8. Malacothrixcalifornica Ligulate head Radiate heads, having inner disk flowers and peripheral ray flowers Aster sp Bilabiate heads, i.e., having bilabiate flowers; Acourtiamicrocephala.
9. Discoid heads, with all disk flowers. ChaenactisartemisiifoliaandChaenactisgabriuscula Disciformheads, with inner staminate or bisexual and outer pistillateflowers. Cotulacoronopifolia, brass buttons. Note reduced, 4-merous flowers
10.
11. The perianth is biseriate or uniseriate with hypanthium absent.
12. The calyx, known as the pappus, is modified as 2 ∞ (sometimes connate) awns, scales, or capillary bristles (typically barbed or plumose), pappusabsent in some.Cirsiumvulgare, a thistle.
13. The corolla is sympetalous with 5 [rarely 4] lobes (reduced to 3 marginal teeth in some), of three structural types (also called flower types): (1) bilabiate, corolla zygomorphic with a short tube having upper and lower lips (2) disk, corolla actinomorphicwith short to elongate tube bearing 5 [4] teethlike or elongate lobes; or (3) ray or ligulate, corolla zygomorphic with generally short tube having elongate, flat, extension bearing 3 5 apical teeth.
14.
15. Anthersare basifixed, with apical extensions and sometimes basal lobes, longitudinal and introrse in dehiscence.Ambrosia [Hymenoclea] salsola Discoid heads; male heads Female heads.
16.
17. The styleis solitary and apically two-branched; stigmas are two, occuringas stigmatic lines on the adaxial surface of style branches.Enceliacalifornica -disk flower, showing inferior ovary and corolla Chrysanthemum coronarium
20. The fruit is an achene (or cypsela, an achenederived from an inferior ovary), typically a multiple fruit of achenes, an elongate beak forming between fruit and pappus in some taxa.
21.
22. … Summary The Asteraceae are distinctive in being herbs, shrubs, vines, or trees, the inflorescence a head (capitulum) subtended by an involucre of phyllaries, flowers either bilabiate, disk, or ray/ligulate (heads of many taxa a mixture of central disk flowers and peripheral ray flowers), with the calyx, termed a pappus, modified as scales, awns, or capillary bristles (or absent), the androeciumsyngenesious, and with an inferior ovary with a single, basal ovule, the fruit a multiple of achenes.
23. K 0-∞ (pappus) C (5) [(4)] or (3) in some ray flowers A (5) [(4)] G (2), inferior.
