Annual, biennial or perennial herbs, sometimes shrubs, rarely trees, with or without milky latex, sometimes armed with spines, usually terrestrial, rarely aquatic herbs. Leaves alternate, opposite or rosulate, exstipulate, entire, toothed, lobed or variously dissected. Individual flowers (florets) usually small and numerous, sessile and aggregated on a receptacle, surrounded by an involucre, made up of 1–several series of bracts (phyllaries or involucral bracts) and the whole structure forming a capitulum. Capitula usually solitary or variously arranged in corymbose or paniculate synflorescences. Phyllaries may be herbaceous, fully scarious or at the margins only or chartaceous, usually with a sclerified portion in the centre (sterome) which may be undivided or divided into two parallel parts. Receptacle naked (epaleate) or bearing scales (paleate) or long hairs or bristles, receptacular surface with or without scale like ridges. Capitula with all florets of one sexual state, either male, female or hermaphrodite (homogamous) and heterogamous when florets of more than one sexual state are present. Homogamous capitula may be discoid having only disc florets or ligulate bearing only ligulate florets. Heterogamous capitula are radiate having disc florets in the centre and peripheral ray florets or radiant bearing disc florets in the centre and peripheral florets with ± dilated, radical to strongly bilateral corolla or disciform bearing perfect or functionally male disc florets in the centre and peripheral filiform florets. Florets are epigynous, bisexual, female or male (at least functionally) or sterile (neuter). Calyx often represented by a pappus of 1 or more series of bristles, scales or awns on the apex of the ovary or sometimes pappus completely absent. Corolla gamopetalous, tubular, fililform, ligulate or rarely bilabiate, usually 3 or 5 – toothed, rarely absent. Stamens 5, epipetalous, anthers connate forming a tube round the style, filaments free, rarely anthers free, dehiscence introrse, calcarate or ecalcarate, caudate or ecaudate or sometimes sagittate, endothecial tissues polar or radial; filaments usually with a collar. Ovary inferior, 1–celled. Style usually divided above into two branches with acute or obtuse sweeping hairs reaching below the bifurcation or not. Fruit unicellular indehiscent, cypselas (achene) with or without ribs, sometimes with distinct carpopodium (basal attachment area), very rarely a drupe.

Asteraceae, the second largest family of Angiosperms after Orchidaceae in terms of number of species but largest in number of genera, comprises of ca 1600 genera and ca 24000 species, present almost every where with the exception of Antartica.

Asteraceae is also the largest family in Pakistan, represented by 188 genera and 770 species including some commonly cultivated taxa also. Volume 224 (Asteraceae – VI) of the Flora of Pakistan is the last volume/ part of the family In the first volume of Asteraceae (I) – Anthemideae, a infra-familial key pertaining to the tribes present in Pakistan was provided. The present volume VI is now being published almost after 18 years, since then lot of changes have taken place particularly based on molecular and phylogenetic studies resulting into reshuffling of number of genera from one tribe to another. The circumscription of quite a few tribes is greatly changed. Some old and forgotten tribes and genera are resurrected even some new tribes are recognized/ described. New genera are being described continuously and many polyphyletic genera are splitted into a number of satellite and smaller genera. Therefore, it seemed necessary to provide a new key for the tribes of Asteraceae occurring in Pakistan. In all 19 tribes in our area are recognized. There is a controversy in the recognition of subfamilies for instance Bremer (Asteraceae: Cladistics and Classification, 1994) recognized 3 subfamilies and 16 subtribes; Panero & Funk (Proc. Biol. Soc. Washington 115: 900-922. 2002) recognized 10 subfamilies whereas Kadereit & Jeffery (The Families and Genera of Flowering Plants Vol. VII. 2007) recognized 5 subfamilies. Not going in the details of the classification, we have followed Jeffrey in Kadereit & Jeffrey, l. c. in general outline and arrangement of tribes.

Key to the tribes, treated in Flora of Pakistan along with the synopsis of the genera are provided. Genera within each tribe are alphabetically arranged. Volume number against each genus is also given in parenthesis.