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  Nymphaeaceae: Nuphar lutea

  R. Neil Reese

  Nuphar lutea is a perennial aquatic plant with stout, creeping rhizomes anchored in muddy substrates of freshwater ponds, lakes, and slow-moving streams. The floating leaves are orbicular to ovate, 10 to 25 cm long and 8 to 20 cm wide, with a heart-shaped base, thick and leathery with smooth margins and a smooth, glossy upper surface. The solitary flowers, borne on thick stalks rising above the water, have 4 to 6 broadly ovate sepals measuring 15 to 25 mm long, enclosing numerous bright yellow petals about 10 to 15 mm long and 3 to 5 mm wide, which are oblong to spatulate in shape and arranged in multiple layers. The flower contains 40 to 60 stamens with slender filaments and yellow anthers arranged in several concentric whorls around numerous free pistils. Each pistil has a short style and a small, rounded stigma. The fruit is an aggregate of achenes embedded in the spongy receptacle, maturing underwater into a berry-like structure, 3–6 cm in size, containing many small seeds released gradually as the fruits disintegrate. Yellow waterlily, as recognized by the USDA, is native to South Dakota, found in some natural and artificial wetlands, ponds, lakes, and slow-moving waters.

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  Oleaceae: Fraxinus pennsylvanica

  R Neil Reese

  Fraxinus pennsylvanica is a large tree reaching 20 m tall with dark gray to brown, furrowed bark. The younger branches go from greenish with white lenticels (pores) to brown to gray and can be smooth to hairy. The petiolate, opposite leaves are compound odd-pinnate,11-30 cm long, with 5-9 leaflets. The leaflets are lanceolate to elliptic, 6-15 cm long and up to 5 cm wide, with short stalks. The first pair of leaflets is usually the shortest. The margins usually have small teeth, the upper surface is dark green and smooth and the lower surface is paler with short hairs along the midvein or across entire surface. The trees are dioecious, having either male or female flowers. The inflorescences consist of panicles, 3-5 cm long, in the axils of leaves on the first year branches. The flowers have an irregularly toothed, cup-shaped calyx, no petals and either 2-3 stamens or a pistil with a long style. The fruit is a tan, narrowly oblanceolate single samara. Green ash blooms in April and May in flood plains, ravines and along stream and lake shores throughout South Dakota.

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  Onagraceae : Calylophus serrulatus

  R. Neil Reese

  Calylophus serrulatus is a perennial herb with few to many simple to branched, decumbent to erect stems, 5-80 cm long. The simple, alternate leaves are linear to lanceolate, 1-10 cm long and 1-12 mm wide, smooth to slightly hairy on top and generally hairy on the under surface. The blades are sessile to semipetiolate, the leaf tapering to the base and having a pointe tip, with margins that are entire to toothed. The 4-merous flowers are axillary in the upper parts of the stems. The sepals are 1.5-9 mm long and 2-6 mm wide, distinctly keeled, hairy below, with free tips 1-4 mm long. The 4 yellow petals are 5-20 mm long and about as wide. There are 2 series of stamens, one attached to the sepals and the other the petals, the former longer than the latter, and the stigma is ~2 mm wide in the center of the flower. The fruit is a capsule, 10-30 mm long and 1-3 mm wide. Yellow sundrops bloom from May into September on roadsides in rocky to sandy prairies and open woodlands in much of South Dakota.

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  Onagraceae : Chamerion angustifolium ssp. circumvagum

  R. Neil Reese

  Chamerion angustifolium ssp. circumvagum is a stout, erect perennial herb with simple to branched, red stems growing up to 3 m tall, that are smooth to occasionally having short, stiff hairs toward the top. This plant has an large root system, producing extensive colonies by forming shoots on lateral roots. The alternate leaves are lanceolate, with an acute tip, 2-20 cm long and 4-35 mm wide and arranged in a spiral. The leaves are sessile or nearly so, with a strong midvein and margins that are usually wavey. The inflorescence is a terminal many-flowered raceme. The slightly irregular flowers are drooping in the bud, the 4 spreading, green to purple sepals are lanceolate, 7-16 mm long and less than 3 mm wide. The 4 pink to magenta petals are obovate, tapering to a short claw, 10-20 mm long and 6-11 mm wide, usually with a notch. There are 8 slightly unequal stamens surrounding a pistil with a densely white haired ovary 8-18 mm long atop of a pedicel 4-12 mm long, with a white to purplish style, 10-20 mm long, with a ring of hairs at its base and topped by a 4-lobed stigma. The fruit is a capsule 4-10 cm long on a pedicel up to 2.5 cm long, containing may long-haired seeds. Fireweed blooms from June through September in open woodlands and disturbed areas, especially after fires in western South Dakota.

  Synonyms: Epilobium angustifolium, Chamaenerion angustifolium

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  Onagraceae: Epilobium ciliatum

  R Neil Reese

  Epilobium ciliatum is a perennial herb with erect, simple to branched stems, 5-120 cm in height, green, hairless on the lower portions of the stem and the upper stem with a covering of short hairs mixed with glandular hairs, often in lines running down from the leaves. The leaves are mostly opposite toward the base and alternate on the upper stem, the lower leaves are smooth, obovate with distinct petioles and broader than the upper lanceolate leaves that are nearly sessile and sparsely covered in short hairs mixed with glandular hairs, especially along the midvein. The blades are 3-12 cm long and 5-45 mm wide, blunt to pointed at the tip, and the margins have small widely spaced teeth. The flowers are single at the ends of stems and in the upper leaf axils, atop a short peduncle, <12 mm>long, followed by a slender ovary, about 25 mm long, that is slightly wider than the peduncle. The 4 small, greenish red sepals that cup the flower are 1.5-5 mm long. The sepals, peduncle and ovary are all variously covered in short hairs mixed with gland-tipped hairs, often in lines. The 4 petals are white to pink to rose-purple, notched and < 5 mm long. There are 8 unequal stamens surrounding a white, club-shaped style. The fruit is a long, slender capsule, 4-10 cm long, drying to brown then splitting lengthwise from the top down in 2 to 4 segments. The seeds are brown, 1-1.5 mm long with a tuft of long, white hairs. Fringed willowherb blooms from July into September in moist, often disturbed sites scattered throughout South Dakota.

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  Onagraceae : Oenothera biennis

  R. Neil Reese

  Oenothera biennis is a biennial herb with greenish, erect branching stems 50-200 cm tall, often covered with hairs. The first year plants form rosettes of petiolate leaves, oblanceolate to spatulate, 6-30 cm long, 1-7 cm wide, with an entire to wavey margin and pointed tips. The second year the stems elongate and the cauline leaves are alternate, lanceolate to oblanceolate, 1-10 cm long and 4-20 mm wide with wavey to sparsely toothed margins and pointed tips. The lower stem leaves petiolate, becoming reduced in size and sessile toward the top. The inflorescence is a terminal spike, sometimes with branches, the flowers subtended by hair covered bracts 1-3 cm long. The flower buds are erect and open near sunset. The slender, greenish yellow floral tube is is 2-5 cm in length, with a scattering of hairs. The 4 linear-lanceolate sepals are 1-2.5 cm long with free lobes 1-4 mm long. The 4 yellow obovate petals are 1-2.5 cm long, notched, and become reddish before wilting. There are 8 yellow stamens surrounding a style with a cross-shaped stigma in the center. The fruit is an ascending, hairy, cylindrical capsule, 1.5-3.5 cm long and 3-6 mm in diameter. Common evening primrose blooms From July into October along streams and lakeshores, open woodlands and waste places scattered throughout South Dakota.

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  Onagraceae : Oenothera caespitosa

  R. Neil Reese

  Oenothera caespitosa is a perennial, acaulescent, mound forming herb from a branching caudex. Mature plants are typically 15-25 cm high and up to ~60 cm wide, with lateral roots giving rise to new plants. The leaf blades are oblanceolate to nearly linear, 3-21 cm long, 1-5 cm wide, with a winged petiole that is often as long as the blade. The margins vary greatly from almost entire to pinnately lobed to having irregular teeth that are rounded to sharp. The leaf blades, veins and margins can be variously covered with hairs or with hairs lacking. The flowers are solitary in the leaf axils, open near sunset and have a sweet scent. The floral tube is 3-8 cm long, slender and flared toward the end, often reddish in color. The sepals are 2.5-3.5 cm long lanceolate with pointed tips. The white petals are heart-shaped, 2.5-5 cm long, changing to pink after pollination. The 8 stamens are unequal in length and about 2/3 the length of the petals. The style is about as long as the petals and has a 4-lobed stigma. The fruit is a hard, lumpy, elongated capsule, 2-5 cm long with a constricted end. Gumbo lily blooms from May into August on dry, rocky prairies, hillsides and open woodlands in western and central South Dakota.

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  Onagraceae: Oenothera serrulata

  R. Neil Reese

  Oenothera serrulata is a biennial or short-lived perennial herb growing from a deep taproot with an erect, 30 to 90 cm tall, branched stem often covered in fine hairs. The basal leaves are lanceolate to narrowly ovate, 5 to 15 cm long and 1 to 3 cm wide, with finely serrated (serrulate) margins, and short petioles. The stem leaves are smaller and more linear. Flowering occurs from late spring into mid-summer (May–July). The flowers are large and showy, born singly or in loose clusters on elongating stems, opening in the late afternoon or evening and lasting into the night. Each flower has four sepals, narrowly lanceolate and 10 to 15 mm long, which reflex as the flower opens. The corolla consists of four petals, bright yellow fading to orange with age, each 25 to 40 mm long and 10 to 15 mm wide, broadly obovate to spatulate in shape with a slightly notched apex. The flower contains eight stamens with slender filaments and conspicuous yellow anthers arranged around a single pistil. The ovary is superior with a slender style, about 15 to 20 mm long, terminating in a four-lobed stigma approximately 3 to 4 mm wide; the lobes are elongated and slightly papillose. The fruit is a slender capsule, 4 to 7 cm long, maturing in late summer, containing numerous small seeds. Serrate-leaved evening primrose is native to South Dakota, typically found in sandy or rocky soils of prairies, open woodlands, and disturbed sites across the central and western parts of the state.

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  Onagraceae : Oenothera suffrutescens

  R. Neil Reese

  Oenothera suffrutescens is a perennial herb, usually with several branched stems growing 20-100 cm tall, from a branching caudex and spreading underground stems the generate new plants and form large colonies. The simple, alternate leaves are almost sessile, linear to narrowly elliptic, 5-60 mm long and 1-7 mm wide with a pointed tip, the margins entire to having a few small teeth. The inflorescence is a spike-like raceme, 5-60 cm long on a peduncle that is 1-6 cm long. The zygomorphic flowers appear sessile, each subtended by a bract. The floral tube is 4-12 mm long, with 4 sepals 5-10 mm long and 4 clawed (narrowed) petals 3-9 mm long and 2-4 mm wide, that are initially white, then changing to red-orange or reddish brown. There are 8 stamens, the anthers red or yellow and a central pistil with a style 10-20 mm long topped with a 4-lobed stigma. The fruit is a capsule 4-9 mm long constricted at the base. This species is highly variable in habit, flower color, size and pubescence, with plants ranging from smooth to densely hairy. Scarlet guara blooms from May into August in dry prairies, open wooded hillsides and stream valleys throughout South Dakota.

  Synonym: Guara coccinea

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  Orchidaceae: Corallorhiza striata

  R Neil Reese

  Corallorhiza striata is a perennial saprophytic herb, lacking roots and growing from a much-branched rhizome, with erect stems 15-45 cm tall. The simple stems are succulent, yellow to red to purple to brown, wrapped with membranous bracts, 1-14 cm long. The inflorescence is a terminal raceme, 5-16 cm long with up to 35 flowers loosely arranged and subtended by bracts <4 mm long. The flowers are>nodding, yellow tinged with red to purple stripes. There are 3 narrow sepals, sometimes striped, 5-18 mm long, and 2-5 mm wide and 3, often purplish striped, petals the 2 lateral ones are about the same length as the sepals. The lower petal forms a broad, fleshy, reflexed bilobed lip, 3-16 mm long and 3-8 mm wide. The fruit is an elliptic capsule 1.2-2 cm long. Striped coralroot blooms in May and June in cool, coniferous woodlands in decaying litter in western South Dakota.

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  Orchidaceae: Platanthera dilatata

  R Neil Reese

  Platanthera dilatata is a perennial herb growing 15-70 cm tall. The mostly alternate, lanceolate leaves are cauline, 3-20 cm long and up to 3 cm wide with a pointed tip. the inflorescence is a loose to densely packed raceme, 5-25 cm long with 10-50 flowers, subtended by lanceolate floral bracts 5-40 mm long. The white flowers have 2 broad petal-like sepals that flare laterally, 4-8 mm long. Two lateral petals and an upper sepal form a hood, 4–6 mm long. The lower lip is narrower than the side sepals and initially curves up, touching the tip of the hood, and then flowing downward forming a sac-like to slender spur. The fruit is an ellipsoid capsule 8–15 mm long and 3-4 mm wide. White bog orchid is fairly rare in SD. It blooms in July in swampy forests and wooded bogs in and around Lawrence County in the State.

  Synonym: Habeneria dilatata

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  Oxalidaceae: Oxalis dillenii

  R. Neil Reese

  Oxalis dillenii is a small annual herbaceous plant growing 10 to 30 cm tall with slender, branching stems that are often slightly hairy. The trifoliate leaves are composed of three heart-shaped leaflets, each 1 to 2 cm long and 1 to 1.5 cm wide, with a distinct fold along the midrib and a bright green color. The flowers are borne singly or in small clusters on slender stalks above the foliage, blooming from May through October. Each flower has five green, lanceolate sepals about 4 to 6 mm long and 1.5 to 2 mm wide. The corolla consists of five bright yellow petals, each 8 to 12 mm long and 4 to 6 mm wide, obovate in shape with a rounded apex. The flower contains ten stamens with filaments of varying lengths and yellow anthers arranged around a superior ovary. The pistil has a single style approximately 5 to 7 mm long, terminating in a capitate (head-shaped) stigma about 1 to 1.5 mm wide. The fruit is a cylindrical capsule 10 to 15 mm long and 2 to 3 mm wide, developing after flowering from June through October; it dehisces explosively to release numerous small seeds. Southern Wood-sorrel is considered a native weed in South Dakota. It is difficult to distinguish from Oxalis stricta without a microscopic analysis of mature specimens. Oxalis dillenii has short, dense appressed hairs on the stems. The unbranched flower clusters typically have two flower buds, and the fruits of erect capsules are attached to bent or spreading stalks.

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  Oxalidaceae: Oxalis violacea

  Richard Neil Reese

  Oxalis violacea is a perennial herbaceous plant growing 15 to 40 cm tall from fibrous root system with small corms. The trifoliate leaves consist of three heart-shaped leaflets, each 1.5 to 3 cm long and 1.5 to 2.5 cm wide, with smooth margins and they often have a purplish tint on the underside. The leaves are petiolate with slender stalks 5 to 12 cm long. The flowers are borne singly on slender stalks above the foliage, blooming from April through June. Each flower has five green, lanceolate sepals about 6 to 8 mm long and 1.5 to 2.5 mm wide. The corolla consists of five petals, violet to lavender in color, each 10 to 15 mm long and 6 to 8 mm wide, obovate to broadly spatulate with a rounded apex. The flower contains ten stamens in two whorls with filaments of varying lengths and purple anthers arranged around a superior ovary. The pistil has a single style approximately 6 to 8 mm long, terminating in a capitate stigma about 1.5 to 2 mm wide. The fruit is a cylindrical capsule 12 to 18 mm long and 2 to 3 mm wide, developing after flowering from May through July; it dehisces explosively to release numerous small seeds. Violet wood-sorrel is native to South Dakota, commonly found in moist prairies, open woodlands, and along stream banks throughout the eastern and central parts of the state.

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  Papaveraceae : Argemone polyanthemos

  R Neil Reese

  Argemone polyanthemos is an annual to biennial plant with one to a few stems growing from a taproot. Plants vary greatly in size from 0.25 to 1.25 m in height with stems 7-20 mm in diameter. The stems are waxy with few to many yellowish prickles. The leaves are waxy with the upper surface smooth to bearing scattered prickles on the veins, with more prickles on the lower surface. The lower leaves are oblanceolate, deeply pinnately lobed, 7-25 cm long by 3-10 cm wide. The lobes are elliptical to obovate with undulating irregularly spiney-toothed margins and the petioles are winged. The leaves are reduced and become less lobed toward the top, but the margins are like those of the lower leaves. The flowers are 5-12 cm in diameter and are subtended by 2 bracts that are shorter than the sepals. The 3-6 yellowish sepals are 6-10 mm long. The 6-12 white petals are arranged in 2 rows, 2.5-5 cm long and nearly as wide. The center of the flower is dominated by numerous (~150) yellow stamens and the has 3-5 carpels. The fruit is a capsule 2.5-4 cm by 1-1.5 cm wide. The seeds are shiny, dark brown and round. Prickly poppy blooms from May until September. All parts of the plant have a yellow sap that stains the skin and clothing.

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  Papaveraceae : Sanguinaria canadensis

  R. Neil Reese

  Sanguinaria canadensis is a perennial herb with shallow, extensively branched rhizomes, 6-15 mm in diameter, that contain a red juice. The ends of the rhizome branchjes produce I leaf and 1 flower scape. At anthesis the leaf is usually shorted than the scape, but the petiole and blade rapidly expand and soon over tower the flower scape. The petiole reaches 10-35 cm in length, and the leaf blade becomes 6-20 cm long by 8-20 cm wide. The blade usually 3-7 lobed, almost circular in outline, green on top and waxy below, the margins entire to wavey. The flower forms at the end of a peduncle 5-12 cm long and has 2 rounded, membranous sepals, 2-12 mm long and 5-8 mm wide. The 8 (sometimes up to 16) white petals are oblanceolate to elliptic, 10-30 mm long and 5-12 mm wide, with 4 petals usually slightly larger than the others. The numerous stamens are up to 1 cm long with yellow anthers and the style is 2-lobed. The fruit is a spindle-shaped capsule, 3-5 cm long and 7-11 mm wide, containing ovoid, reddish brown seeds that have a prominent crest. Bloodroot blooms in late March into May on woodland slopes along the eastern edge of South Dakota.

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  Pinaceae: Picea glauca

  R. Neil Reese

  Picea glauca is a tall, evergreen conifer that can reach heights of 20 to 30 meters or more. It has a conical crown with horizontal to slightly drooping branches, a straight trunk with thin, scaly, gray-brown bark. Needles are attached individually and arranged spirally around the twig. They are stiff, sharp, four-sided, 1 to 2.5 cm long, and bluish green to gray green with a whitish waxy coating. Male cones are small, cylindrical, and yellowish, producing pollen released from May to June. Female cones are green when young, maturing to brown in fall, typically 3–7 cm long, with thin, flexible scales. They mature from September through October, with seed dispersal occurring shortly after. The bark, needles, and cones are distinctive to this species. White spruce is native to boreal forests across much of North America, including parts of South Dakota, favoring cooler, moist environments and well-drained soils. Black Hills spruce is a variety of white spruce that is native to a geographically isolated area in and around the Black Hills of South Dakota. It was originally called Picea glauca var. densata, but many experts now designate it as Picea glauca ‘Densata’ because its differences from the species are judged insufficient to justify classification as a botanical variety.

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  Pinaceae: Pinus contorta

  R. Neil Reese

  Pinus contorta is a medium-sized evergreen conifer reaching heights of 15 to 30 meters. It has a narrow, conical crown with dense branches. The bark is thin and scaly on young trees, becoming thick and deeply furrowed with age. Needles occur in pairs (2 per fascicle), are slender and sharp-pointed, 3 to 7 cm long, often twisted and dark green. Male cones are small, cylindrical, 1 to 3 cm long and about 0.5 to 1 cm wide, releasing pollen from May to June. Female cones are oval to conical, 3 to 7 cm long and 2 to 3 cm wide, often serotinous (remaining closed until exposed to fire or heat), they mature over two seasons, changing from a purple green to a light brown color in September or October. Lodgepole pine is native to the Black Hills of South Dakota where it grows in cooler, moist, higher elevation sites, often mixed with ponderosa pine and spruce. It is well adapted to fire ecology.

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  Pinaceae : Pinus ponderosa

  R. Neil Reese

  Pinus ponderosa is a large evergreen tree with a pyramid-shaped crown that broadens with age and can reach 35 m in height. The trunk is straight, gray brown and furrowed when young, becoming scaley and gray mixed with orange brown with age, and the branches are gray black in color. The needle-like leaves are clustered toward the branch tips, usually 3 (2) per fascicle, 8-20 cm long, with small teeth along the margins. The fascicles emerge from a membranous, orange brown, deciduous sheath that is 1.5-2.5 cm long. Ponderosa pines are monoecious, the male cones are yellow orange, cylindrical, 1.5-3 cm long, in axillary clusters of 10-20 cones. The female cones are brown, woody, broadly ovoid, 6-12 cm long, 6-8 cm wide, and mature in the second year. Each cone scale has a thin prickle on the outer side. The seeds are in pairs underneath the scales, 6-7 mm long with a papery wing 3-4 times as long as the seed. The cones release pollen in May and June on low mountains and rocky hillsides in western and southcentral South Dakota.

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  Plantaginaceae : Plantago rugelii

  R. Neil Reese

  Plantago rugelii is a perennial herb growing from a short, erect caudex forming a low rosette of leaves with smooth, slender flowering stalks that can reach 35 cm in height. The leaf blades are broadly elliptic to ovate, 5-20 cm long and ½ to 2/3 as wide, narrowed at the base and rounded to pointed at the tip, with 5-9 major veins and entire to finely toothed margins. The petioles are 2-20 cm long, winged, and reddish toward the base. The inflorescence consists of 1-several terminal spikes, 5-20 cm long, sitting atop the smooth peduncle. Each flower is subtended by bracts 1.5-2.3 mm long, the 4 sepals are 2-2.5 mm long and the corolla forms a white to purple tube with 4 short lobes. The fruit is a capsule 6-8 mm long containing 4-10 black seeds. Blackseed plantain blooms from May into October in moist, often shaded woodlands and parklands along the eastern and western borders of South Dakota. This species is very similar to P. major, an introduced weed common in lawns and gardens throughout the world.

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  Poaceae: Alopecurus pratensis

  R. Neil Reese

  Alopecurus pratensis is a perennial grass in the Poaceae family. It forms dense tufts from a fibrous root system and can also spread via short rhizomes, sometimes forming loose sod. The stems (culms) are erect, simple, and unbranched, typically 40–110 cm in height and are smooth with little or no pubescence. Leaves are mostly basal, soft, flat, and linear, 3–10 mm wide and up to 35 cm long, with a rough texture and finely serrated margins; the ligule is long (up to 8 mm), membranous, and pointed, which is a distinguishing feature. Cauline leaves are fewer and shorter. Inflorescences appear from April to June and are dense, cylindrical spikes (5–12 cm long) that resemble a fox’s tail. Each bisexual spikelet is subtended by two glumes and contains a single floret with one lemma, a short palea, and a straight awn (5–8 mm) extending just beyond the glumes. The fruit is a caryopsis (grain), 2–3 mm long, narrow, and brown at maturity, ripening in early to mid-summer. Meadow foxtail is an introduced, cool-season grass in South Dakota, commonly found in moist meadows, pastures, ditches, and along streambanks, and is most abundant in the eastern part of the state and areas with higher soil moisture.

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  Poaceae: Andropogon gerardii

  R. Neil Reese

  Andropogon gerardii is a perennial warm season bunch grass. Mature plants have a well-developed fibrous root system 2-3 m deep, sending out short rhizomes, forming large dense bunches. The stems grow 1-3 m tall and become purplish toward the base. which grows 5 dm to 20 dm in height. These culms are solid and grooved on one side. The leaves have prominent midribs but are not keeled, many at the base of the plant and a few coming from the culm. The ligule is a fringed membrane 0.4-2.5 mm long. The inflorescence is a raceme of 3 (2-6) narrow racemes alternately arranged along the top of the stem, often looking like a turkey foot. Each raceme contains many pairs of spikelets, each pair having a stalked spikelet with another stalkless spikelet at the base of the stalk. The stalkless spikelet usually has a fertile, perfect floret with an awn, and the stalked spikelet is sterile or has a staminate flower that is awnless. This species is commonly found in pastures, along roadsides, and in open prairies. Big bluestem has green rust-red flowers that bloom from July to October.

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  Poaceae : Bouteloua curtipendula

  R. Neil Reese

  Bouteloua curtipendula is a rhizomatous perennial, warm season bunchgrass, with solid, erect culms arising in clumps. The leaf blades are rolled in the bud, but flat at maturity, 2-30 cm long and 2-6 mm wide. The upper surface is rough to the touch and often has hairs, especially along the margins. The lower surface is smooth. The ligule is fringed to eroded in appearance and less than 1 mm long. The inflorescence consist of 20-45 branches, 5-14 mm long, each with 3-8 spikelets, along the top 15 to 25 cm of the culm. The spikes often fall to one side of the stem, which gives the plant its name. Each spikelet is 4.5 to 10 mm long, with 2 glumes (bracts) and 2 florets, 1 sterile and 1 fertile with orange to brownish red anthers and a feathery 2 white stigmas. The fruit is a 1-seeded grain. Sideoats grama blooms from Jun into August on open grasslands and in woodland openings throughout South Dakota.

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  Poaceae : Bouteloua dactyloides

  R. Neil Reese

  Bouteloua dactyloides is a perennial, strongly stoloniferous, mat-forming grass, with solid culms that grow 3-20 cm in height. The leaves are rolled in the bud and flat at maturity, 1-10 cm long and up to 2 mm wide, smooth except with a few hairs in the collar region. The ligule is a fringe of hairs <1 mm>long, often flanked by long hairs. The plants are dioecious, the male inflorescences are on slender culms Having 2-5 one-sided branches, 7-13 mm long with 2 rows of spikelets each surrounded by 2 unequal bracts (glumes) one 1.4-3 mm the other < 5 mm long , surrounding 2 florets with 3 or fewer stamens. The male inflorescences are often retained into the fall. The female plants produce spikelets in 2-3 burr-like clusters subtended by modified foliage leaves, with 2-3, 1-flowered spikelets per burr. The fruit are grains that are retained in the burr. Buffalograss blooms from April into June in prairies predominantly on western South Dakota.

  Synonym: Buchloe dactyloides

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  Poaceae : Bouteloua gracilis

  R. Neil Reese

  Bouteloua gracilis is a mat-forming perennial grass, growing from short rhizomes, with solid culms reaching up to 50 cm in height. The leaf blades are C-shaped in the bud and flat to slightly rolled at maturity, 1-19 cm long and 0.5-2.5 mm wide. The leaf surfaces are often rough to the touch and may have hairs on one or both sides. The ligule is a short fringe of hairs less than 0.5 mm long. The inflorescence consists of 1-3 branches, 14-40 mm long bearing numerous spikelets. Each spikelet is surrounded by a pair of unequal glumes (bracts) with hairs along the midribs, one < 3.5 mm the other < 6mm long, containing 1 sterile and 1 fertile floret, each with a short awn. Fruit are single seeded grains. Blue grama blooms from June through August on dry prairies and waste grounds throughout South Dakota.

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  Poaceae : Bouteloua hirsuta

  R. Neil Reese

  Bouteloua hirsuta is a tufted perennial grass, with solid, erect and sometimes bent culms, which grow 10 cm to 45 cm in height. The leaves are basal and alternate on the culms, c-shaped in the bud and flat to rolled at maturity. The blades are 5-25 cm long and 1-3 mm wide, with thickened margins and long, white hairs with pimple-like bases on at the base of the blade, on the margins and occasionally on either or both surfaces. The leaf sheath is smooth to hairy, especially near the ligule and the ligule is a fringe of hairs <0.5 mm long. The inflorescence has 1 (occasionally 2+) branch, 15-30 mm long, that has 20 to 50 spikelets arranged on one side of the rachis, tightly packed in 2 rows, with the tip of the rachis extending 5 to 10mm beyond the terminal spikelet. The spikelets each have 2 unequal bracts (glumes) with extended tips (awns) that are green to purple, one <4 mm long and the other 5 to 6 mm long with hairs along the midrib, which enclose one fertile and usually one sterile floret. The fruit is a 1-seeded grain, oblong-elliptic, brown, 2.5 to 2.6 mm long. Hairy grama blooms from July into October in prairies and pastures in southern South Dakota.