Bidens L.

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

Morphology General Habit

Annual (in Somalia) or perennial herbs or shrubs

Morphology Leaves

Leaves opposite, petiolate, pinnately 3–9-lobed to bipinnatisect

Morphology Reproductive morphology Inflorescences

Capitula erect at anthesis, in open corymbose or paniculate cymes; receptacle flat to conical, paleate

Morphology Reproductive morphology Inflorescences Bracts Phyllaries

Outer phyllaries herbaceous, 1–3-veined, 1-seriate Inner phyllaries grey- or orange-striated with yellow scarious margins, membranous, 1-seriate

Ray

Ray florets yellow or white, neuter or pistillate, rarely with pistillodes or staminodes

Morphology Reproductive morphology Inflorescences Bracts Palea

Paleae membranous, white to pale yellowish-brown, 2–9-striated, oblong-linear

Morphology Reproductive morphology Flowers Disc

Disk florets yellow, bisexual; corolla 5-lobed; anthers brown, caudate or sagittate at the base, with triangular-ovate appendage; style branches penicillate

Morphology Reproductive morphology Fruits

Achenes flattened or tetragonal, black, striate-sulcate, variously hairy, not winged, margins sometimes callose-thickened

Morphology Reproductive morphology Seeds Pappus

Pappus aristae 2–4, rarely absent, backwardly barbed, trigonous at base.

Distribution

Genus of over 200 species, with worldwide distribution, and with centers of diversity in Africa and Mexico.

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

Morphology General Habit

Herbs, shrubs, or sometimes vines; leaves mostly alternate, simple and toothed, or variously divided

Morphology Reproductive morphology Flowers

Heads usually radiate (rarely discoid only), solitary or few at ends of branches, sometimes in panicles; involucre more or less bell-shaped, of rather few phyllaries in 1 or 2 series; receptacle flat or slightly raised, bearing flat scales subtending the florets

Ray

Ray-florets in 1 series, usually neuter and sterile

Disc

Disc-florets perfect and fertile, tubular and 5-toothed; anthers entire at the base or minutely sagittulate; style-arms hairy and appendaged at the top

Morphology Reproductive morphology Fruits

Achenes compressed or 4-angled, usually oblong or linear-oblong; pappus of 2–4 (rarely 6) awns usually upwardly or downwardly barbed, rarely smooth or lacking.

Distribution

A cosmopolitan genus of about 230 species.

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

Morphology General Habit

Erect, procumbent or scandent, annual or perennial, glabrous or pilose  herbs  or shrubs

Morphology Stem

Stems terete or angled

Morphology Leaves

Leaves opposite, simple, toothed or pinnatisect, rarely ternate

Morphology Reproductive morphology Inflorescences

Inflorescence corymbose-paniculate, white, yellow or rarely red-flowered

Morphology Reproductive morphology Inflorescences Capitulum

Capitula homogamous, discoid or heterogamous and radiate; involucre campanulate or hemispherical, 2–(3–4)-seriate, outer phyllaries unequal, foliaceous; inner series smaller and membranous; receptacle flat, scaly; scales ± flat, subtending disc florets

Ray

Ray florets 1-seriate, ligulate, neuter, rarely pistillate; disc florets tubular, bisexual, fertile; style arms with shortly conical appendage

Morphology Reproductive morphology Fruits

Achenes oblong-cuneate, ± 3–4-angular, apex truncate; pappus of 2–4, rigid, persistent, retrorsely or occasionally antrorsely barbed awns.

Distribution

A genus of about 200 species, distributed throughout temperate Eurasia, N Africa and N & S America; one species in Iraq.

Etymology

Bidens (from Lat. bi, two, dens, tooth).