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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 : 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: 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.

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  Poaceae: Bromus tectorum

  R Neil Reese

  Bromus tectorum is an annual grass with hollow, erect to ascending stems, 20-60 cm tall, with many soft white hairs on the lower leaves and stems and fewer hairs toward the top. The leaf blades are flat, 1-19 cm long and 1-5 mm wide. The ligule is membranous, 2 to 5 mm long, jagged along the top edge. The inflorescence is a panicle, 4-20 cm long, nodding to one side with arching branches. The lower branches have up to 8 spikelets per branch, with the upper usually with only 1 or 2. The pedicellate spikelets are lance-elliptic, 10 to 25 mm long, with a long awn. The spikelets contain 4-7 florets and one or more of the terminal florets may be sterile. The fruit is a 1-seeded grain. Cheatgrass blooms in May and June in disturbed areas throughout South Dakota.

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  Poaceae: Cenchrus longispinus

  R Neil Reese

  Cenchrus longispinus is an annual grass with solid culms 20-60 cm tall. Multiple culms can be sprawling, ascending or erect, are smooth, often branching and mostly covered by the sheaths. The stem is often reddish at the base and light green above. The ligule is fringed with short, white hairs, 0.6-1.8 mm long. The sheath is contracted where the blade emerges, open at the front, and sometimes with a few long hairs at the constriction. The alternate leaves , 4-14 cm long, 3-7 mm wide, rough on the upper surface, mostly smooth on the lower, flat, folded lengthwise, or rolled up along the edges. The inflorescence consists of terminal and axillary spike-like clusters of burs, 2.5-10 cm long. Each bur has 30 or more spines of various sizes, the largest ones 3-5 mm long. There are with 2 or 3 spikelets per bur and 2 florets per spikelet, 1 fertile and the second staminate of sterile. The fruit are a single grain per spikelet that are retained within the bur. Sandbur blooms from July into September in disturbed ground throughout South Dakota.

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  Poaceae : Hierochloe hirta

  R. Neil Reese

  Hierochloe hirta is a perennial rhizomatous sod-forming grass with erect, hollow, hairless culms that grow 10 to 70 cm in height. The culms appear early in the spring and large tufts of basal leaves follow. The shiny leaf blades are rolled in the bud and flat at maturity, 10-30 cm long and 2-5 mm wide, with the 2-3 alternate culm leaves being much shorter and somewhat narrower, occasionally with hairs at the collar. The ligule of the culm leaves is membranous and 2-3 mm long. the inflorescence is a 4-9 cm long panicle of 3-floret spikelets, with the 2 lower florets having just stamens and the upper one being perfect. The 3 spikelets are surrounded by 2 bracts (glumes) that are usually membranous, hairless and slightly unequal in length. The bracts subtending the individual florets (lemma and palea) are often hairy. Sweetgrass blooms from May into July in wet meadows, sloughs and marshes in the northeastern and southwestern portions of South Dakota.

  Synonym: Anthoxanthum hirtum

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  Poaceae : Panicum virgatum

  R. Neil Reese

  Panicum virgatum is a rhizomatous perennial clump-forming grass, with multiple, erect hollow culms, that grows to 1.5 m tall. The leaves are all alternate, ascending to droopy, the leaf blades flat to rolled upward, 15-55 cm long and 5-11 mm wide, smooth to hair covered, particularly on the upper surface above the ligule. The ligule is 2-4 mm long consisting of a fringe of hairs on a membranous base. The inflorescence is a very open and diffuse panicle, 20-45 cm long, with slightly compressed, purplish spikelets, containing 1 fertile and 1 often staminate floret, surrounded by unequal bracts (glumes), the smaller 2.3-4 mm long and the larger 3.3-6 mm long, narrowly egg-shaped and tapering to a pointed tip. The glumes spread apart as the flower develops, with the stamens and styles becoming visible. A single grain develops in each spikelet. Switchgrass blooms from July through September in moist lowlands and prairies throughout South Dakota.

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  Poaceae : Phleum pratense

  R. Neil Reese

  Phleum pratense is a tufted perennial grass with smooth, hollow, erect, bulbous-based culms that grow 55-140 cm in height. The leaves are rolled in the bud and flattened at maturity. The blades are 3-27 cm long, up to 8 mm wide and occasionally rough to the touch. The leaf sheaths are open with a membranous ligule, 2-5 mm long, V-shaped at the front, white, and ragged at the top. The inflorescence is a cylindrical spike-like raceme of single-flowered spikelets, 2-25 cm long and < 1 cm wide. Each spikelet has a pair of equal bracts (glumes), 3 to 4 mm long including the awn. The fruit is a single grain, often retained within the glumes. Timothy blooms from late May into early August in pastures, along roadsides and in ditches scattered throughout South Dakota. This species was introduced as a forage grass and has become naturalized in many areas.

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  Poaceae : Schizachyrium scoparium

  R. Neil Reese

  Schizachyrium scoparium is a tuft forming, perennial bunchgrass with short rhizomes and solid, slightly flattened culms that grow to 1 m in height. The leaf bluish colored blades are folded and sometimes rolled under, smooth to hair, especially near the collar, 4-30 cm long and up to 4 mm wide. The usually hairless sheath has a keel and the membranous ligule is fringed and < 2.5 mm long. The flowering culms are many branched, each terminating in a single spicate straight to undulating raceme, 2-6 cm long, the rachis and pedicels hairy. The copper colored spikelets occur in pairs, one sessile and perfect with bracts (glumes) 6-9 mm long, the other pedicellate and usually staminate with glumes 3-6 mm long. Little bluestem blooms from July into October on prairies throughout South Dakota.

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  Poaceae : Sorghastrum nutans

  R. Neil Reese

  Sorghastrum nutans is a perennial bunchgrass from a short rhizome with hollow, erect culms, 0.6-2 m tall, that have hairy nodes. The leaf blades are rolled in the bud and flat at maturity, 5-60 cm long, 3-12 mm wide, with a prominent midrib near the base. The sheath is smooth to hairy, with projections from the collar and joined to the firm, membranous ligule that is 2-7 mm long. The inflorescence is a condensed panicle, 11-27 cm long, bearing perfect spikelets with an associated naked pedicel. The inflorescence branches and pedicels are covered with white hairs. The hairy subequal, 5-8 mm long and brownish colored bracts (glumes) surround 2 florets, one fertile one and one sterile with a long, twisted awn. The anther are exerted, 3-5 mm long. Indian grass blooms from late July into October on open prairies scattered throughout South Dakota.

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  Poaceae : Zizania palustris

  R. Neil Reese

  Zizania palustris is an annual, solitary-stemmed grass that can grow to over 2 m tall. The erect culms are round, hollow and smooth except at the nodes where they can be hairy. There are both basal and alternat leaves on the culm. Early leaves float on the water’s surface. The leaf blades are rolled in the bud and flat at maturity, 5-100 cm long and 5-35 mm wide. The leaf sheaths are open, smooth with hairs at the collar and base, with a membranous ligule 7-20 mm long. the inflorescence is a much-branched panicle, 15-60 cm long, with male (staminate) spikelets below and female (pistilate) spikelets above. The branches are initially erect with the staminate ones spreading or drooping at maturity. The male spikelets are reddish in color, with 6 stamens that are 4-6 mm long. The female spikelets are paler, 12-15 mm long with a terminal awn 2.5-6.5 cm long. Both the staminate and pistilate spikelets lack glumes (bracts). The fruit is a dark, slender cylindrical grain up to 30 mm long and 2 mm wide. Northern wild rice blooms in July and August on the margins of streams lakes and ponds along the eastern and southern borders of South Dakota.

  Synonyms: Zizania aquatica var. interior, Z. interior

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  Polemoniaceae : Phlox pilosa

  R. Neil Reese

  Phlox pilosa is a perennial herb from a stout rootstock, with I-several branching stems with 6-12 nodes, growing 20-75 cm tall, covered with simple and/or glandular hairs. The simple, alternate, sessile leaves are narrowly lance-linear, 30-100 mm long, 3-30 mm wide and hairy, especially along the entire margins and the midvein. The inflorescence is a panicle with up to 100 flowers with pedicels usually les than 10 mm long and covered with glandular hairs. The calyx is 8-15 mm long, the tube and 5 lobes about equal in length and covered with glandular hairs. The white, pink or purple corollas have a tube 8-16 mm long with 5 reflexed oblanceolate to obovate lobes 10-12 mm long and 6-8 mm wide. The style is 3-lobed and 1-3 mm long. the fruit is an ovoid capsule. Prairie phlox blooms from May into July in open woods and meadows in eastern South Dakota.

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  Polygonaceae : Eriogonum annuum

  R. Neil Reese

  Eriogonum annuum is an annual to biennial herb with 1 to a few erect, simple to branched stems, 10-100 cm tall and covered with silver-gray hairs. The plants start with a few, short-lived, simple, oblanceolate basal leaves, 2-5 cm long. The alternate, petiolate cauline leaves appear similar to the basal leaves, with most of them toward the base of the stem. The inflorescence is a terminal cyme, often with smaller cymes at the ends of the lower branches. The open cymes have a helicoid, bi or trichotomous branching pattern. The flowers are subtended by a sessile, membranous, calyx-like involucres that are funnel-shaped, 2.5-3 mm long, with shallow teeth. The perianth is composed of 6 white segments, sometimes with a pinkish tinge, the insides are hairy and the outer members are wider than the inner ones. There are 9 stamens and a 3 styles. The fruit are smooth achenes. Annual wild buckwheat blooms from July into September on dry, open grasslands in western and southern South Dakota.

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  Polygonaceae : Eriogonum flavum

  R. Neil Reese

  Eriogonum flavum is a perennial mat-forming herb from a thick, branched, woody caudex, usually having old leaf bases attached. The oblanceolate, petiolate, basal leaves are crowded, 3-8 cm long, 3-14 mm wide, green to grayish due to hairs on the upper surface and hairy beneath. The flowering stems are leafless, 4-25 cm tall, hairy, with leaf-like bracts subtending a compound umbel inflorescence, that have hairy rays up to 3 cm long. the cymose clusters of flowers are subtended by a few reduced bracts. The flowers have a campanulate involucre that is 4-6 mm long with shallow or lacking lobes. The perianth is 6-merous, 4-6 mm long, yellow to sometimes pink tinged, with hairs on the outside, narrowed to a short pedicel-like base. There are 9 stamens and 3 styles that are all exerted from the perianth. The fruit are elongated achenes with a tuft of hair at the top. Yellow wild buckwheat bloom from May into September on dry plains and ridges in western South Dakota.

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  Polygonaceae : Polygonum amphibium

  R. Neil Reese

  Polygonum amphibium is a rhizomatous perennial herb, with floating, prostrate to erect stems, growing to 2 m in length, often hairless when rooted in water or with hairs when growing on dry land. The simple, alternate leaves are 3-20 cm long, 1-8 cm, wide with entire margins, hairy to smooth surfaces, blunt-tipped or tapered to a point, slightly tapered to rounded at the base, sessile to having long petioles on aquatic forms. At the node there is a sheath that can be brown and papery to forming a green collar around the stem. The inflorescence consist of 1 or 2 spike-like racemes, 5-10 cm long, either long and slender or short and more thimble-shaped depending on whether the plant is aquatic or terrestrial. The flowers have 5 pink tepals, 4-5 mm long, with 8 unequal stamens both included and exerted, and 2 styles. The fruit is a lenticular achene 2.54 mm long. Polygonum amphibium is a variable species, with both terrestrial (var. emersa) and aquatic forms (var. stipulacea) that have been formally recognized. In South Dakota both forms can be found, sometimes in the same location, and are treated here as part of a single complex. Water smartweed blooms from June into September in wet places throughout South Dakota.

  Synonyms: Persicaria amphibia, Polygonum coccineum

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  Polygonaceae : Rumex venosus

  R. Neil Reese

  Rumex venosus is a perennial herb from a branching rhizome with erect, branching, reddish, flowering stems that grow 15–40 cm tall. The simple, alternate, petiolate, cauline leaves are lanceolate to ovate, 3–10 cm long with thick leathery blades that are pointed at the tip. The lower most leaves are generally reduced in size. The inflorescence is a panicle with few branches, becoming showy in fruit. The perfect flowers have 2 whorls of tepals 3-4 mm long at anthesis, with 6 stamens and 1 pistil. The outer 3 tepals remain small, the inner tepals (valves), enlarge with the fruit development, becoming reddish, 20–45 mm long orbicular with a cordate-base and lacking growths (tubercles). The fruit are light brown achenes, 5-7 mm long. Wild begonia blooms from April into July on sandy dunes and riverbanks in southern and western South Dakota.

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  Primulaceae : Dodecatheon pulchellum

  R. Neil Reese

  Dodecatheon pulchellum is a perennial herb growing from white, fibrous roots and having erect flowering stems (scapes) that reach up to 50 cm in height. The simple leaves arise from a woody caudex, forming a basal rosette. The oblanceolate to spatulate leaf blades are gradually tapered into a petiole, 4-25 cm long including the petiole, 1-6 cm wide, with entire margins. The inflorescence is a few to many flowered umbel, subtended by a few bracts < 1.5 cm long, with pedicels 1-5 cm long at flowering. The calyx tube is 2-4 mm long with pointed lobes 2-6 mm long. the yellow and red corolla tube has magenta to lavender, reflexed lobes that are 9-20 mm long. the yellow stamens are inserted opposite the corolla lobes, fully protruding and surrounding the style. The fruit is a many-seeded cylindric to ovoid capsule, 7-17 mm long and 4-7 mm wide. Shootingstars bloom in May and June in moist prairie meadows and open woodlands in western South Dakota.

  Synonym: Primula pauciflora

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  Ranunculaceae : Actaea rubra

  R Neil Reese PhD

  Actaea rubra is a perennial herb 50-90 cm tall with a somewhat woody base. Stems usually unbranched, glabrous below and puberulent above. There are 1-3 alternate cauline leaves, pinnate to triternate-pinnate, the largest with a long petiole up to 16 cm long. The leaf blades are 15-35 cm long, the ultimate leaflets are broad and irregularly toothed. The inflorescence is a terminal raceme, 1-3 cm long in flower and up to 10 cm in fruit. The small flowers have 3-5 sepals, 2.4-3.7 mm long and 3-5 (10) white, spatulate petals, < 3.5 mm long, both rapidly lost after the flowers open. Baneberry has numerous stamens and a single pistil. The fruit are red or white 9-16 seeded berries, 7-13 mm in diameter. They bloom in May and June in moist soils in wooded areas along the western and easter borders of South Dakota.

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  Ranunculaceae : Anemone canadensis

  R. Neil Reese

  Anemone canadensis is a perennial herb, which grows 10 cm to 60 cm in height, growing from ascending caudices on long, thin rhizomes. The leaves are basal and mostly long-petioled with 3 to 5 lobes which are sharply toothed. The flowers have 5 (4-6) white, petal-like sepals which are obovate 10–20 mm long by 5–15 mm wide. There are 80-100 yellow stamens surrounding a cluster of pistils. The fruiting body is a cluster of achenes 9-16 mm long by 12-19 mm wide. Meadow anemone blooms from May to July in moist prairies, woodlands and meadows throughout much of South Dakota.