the similar wild leek (A. tricoccum) are wider with reddish petioles. IA, IL, IN, MI, MN, MO, OH, WI. Widespread, more common than many maps indicate. PR/CB

Allium tricoccum

Alliaceae

wild leek, ramps

Rich, moist upland woods, ravines. Summer.

A glabrous perennial herb from a bulb, unbranched, 8–12 in. tall, commonly occurring in large colonies. Leaves flat, oval to broadly elliptic, bright green, 4–12 in. long × 2–4 in. wide, tapering abruptly to a distinct reddish sheath and petiole (see inset), mostly present only in spring, smelling of onion when bruised, somewhat resembling ornamental tulip leaves. Flowers regular, about ¼ in. wide, with 6 tepals. Inflorescence usually with 18–50 flowers in a rounded umbel atop a leafless stalk. Shiny black seeds evident in late summer and fall. IA, IL, IN, MI, MN, MO, OH, WI. Widespread and locally common.
MAH/CR

Nothoscordum bivalve

Alliaceae

false garlic

Prairies, glades, exposed bluffs, woodlands. Spring.

An erect perennial, unbranched except in inflorescence, glabrous, 4–12 in. tall. Leaves all basal from a bulb, linear, flat, non-odoriferous, 4–12 in. tall × ¹/₁₆–⅛ in. wide. Flowers regular, about ½ in. wide, with 6 spreading tepals, each with a greenish-yellow base, 5–8 in a terminal umbel. This species looks remarkably like an onion (Allium) but lacks the onion odor. A good way to make a quick distinction is simply to bruise a leaf and smell it. IL, IN, MO, OH. Occurs mostly in the Midwest’s lower third, being particularly common in the Ozark Highlands. SN

Froelichia floridana

Amaranthaceae

prairie cottonweed, large cottonweed, plains snakecotton

Sparsely vegetated sand, savannas, gravel bars, roadsides, railroads. Spring, summer, fall.

A hairy, mostly unbranched annual to 3 ft. tall. Leaves opposite, entire, to 4 in. long × ¾ in. wide, mostly on lower third of stem. Flowers regular, to ⅓ in. wide, with white-woolly calyx sometimes pink at 5-lobed tips, lacking petals, in 5-ranked spikes to 4 in. long in upper part of plant, terminal spike solitary, lateral spikes opposite and well spaced along stem. Slender cottonweed (F. gracilis) is shorter and more branched with leaves to ½ in. wide and flowering spikes to 1½ in. long. IA, IL, IN, MI, MN, MO, OH, WI. Primarily in the Mississippi and Kankakee drainages with scattered occurrences elsewhere. MJH

Hymenocallis occidentalis

Amaryllidaceae

spiderlily

Floodplain forests, swamps, wet flatwoods, moist slopes. Summer.

An erect, glabrous perennial from a bulb, 2–3 ft. tall. Leaves basal, somewhat fleshy, linear and strap-shaped, glaucous, 1–2 ft. long × 1–2½ in. wide. Flowers regular, up to 6 in. wide composed of 6 spreading tepals and a shallow, funnel-shaped tube about 2 in. wide bearing 6 upcurved stamens. Inflorescence of 2–6 fragrant flowers atop a naked peduncle. Fruit a broadly triangular capsule. This spectacular plant blooms during the hottest part of the summer, typically late July into August. IL, IN, MO. Restricted primarily to the southwestern counties of the Eastern Forests. MAH

Angelica atropurpurea

Apiaceae

great angelica, purplestem angelica

Marshes, fens, seeps, sedge meadows, streambanks, swamps, ditches. Spring, summer.

A perennial to 10 ft. tall, unbranched except toward top. Leaves alternate on long petioles with inflated sheathing bases connecting to purple, glaucous, hollow stem; lower leaves to 2 ft. long and wide, 2–4 times compound with toothed leaflets to 4 in. long × 2 in. wide; upper leaves smaller. Flowers regular, with 5 petals, to ¼ in. wide, numerous, forming nearly spherical compound umbels to 9 in. wide; several inflorescences at top of plant. IA, IL, IN, MI, MN, OH, WI. Primarily in the Northern Lakes and northern portion of the Eastern Forests, extending to some extent into northern portion of the Tallgrass Prairie. SN

Angelica venenosa

Apiaceae

hairy angelica, wood angelica

Rocky forests, savannas, prairies, streambanks. Spring, summer.

A perennial to 5 ft. tall. Leaves alternate and basal, petiolate with slightly inflated sheathing bases connecting to purplish stem; lower leaves to 10 in. long, 2–4 times compound with toothed leaflets to 2 in. long × ½ in. wide; upper leaves smaller. Flowers regular, small, with 5 petals, forming several flat to hemispherical compound umbels to 6 in. wide at top of plant. Fruit short-hairy. Lovage (Ligusticum canadense), mostly restricted to the Ozark Highlands, has ridged, glabrous fruit. IL, IN, MI, MO, OH. Southeastern corner of MI; throughout the Ozark Highlands and eastern portion of the Eastern Forests, scattered elsewhere in the Eastern Forests. AG

Chaerophyllum procumbens

Apiaceae

wild chervil

Floodplain forests, stream terraces, moist woodlands. Spring.

A weakly ascending annual, branching, glabrous to sparsely hairy, 6–18 in. long. Leaves alternate and also basal, broadly ovate in outline, finely divided, 2–4 times compound, to 4 in. long and about as wide. Flowers regular, about ⅛ in. wide, 5-petaled, in compound umbels. Fruit elliptic, about ¼ in. long. This dainty spring ephemeral blooms early, sets seed, and disappears before summer’s arrival. The uncommon var. shortii differs from typical var. procumbens by the presence of hairs on the fruit. Southern wild chervil (C. tainturieri) has lanceolate fruit. IA, IL, IN, MI, MO, OH, WI. Mostly common except absent from muchs of the Northern Lakes. MAH

Cicuta bulbifera

Apiaceae

bulblet-bearing water hemlock

Marshes, bogs, swamps, lake and stream margins. Summer, fall.

A spindly, glaucous perennial to 4 ft. tall. Leaves alternate, to 12 in. long × 8 in. wide, smaller above, petiolate, pinnately compound with linear, toothed leaflets to ¼ in. wide, with veins ending in sinuses of teeth. Flowers regular, to ⅛ in. wide with 5 shallowly lobed petals, forming flat, compound umbels to 3 in. wide at ends of branches and on stalks from upper leaf axils. The bulblets that develop in upper part of plant are a means of vegetative reproduction. Extremely poisonous if ingested. IA, IL, IN, MI, MN, OH, WI. Mostly in the Northern Lakes and adjacent portions of the Tallgrass Prairie and Eastern Forests. PD

Cicuta maculata

Apiaceae

water hemlock

Floodplain forests, swamps, fens, marshes, shores. Spring, summer.

A perennial with hollow stems, erect and commonly ascending, branched, glabrous, pale but sometimes mottled with purple at base. Leaves alternate and basal, petiolate to sessile, broadly ovate, 2 or 3 times pinnately compound with toothed margins, up to 1½ ft. long × 10 in. wide. Flowers regular, about ⅛ in. wide, 5 obovate petals, in compound umbels with about 20+ flowers per umbellet. Water hemlock is reputed to be the most poisonous native plant in all North America. Ingestion by livestock or humans may lead to death in as little as 15 minutes. IA, IL, IN, MI, MN, MO, OH, WI. Widespread and common throughout. SN

Conium maculatum

Apiaceae

poison hemlock

Disturbed areas, roadsides, ditches, pastures. Spring, summer.

A biennial, erect, stems hollow, branching above, glabrous and often glaucous, spotted with purple, 4–8+ ft. tall. Leaves alternate and basal, 3 or 4 times pinnately compound and highly dissected, lower ones long-petiolate, upper nearly sessile, broadly triangular, with toothed margins, up to 1½ ft. long × 1 ft. wide. Flowers regular, about ⅛ in. across, with 5 obovate petals, in compound umbels, about 20+ per umbellet. Malodorous. The sap is reported to have been the poison that killed Greek philosopher Socrates. IA, IL, IN, MI, MN, MO, OH, WI. Introduced from Eurasia. Widespread and common but less so in northern counties. MAH

Cryptotaenia canadensis

Apiaceae

honewort

Moist upland forests, floodplain forests, stream terraces, seeps. Spring, summer.

An erect perennial, branching, glabrous, 1–2½ ft. tall. Leaves alternate, petiolate or sessile upward, once compound with 3 leaflets, these lanceolate to ovate, some divided, with sharply toothed margins, 2–4 in. long × 1–4 in. wide. Flowers regular, about ¹/₁₆ in. wide, with 5 obovate petals, in compound umbels, up to 10+ or so in each umbellet. Honewort possibly gets its name for having been used to treat hones (a former name for tumors or swellings of the cheek). IA, IL, IN, MI, MN, MO, OH, WI. Common and widespread, possibly in every county. SN

Daucus carota

Apiaceae

Queen Anne’s lace, wild carrot

Roadsides, old fields, meadows, ditch banks, waste areas. Spring, summer, fall.

An erect biennial with some branching, commonly rough-hairy, 2–4 ft. tall. Leaves alternate, lowest petiolate, oblong, 2–4 times pinnately compound, smallest segments linear to lanceolate, up to 9 in. long × 2–6 in. wide. Flowers regular, ¹/₁₆–⅛ in. wide, with 5 obovate petals, the middle flower commonly dark purple in a 3- to 5-in.-wide flat-topped compound umbel with large, divided bracts beneath. Queen Anne’s lace is the ancestor of the cultivated carrot. The similar caraway (Carum carvi) lacks large bracts beneath the umbels. IA, IL, IN, MI, MN, MO, OH, WI. Introduced from Eurasia. Common throughout. SN

Erigenia bulbosa

Apiaceae

harbinger of spring, pepper and salt

Moist and floodplain forests. Spring.

A glabrous, sprawling perennial to 8 in. tall. Leaves basal or alternate, to 5 in. long × 3 in. wide, 2 or 3 times ternately compound. Flowers regular, to ⅕ in. wide, with 5 petals that contrast with dark purple-black anthers, in tight clusters within flat compound umbels at top of plant. Often with reddish-brown stems that contrast sharply with bright green foliage. One of our earliest-blooming native wildflowers and thus a true harbinger of spring. IL, IN, MI, MO, OH, WI. Widespread in the Eastern Forests, Ozark Highlands, and southeastern portion of the Northern Lakes; less common in southeastern portion of the Tallgrass Prairie. SN

Eryngium yuccifolium

Apiaceae

rattlesnake master

Wet to dry prairies, savannas, barrens, glades. Summer.

A glabrous, gray-green perennial to 5 ft. tall, unbranched except in inflorescence. Leaves alternate, clasping, mostly near base of plant, to 2½ ft. long × 1½ in. wide, much smaller above, strap-like with parallel veins and sparse spine-tipped marginal teeth. Flowers regular, tiny, with 5 shallowly lobed petals, forming several conspicuous spiny round clusters to 1 in. wide at top of plant. The specific epithet is a reference to yucca-like foliage, and the common name alludes to use of roots by Native Americans to treat rattlesnake bites. IA, IL, IN, MI, MN, MO, OH, WI. Widespread in the Ozark Highlands and southern portion of the Tallgrass Prairie, less frequent elsewhere. EH

Heracleum maximum

Apiaceae

cow parsnip

Floodplains, wet meadows, forest openings, thickets. Spring, summer.

A bristly-hairy perennial to 8 ft. tall. Leaves basal and alternate, compound with 3 large, deeply and sharply lobed, toothed leaflets, to 20 in. long and wide, largest at base, smaller, simple and 3-lobed above, with conspicuously inflated sheaths at base of petioles. Flowers irregular, with 5 uneven, notched petals, to ¼ in. wide, numerous, forming flat, compound umbels to 8 in. wide, with up to 50 umbellets per umbel; several umbels in upper part of plant. Giant hogweed (H. mantegazzianum), introduced from Europe, is larger with larger leaves and has 70+ umbellets per umbel. IA, IL, IN, MI, MN, MO, OH, WI. Throughout, but rare in the Ozark Highlands. SN

Osmorhiza longistylis

Apiaceae

anise root

Rich upland forests, moist woodlands. Spring.

An erect perennial, branched, glabrous or hairy, 1½–3 ft. tall. Leaves alternate, petiolate, 2 or 3 times pinnately compound, 2–9 in. long × 5–9 in. wide, triangular with toothed leaflets, emits anise scent when bruised. Flowers regular, about ⅛ in. wide, with 5 oblanceolate petals, in a compound umbel with 10+ flowers per umbellet, leafy bracts present beneath umbellets, styles ⅛ in. long, persistent in fruit (see inset). The wide-ranging sweet cicely (O. claytonii) has shorter styles and lacks strong anise scent. Mountain sweet cicely (O. berteroi) of the upper Great Lakes lacks leafy bracts beneath umbellets. IA, IL, IN, MI, MN, MO, OH, WI. Common throughout. MAH/SN

Oxypolis rigidior

Apiaceae

cowbane, stiff cowbane

Marshes, fens, wet prairies, sedge meadows, swamps, seeps, floodplains, ditches. Summer, fall.

A glaucous perennial to 5 ft. tall. Leaves alternate, to 1½ ft. long, smaller above, petiolate with inflated, papery sheath, pinnately compound with up to 11 entire to irregularly sparsely toothed leaflets to 4 in. long × 1 in. wide, with veins ending in tips of teeth and leaflet margins rolled under. Flowers regular, to ⅛ in. wide, with 5 shallowly lobed petals, forming domed, compound umbels to 6 in. wide in upper part of plant. Water parsnip (Sium suave) has abundant, regularly spaced teeth on leaflets (or leaves deeply dissected). IA, IL, IN, MI, MN, MO, OH, WI. Scattered to widespread but absent in northernmost regions. SN

Perideridia americana

Apiaceae

wild dill, eastern yampah

Moist floodplain forests, dry upland forests, prairies, glades. Spring, summer.

An erect perennial, glabrous, 2–4 ft. tall. Leaves alternate, petiolate, oblong-ovate to triangular, 1–3 times pinnately compound with very narrow and entire leaf segments, 1–6 in. long × 3–4 in. wide. Flowers regular, about ⅛ in. wide, with 5 obovate and notched petals, in round-topped compound umbels of 10+ per umbellet. Shortly after flowering and fruiting in early summer, plants go into senescence. One common name is a reference to its similarity to garden dill (Anethum graveolens), as both have very narrow leaf segments. IL, IN, MO, OH. Most occurrences are in northern IL and the Ozark Highlands. ST

Ptilimnium nuttallii

Apiaceae

laceflower, Ozark mock bishop’s-weed

Wet prairies, wet spots in glades, wet areas along railroads. Summer.

A glabrous annual to 2 ft. tall. Leaves alternate, to 2 in. long and wide, short-petiolate, pinnately compound to twice compound with filiform leaflets. Flowers regular, to ⅛ in. wide with 5 shallowly lobed petals, forming slightly domed compound umbels to 2½ in. wide at ends of branches at top of plant, umbels subtended by 3–15 filiform bracts. Fruit smooth and spherical. Big mock bishop’s-weed (P. costatum) is a taller plant with longer leaves and larger umbels. IL, MO. Scattered in the Ozark Highlands and surrounding portions of the Eastern Forests and the Tallgrass Prairie. DT

Sanicula canadensis

Apiaceae

black snakeroot

Mesic and dry-mesic upland forests. Spring, summer.

An erect biennial, unbranched, glabrous, 6–24 in. tall. Leaves alternate, petiolate, 3–5 times palmately divided with toothed margins, up to 5 in. long × 4–5 in. wide. Flowers regular, with 5 obscure greenish-white petals, both male and perfect present, the latter bristly, with straight styles that are concealed by bristles, in small compact umbels of 2 or 3 perfect flowers and up to 7 male ones per umbellet. Fruits rounded and bristly. Clustered black snakeroot (S. odorata) has longer styles and yellow flowers and usually blooms earlier than black snakeroot. IA, IL, IN, MI, MN, MO, OH, WI. Common and widespread, less so in the Northern Lakes. KC

Sanicula trifoliata

Apiaceae

beaked snakeroot

Mesic upland forests, stream terraces. Spring, summer.

An erect biennial, glabrous, 1–2½ ft. tall. Leaves alternate, petiolate, palmately compound with 3 leaflets, coarsely toothed, up to 4 in. long × 5–7 in. wide. Flowers regular, 5-petaled, greenish-white and obscure, both male and perfect present, the latter bristly, with styles straight, shorter than and concealed by bristles, calyx lobes equal to the bristles and forming a small beak atop the fruit, in compound umbels of 2 or 3 perfect flowers and up to 5 male ones per umbellet. Fruit ¼ in. long and bristly, looking like a miniature pineapple. IA, IL, IN, MI, MN, OH, WI. Most common in Eastern Forests and southern Northern Lakes. SN

Sium suave

Apiaceae

water parsnip