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  Fabaceae: Securigera varia

  R. Neil Reese

  Securigera varia is a perennial herbaceous vine or groundcover growing from a fibrous root system. The stems are slender, sprawling to trailing, smooth or slightly hairy, and can reach up to 1 to 2 meters long, often forming dense mats. The leaves are alternate and pinnately compound with 15 to 25 leaflets. Each leaflet is oblong to lanceolate, measuring 1 to 3 cm long and 0.5 to 1.5 cm wide, often with a small tooth-like point at the tip. The upper leaf surface is dark green and glabrous (smooth), while the lower surface is lighter green and may have fine hairs. Leaf margins are entire or slightly serrated. Petioles are short, typically 1 to 3 cm long, supporting the leaflets in a feather-like arrangement. Plants bloom from June through September. The inflorescence is a terminal umbel with 15 to 30 pink to lavender flowers, each about 15 to 20 mm in diameter. Each flower has five free, small green sepals that are ovate and about 2 to 3 mm long, and five free petals forming the typical papilionaceous (butterfly-like) shape of legumes: a large banner petal (10–15 mm), two wing petals (8–12 mm), and two keel petals (7–10 mm) fused at the base. There are ten stamens per flower, nine filaments fused into a tube and one free (diadelphous), and yellow anthers about 1 to 2 mm long. The pistil is single with one carpel forming a simple ovary about 5 to 7 mm long, a style about 6 to 8 mm long, and a small stigma. The fruit is a slender, cylindrical legume pod about 3 to 6 cm long that ripens from August to October and contains several seeds. . Crownvetch is native to Europe and Asia but has become naturalized in South Dakota, commonly found in disturbed sites, open fields, roadsides, and is used as a groundcover in erosion control plantings, primarily in the eastern parts of the state.

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  Fabaceae: Strophostyles leiosperma

  R. Neil Reese

  Strophostyles leiosperma is an annual or short-lived perennial, herbaceous vine with a slender, twining or trailing form. It grows from a taproot. Vines typically reach 30 to 120 cm in length and may climb or sprawl over adjacent vegetation. Stems are thin, green to purplish, and covered with fine, appressed hairs. Leaves are alternate and trifoliate. Leaflets are oblong to ovate, 2–6 cm long and 1–3 cm wide, with entire to slightly lobed margins and a pointed tip. Leaf color is medium to dark green above and paler below, sometimes with sparse appressed hairs on both surfaces. Petioles are present and usually 1–5 cm long. Stipules are present at the base of the petiole, small and linear, but easily overlooked. Flowering occurs from June to September. The inflorescence is a short, axillary raceme bearing 1–6 papilionaceous (pea-like) flowers. Each flower is about 1–2 cm long. The calyx consists of five green sepals, 3–7 mm long, fused at the base with short, broad lobes and fine hairs. The corolla has five petals, with the standard (banner) petal being pink to pale purple (sometimes white), broad and slightly notched, and about 12–20 mm long; the wings and keel are smaller, pale pink to white. There are ten stamens, nine fused and one free, with white filaments and yellow anthers, typical of the pea family. The pistil is single, about 1 cm long, with a slender style and a small, capitate stigma. Fruit is a slender, straight or slightly curved pod (legume), 3–6 cm long and about 5 mm wide, green turning brown at maturity, usually from August to October. The pod splits open to reveal smooth, oval seeds (a distinguishing feature), tan to brown, about 3–4 mm long. Slick-seed fuzzybean is native to South Dakota, found mostly in the eastern and southeastern parts of the state in open woodlands, prairies, roadsides, and disturbed sites, particularly in sandy soils.

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  Fabaceae : Thermopsis rhombifolia

  R. Neil Reese

  Thermopsis rhombifolia is a perennial rhizomatous herb, with 1 to several ascending to erect stems, 15–60 cm tall, with or without a covering of short, stiff hairs. This species is often colony forming in open prairies. The alternate, palmately trifoliate leaves have leaflets that are ovate, 15–50 mm long and 10-20 mm wide, with a few to many appressed hairs. The inflorescence consists of subterminal racemes, 3–10 cm long. The calyx forms a hairy, bilabiate tube, 4-5 mm long, the upper lip having 2 united teeth, 3-4 mm long , and the lower lip with 3 teeth 2-3 mm long. The papilionaceous corolla has yellow petals, the banner often has purple spots and is 17-22 mm long, the wings are 15- 18 mm long, and the oblong keel is 14-16 mm long. The flowers have 10 separate stamens. The fruit is a legume, 3–8 cm long with 3 to 10 seeds, constricted between the ~5 mm long seeds. Goldenpea blooms from April into June on open prairies, hillsides and woodlands in western South Dakota.

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  Fabaceae: Trifolium pratense

  R. Neil Reese

  Trifolium pratense is a short-lived biennial or perennial herbaceous legume that develops a deep, branched taproot system. The plant reaches a height of 20 to 80 cm with erect to decumbent, multi-branched stems that are distinctly hairy to nearly hairless. The leaves are alternate and trifoliate. The leaflets are medium green, often marked with a distinctive pale green or whitish V-shaped crescent on the upper surface; each leaflet measures 1.5 to 4.5 cm long and 1 to 3 cm wide, varying in shape from ovate to elliptic. The upper surface is sparsely hairy, while the lower surface is more noticeably pubescent, particularly along the prominent veins. Long petioles are present, measuring 2 to 10 cm on lower leaves and becoming shorter or nearly absent near the top of the stem. Large, prominent stipules are present at the base of the petiole; they are ovate, up to 3 cm long, membranous, pale green with darker green or purple veining, and terminate in a sharp, bristle-like tip. Flowering occurs from May to September, producing a dense, globose to ovoid terminal inflorescence measuring 2 to 3.5 cm in diameter, which is usually closely subtended by a pair of reduced leaves. The calyx consists of 5 fused sepals forming a narrow, hair-fringed tube about 3 to 4 mm long with unequal, needle-like lobes (the lowest lobe being the longest at up to 4 mm); it is light green to reddish-purple. The corolla features 5 fused petals displaying the classic papilionaceous (pea-like) structure, measuring 12 to 15 mm long and ranging in color from deep pinkish purple to magenta. The androecium consists of 10 stamens that are diadelphous (9 fused into a tube surrounding the pistil and 1 free), featuring tiny, yellow anthers. The gynoecium contains 1 pistil with a superior, single-celled ovary, a slender style, and a small, capitate stigma. The fruit is a small, egg-shaped pod measuring 2 to 3 mm long that breaks open transversely to release a single, kidney-shaped seed shifting from yellow to purplish brown upon reaching maturity from July to October. Red clover is introduced and not native to South Dakota, it is originally native to Europe, Western Asia, and Northwest Africa but it is now naturalized widely across all counties of the state, thriving in pastures, agricultural fields, lawns, roadsides, and disturbed open areas.

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  Fabaceae : Vicia americana

  R. Neil Reese

  Vicia americana is a rhizomatous, perennial herb, the stems sprawling to climbing, 20-100 cm long and smooth to having a sparse covering of hairs . The alternate leaves are compound pinnate with 4 to 8 pairs of elliptical to linear leaflets 10-38 mm long , a pair of stipules ~8 mm long, and with a tendril at the end of the leaf. The inflorescences are racemes in the axils of the upper leaves. The peduncles are well developed with 3-10 flowers. The calyx forms a tube 3.5-5.5 mm long with unequal teeth, the upper short and broad the lower narrower and pointed, 1.2-4 mm long. The papilionaceous corolla is blue to purple, rarely white. The banner is 12-25 mm long and the wings and keel shorter. The fruit is a legume, 2.5-3.5 cm long with 2-14 seeds. American vetch blooms from May to July in a variety of dry, open to moist, shaded habitats; mixed grass prairie, sagebrush steppe, meadows, pine forest, and deciduous woodlands throughout South Dakota.

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  Fumariaceae : Dicentra cucullaria

  R. Neil Reese

  Dicentra cucullaria is perennial herb, which grows 6 cm to 30 cm in height, with the flower stems and basal leaves rising directly from a scaly rootstock. The erect to ascending basal leaves have long petioles (5-15 cm}, the compound pinnatifid blades are ovate to triangular, 10-26 cm long, divided 2-3 times into lacy segments 1-3 mm wide, with entire margins. The flowering stems (scapes) are 10-30 cm tall, terminating in a raceme of 3-15 flowers, subtended by whitish bracts. The flowers are shaped like pantaloons. The 2 membranaceous sepals are white, sometimes streaked with purple, 2-3.5 mm long and 1.5-2.5 mm wide. The 4 white petals are yellow tipped, the outer 2 petals are spurred 10-15 mm long, the inner pair, oblanceolate, 7-12 mm long and convergent coherent at the top. The fruit is a capsule, 10-15 mm long, 3-6 mm in diameter. Dutchman’s breeches bloom from March into May in moist woods in eastern South Dakota.

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  Gentianaceae: Frasera speciosa

  R Neil Reese

  Frasera speciosa is perennial herb with a simple, erect stem, 20–150 cm in height, that is smooth to having a covering of tiny, scattered hairs. It grows from a woody base surrounded by a rosette of large oblanceolate leaves that measure 7–25 cm long. The lanceolate cauline leaves are whorled, smaller and more linear than the basal leaves. The inflorescence is a tall, erect panicle with flowers densely clustered at the top and spread out in separated clusters below. The numerous whorls of flowers are each subtended by gradually reduced, leafy bracts. The flowers have a calyx of 4 narrow, green pointed sepals, 8–15 mm long, and a corolla of 4 broad, yellow green pointed petals, 1-2 cm long, each with purple spots and two fringed nectary pits at the base. There are four stamens tipped with large anthers and a central ovary. The plant is monocarpic, growing as a rosette of leaves for several years and only producing a flowering stem once before it dies. The fruit is an oblong capsule, 1–2 cm long. Monument plant blooms from May to August depending upon elevation. It grows in meadows, woodlands, and mountain forests, primarily at moderate to high elevations in western South Dakota.

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  Gentianaceae: Gentiana affinis

  R. Neil Reese

  Gentiana affinis is a perennial, herbaceous plant with a fibrous root system and short rhizomes, forming low clumps. Mature plants typically reach 10–40 cm in height. Stems are erect, slender, and usually unbranched, with a smooth surface. Leaves are opposite or whorled, simple, lanceolate to elliptic, 2–8 cm long and 0.5–2 cm wide, with entire margins and acute tips. Leaf surfaces are dark green and glabrous on both sides. Petioles are absent or very short. Flowering occurs from July to September, with solitary or paired, large, tubular, trumpet-shaped flowers about 3–5 cm long. Flowers are typically deep blue to violet, sometimes with lighter markings, and remain closed or only slightly open at the mouth (hence “closed gentian”). The calyx is composed of five green sepals, 10–15 mm long, lanceolate and free or slightly fused at the base. The corolla is tubular with five lobes, 30–50 mm long, with a smooth texture and slightly flared tips. Stamens number five, attached to the corolla tube, with yellow anthers. The pistil is single, with a superior ovary, slender style, and capitate stigma. The fruit is a dry, dehiscent capsule, 15–25 mm long, containing numerous small seeds, maturing from late summer to early fall. Prairie gentian is native to South Dakota and is found in western prairies, open meadows, and rocky slopes, favoring well-drained, sandy to loamy soils in full sun to partial shade.

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  Gentianaceae : Gentiana andrewsii

  R. Neil Reese

  Gentiana andrewsii is perennial herb growing 10-70 cm tall, the stems smooth to minutely hairy. The simple, opposite leaves are 1.8-8.4 cm long and 0.5-3.5 cm wide, sessile, tapering to a point, and the leaves tend to become larger as they ascend the stem. The inflorescence is a dense terminal cluster of flowers, occasionally with additional clusters in the axils of upper nodes. The calyx tube is 10-12 mm long with 5 lanceolate lobes 4-10 mm long. The blue to purplish, occasionally white, corolla forms a 2.8-4 cm long, closed tube, the petals incurved, with the flowers resembling large buds. The fruit is a capsule, ~25 mm long, and wrapped with the dried petals and contains numerous winged seeds. Closed bottle gentians bloom in August and September in wet meadows, prairies and woods in western and northeastern South Dakota.

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  Gentianaceae : Gentiana puberulenta

  R. Neil Reese

  Gentiana puberulenta is a perennial herb with simple, erect to ascending stems, rarely branched, the stems typically reddish tinged, with a covering of minute, soft hairs, and growing 15-50 cm in height. The simple, opposite leaves are sessile to subsessile, lanceolate, 1-5.5 cm long and 0.3-2 cm wide, with entire margins. The leaf pairs are at right angles to those above and below. The inflorescences are in clusters of 3-10 flowers at the top of the stem and sometimes also in the upper leaf axils. The calyx forms a tube, 7-18 mm long with lobes, 4-18 mm long. The blue purple to rose-violet corolla is funnel-shaped, 3-4 cm long, with the lobes erect to spreading. Inside the tube, the base of the petals is white with dark blue stripes or streaks. The fruit is a capsule that contains numerous winged seeds. Downy gentian blooms from August into October in drier prairies and upland woods on the eastern and western borders of South Dakota.

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  Geraniaceae: Erodium cicutarium

  R. Neil Reese

  Erodium cicutarium is an annual or biennial taprooted herbaceous species that initially forms a rosette with stems that typically grow 10–50 cm tall. The stems are slender, often reddish or purplish, and may be hairy or smooth. Leaves are 3–10 cm long, pinnately divided with narrow lobes, giving a fern-like appearance. Flowering occurs from spring through late summer (April–September). The flowers are borne singly or in small clusters on slender stalks. Flowers are small, typically 1–2 cm across, with five pink to purple petals that measure 10 to 15 mm in length and about 4 to 7 mm in width. Their edges are smooth, and the petals have a delicate, slightly translucent texture that enhances the visibility of the darker venation. The sepals are generally smaller than the petals, measuring about 6 to 9 millimeters long and 1.5 to 3 millimeters wide. They are often covered with fine hairs, giving them a slightly fuzzy appearance. Flowers are bisexual, with five stamens and a pistil. Fruit is distinctive: a long, beak-like style attached to a small seed capsule, this "stork's-bill" shape aids in seed dispersal by “catapulting” seeds away. Common Stork’s-bill is introduced and widespread in South Dakota, growing in disturbed sites, roadsides, fields, and grasslands, especially in drier areas.

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  Geraniaceae: Geranium carolinianum

  R. Neil Reese

  Geranium carolinianum is a winter or summer annual, or occasionally a biennial, herbaceous forb that develops from a shallow, fibrous taproot system. The plant typically grows to a height of 10 to 40 centimeters (occasionally up to 65 centimeters), producing erect, loosely ascending, or sprawling, multi-branched stems that are round, frequently pinkish red to reddish-brown, and covered in dense, short, downward-pointing or spreading white hairs. Leaf insertion is primarily alternate along upper branches but opposite below. The leaves are simple, grayish-green, and round to kidney-shaped, measuring 2 to 7 cm in length and width. They are deeply palmately cleft into 3 to 9 primary lobed segments, which feature bluntly toothed or secondary narrow-oblong ultimate segments. Both the upper and lower leaf surfaces are finely pubescent and hairy. Long, hairy petioles are present on lower leaves (often exceeding several centimeters), while upper leaves have much shorter petioles; pairs of small, pointed stipules are present at the nodes and leaf bases. Flowering occurs from March to July in tight, compact, or loose terminal umbel-like clusters roughly 1 to 3 cm across. Each flower features 5 free, green, ovate sepals that are 4 to 8 mm long, heavily pubescent, and adorned with distinct, stiff, pointed awn-tipped or bristle-tipped apexes. The corolla contains 5 free, pale pink, lavender, or white petals that are 4 to 8 mm long (roughly equal to or slightly shorter than the sepals), radially symmetrical, and often notched or slightly indented at the apex. Inside the corolla are 10 fertile, glabrous stamens arranged in two whorls, featuring yellowish-white filaments and small, purplish anthers. The single compound pistil contains a 5-lobed superior ovary connected to an elongated, fused central style column with 5 yellow, spreading stigma branches. The fruit is a dry schizocarp, resembling an upraised crane’s bill, measuring 19 to 25 mm long including the elongated style column or beak. It matures from late spring through mid-summer, splitting from the base into 5 dark brown, hairy, single-seeded mericarp sections. Carolina crane's-bill is native to South Dakota, where it can be found in scattered locations across the state, particularly in the southern and western counties (such as Pennington County), thriving in dry, gravelly, or sandy soils, open fields, disturbed areas, rocky woods, and prairies.

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  Geraniaceae: Geranium richardsonii

  R. Neil Reese

  Geranium richardsonii is a perennial herbaceous forb that grows from a stout, woody taproot and develops a branched, rhizomatous caudex over time. The plant typically reaches a height of 30 to 90 cm, having erect or ascending stems that are glabrous to sparsely hairy near the base but become heavily clad in sticky, glandular-tipped hairs throughout the upper canopy. Leaf insertion along the stem is opposite, though the plant also maintains a robust mound of basal leaves on elongated petioles measuring 5 to 30 cm in length. The leaves are simple, light to deep green, measuring 3 to 15 cm in width, and are deeply palmately cleft 75% to 85% of the way to the base into 3 to 7 primary, sharply toothed, rhombic lobes. Both the upper and lower leaf surfaces are covered in soft, fine puberulent hairs; pairs of lanceolate, slender stipules are present flanking the leaf bases at the nodes. Flowering occurs from June to August in loose, terminal, few-flowered cymes or two-flowered pseudo-umbels. Each flower contains 5 free, green, overlapping sepals that are 6 to 11 mm long, densely glandular-pubescent, and terminate in a distinct, stiff awn-tip 1 to 3 mm long. The corolla is composed of 5 free, distinctively spreading, white to pale lavender-pink petals that are 10 to 18 mm long, and are roughly 1.5 to 1.8 times longer than they are wide. The petals have rounded or slightly notched apexes and prominent purple or pink veins tracking down to a soft-hairy adaxial base. Arranged within the corolla are 10 fertile stamens measuring roughly 6 to 8 mm long, which possess cream-colored filaments and contrasting purple to blue-tinged anthers. The single compound pistil features an elongated, superior, 5-lobed ovary connected to a central style column that separates at the tip into 5 slender, spreading, pink-to-purple stigma branches. The resulting fruit is a dry, elongated schizocarp resembling a crane's bill, measuring 20 to 28 mm long. It matures from late summer into autumn, splitting elastically from the base into 5 separate, single-seeded, glandular-puberulent mericarp bodies. Richardson's geranium is native to South Dakota, where it occurs primarily within moist forest drainages, shaded canyons, and riparian meadows of the central and northern Black Hills region.

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  Geraniaceae: Geranium viscosissimum

  R Neil Reese

  Geranium viscosissimum is a perennial herb growing with 1 to a few branching stems that form clumps. The stems, 30-90 cm tall, generally have short, stiff hairs below and longer hairs toward the top near the flowers, with glands throughout, the foliage is sticky to the touch. The petiolate leaves are mostly basal, with flat stiff hairs and glands that exude the sticky substance. The blades are 5-10 cm wide, palmately lobed with 5-7 sharply toothed divisions. The few culm leaves are mostly opposite, nearly sessile and somewhat smaller than the basal leaves. The inflorescence consist of small clusters of two to several pedicellate flowers attached to axillary peduncles. The 5 sepals are 8-12 mm long, pointed with short hairs on the tips. The 5 petals are pink to purple, 14-20 mm long, with long hairs toward the base and darker stripes converging on the center. There are 10 fertile stamens and a 5-parted style. The fruit are capsules with glandular-stiff-hairs and are shaped like an upraised crane's bill. Sticky geranium blooms from May into August in open woods and along streambanks in western South Dakota.

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  Hydrophyllaceae : Hydrophullum virginianum

  R. Neil Reese

  Hydrophyllum virginianum is a rhizomatous perennial herb with stems growing 10 to 90 cm in height. It has basal and alternate cauline leaves that are deeply pinnately divided, 5-30 cm long and 5-15 cm wide, with 5-9 ovate lanceolate to rhombic segments, each up to 11 cm long with the lowest pair distinct. The petioles are 5- 25 cm long and the leaf blades often have white markings that look like water spots. The inflorescence consists of 1-several subcapitate clusters of flowers, the peduncles 2-20 cm long, lifting the flowers above the leaves, and each flower has a pedicel up to 1 cm in length. The 5 linear lobes of the calyx are 4-7 mm long and have hairs along the edges. The bell-shaped corollas are white to purple, the tube 3-5 mm long with 5 lobes 3-5 mm long. The stamens are exerted 4-8 mm beyond the petals and the style is exerted by 5-10 mm. The fruit is a 2-seeded capsule. Waterleaf blooms from May into July in mesic woodlands in eastern South Dakota.

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  Iridaceae : Iris missouriensis

  R. Neil Reese

  Iris missouriensis is a rhizomatous perennial herb with erect, leafless. flower stalks (scapes) 25-60 cm tall. The basal leaves are linear, 25-45 cm long and usually less than 1 cm wide. The 1-2 flowers emerge from a spathe, 5-7.5 cm long. Each flower has 3 light to dark blue, spreading or reflexed sepals, 4-6 cm long, lined with purple and with a whitish blotch at the base, and three smaller, upright blue petals. There are 3 stamens opposite the sepals. The fruit is an oblong, 6 angled capsule, 5-8 cm long. Western blue flag blooms in June and July in wet meadows, along streambanks and open woodlands in western South Dakota.

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  Iridaceae: Sisyrinchium campestre

  R. Neil Reese

  Sisyrinchium campestre is a perennial herb growing 15 to 40 cm tall from a fibrous root system with short rhizomes. The stems are slender, erect, and smooth or slightly rough. Leaves are narrow, grass-like, linear to lanceolate, typically 10 to 25 cm long and 2 to 5 mm wide, with entire margins. The upper and lower leaf surfaces are smooth and bright green. The plant blooms from May through July. The inflorescence consists of a solitary flower or a cluster of a few flowers at the top of a stem. The flower stalks are enclosed within 2 leaf-like bracts, green to purplish brown, the outer one 3-5 cm and the inner one about half as long. Flowers are star-shaped, about 15 to 25 mm in diameter, with six tepals (petal-like segments) that are pale blue to light violet with a yellow base. Each tepal is about 7 to 12 mm long and 3 to 5 mm wide, with a smooth texture and entire margins. There are six stamens per flower, forming a column of with filaments about 5 to 7 mm long and yellow anthers about 2 to 3 mm long. The pistil consists of three fused carpels forming a compound ovary with three locules, a style about 5 to 6 mm long, and a trifid stigma. The fruit is a 3-lobed capsule about 6 to 8 mm long that ripens from July to August, releasing numerous small seeds. Prairie blue-eyed grass is native to the eastern parts of South Dakota, commonly growing in prairies, open woods, and meadows.

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  Iridaceae: Sisyrinchium montanum

  R. Neil Reese

  Sisyrinchium montanum is a perennial herb growing 15 to 40 cm tall from a fibrous root system with short rhizomes. The stems are winged, slender, erect, and smooth to slightly rough. Leaves are narrow, grass-like, linear to lanceolate, typically 10 to 25 cm long and 2 to 5 mm wide, with entire margins. The upper and lower leaf surfaces are smooth and bright green. The plant blooms from May through July. The inflorescence consists of solitary or small clusters of star-shaped flowers about 15 to 25 mm in diameter, initially enclosed in ovate to lanceolate bracts that are smooth in texture, and measure 10 to 20 mm long. The spathe bracts are positioned opposite each other at the base of the flower cluster and often have a slightly membranous margin. Each flower has six tepals that are pale blue to violet with a yellow base. Tepals measure about 7 to 12 mm long and 3 to 5 mm wide, with a smooth texture and entire margins. There are six stamens per flower, with filaments about 5 to 7 mm long and yellow anthers about 2 to 3 mm long. The pistil consists of three fused carpels forming a compound ovary with three locules, a style about 5 to 6 mm long, and a trifid stigma. The fruit is a 3-lobed capsule about 6 to 8 mm long that ripens from July to August, releasing numerous small seeds. Mountain blue-eyed grass is native to South Dakota, commonly found in moist meadows, open woods, and along streambanks, mostly in the northern and western parts of the state.

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  Lamiaceae: Agastache foeniculum

  R. Neil Reese

  Agastache foeniculum is a perennial rhizomatous herb, which grows 0.6 m to 1 m in height. The stems are square with opposite ovate to broad to lanceolate simple leaves, greenish above and whitish underneath due to fine, appressed hairs the leaf margins are finely toothed. When crushed the leaves smell of anise. Flowers open in July and August and are arranged in a terminal spike-like raceme. The tubular calyx is 5 toothed 5-7 mm long and lavender toward the tips. The corolla is 2-lipped 7-10 mm long and lavender to bluish-purple in color. Stamens 4 and exerted from corolla. Pistil with 2 carpels with a 2-part style. Fruit are 4 nutlets. Lavender hyssop blooms from June through September. This species is commonly found in upland woods and prairies in both eastern and western South Dakota.

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  Lamiaceae: Glechoma hederacea

  R. Neil Reese

  Glechoma hederacea is a perennial, creeping herbaceous plant that spreads by stolons, forming dense mats on the ground. Stems are square in cross-section, typically reaching 10–50 cm in length, hairy, and spreading laterally or creeping along the soil surface, often rooting at nodes. Leaves are opposite, rounded to kidney-shaped with scalloped edges, 2–4 cm across, and aromatic when crushed. Flowering occurs from spring to early summer (April–June). The flowers are small, tubular, and bilaterally symmetrical, borne singly or in small clusters from leaf axils. They are typically light purple to bluish with darker purple markings on the lower lip. Each flower has five sepals and five petals. The sepals form a tubular calyx about 0.5–1 cm long, with five pointed lobes that are lanceolate in shape. The petals are fused into a two-lipped corolla about 1–1.5 cm long: the upper lip is hooded and two-lobed, while the lower lip spreads out and is three-lobed with a slightly notched center lobe. Flowers are bisexual with four stamens and a single, superior ovary formed from two fused carpels, which develops into a four-lobed schizocarp fruit that splits into four one-seeded nutlets that mature in late summer. Ground ivy is introduced and widespread in South Dakota, found in lawns, gardens, roadsides, and shaded disturbed areas.

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  Lamiaceae: Lamium amplexicaule

  R. Neil Reese

  Lamium amplexicaule is an annual herbaceous plant growing 10 to 40 cm tall with a fibrous root system. The stems are square in cross-section, sprawling to ascending, and covered with fine hairs. Leaves are opposite, simple, and broadly ovate to orbicular with rounded or slightly lobed margins, measuring about 2 to 5 cm long and wide. Leaves are sessile, clasping the stem (amplexicaul). The leaf surfaces are hairy and rough to the touch. The inflorescence consists of whorls of tubular, two-lipped flowers arranged in leaf axils, flowering from early spring to early summer (March–June). The calyx is composed of five sepals fused into a tubular cup about 5 to 8 mm long, with five pointed lobes that are ovate-lanceolate in shape and covered with fine hairs. The corolla is bilabiate, about 1 to 1.5 cm long and 0.5 to 0.8 cm wide, with the upper lip forming a hood that is broadly ovate and rounded, while the lower lip is three-lobed with the central lobe being the largest and slightly notched. The petals are pink to purple with darker markings on the lower lip. The flowers have four stamens, two long and two short, and a superior ovary with a bifid style. The fruit is a schizocarp that splits into four nutlets. In South Dakota, Henbit deadnettle is an introduced species, native to Eurasia, commonly found in disturbed sites, lawns, gardens, fields, and roadsides statewide.

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  Lamiaceae: Lamium purpureum

  R. Neil Reese

  Lamium purpureum is a winter annual, herbaceous dicot supported by a shallow, ultra-fine fibrous root system. The plant typically reaches a height of 10 to 30 cm. Its stems are sharply four-angled (square), mostly hollow, and branched at the base before growing erect. Leaf insertion is opposite along the stem. The simple leaves are broad-ovate to cordate, 1 to 4 cm long and wide, featuring deeply rounded-toothed margins and a blunt apex. While lower leaves are medium green, the upper leaves are densely crowded and conspicuously tinted with a reddish-purple hue. Both upper and lower leaf surfaces are covered in fine, soft hairs with prominent, wrinkled reticulate veining. A petiole is present, measuring 1 to 3 cm long on lower leaves, but becoming much shorter or nearly sessile on the topmost purple-tinted floral bracts. Flowering occurs primarily in early spring through mid-summer (March to July), though it can bloom sporadically during any mild period. The inflorescence consists of dense, multi-flowered axillary whorls stacked vertically at the stem apex to form a compact, leafy spike. The calyx consists of 5 fused sepals that form a tubular base roughly 5 to 7 mm long, terminating in 5 narrow, free, lanceolate, hair-fringed teeth that spread wide as the fruit develops. The corolla consists of 5 fused petals forming a two-lipped, elongated tube measuring 10 to 15 mm long. It is pinkish purple to lavender, with a hood-like upper lip that arches and a spreading, 3-lobed lower lip marked with deeper purple spots. Tucked beneath the hooded upper lip are 4 stamens arranged in two unequal pairs (didynamous); they bear small, dark purple, hairy anthers with pale yellow pollen. The single pistil consists of a superior, deeply 4-lobed ovary and a slender style that splits into 2 equal stigma lobes at its tip. The fruit is a dry schizocarp that splits into 4 distinct, 3-angled, club-shaped, obovoid nutlets. These nutlets measure 2 mm long, are greyish brown with small white speckles, and reach full maturity from May through August. Purple deadnettle is not native to South Dakota. It is an introduced species native to Eurasia and North Africa. In South Dakota, it is naturalized across scattered counties, predominantly in agricultural regions, urban settings, and eastern river valleys. It is commonly found in disturbed habitats, including home lawns, gardens, cultivated crop fields, nursery plots, parklands, and roadside ditches.

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  Lamiaceae: Leonurus cardiaca

  R. Neil Reese

  Leonurus cardiaca is a perennial herbaceous plant growing 0.5 to 1.5 meters tall. It has a fibrous root system with occasional short rhizomes. The stems are square in cross-section, erect, and typically covered with fine hairs. Leaves are opposite, simple, and palmately lobed with 3 to 5 deep lobes, measuring about 5 to 12 cm long and wide. Leaves are petiolate, with petioles approximately 2 to 5 cm long, and the leaf surfaces are sparsely to moderately hairy. The leaf margins are coarsely toothed. The inflorescence is a dense, interrupted spike of whorled flowers around the stem, flowering from mid to late summer (June–August). The calyx consists of five sepals fused into a tubular base about 4 to 7 mm long with five triangular-ovate, pointed lobes covered in fine hairs. The corolla is tubular, bilabiate, measuring about 8 to 12 mm long and 5 to 7 mm wide, with a hooded upper lip and a three-lobed lower lip; the petals are pink to purplish in color. Flowers have four stamens, two long and two short, and a superior ovary with a bifid style. The fruit is a schizocarp that splits into four nutlets. Motherwort is an introduced species native to Europe and parts of Asia. In South Dakota, it is found scattered in disturbed habitats, roadsides, and fields throughout the state.

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  Lamiaceae : Mentha arvensis

  R. Neil Reese

  Mentha arvensis is an aromatic, perennial, rhizomatous herb with square, simple to branched, ascending to erect stems growing from 30-90 cm tall. The stems are usually hairy to nearly smooth with rings of hairs at the nodes. The simple, opposite leaf blades are lanceolate to ovate, 2.5-12 cm long and 5-40 mm wide, slightly small toward the top, with the upper surface generally without hairs and the lower surface with hairs along the veins. The margins are toothed with hairs along the edges and the petioles are 3-15 mm long. The inflorescence consist of paired 8-30 flowered cymes in the axils of leafy bracts. Each flower with a pedicel 1-3 mm long. The 5-lobed hairy calyx is tubular to bell-shaped, 2.5 -3.3 mm long, with teeth about ¼ length of the tube. The weakly bilabiate corolla is whitish to lavender in color, 4.5-6.5 mm long. The 4 stamens and the style are exerted from the corolla by 1-2 mm. the fruit are 4 nutlets. Field mint blooms from July into September in moist shaded sites, streambanks, lake shores and marshes throughout South Dakota.

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  Lamiaceae: Monarda fistulosa

  R. Neil Reese

  Monarda fistulosa is an aromatic, rhizomatous perennial herb with simple to branched, square stems, 30-120 cm tall, the upper portions hairy. The simple, opposite leaves are petiolate (10-25 mm long). The blades are lanceolate to ovate, 2-5 cm long and 4-20 mm wide, with small glands, a pointed tip, and toothed to subentire margins. The inflorescence is a terminal cluster of flowers on the main stem and branch ends, 1-5 cm wide, excluding the corollas, and subtended by green to whitish bracts, 1-2.5 cm long. The calyx forms a hairy tube, 5.5-11 mm long with teeth up to 1.5 mm long. The pale to dark lavender (rarely white) bilabiate corolla is 2-3.5 cm long, the outer surface hairy, the tube at the base slender, 15-25 mm long, the upper lip erect and shorter than the tube, and the lower lip is spreading, 3-lobed. The stamens are exerted from the upper lip. The fruit are 4 brown to black nutlets, 1.5-2 mm long. Beebalm blooms from June into September on prairie hillsides, along roads and open woodlands in most of South Dakota.