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  Asteraceae: Heliopsis helianthoides

  R. Neil Reese

  Heliopsis helianthoides is a perennial herbaceous plant that grows from a fibrous root system with creeping rhizomes that form dense clumps or colonies over time. The stems are erect, branching and typically reach 60 to 150 cm tall. Leaves are opposite or alternate, ovate to lanceolate, measuring 7 to 15 cm long and 3 to 7 cm wide. The leaf margins are serrated with coarse teeth, and the surface is rough to the touch. Leaves have pointed tips and tapering bases, attaching via short petioles. The plant has a bushy habit. Flowering occurs from mid to late summer (July–September). Inflorescences consist of bright yellow, daisy-like flower heads about 4–7 cm across. Each flower head is surrounded by several series of green, lanceolate to ovate involucral bracts about 10 to 15 mm long, often with fine hairs. The ray florets number about 10 to 20, with petals that are oblong to spatulate, measuring 2.5 to 4 cm long and 5 to 10 mm wide, with smooth edges. Disc florets are tubular, perfect (bisexual), about 3 to 5 mm long, with five lobes at the corolla tip. Stamens are fused into a tube around the style, which divides into two stigmatic branches. The fruit is a small, dry achene, 3 to 4 mm long, with no pappus or with a pappus of short hairs, that matures in late summer. Smooth oxeye is native to South Dakota and commonly found in prairies, open woodlands, and along roadsides and disturbed sites across the state.

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  Asteraceae : Heterotheca villosa

  R. Neil Reese

  Heterotheca villosa is a perennial herb with simple to branched sprawling to somewhat erectnstems, 10-50 cm long, arising singly or in clusters from a taproot. The upper stems are hairy with sessile or stalked resin glands. Leaves are simple, alternate and petiolate toward the base, becoming sessile toward the upper portions of the stems. The middle cauline leaves are oblanceolate, 1-3 cm long and 3-8 mm wide. The inflorescence is flat topped to paniculate with 3-30 heads coming from each branch, with each head surrounded by an involucre of 4-9 series of bracts with a total height of 7-12 mm. there are 20-30 ray flowers , the golden ligules 8-12 mm long and about as many yellow disk flowers, 5-8 mm long. The achenes have an outer scaley pappus and an inn bristly one. Golden aster blooms from July through September on sandy upland sites in both eastern and western South Dakota.

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  Asteraceae: Leucanthemum vulgare

  R. Neil Reese

  Leucanthemum vulgare is a perennial herbaceous plant typically growing 20 to 80 cm tall. It has a fibrous root system with short rhizomes. The stems are erect and glabrous to sparsely hairy. Leaves are alternate and simple, with the basal leaves being spatulate to ovate-lanceolate, measuring about 5 to 15 cm long and 1 to 4 cm wide, and the upper stem leaves becoming smaller and more lance-shaped. Leaf margins are irregularly toothed or lobed, and the surfaces are mostly smooth. Leaves are sessile or have very short petioles, usually less than 1 cm. The inflorescence is a solitary flower head (capitulum) borne on a long peduncle, flowering from late spring through summer (May–August). The flower heads are 3 to 6 cm in diameter, composed of numerous white ray florets approximately 15 to 25 mm long and 4 to 7 mm wide surrounding a central disc of yellow tubular disc florets about 5 to 8 mm long. The flower head is subtended by several rows of green to straw-colored bracts (involucre) that are lanceolate to ovate and typically 10 to 20 mm long. The fruit is a small achene about 2 to 3 mm long. In South Dakota. Oxeye daisy is native to Europe but widely naturalized and considered invasive in South Dakota. It is commonly found in disturbed prairies, grasslands, meadows, roadsides, and disturbed sites.

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  Asteraceae : Liatris aspera

  R. Neil Reese

  Liatris aspera is a perennial herb with 1 or more usually unbranched green or purplish stems arising from a thickened corm-like rootstock and growing 40-120 cm in height. The alternate, simple leaves are petiolate, narrow and blade-like with a prominent central vein and pointed tip, 5-40 cm long and 6 to 40 mm wide at the base of the stem, becoming smaller and sessile upward. The leaves are entire and have a rough texture from a covering of short stiff hairs. The inflorescence is an elongate and spikelike cluster of campanulate heads, 1.5-2.5 cm in diameter. The heads have an involucre of loosely spreading, greenish to purple bracts. The 25-40 flowers are all tubular, pink to purplish in color (occasionally white), star shaped and hairy within and the pappus is composed of finely barbed hairs. The achenes are 4-5 mm long with a pappus of long hairs. Rough blazing star blooms from July through September open slopes, prairies and meadowlands of eastern South Dakota.

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  Asteraceae : Liatris punctata

  R. Neil Reese

  Liatris punctata is a perennial herb with erect or slightly spreading stems arising singly or in clusters from a taproot-like rootstock and growing 10 to 80 cm in height. The numerous simple leaves are densely packed on the stem, very narrow and linear, up to 15 cm long and 5 mm wide near the base of the plant, becoming smaller toward the top. The leaves are entire, tend to point upward but may be more spiraling at the base of the plant. They are covered with resin dots (punctate) and have short white hairs around the margins. The inflorescence is a spike-like arrangement of cylindrical heads 1.5-2 cm tall with an involucre of narrow overlapping pointed bracts. The 4-8 pink to purple disk flowers are all tubular and star shaped, the inside covered with soft, thin hairs. Dotted-gayfeather blooms from July to October on dry prairies, native pastures and open uplands, especially on sandy soils, throughout South Dakota.

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  Asteraceae : Lygodesmia juncea

  R. Neil Reese

  Lygodesmia juncea is a perennial herb arising from a woody rhizome, growing from 10 cm to 70 cm in height and having a yellow milky sap. The mostly erect to ascending stems are green, stiff, hairless and much branched. The stems often have round 1 cm wide galls made by a solitary wasp. These are few leaves, the lower ones are entire, linear to linear lanceolate, less than 4 cm long and 3 mm wide and pointed at the tip. The upper leaves become smaller as they ascend the stem and are reduced to scales in the upper plant. There are numerous heads, each single at the end of a branch. The involucre is cylindrical, about 1.5 cm tall, the green bracts in 2 series, the outer short and unequal in length, the inner long and narrow. Each head has 5 pink to lavender, sometimes whitish ray flowers, the ligule is 10-12 mm long with 5 small teeth at the tip. The fruit are cylindrical achenes 6-10 mm long with a tuft of white to light brown hairs. Rush skeletonweed is commonly found from low to mid elevations throughout South Dakota, in dry grasslands, sagebrush steppes, and open pine woodlands, often on disturbed sites. Lygodesmia juncea blooms from June to August.

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  Asteraceae : Machaeranthera pinnatifida

  R. Neil Reese

  Machaeranthera pinnatifida is an evergreen, perennial herb usually with numerous, ascending to erect stems, branched above, reaching 5-40 cm in height, with at least the upper 1/3 covered with minutely glandular and short wooly hairs. The simple alternate leaves are oblong to linear subspatulate, 1–6 cm long and 2-10 mm wide, toothed with bristle-tipped teeth or deeply pinnate lobes that are linear and spine-tipped. Inflorescence is a flat-topped cluster of heads, each solitary on a branch tip. Heads are radiate with a hemispheric involucre 6–9 mm long with 5 or 6 series of bracts that are hairy and sticky to the touch, the outer ones green and the inner ones whitish. There are 14 to 60, yellow ray flowers with ligules 4–10 mm long, and 30 to 150 disk flowers with yellow corollas 4–6 mm long. Achenes are about 2 mm long. Spiny goldaster blooms from May through September on open prairies and plains throughout South Dakota.

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  Asteraceae: Microseris nutans

  R. Neil Reese

  Microseris nutans is a perennial herbaceous plant typically growing 10 to 50 cm tall. It has a deep taproot and a basal rosette of leaves. The leaves are simple, variable in shape but generally lanceolate to oblong, often with irregularly toothed or lobed margins, measuring about 5 to 20 cm long and 1 to 4 cm wide. Leaf surfaces are smooth or slightly hairy, and they are borne on short petioles or sessile. The flowering stalk is leafless, 15–60 cm tall and bears a solitary flower head (capitulum) that nods or droops before opening, hence the name "nodding." Flowering occurs from late spring to midsummer (May–July). The flower head is about 2 to 4 cm in diameter, composed of numerous yellow ray florets that are strap-shaped and typically 15 to 30 mm long. The involucre consists of several series of green to reddish bracts that are lanceolate to ovate and 10 to 20 mm long. The fruit is a small achene with a pappus of fine bristles. Nodding Microseris is native to parts of western North America, including South Dakota, typically found in grasslands, open woods, and rocky slopes, especially in the western and Black Hills regions.

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  Asteraceae: Nabalus racemosus

  R. Neil Reese

  Nabalus racemosus is a perennial herbaceous plant native to North America. It typically grows 30 to 90 cm tall and emerges from a thick, fleshy, and sometimes branched rootstock. The stems are erect and slender, often branching near the top. The leaves are alternate and mostly basal, becoming smaller and more lanceolate up the stem. Basal leaves can be large, up to 20 cm long, with toothed or lobed margins, while upper stem leaves tend to be narrower and simpler. The surfaces range from smooth to slightly hairy. Flowering occurs from late summer to fall (August to October). The inflorescence is a loose, elongated raceme or panicle of numerous small flower heads, each about 1 to 1.5 cm in diameter. Each flower head consists of white to pale lavender ray florets surrounding yellow disc florets. The ray florets are strap-shaped 10 to 15 mm in length and 2 to 3 mm in width. The disc florets are fertile, 4 to 6 mm long and 1 to 1.5 mm wide, tubular, narrow and cylindrical, with five tiny lobes at the mouth of the opening. The involucre bracts are green, lanceolate, and measure about 5 to 8 mm long, forming a cup around the flower head. Fruits are small achenes, 3 to 5 mm in length, with a pappus of fine bristles, 5 to 7 mm long. White rattlesnake root is native to South Dakota, typically found in moist woodlands, forest edges, and shaded ravines, particularly in the eastern and southeastern parts of the state.

  Synonym: Prenanthes racemosa

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  Asteraceae : Packera cana

  R. Neil Reese

  Packera cana is a perennial herb growing 10-30 cm tall, the stems and leaves densely covered with felt-like hairs giving them a silvery gray color. The leaves are simple and alternate. The rosette of basal leaves and the lowest cauline leaves have long petioles, the blade ovate to lanceolate, 2.5-5 cm long and 1-3 cm wide, with a blunt to rounded tip, and with margins that are entire to slightly toothed. The upper cauline leaves are much reduced. The is a corymbiform cyme with 6-15 heads. Each head has an involucre of 13-21 bracts measuring 5-6 mm in length. There are 8-13 ray flowers, the yellow ligules 7-10 mm long (occasionally absent), surrounding many yellow disk flowers, their corollas with 5 shallow teeth. The cylindrical achenes are about 2 mm long with a pappus of longer white hairs. Woolly groundsel blooms from May through July on open dry plains predominantly in western South Dakota.

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  Asteraceae: Packera plattensis

  R. Neil Reese

  Packera plattensis is a perennial herbaceous plant growing 20 to 60 cm tall with erect, unbranched or sparsely branched stems covered in fine hairs. It has a fibrous root system with a short, woody caudex at the base, from which multiple stems arise. The basal leaves are petiolate, with petioles 5 to 15 cm long, supporting ovate to lanceolate blades 5 to 12 cm long and 2 to 6 cm wide, often pinnately lobed with irregular teeth. Stem leaves are smaller and sessile or clasping. The inflorescence is a loose corymb of several flower heads blooming from May through July. Each flower head consists of 13 to 21 bright yellow ray florets, each 10 to 18 mm long and 3 to 5 mm wide, surrounding numerous tubular disc florets. The involucre has 2 to 3 series of green, lanceolate bracts, 8 to 12 mm long and 2 to 3 mm wide. The disc florets have five-lobed corollas about 4 to 6 mm long. The stamens number five per disc floret, with slender filaments and yellow anthers fused into a tube around the style. The pistil has a single style with two elongated stigmatic branches approximately 3 to 4 mm long. The fruit is a small, dry achene about 2 to 3 mm long and 1 mm wide, topped with a pappus of white bristles approximately 5 to 7 mm long. Prairie groundsel is native to South Dakota, commonly found in prairies, open fields, and disturbed sites across much of the state.

  Synonym: Senecio plattensis

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  Asteraceae :Pseudognaphalium macounii

  R. Neil Reese

  Pseudognaphalium macounii is a perennial herb growing 15 to 60 cm tall from a woody rootstock, with erect to ascending , slender stems, covered in fine, woolly hairs giving a grayish-white appearance. The leaves are alternate, with the lower leaves borne on petioles 1 to 4 cm long and upper leaves sessile; leaf blades are lanceolate to narrowly ovate, 2 to 6 cm long and 0.5 to 1.5 cm wide, with entire to slightly toothed margins, curled under near the base. Both upper and lower leaf surfaces are densely covered in woolly, white to gray hairs, creating a soft, felt-like texture. The inflorescence consists of dense clusters of small, yellowish-white flower heads arranged in terminal cluster of campanulate heads blooming from July through September. Each flower head is surrounded by an involucre of 4-5 series of cream to straw colored, papery bracts in 4.5-5.5 mm long. The calyx is modified into a pappus of fine bristles aiding in wind dispersal of the fruit. Flowers are disk florets with tubular yellow corollas approximately 3 to 5 mm long. There are 5 stamens per floret, they have slender filaments and yellow anthers, inserted near the base of the corolla tube, their anthers forming a tube around the style. The pistil has a slender style topped with a two-branched stigma. Fruit matures from August through October as a small achene, 1 to 2 mm long, topped with the pappus bristles (2–4 mm long). Native to South Dakota, Macoun’s everlasting grows in dry open woods, grasslands, and rocky slopes, often on well-drained sandy or gravelly soils predominantly in Lawrence and Pennington Counties.

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  Asteraceae : Ratibida columnifera

  R. Neil Reese

  Ratibida columnifera is a perennial herb with green stems arising singly or in clusters from a taproot, growing from 30 to 100 cm in height. The stems are hairy and often branched. The simple, alternate leaves are hairy and have many small glands, growing up to 15 cm long and 6 cm wide, deeply pinnately to bipinnately lobed (5-11 lobes), the ultimate segments being linear to oblong and often very unequal. One to a few heads sit atop a long peduncle, with 2 series of reflexed involucral bracts. Each head consists of 4 to 12 drooping, yellow, purplish-red, or purplish-red with yellow bordered ray florets that surround a columnar receptacle that is up to 5 cm long. The column is covered with numerous purplish disk florets, which open starting at the base of the column and moving upward. the achenes are 1.5-3 mm long with short hairs on the inner edge. Prairie coneflower blooms from June to September along roadsides in open prairies and disturbed fields throughout all of South Dakota.

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  Asteraceae Ratibida pinnata

  R Neil Reese

  Ratibida pinnata is a perennial herb with 30-120 cm, simple, hairy stems arising singly or in clusters from a rhizome. The stems can become branched in the region the inflorescence develops. The simple, alternate, petiolate leaves are up to 40 cm long and deeply pinnately divided, with the larger segments pointed and lance-ovate in shape. The margins vary from coarsely toothed to entire and the leaf surfaces are covered with short stiff hairs. The leaves are reduced in size as they ascend the stem becoming bract-like near the top. There are 1 to 12 flower heads at the top of the plant, each at the end of a long peduncle, and having a globular to oblong receptacle 1-2.5 cm tall and 1-2 cm wide, surrounded by 10-14 involucral bracts in 2 series. The heads have up to 15 yellow ray flowers, the ligules 3-6 cm long, spreading to drooping. The numerous greenish purple to brown disk flower’s corollas are 1.3-3 mm long and lack a pappus. The achenes are 2-3 mm in length. Gray-headed coneflower blooms from June through September in prairies and open woodlands on the eastern edge of South Dakota.

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  Asteraceae : Rudbeckia hirta

  R. Neil Reese

  Rudbeckia hirta is an annual (sometimes biennial or perennial) herb with ascending stem growing 30–100 cm tall. The stems are covered in long, white, stiff, spreading hairs and are generally unbranched or have a few branches in the upper half. The leaves are simple, alternate, petiolate, mostly basal, extremely variable in shape. The lower leaves are oblanceolate, 10–18 cm long and covered by coarse hair. The middle leaves are short petioled, lance-linear and reduced in size. The upper-most leaves are greatly reduced and sessile. The leaf margins are entire o with a few shallow teeth. The inflorescence consist of 1 to a few long-stalked flower heads at the top of the plant and arising from upper leaf axils. The receptacle is up to 2 cm in diameter, hemispheric to ovoid surrounded by hairy, elongated involucral bracts. There are 18-21 yellow to yellow-orange ray flowers with ligules 2-4 cm long, sometimes purplish near their base, surrounding the numerous brown to purplish brown disk flowers. The achenes are four-sided, ~2 mm long and lack a pappus. Black-eyed Susan bloom from May to September, mostly in disturbed prairies, roadsides and waste areas in northeast and southwest South Dakota.

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  Asteraceae: Rudbeckia laciniata

  R. Neil Reese

  Rudbeckia laciniata is a perennial herbaceous plant growing 1 to 3 meters tall from a thick, fibrous, rhizomatous rootstock. Stems are erect, smooth to slightly hairy, and often branched. Leaves are alternate and deeply pinnatifid or lobed, with basal leaves typically larger, measuring 15 to 40 cm long and 8 to 20 cm wide, with leaf segments lanceolate to linear, pointed, and sharply toothed. Upper stem leaves are smaller, 5 to 15 cm long and 3 to 8 cm wide, with similarly dissected lobes. Leaf surfaces are smooth to slightly hairy, and petioles range from 2 to 10 cm in length. The inflorescence is a large, flat-topped cluster of flower heads blooming from July to September. Each flower head is subtended by an involucre composed of several (usually 8 to 12) overlapping green bracts, which are lanceolate to ovate, 12 to 20 mm long and 3 to 6 mm wide, with smooth to slightly hairy surfaces and often pointed tips. Each head has a central dome-shaped receptacle covered with numerous small disk florets, surrounded by 10 to 20 bright yellow ray florets. Ray florets are strap-shaped, 3 to 6 cm long and 5 to 10 mm wide. Disk florets are tubular, about 5 to 7 mm long. The disk florets have both stamens and pistils; stamens number around 5 per floret with anthers fused into a tube about 2 to 3 mm long. Pistils are single per floret, with styles about 3 to 4 mm long, ending in bifid stigmas. Fruits are dry, one-seeded achenes about 3 to 5 mm long, slightly curved and ribbed, dark brown to black at maturity. In South Dakota, cutleaf coneflower grows in moist woodlands, floodplains, and along stream banks, scattered mostly in the eastern and southeastern parts of the state.

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  Asteraceae: Senecio crassulus

  R. Neil Reese

  Senecio crassulus is a perennial herb growing 30 to 60 cm tall from a fibrous root system. The stems are erect, smooth to slightly hairy, and succulent in texture. The plant flowers from July through September. Leaves are alternate, simple, succulent, lanceolate to narrowly ovate, 3 to 8 cm long and 1 to 3 cm wide, with entire margins. The upper leaf surface is smooth and bluish green, the lower surface paler and glabrous. Petioles are short, about 1 to 2 cm long. The inflorescence is a corymb or loose cluster of yellow composite flowers about 10 to 15 mm in diameter. Each flower head is surrounded by narrow, lanceolate involucral bracts about 3 to 5 mm long and 0.5 to 1 mm wide, free and arranged in several series. The corolla of ray florets has a single strap-shaped petal about 7 to 10 mm long and 2 to 3 mm wide, free and spreading, while disc florets have tubular corollas about 5 to 7 mm long. Stamens number five per floret, with filaments fused into a tube around the style and anthers about 1 to 2 mm long. The pistil is single, about 1 to 2 mm long, a style about 2 to 3 mm long, and a bifid stigma. The fruit is a small achene about 2 to 3 mm long that matures from August to October, topped with a pappus of fine hairs for wind dispersal. Thickleaf ragwort is native to South Dakota, found in dry open sites, rocky slopes, and prairies mainly in the western regions of the state.

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  Asteraceae: Senecio integerrimus

  R. Neil Reese

  Senecio integerrimus is a perennial herb growing 30 to 90 cm tall from a fibrous root system. The stems are erect, mostly smooth with occasional fine hairs, somewhat succulent, and may branch toward the top. Leaves are alternate, simple, lanceolate to narrowly ovate, 5 to 15 cm long and 1 to 5 cm wide, with entire or slightly toothed margins. The upper leaf surface is smooth and dark green, while the lower surface is lighter and glabrous or sparsely hairy. Petioles are short to moderate in length, 1 to 4 cm long. The plant flowers from June through August. The inflorescence is a corymb or loose cluster of 6 to 20, short-stalked, yellow composite flowers about 15 to 25 mm in diameter. Each flower head consists of numerous small florets surrounded by narrow, lanceolate involucral bracts about 5 to 8 mm long and 1 to 1.5 mm wide, free and arranged in several series. Linear-oblong ray flowers (8 to 13) have a strap-shaped petal about 10 to 15 mm long and 3 to 5 mm wide, free and spreading, while disc florets have tubular corollas about 6 to 8 mm long. There are five stamens per floret, with filaments fused into a tube around the style and anthers about 2 to 3 mm long. The pistil is single, about 2 to 3 mm long, a style about 3 to 4 mm long, and a bifid stigma. The fruit is a small achene about 3 to 4 mm long that matures from July to September, topped with a pappus of fine hairs. Lambstongue ragwort is native to South Dakota, found in prairies, open woods, meadows, rocky slopes, and disturbed sites, primarily in the central and western parts of the state.

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  Asteraceae: Silphium perfoliatum

  R. Neil Reese

  Silphium perfoliatum is a robust perennial herb growing 1.5 to 3 meters tall from a deep, long-lived central taproot combined with shallow, aggressive rhizomes that enables the plant to form dense, extensive colonies. The stems are stout, erect, smooth to slightly rough. The plants are notable for the large, opposite, triangular to ovate leaves, 10 to 25 cm long and 8 to 20 cm wide that are fused at the base around the stem, forming a distinctive “cup” which collects water. Leaves have entire margins, the upper leaf surface is rough and dark green, while the lower surface is lighter and may have fine hairs. Petioles are absent. The plant flowers from July through September. The inflorescence is a large, flat-topped cluster of yellow composite flowers about 25 to 40 mm in diameter. Each flower head consists of 10 to 20 ray and numerous disc florets. The involucre consists of several series of overlapping green bracts, lanceolate to ovate in shape, and typically smooth or slightly hairy along the edges. Ray florets are strap-shaped, bright yellow, about 15 to 20 mm long and 3 to 5 mm wide. Disc florets are narrow, tubular, 5 to 7 mm long and also yellow. Stamens number five per floret, with filaments fused into a tube around the style and anthers about 2 to 3 mm long. The pistil consists of two fused carpels forming a compound ovary with two locules, about 3 to 5 mm long, a style about 4 to 6 mm long, and a bifid stigma. The fruit is a small, dry achene about 5 to 7 mm long that matures from September to October and is equipped with a pappus of fine scales aiding in dispersal. Cup plant is native to South Dakota, commonly found in moist prairies, streambanks, and wetland edges in the eastern part of the state.

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  Asteraceae: Solidago altissima

  R. Neil Reese

  Solidago altissima is a perennial, herbaceous plant with a fibrous root system and well-developed short rhizomes that form loose colonies. Mature plants typically reach 1–2.5 meters in height. The stems are erect, slender, often branching and reddish or purplish near the base, rough to the touch due to short hairs. Leaves are alternate, simple, somewhat thick and firm, lanceolate to linear-lanceolate, 7–15 cm long and 1–2.5 cm wide, with serrated margins. Leaf surfaces are green, with the upper surface rough and the lower surface softly pubescent; petioles are absent or very short (sessile leaves). Flowering occurs from August to October, with the inflorescence a large, branched, pyramidal panicle up to 40 cm long, composed of hundreds of tiny yellow flower heads. Each head has an involucre with 3-4 whorls of overlapping, lanceolate, green to yellowish bracts, 2–3 mm long, narrowly bell-shaped. Each head has 7–15 yellow ray florets, each 2–4 mm long and 0.5–1 mm wide, and 3–10 yellow disc florets. Stamens are five per disc floret, with yellow anthers about 1.5 mm long, forming a tube around the style. The pistil consists of a single compound ovary per floret, with a style 2–3 mm long ending in a bifid stigma. The fruit is a small, dry, ribbed cypsela (achene), 1–2 mm long, grayish brown, maturing in late fall; each is tipped with a white to pale brown pappus of fine bristles, 2.5 to 3.5 mm long, aiding wind dispersal. Tall goldenrod is native to South Dakota and is found throughout the state, especially in prairies, open woodlands, roadsides, and other disturbed sites with full sun and well-drained soils. This species and Solidago canadensis are very similar. The pappus of altissima is slightly longer and the leaves are thicker and firmer.

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  Asteraceae : Solidago canadensis

  R. Neil Reese

  Solidago canadensis is a perennial, herbaceous plant with a fibrous root system and well-developed creeping rhizomes, often forming dense colonies. Plants typically reach 0.5–2 meters in height. The stems are erect, slender, unbranched below the inflorescence, and covered with short, fine hairs, especially toward the upper portions. Leaves are alternate, simple, 3-nerved, mostly lance-elliptic, 6–15 cm long and 1–3 cm wide, broadest near the middle, and tapering toward the base and to a sharp point at the tip. Leaves are sessile or have very short petioles and the margins are mostly sharply toothed except near the leaf base (leaves may be toothless or nearly so just below the flower clusters). Upper leaf surfaces are medium to dark green and rough-textured, while lower surfaces are lighter green and softly pubescent along the veins and occasionally over much of the surface. Flowering occurs from August through October, with the inflorescence forming a large, plume-like, branching panicle up to 40 cm long, composed of numerous small yellow flower heads. Each involucre is bell-shaped, 2–3 mm long, with several overlapping, greenish to yellowish, lanceolate phyllaries. Each head contains 7–15 yellow ray florets (about 2–4 mm long, 0.5–1 mm wide) and 3–10 yellow disc florets. Stamens are five per disc floret, with yellow anthers about 1.5 mm long, forming a tube around the style; the prominent style is 2–3 mm long with a bifid stigma. The fruit is a small, dry, ribbed cypsela (achene), 1–2 mm long, grayish brown, maturing in late fall; each is topped by a white to pale brown pappus of fine bristles, 1.8 to 2.2 mm long. Canada goldenrod is native to South Dakota and is common throughout the state, found in prairies, fields, roadsides, and other disturbed or open habitats with full sun and well-drained or moderately moist soils. Solidago canadensis and Solidago altissima are difficult to differentiate. S. altissima has longer pappus hairs and thicker, firmer leaves that are minutely toothed or mostly toothed in the tip half where S. canadensis leaves are thinner, laxer, mostly toothed nearly to the leaf base, and is generally less hairy throughout.

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  Asteraceae: Solidago gigantea

  R. Neil Reese

  Solidago gigantea is a perennial, herbaceous plant with a fibrous root system and stout, creeping rhizomes that often form loose colonies. Mature plants typically reach 1–2.5 meters in height. The stems are erect, round, and characteristically smooth and hairless (glabrous), often with a reddish or purplish hue, distinguishing them from other goldenrods with rough stems. Leaves are alternate, simple, lanceolate to narrowly lanceolate, 8–20 cm long and 1–4 cm wide, with sharply serrated margins. The upper leaf surface is medium to dark green and smooth, while the lower surface is paler and glabrous or sparsely hairy; leaves are sessile or have very short petioles. Flowering occurs from August to October, with the inflorescence forming a large, open, plume-like panicle up to 40 cm long, composed of numerous small, bright yellow flower heads. Each involucre is bell-shaped, 2–4 mm long, with several overlapping, greenish to yellowish, lanceolate phyllaries. Each flower head contains 7–15 yellow ray florets (2–4 mm long, 0.5–1 mm wide) and 3–10 yellow disc florets. Stamens are five per disc floret, with yellow anthers about 1.5 mm long, forming a tube around the style. The pistil consists of a single compound ovary per floret, with a slender style 2–3 mm long and a bifid (two-parted) stigma. The fruit is a small, dry, ribbed cypsela (achene), 1–2 mm long, grayish brown, maturing in late fall, each topped with a white to pale brown pappus of fine bristles 2 to 2.5 mm long. Giant goldenrod is native to South Dakota and is found widely across the state, especially in moist prairies, stream banks, wet meadows, ditches, and low-lying open areas with full to partial sun and moist to wet soils. Solidago gigantea is one of several large goldenrods that grow in SD. The lack of hairs on the stems (some have a waxy coating) and little or no hairs on the leaf surfaces help to distinguish it from S. altissima and S. canadensis.

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  Asteraceae: Solidago missouriensis

  R. Neil Reese

  Solidago missouriensis is a perennial, herbaceous plant with a fibrous root system and short, thick rhizomes, often forming loose clumps rather than dense colonies. Mature plants typically reach 30–90 cm in height. The stems are erect, slender, often reddish at the base, and usually sparsely hairy or nearly glabrous. Leaves are alternate, simple, and mostly linear to narrowly lanceolate, with the largest basal leaves reaching 10–25 cm long and 0.5–2.5 cm wide; upper stem leaves are much smaller, 2–10 cm long and 2–7 mm wide, and become progressively reduced toward the inflorescence. Leaf margins are entire to slightly toothed; upper surfaces are green and smooth, while lower surfaces are usually paler and may be slightly hairy. Petioles are present on basal leaves (up to 5 cm long), but upper leaves are sessile. Flowering occurs from July to September, with the inflorescence forming a narrow, arching or one-sided panicle (raceme-like) up to 20 cm long, with numerous small, bright yellow flower heads. Each involucre is bell-shaped, 2.5 to 4.5 mm long, with several overlapping, green to yellowish, lanceolate phyllaries. Each head contains 5–12 yellow ray florets (2–3 mm long, 0.5–1 mm wide) and 3–8 yellow disc florets. Stamens are five per disc floret, with yellow anthers about 1–1.5 mm long, forming a tube around the style. The pistil consists of a single compound ovary per floret, with a slender style about 2 mm long and a bifid stigma. The fruit is a small, ribbed cypsela (achene), 1–2 mm long, brownish when mature in late summer to early fall, each topped with a single row of white to pale brown pappus bristles, 2.5 to 3 mm long. Missouri goldenrod is native to South Dakota, found throughout the state in prairies, open hillsides, roadsides, and dry, sandy, or rocky soils in full sun.

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  Asteraceae: Solidago mollis

  R. Neil Reese

  Solidago mollis is a perennial herb with a single or clusters of several ascending, grayish green stems arising from a rhizome and growing from 10 to 70 cm tall. There are both basal and alternate cauline leaves, thickish, firm, 3-nerved, elliptic to lanceolate, 3-8 cm long and 1-3 cm wide. The leaves are sessile or nearly so, the margins are subentire to irregularly toothed, and their size is reduced in the upper regions of the stem. The inflorescence is a dense, compact to elongated panicle of yellow heads. The heads have an involucre of overlapping bracts with a total height of 3.5-6 mm, with 6-10 ray flowers, corollas 3-4 mm tall with ligules 1-3mm in length, and 3-8 disk flowers, 2-5 mm tall. The achenes are short ~2 mm and hairy with a pappus of bristles. Velvety goldenrod blooms from July through October on dry or drying open prairies and open woods through South Dakota.

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  Asteraceae: Solidago rigida

  R. Neil Reese

  Solidago rigida is a perennial, herbaceous plant with a fibrous root system and short, thick rhizomes or a branched caudex, forming loose clumps rather than dense colonies. Mature plants typically reach 50–120 cm in height. The stems are stout, erect, unbranched below the inflorescence, and covered with coarse, stiff hairs (hispid), giving them a rough texture. Leaves are alternate, simple, and thick-textured (coriaceous), with the largest basal leaves spatulate to oblong, 10–30 cm long and 3–8 cm wide, tapering to a long petiole (up to 10 cm); stem leaves are smaller, 5–15 cm long and 1–3 cm wide, becoming sessile or clasping toward the top of the stem. Leaf margins are entire or slightly wavy; both upper and lower surfaces are gray green, densely covered with short, stiff hairs, and rough to the touch. Flowering occurs from August to October, with the inflorescence forming a dense, flat-topped to slightly rounded corymb or panicle up to 20 cm across, with numerous bright yellow flower heads. Each involucre is hemispheric to bell-shaped, 5-9 mm tall, with overlapping, green, broadly lanceolate to ovate phyllaries, often with stiff hairs. Each head contains 8–20 yellow ray florets (5–8 mm long, 1–2 mm wide) and 15–31 yellow disc florets. Stamens are five per disc floret, with yellow anthers about 2 mm long, forming a tube around the style. The pistil consists of a single compound ovary per floret, with a slender style about 3 mm long and a bifid stigma. The fruit is a small, ribbed cypsela (achene), 2–3 mm long, prominently ribbed, brown when mature in late fall, each topped with a single row of stiff, yellowish pappus bristles. Stiff goldenrod is native to South Dakota and is found throughout the state in prairies, open woodlands, rocky hillsides, and occasionally roadsides, preferring dry to moderately moist, well-drained soils in full sun.