Herbs, annual or perennial, sometimes shrubs or climbers, rarely arborescent, often
with stolons, rhizomes, tubers or fleshy roots, variously pubescent or glandular, rarely
laticiferous. Leaves alternate or opposite) sometimes radical, simple or sometimes 2 to
many foliate, entire to variously dissected; stipules absent. Flowers actinomorphic or
zygomorphic, hermaphrodite, unisexual or neuter, 1 to numerous, aggregated on a
common receptacle, enclosed by a common involucre of bracts (phyllaries) forming the
heads or capitula. Phyllaries in one or more series, free or connate, valvate or imbricate,
green or coloured, herbaceous or scarious. Capitula sessile or peduncled, variously
arranged spikes, corymbs, panicles or rarely in glomerules; .homogamous or
heterogamous or sometimes monoecious, discoid (all florets alike, perfect and have
tubular corolla) or ligulate (all florets perfect but with ligulate corolla; ligules
conspicuous) or disciform (outer florets filiform, pistillate; ligules inconspicuous) or
radiate (ray florets on the periphery, either neutral or pistillate and disc florets on the rest
of the receptacle). Receptacle flat, convex, concave or conical, paleaceous or naked.
Calyx absent or reduced to pappus of bristles, awns or scales. Corolla sympetalous, of
4 - 5 petals, tubular, ligulate or bilabiate. Stamens 5 or rarely 4, epipetalous, alternating
with corolla lobes; anthers 2-loculed, connate (syngenesious) forming a tube around the
style, oblong, introrse with sterile tips, obtuse or sagittate or caudate and tailed at base,
dehiscing lengthwise. Style branches 2, filiform or broader, appendaged or not. Ovary
inferior, unilocular, terete or compressed; ovuie solitary. Fruit an achene (Cypsela),
variously ridged and grooved or striate, smooth of with ornamentations, often crowned
by the persistent pappus. Pappus in one or more series, simple or feathery, often replaced
by bristles, awns or scales. Seeds exalbuminous.
The family constitutes the largest vascular plant family with ca 30,000 species and
over 1100 genera. Although the family is well represented in temperate or subtropical
regions, the species have adopted to varied ecological conditions. In lowland areas, a
large number of species have become adventive. In India, the family is represented by
ca 900 species under 167 genera. The species are distributed widely along sea coasts,
cultivated fields, alpine areas in Himalayas and in cold deserts of Ladakh and Lahul-Spiti.
A vast majority of them are recent introductions and some obnoxious weeds in the
agriculture fields are Eupatorium spp., Mikania micrantha, Parthenium hysterophorus,
Ageratum conyzoides. A. houstonianum, Tagetes minuta, Acanthospermum hispidum,
Xanthium indicum and a few others.
Economically the family is important as the source of Sunflower and Safflower oil.
Many are useful in native medicines. Several ornamental taxa belonging to
Chrysanthemum. Dahlia, Cosmos, ragetes, Calendula, Zinnia and a few others are
popular throughout the world.
Asteraceae form a distinct group whose phylogenetic relationship within the family
as well as with other families are not clearly established. Many consider that Asteraceae
are allied to both Campanulales and Calycerales (Takhtajan , 1980). Based on
palynological evidences (Skvarla et al. 1977) the family is said to be closely related to
Calyceraceae. According to Cronquist (1981) the Calyceraceae can be no more than
'Collateral allies' of Asteraceae. The family differs from Campanulaceae in having
flowers aggregated into capitulum surrounded by involucral bracts, connate anthers, the
2-lobed or 2-fid style, definite number of carpels and ovules and nonendospermous
seeds. Therefore, derivation of Asteraceae from Campanulaceae stock is also ruled out.
Rubiales have also been considered as a possible ancestral group by Cronquist
(1981). But Asteraceae are quite distinct chemically as well as morphologically.
According to Cronquist (1981) the ancestry of Asteraceae probably lies in or near the
Rubiaceae, along a line parallel in some respects to the line leading to the Dipsacales and
Calycerales.
Within the family, the phylogenetic relationship among the various tribes is also no~
clear. Some authors consider Heliantheae as the most primitive tribe (Cronquist, 1958).
Yet others consider Vemonieae, Mutisieae, Senecioneae as the primitive tribes. In the
present treatment of the family Bentham & Hooker's (1873) arrangement of tribes is
broadly followed, except for tribe Tageteae which has been treated as a distinct tribe.
Literature.
BENTHAM, G. (1873). Notes on the classification, history and geographical distribution
of Compositae. J. Linn. Soc. Bot. 13: 335 - 577. BENTHAM, G. & J.D. HOOKER(1873). Compositae. Genera
Plantarum 2: 163 - 533. CARLQUIST, S. (1976). Tribal interrelationships and Phylogeny of the Asteraceae.
Aliso 8: 465-492. CLARKE. C.B.
(1876) compositae Indicae, London. CRONQUIST, A. (1955). Phylogeny
and Taxonomy of the Composilae. Am. Midl. Nat. 53: 478 - 511. CRONQUIST, A. (1977). the compositae
revisited. Brittonia 29: 137 - 153. CRONQUIST, A. (1981). An integrated system of classification of flowering
plants. p.p. 1262. New York. HEYWOOD, V.H., J.B. HUBOURNE & B.L. TURNER (1977). The Biology
and chemistry of the compositae 2 vols. Academic Press, London. HOFFMAN, O. (1894). Compositae in
Engler & Prantl. Nat. Pflanzenfam. IV. 5: 87 - 387. HOOKER, J.D. (1881). Compositae in Flora of British
India 3: 219 - 419. RAO, R.R. et al. (1988). Florae Indicae Enumeratio-Asteraceae. Bot. Surv. India, Calcutta.
SKVARIA, J.J., B.L.
TURNER, V.C. PATEL & A.S. TOMB (1977). Pollen morphology in the compositae
and in morphologically related families. In V.H. HEYWOOD & J.B. HAUBOURNE (eds.) The Biology and
Chemestry of Compositae 1: 141 - 259. Academic Preas London. SMALL, J. (1917-1919). the origin and
development of the compositae. New Phytol. 16: 157 - 177, 198 - 221, 253 - 276; 17: 13 - 40, 69 - 94, 114 - 142, 200 - 230; 18. 1 - 35, 65 - 89, 129 - 176, 201 - 234. SOLBRIG, O.T.
(1963). Subfamilial nomenclature in Compositae.
Taxon 12: 229 - 235. SOLBRIG, O.T.
(1963). The Tribes of Compositae in the Southeastern United Slates. J.
Arn. Arb. 44: 436 - 461. TAKHTAJAN, A. (1980). Outline of the classification of Flowering Plants
(Magnoliophyta) Bot. Rev. 46: 225 - 359. Columbia Univ. Press, New York. WAGENITZ, G. (1975).
Systematics and Phylogeny of the Compositae (Asteraceae) Pl. Syst. Evol. 125: 29 - 46.
KEY TO THE TRIBES
1a. Capitula homogamous; florets all ligulate or tubular or tubuliform
2
b. Capitula heterogamous; florets both ray and Disk
10
2a. Florets all ligulate (florets all ligulate in calamiris but achenes silky, villous.)
b. Involucral bracts 1-many seriate, not connate as above
17
17a. Pappus of white, copious, capillary hairs (paleaceous in Seneciograhomi and S. belgamensis, but
leaves white tomentose beneath with prominent venation)
