The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

little ironweed

ironweed

Habit Annuals (perhaps persisting), 2–6(–12+) dm.
Leaves

blades 20–35(–50+) × 12–25(–30+) mm (including petioles).

mostly cauline (at flowering);

petioles ± winged;

blades ovate to trullate, deltate, oblanceolate, or spatulate, bases ± cuneate, margins serrate, apices rounded to acute, abaxial faces ± hirtellous to densely piloso-strigillose, resin-gland-dotted, adaxial faces ± scabrellous or glabrate.

Bracts

± linear at proximal nodes, wanting distally.

Peduncles

3–10(–20+) mm.

Involucres

± campanulate to turbinate or hemispheric, 4–5 mm diam.

Florets

13–20(–24+);

corollas lavender to pink or purplish, tubes longer than funnelform throats, lobes 5, lance-linear, ± equal.

Phyllaries

3–4 mm.

24–32+ in 3–4+ series, the outer subulate to lanceolate, inner ± lanceolate, all ± chartaceous, margins entire, tips apiculate to spinose, abaxial faces ± strigillose, ± resin-gland-dotted.

Heads

discoid, ± pedunculate, not subtended by foliaceous bracts, (12–)40–100+ in ± corymbiform arrays (6–)10–15+ cm diam.

Cypselae

1.5–2 mm;

pappi white, outer scales 0.1–0.3 mm, inner bristles 3–4 mm.

± columnar, not ribbed, ± strigillose;

pappi of ± 20 ± persistent outer scales, plus ± 20 caducous inner bristles.

x

= 9 (18?).

2n

= 36.

Cyanthillium cinereum

Cyanthillium

Phenology Flowering year-round.
Habitat Disturbed places
Elevation 0–10 m (0–0 ft)
Distribution
from FNA
FL; Mexico; Central America; South America; West Indies; Asia; Africa; Indian Ocean Islands; Pacific Islands [Introduced in North America]
[BONAP county map]
from FNA
FL; probably paleotropical in origin; now widely established in tropical and warm-temperate regions as naturalized ruderals [Introduced in North America]
[BONAP county map]
Discussion

Species 1–2 (1 in the flora).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 19, p. 205. FNA vol. 19, p. 204.
Parent taxa Asteraceae > tribe Vernonieae > Cyanthillium Asteraceae > tribe Vernonieae
Subordinate taxa
C. cinereum
Synonyms Conyza cinerea, Vernonia cinerea
Name authority (Linnaeus) H. Robinson: Proc. Biol. Soc. Wash. 103: 252. (1990) Blume: Bijdr. Fl. Ned. Ind., 889. (1826)
Web links