ASTERACEAE – ASTER FAMILY Plant: herbs (annual or perennial), some shrubs, rarely vines or trees. Stem: Root: Often with tubers, rhizomes, stolons, or fleshy roots Leaves: mostly simple, some compound, alternate or opposite, rarely whorled. Flowers: flower head supported by an involucre (whorl of green bracts or phyllaries); each head composed of small flowers (composite) of flat ray-like (ligulate) flowers on the outside (ray flowers) and central tube-like flowers (disk flowers) – some species may have only one or the other. Calyx absent or modified into hairs, bristles, scales or a crown (pappus); 5 stamens (syngenesious -united by anthers); 5 united petals (sympetalous), receptacle may also have hairs or bristles. Both pappus and receptacle hairs/bristles may be used in ID. Fruit: achene (small, one-seeded, inferior ovule, 2 carpels, hard shell fruit) often with persisting crowned pappus which helps with seed dispersal. Other: Very large family, divided into sub-families and tribes, once named Compositae; 1-2,000 genera, 20,000+ species. Dicotyledons Group WARNING – family descriptions are only a layman’s guide and should not be used as definitive Flower Morphology in the The family Asteraceae (Compositae) is a composite flower Asteraceae (Aster Family) (many flowers in one) on a receptacle (base or expanded portion of the stem). This is a very large family with many variations in structure. Some nomenclature below. Ray florets – tubular at Phyllaries (bracts), base, then a flat ray or usually green, often ligulite in whorls or series in a wide variety of Disc florets (tubular shapes shaped, usually 4 or 5 lobed Receptacle or base The three most common plans are: 1. Radiate – contains 2. Ligulate – contains 3. Discoid – contains both ray and disc florets only ray florets only disc florets Woodland Sunflower Two-Flowered Cynthia Flower Morphology in the Composites can be monoecious (separate male and female florets Asteraceae (Aster Family) on same plant) or dioecious (male and female on different plants) but most are perfect (hermaphroditic – both male (staminate) and female (pistillate) structures within the same floret. Ray florets in most species are not fertile. Many in this family reproduce in 2 phases to reduce chance of self-fertilization: 1. Filaments fuse and elongate – style then pushes out pollen – 2. Style then moves first phase through the filaments and opens to receive pollen – second phase Disc Florets Achene Receptacle Achene – a hard one- seeded structure usually with a pappus (modified calyx) present attached to seed - aids in dispersal (hairs, bristles, scales, wings, etc.) – often important to ID some species Dandelion Tall Blue Lettuce Wingstem Dwarf Dandelion Flower Morphology in the Asteraceae (Aster Family) Common Yarrow Great Indian Nodding Thistle Plantian Pussytoes sp. Prickly Yellow Lettuce Tall Beggar Ticks Chicory Tall Rattlesnakeroot Purple Cone-Flower Scaly Blazing Star Prairie Dock Sneezeweed Star Tickseed White Heath Aster Western Ironweed Rough Goldenrod Cocklebur Yellow Salsify Cutleaf Coneflower ASTERACEAE – ASTER FAMILY [Common] Yarrow [Milfoil]; Achillea millefolium L. (Introduced) Oppositeleaf Spotflower; Acmella oppositifolia (Lam.) R.K. Jansen var. repens (Walter) R.K. Jansen White Snakeroot; Ageratina altissima (L.) King & H.E. Robins. var. altissima Orange Agoseris; Agoseris aurantiaca (Hook.) Greene Common [Annua] Ragweed; Ambrosia artemisifolia L. Lanceleaf [Southern] Ragweed; Ambrosia bidentata Michx. Great Ragweed; Ambrosia trifida L. Prairie Broomweed [Broom Snakeroot]; Amphiachyris dracunculoides (DC.) Nutt. Pearly Everlasting; Anaphalis margaritacea (L.) Benth. Littleleaf [Rosy] Pussytoes; Antennaria microphylla Rydb. Field [Flagged] Pussytoes; Antennaria neglecta Greene Large Plantain-Leaved [Smooth, Parlin’s] Pussytoes; Antennaria parlini Fern. Corn Chamomile; Anthemis arvensis L (Introduced) Golden Chamomile (Yellow Cotula); Anthemis tinctoria L. (Introduced) Greater Burdock; Arctium lappa L. (Introduced) Common [Lesser] Burdock; Arctium minus Bernh. (Introduced) Pale Indian Plaintain; Arnoglossum atriplicifolium (L.) H.E. Robins. Groovestem [Prairie] Indian Plantain; Arnoglossum plantagineum Raf. Great Indian Plaintain; Arnoglossum reniforme (Hook.) H.E. Robins. Sweet Sagewort [Wormwood]; Artemisia annua L. (Introduced) Silver Sagebrush; Artemisia cana Pursh White Sagebrush; Artemisia ludoviciana Nutt. ssp. ludoviciana Alpine [Rocky Mountain] Sage [Brush]; Artemisia scopulorum A. Gray Big Sagebrush; Artemisia tridentata Nutt. Common Wormwood [Mugwort]; Artemisia vulgaris L. (Introduced) ASTERACEAE – ASTER FAMILY Desert Marigold; Baileya multiradiata Harv. & A. Gray ex A. Gray Texas Greeneyes; Berlandiera betonicifolia (Hook.) Small Romerillo [Beggarticks]; Bidens alba (L.) DC. var. radiata (Sch. Bip.) Ballard ex T.E. Melchert Bearded Beggarticks [Tickseed Sunflower]; Bidens aristosa (Michx.) Britton Spanish Needles; Bidens bipinnata L. Nodding Bur-Marigold [Beggartick]; Bidens cernua L. Crowned [Tall; Swamp] Beggarticks [Marigold]; Bidens coronata (L.) Britton Devil's [Common] Beggartick [Sticktight]; Bidens frondosa L. Threelobe Beggarticks; Bidens tripartita L. Tall Beggar’s Ticks; Bidens vulgata Greene Bushy Seaside Tansy [Saltmarsh Ox-Eye]; Borrichia frutescens (L.) DC. False Boneset; Brickellia eupatorioides (L.) Shinners (var. eupatorioides and var. corymbulosa) Common Yarrow [Milfoil] USDA Achillea millefolium L. (Introduced) Asteraceae (Aster Family) Oak Openings Metropark, Lucas County, Ohio Notes: 3-5+, 3-lobed rays per flower, white (rarely pink), disc flowers mostly white to gray with yellow glands, florets in umbels; leaves finely (2-3) pinnately divided; stem somewhat pubescent to woolly; native and introduced – varieties disputed (many proposed); summer to fall [V Max Brown, 2004] Oppositeleaf Spotflower USDA Acmella oppositifolia (Lam.) R.K. Jansen var. repens (Walter) R.K. Jansen Asteraceae (Aster Family) Bald Knob National Wildlife Refuge, White County, Arkansas Notes: receptacle very conical, 5-15 yellow ray flowers, disc yellow to somewhat orange, bracts in 2+ rows and sharp pointed; leaves variable, mostly opposite but upper sometimes alternate, ovate to lanceolate, variably toothed, usually sharp pointed; stem hairy; mostly in wet areas; summer to fall [V Max Brown, 2007] White Snakeroot USDA Ageratina altissima (L.) King & H.E. Robins. var. altissima Asteraceae (Aster Family) Maumee River Metroparks, Lucas County, Ohio Notes: discoid; disc flowers (9-25) white in a panicle or cluster, bracts in overlapping series; leaves opposite, short to long petiolate, mostly triangular to somewhat ovate, acute tip, with teeth; fruits 5-angled and mostly linear; plant reported to be toxic to animals and humans; late summer to fall [V Max Brown, 2004] Orange Agoseris USDA Agoseris aurantiaca (Hook.) Greene Asteraceae (Aster Family) Rocky Mountain National Park Notes: ligulate; flowers very deep orange, phyllaries purple spotted; solitary flower; leaves basal, mostly entire, sometimes a few lobes; low elevations to alpine; summer [V Max Brown, 2012] Common [Annual] Ragweed USDA Ambrosia artemisiifolia L. Asteraceae (Aster Family) Maumee River Metroparks, Lucas County, Ohio Notes: discoid; staminate flower spikes up to 6-8 in, pollen yellow, heads stalked, green phyllaries in single row, pistillate flowers in clusters (or solitary) in leaf axils below the staminate spikes; leaves alternate or opposite, irregularly and deeply 2-3 pinnately lobed with 6+ lobes; stem and leaves with variable pubescence; varieties; late summer to fall [V Max Brown, 2004] Staminate Spike Pistillate flowers Lanceleaf [Southern] Ragweed USDA Ambrosia bidentata Michx. Asteraceae (Aster Family) Taum Sauk Mountain State Park, Iron County, Missouri Notes: discoid; staminate flower solitary dense spikes, terminal lobe of involucre with long stiff hairs, pistillate heads in axillary clusters or solitary below the staminate spike; leaves mostly alternate, sessile, lanceolate usually, often with 1 or 2 basal lobes, hairy; stem hairy (short spreading and longer stiff hairs); summer to fall [V Max Brown, 2010] Great [Giant] Ragweed USDA Ambrosia trifida L. Asteraceae (Aster Family) Maumee River Metroparks, Lucas County, Ohio Notes: discoid: large plant (up to 3 m+); staminate flowers in terminal spikes; pistillate flowers in clusters (or solitary) in leaf axils; leaves large with mostly 3 (sometimes 5) deep palmate lobes, toothed (rarely entire), with variable petiole length; stem leaves with variable pubescence; plant variable in morphology; late summer to early fall [V Max Brown, 2004] Staminate Spike Pistillate Desert Marigold USDA Baileya multiradiata Harv. & A. Gray ex A. Gray Asteraceae (Aster Family) Red Rock Canyon National Conservation Area, Clarke County, Nevada Notes: ray flowers yellow (3050+), disc flowers yellow (many), bracts in overlapping rows; leaves on basal half of plant, pinnate to somewhat linear; stem, leaves and bracts densely white hairy; desert habitat; late spring to fall [V Max Brown, 2014] Prairie Broomweed [Broom USDA Snakeroot] Amphiachyris dracunculoides (DC.) Nutt. Asteraceae (Aster Family) Tallgrass Prairie National Preserve, Chase County, Kansas Notes: ray flowers yellow (7-12), disc flowers yellow; bracts glabrous, in overlapping rows, somewhat triangular, resin dotted; leaves mostly sessile to short petiolate, mostly linear, also resin dotted; stem seems woody at base, much branched and bushy in upper half; summer to fall (also called Gutierrezia d.)