Artemisia Genus wormwood Asteraceae

Artemisia vulgaris. Christian Fischer.

Artemisia vulgaris plant in bloom. Christian Fischer. (Accessed 10/2017).

Artemisia Genus herbs or sub-shrubs, they are Annuals, biennials, or perennials. Usually aromatic.

Artemisia stelleriana (dusty miller). MBGargiullo, backdune, Falmouth MA. 9/16/2017

Artemisia stelleriana (dusty miller). MBGargiullo, backdune, Falmouth MA. 9/16/2017

Leaves alternate, mostly pinnately divided to finely dissected.

Flowers very small in small heads. All disk flowers; the outer (involucral) bracts of the heads mostly papery, thin, overlapping, in at least 2 rows .

Artemisia Thuilley 2014-08-07 007 (7).© Paul

Artemisia vulgaris.flower heads. Thuilley 2014-08-07 007 (7).© Paul (Accessed 10/2017).

Fruit dry, very small achenes without appendages. (plumes, teeth, etc.).

Artemisia.vulgaris fruit. © 2003, 2004, 2005 J.K. Lindsey.

Artemisia.vulgaris fruit. © 2003, 2004, 2005 J.K. Lindsey. (Accessed 10/2017).

Ageratina altissima  (Eupatorium rugosum) white snakeroot Asteraceae EURU; Bx, bg, br, bz, pb, sd, sf, up, vc, wv (Yost et al. 1991); NY, bl (Stalter and Tang 2002), ct, hb, iw, rr; Q, a, cu, f, j, u, wl; K, p; R, ah, c, a, cg, fk, gb, js, jw, lp, pr, sv, t;


Eupatorium C. Friedl, Muhlenberg College

Eupatorium C. Friedl, Muhlenberg College (Accessed 4/2014).

Ageratina altissima is a perennial herb, 30-150 cm tall, stems 1-3 together, from a knotty root crown, stems usually hairless below inflorescence. Plant poisonous (Kingsbury 1964). 

Leaves opposite, stalk 10-30 cm long, blade 6-18 cm long, 3-12 cm wide, rather thin, egg-shaped, tip long-pointed, margin coarsely toothed. 

Ageratina altissima close-up. By Steven Baskauf. Copyright © 2017 CC-BY-NC-SA. New England Wild Flower Society.

Ageratina altissima close-up. By Steven Baskauf. Copyright © 2017 CC-BY-NC-SA. New England Wild Flower Society. (Accessed 7/2017).

Flowers bright white, 12-25 per head, no rays, bracteate base 0.3-0.5 cm tall, bracts in 2 rows, sub-equal; inflorescence branched, flat-topped; blooms Aug.-Oct. 

Fruit dry, 1-seeded, 5-angled plumed achene, wind dispersed, seeds eaten by some birds (Martin et al. 1951). 

Wetland status: UPL. 

Frequency in NYC: Common. 

Origin: Native. 

Eupatorium rugosum.David Burg.Van Cortlandt Park, NYC.12:2015

Eupatorium rugosum in fruit.David Burg.Van Cortlandt Park, NYC.12:2015

Habitat: Disturbed, upland woods, along wooded margins of highways, stream corridors; shade and drought tolerant. Tolerant of urban conditions and disturbance. 

Notes: Toxic to deer, so not eaten. Formerly caused poisoning when milk from cows that had eaten E. rugosum was ingested. The toxin is a phenolic and can be lethal. (Kingsbury 1964). Also contains barium sulphate which is toxic in quantity (Yatskievych 2006).

Mikania scandens climbing hemp-weed Asteraceae MISC; Bx, pb; Q, j; R, c, gr, r;

Mikania scandens.Ted Bodner @ USDA-NRCS PLANTS Database.James H. Miller and Karl V. Miller. 2005

Ted Bodner, hosted by the USDA-NRCS PLANTS Database.James H. Miller and Karl V. Miller. 2005. Forest plants of the southeast and their wildlife uses. University of Georgia Press., Athens. (Accessed 5/2014).

Mikania scandens is a perennial, herbaceous vine; stems twining, to 5 m long, usually hairy, roots fleshy. 

Leaves opposite, stalked, blade 3-14 cm long, 2-8 cm wide, base heart-shaped, tip pointed, base deeply lobed, veins palmate, margin entire to few-toothed. 

Flowers dull pinkish, 4 per head, all radially symmetrical (discoid), no rays, basal bracts (involucre) 4, 0.4-0.5 cm long; inflorescence of flat-topped clusters; blooming July-Oct. 

Fruit dry, one-seeded achenes, about 0.2 cm long, white-plumed; wind dispersed in autumn. 

Wetland status: FACW+. 

Frequency in NYC: Infrequent. 

Origin: Native. 

Habitat: Wet, open areas, marshes. Soil pH 5.7-7.5 (USDA 2005). 

Notes: Occasionally aggressive under some conditions. Possibly in response to high nutrient loads or continued disturbance (M. Gargiullo personal observation).  

Iva frutescens marsh-elder Asteraceae  IVFR; Bx, pb, sn; NY, iw, wr; Q, a, dp, fa, fr, i, j; K, do, m, pl; R, gr, mc, mls, pr, sm, t;

Iva frutescens.© DCR-DNH Gary P. Gleming.Virgina Department of Conservation and

Iva frutescens.Arthur Haines.New England Wild Flower 7/2014).

Iva frutescens is a shrub, 0.5-3.5 m tall, bark rather smooth, most stems tend to die back to base during winter making it rather herb-like. 

Leaves opposite below, alternate at branch tips, 4-10 cm long, 1-4 cm wide, gray-green, rather fleshy, margin sharply toothed; leaves expand mid-May (Britton 1874).

 Flowers small, greenish radially symmetrical, tubular, not plumed, female flowers 4-6, male flowers more numerous, anthers yellow; in a compact head arising from a bract-covered base 0.2-0.4 cm long, bracts 4-6; blooming and fruiting Aug.-Oct. 

Fruit dry, 1-seeded, with numerous resin dots (use lens); probably water dispersed. 

Wetland status: FACW+. 

Frequency in NYC: Occasional, but more common near and in salt marsh areas. 

Iva frutescens.Arthhur Haines.New England Wild Flower

Iva frutescens.Arthhur Haines.New England Wild Flower (Accessed 5/2014).

Origin: Native. 

Habitat: Brackish and saline open wetlands, salt marshes, not shade tolerant, soil pH 5-5.7 (USDA, NRCS 2010). 

Notes: Very like Baccharis halimifolia but generally found in wetter soil than is Baccharis. Foliage eaten by Paria thoracica, a Chrysomelid beetle (Krischik and Denno 1990). 

Baccharis halimifolia groundsel bush Asteraceae BAHA; Bx, cm (planted), pb; Q, a, bp; fa, ft, j, wl; NY, bl, iw, rr; K, fl, fs, m; R, c, ca, fk, gr, h, mls, ok, pr, sm, t, wp, x; 


Baccharis halimifolia (groundsel tree; staminate plant).M.B. Gargiullo.Park near Rehoboth Beach DE. 9/2016

Baccharis halimifolia is a shrub 1-3 m tall, bark fibrous gray-brown, new growth green, slightly sticky. 

Baccharis-halimifolia.Forest and Kim

Leaves at Loxahatchee National Wildlife Refuge, Florida – Credit: Forest & Kim Starr – Plants of Hawaii – Image licensed under a Creative Commons Attribution 3.0 License, permitting sharing and adaptation with attribution.

Leaves alternate, stalk short, blade to 6 cm long, 4 cm wide, wedge shaped, upper half coarsely toothed; upper leaves narrow, entire, surface covered with sticky resin, a deterrent to attack by many insects; leaves expand mid May; winter plant leafless 121 days (Britton 1874). 

Flowers very small, inconspicuous, tubular, thread-like, radially symmetrical (discoid), no rays; sexes on separate plants (dioecious); female flowers white-plumed, male flowers flat, yellow due to copious pollen; flowers clustered in dense heads, arising from the expanded top of the floral stalk, and surrounded at their base by small bracts in several overlapping rows, 0.4-0.6 cm tall; heads in branched clusters amid small leaves (bracts); wind pollinated; blooms and fruits Aug.-Oct. 


Baccharis halimifolia (groundsel bush; fruit plumes).Michael Stanton.Corson’s Inlet State Park.10.20.2016

Fruit dry, 1-seeded, achenes, with white plume, wind dispersed into winter. Male plants senesce earlier in Autumn than females.

Wetland status: FACW. 

Frequency in NYC: Frequent. 

Origin: Native. 

Habitat: High salt marsh, beach margins, moist fill near shore soil pH 5.5-7.8 (USDA, NRCS 2010). Not shade tolerant. 

Notes: Very much like Iva frutescens, but generally found on higher ground. Leaves eaten by two species of Chrysomelid beetles, Trirhabda bacharidis, a specialist and Paria thoracica, more of a generalist feeder, the larvae are root feeders. Flowers are attacked by larvae of several flies (Krischik and Denno 1990).  


Xanthium strumarium clotbur; cocklebur Asteraceae XAST*; Bx, pb; NY, hb; Q, a, i, j, rb; K, m; R, ar, c, cs, fk, gr, hs, lc, v;


Xanthium strumarium.T. Beth

Xanthium strumarium.T. Beth (Accessed 5/2014).

Annual C3 herb (Ludwig et al 2010)from a taproot, stem 20 cm to 2 m tall, erect, coarse, glandular-hairy, often sticky and branching, purple-spotted. 

Leaves, alternate above, lowest pair sometimes opposite, broadly oval, margin coarsely toothed or lobed. 

Flowers green, sexes separate, male flowers small, in short, dense, bracteate spikes, pollen highly allergenic (similar to ragweed, Ambrosia), wind pollinated, but mostly self-pollinated; female burs 1-2 cm long, oval-cylindrical with hooked spines, 2 larger in-curved spines at apex, bur 2-chambered each with 1 seed; blooms Aug.-Oct., will not flower if photoperiod is more than 14 hrs. (Weaver and Lechowicz 1983). 

Xanthium strumarium.Steven Baskauf.New England Wild Flower

Xanthium strumarium.fruit.Steven Baskauf.New England Wild Flower ( Accessed 5/2014).

Fruit, dry, to 0.2 cm, flattened achene, toxic, cotyledons contain carboxyatractyloside, (older seedling and plants rough but not toxic); fruits Oct.-Nov. Seeds dispersed into winter by burs clinging to fur or clothing, also able to float for up to 30 days. Seeds buried in soil loose viability within a 2-3 years. 

Wetland status: FAC. 

Frequency in NYC: Occasional. 

Origin: Native to the New World. 

Habitat: Open, disturbed areas especially beaches, shores, fill. An agricultural weed. Prefers sandy soil, pH 5.2-8.0, tolerates flooding and salt. Intolerant of shade. 

Notes: Adaptation to water dispersal and flood tolerance may indicate Cocklebur originally occupied ephemeral stream bank and open flood plain habitats (Marks 1983). Seeds of Cocklebur are attacked by the larvae of a moth, Phaneta imbridana, and of a trypetid fly, Euaresta aequalis. Both insects tend to affect smaller burs rather than larger ones Plants are also attacked by the rust Puccinia xanthii, an obligate parasite of Cocklebur and of Ambrosia spp. The fungus causes damage to leaves, leaf drop, and splitting of petioles and stems. Cocklebur is host to a number of other fungi including Septoria xanthiiCercospora xanthicola, Mycosphaerella xanthicola and other fungi that specialize on Xanthium spp. The nematode Aphelenchoides ritzema-bosi has also been found on Cocklebur (Weaver and Lechowicz 1983).  

Vernonia noveboracensis New York ironweed Asteraceae VENO; Bx, pb; R, lp;


Vernonia noveboracensis.Eleanor

Vernonia noveboracensis. © 2001 Eleanor (Accessed 4/2014).

Vernonia noveboracensis is a perennial herb, 1-2 m tall. Winter plant dark brown with numerous flower heads. 

Leaves alternate, stalkless, lance-shaped, 10-28 cm long, 1.5-6 cm wide, tip long pointed, gradually narrowed to base, rough above, hairy below, margin toothed or almost entire 

Flowers purple, in heads with 30-55 flowers, bracts at base of head 0.7-1.7cm long with long, filament-like tips; inflorescence open, flat-topped to indented; blooms Aug.-Oct. 

Fruit dry, an achene with dark brownish plume. 

Wetland status: FACW+. 

Frequency in NYC: Very infrequent.

 Origin: Native. 

Habitat: Open marshes, wet edges. 

Verbesina alternifolia wingstem Asteraceae VEAL; Bx, br; pb; R;


Verbesina alternifolia.David G.

Verbesina alternifolia.David G. (Accessed 4/2014).

Verbesina alternifolia is a perennial herb 1-3 m tall, stem usually hairy, often winged. 

Leaves alternate, lanceolate, 10-25 cm long, 2-8 cm wide, roughly hairy, esp. above, (hairs often with swollen bases, use hand lens), tip long pointed, base tapering to short stalk, margin toothed to entire. 

Flowers yellow, rays 2-10, 1-3 cm long, sterile, disk flowers yellow, tending to spread out rather loosely even before opening, disk 1-1.5 cm wide, bracts of head few, narrow, loose, bent downward. 

Fruit dry achenes, flat, usually winged, topped by two awns, in a rounded head, spreading in all directions, to 1.5 cm wide. Differs from Helianthus in alt. leaves and open, sloppy flower heads with loose, downward-bent bracts. 

Wetland status: FAC. 

Frequency in NYC: (NYS S2, T) Very infrequent. 

Origin: Native. 

Habitat: Moist woods, shady edges. 

Tussilago farfara coltsfoot Asteraceae TUFA*; Bx, pb; R, cs, lp, pm, t;



Tussilago (Accessed 5/2014).

Tussilago farfara is a perennial herb 5-50 cm tall, colonial from rhizomes. 

Leaves rounded, 5-20 cm long and wide, in basal cluster after flowers fade, toothed and shallowly lobed, appearing angled, base deeply lobed, white-wooly below, leaf stalks elongate, hairy, persisting into winter. 

Flowers yellow, in heads to 3 cm wide, rays narrow, numerous, bracts of flower head 0.8-1.5 cm long, blooming before new leaves appear; blooms April-May, singly on elongate, bracteate stems, flowering stems often in very dense clumps.

Fruit an achene,  plumed, wind dispersed. 

Wetland status: FACU. 

Frequency in NYC: Infrequent. 

Origin: Eurasia. 

Habitat: Disturbed edges, moist roadsides, fill. 

Notes: Life cycle: rapid seed germination in spring following seed dispersal, development of a taproot and rhizomes in summer along with leaf growth and flower bud formation by autumn, leaves die back in winter, flower bud development continues. In spring, flowers bloom before leaves emerge, seed is set, dispersed, flower stem dies back and rhizome fragments. Rhizomes of previous year form leaves the second year and flower the third year (Ogden 1974).