Erigeron L.

Ghazanfar, S. A., Edmondson, J. R. & Hind, D. J. N. (Eds). (2019). Flora of Iraq, Volume 6: Compositae.Kew Publishing

Morphology General Habit

Annual, biennial or perennial herbs

Morphology Leaves

Leaves simple, alternate, spatulate, entire to coarsely dentate; indumentum of vegetative parts of simple, white  spreading  cover  hairs  and  in some species also sessile or short glandular hairs

Morphology Reproductive morphology Inflorescences

Inflorescence of remote hemispherical capitula, capitula solitary or several in corymbs or thyrses

Morphology Reproductive morphology Inflorescences Capitulum

Capitula heterogamous, radiate; involucre turbinate to hemispherical; phyllaries 2–3(–7)-seriate, herbaceous, imbricate, gradate, sometimes subequal; receptacle flat to convex or conical, epaleaceous

Morphology Reproductive morphology Flowers Florets

Florets of 2–3 types, outer female, 1–4-seriate, rays limbs narrow, purplish to bluish, lilac or white, intermediate female or absent, corollas filiform, inner disc florets tubular, hermaphrodite, corollas yellow, 5-lobed; female florets with filiform corolla-tube and ray lacking or very reduced

Morphology Reproductive morphology Fruits

Achenes obovate, compressed, 2–4-ribbed, pale, glabrous or setuliferous; pappus of few to numerous scabrid, dirty white or brownish hairs, sometimes with outer minute subsquamose hairs, accrescent in fruit to up to 1.5 × involucral length, pappus of ray-florets sometimes very rudimentary.

Distribution

A world-wide genus of perhaps ± 170 to as many as ± 400 species (according to Nesom & Robinson 2006) – but on a world scale its delimitation from closely allied genera is incomplete.

Etymology

Erigeron (from the Gr. ήρι, ēri, early and γέρον, geron, old man – the pappus is soon conspicuous in the capitula).

George R. Proctor (2012). Flora of the Cayman Isands (Second Edition). Royal Botanic Gardens, Kew

Morphology General Habit

Erect annual or perennial herbs; leaves usually in a basal rosette and alternate and numerous on the stems, entire, toothed, or deeply divided

Morphology Reproductive morphology Flowers

Heads radiate, solitary or in corymbs or panicles; involucre bell-shaped, with phyllaries in 1–3 series; receptacle flat and naked, pitted

Ray

Ray-florets pistillate, in 2 or more series, with filiform corollas and very short ligules; disc-florets 4–5-toothed

Morphology Reproductive morphology Fruits

Achenes narrow, with pappus of 2–3 rows of bristles.

Distribution

A chiefly temperate and subtropical genus of about 60 species.

Ghazanfar, S. A., Edmondson, J. R. & Hind, D. J. N. (Eds). (2019). Flora of Iraq, Volume 6: Compositae.Kew Publishing

Morphology General Habit

Annual to perennial herbs

Morphology Leaves

Leaves alternate, of varying form, entire, toothed or lobed, often with an indumentum of long or short hairs (or both)

Morphology Reproductive morphology Inflorescences

Inflorescence a branched corymbose panicle

Morphology Reproductive morphology Inflorescences Capitulum

Capitula heterogamous; phyllaries 2–4–seriate, herbaceous, imbricate,often with resinous brown midribs, involucre exceeded at flowering time by conspicuous dirty-white pappus, eventually reflexed with inner surfaces of phyllaries outermost

Morphology Reproductive morphology Flowers Florets

Florets all fertile, with several outer series of minute filiform or ligulate female florets and fewer central tubular hermaphrodite disc-florets

Morphology Reproductive morphology Flowers Corolla

Corolla cream, yellow or purple

Morphology Reproductive morphology Fruits

Achenes compressed, obovate or oblong, off-white to brown, ± pilose; pappus uniseriate, of minutely barbellate bristles, ± equalling florets in length and giving the characteristically fluffy appearance of the inflorescence at flowering.

Etymology

Conyza (a name used by Pliny for a kind of Fleabane, possibly derived either from the Gr. κουνούπι, kounoupi, gnat, or from the Gr. σκόνη, skoni, dust, a reference to the plant’s use as a flea-powder).

Compositae, H. Beentje, C. Jeffrey & D.J.N. Hind. Flora of Tropical East Africa. 2005

Morphology General Habit

Annual or perennial herbs, rarely shrubs or small trees

Morphology Leaves

Leaves alternate or in a rosette, entire to pinnatifid, usually with semi-amplexicaul base, usually with serrate or dentate margins

Morphology Reproductive morphology Inflorescences Capitulum

Capitula disciform or shortly radiate, united in cymes, these in turn united in corymbose or paniculate inflorescences, rarely solitary

Morphology Reproductive morphology Flowers Florets

Marginal florets many, in several rows, tubular and filiform, sometimes with a short ray, white or yellow, the style with short linear branches; central florets hermaphrodite, usually few, yellow or white, tube cylindrical proximally and infundibuliform distally, 5-lobed; anthers obtuse at base, distally with triangular appendages; style branch appendages lanceolate to triangular and papillose

Morphology Reproductive morphology Fruits

Achenes sometimes compressed, usually pubescent, ribbed; pappus uniseriate, of many fine barbellate setae, often fragile.

M. Thulin et al. Flora of Somalia, Vol. 1-4 [updated 2008] https://plants.jstor.org/collection/FLOS

Morphology General Habit

Annual or perennial herbs, rarely shrubs or small trees

Morphology Leaves

Leaves alternate or in a rosette, entire to pinnatifid, usually with semi-amplexicaul base, usually with serrate or dentate margins

Morphology Reproductive morphology Inflorescences

Capitula disciform or shortly radiate, united in cymes, these in turn united in corymbose or paniculate inflorescences, rarely solitary

Morphology Reproductive morphology Flowers Florets

Marginal florets many, in several rows, tubular and filiform, sometimes with a short ray, white or yellow, the style with short linear branches; central florets bisexual, usually few, yellow or white, tube cylindrical below and funnel-shaped above, 5-lobed, anthers obtuse at base, with triangular apical appendage, style branch appendages lanceolate to triangular and pappillose

Morphology Reproductive morphology Fruits

Achenes sometimes flattened, usually pubescent, ribbed; pappus uniseriate, of many fine barbellate bristles, often fragile.

Distribution

Some 60 species in the tropics and subtropics, several weedy and widespread.