Asteraceae tribe Arctotideae

Annuals, perennials [shrubs] (sometimes prickly, sap sometimes milky, e.g., Gazania). Leaves basal and/or cauline; alternate; petiolate or sessile; margins usually pinnately lobed to dissected, sometimes dentate or entire (sometimes revolute and/or prickly). Heads usually heterogamous (usually radiate) [homogamous, discoid], borne singly (on scapiform peduncles) [in corymbiform, racemiform, or umbelliform arrays, sometimes aggregated in second-order heads]. Calyculi 0. Phyllaries usually persistent, in (2–)3–6+ series, distinct or ± connate, usually unequal, usually herbaceous [sometimes fleshy], margins and/or apices sometimes notably scarious (at least inner; sometimes prickly-ciliate). Receptacles flat to conic, epaleate [paleate] (often foveolate). Ray florets in 1–2 series, usually pistillate and fertile or styliferous and sterile, sometimes neuter (sometimes with 4–5 staminodes); corollas mostly white, yellow, orange, blue, red, or purple (rarely with 2 teeth opposite the 3- or 4-toothed laminae). Disc florets usually bisexual and fertile, sometimes functionally staminate; corollas yellow or dark brown to purple, actinomorphic, lobes [4–]5, narrowly triangular or lanceolate to deltate; anther bases obtuse to acute (sometimes ± sagittate, not tailed), apical appendages ± ovate to lanceolate; styles (in bisexual, fertile florets) proximally glabrous, usually distally dilated and ± cylindric (usually hispidulous near bases of cylinders), branches linear (sometimes adhering almost to minutely parted tips or essentially lacking), adaxially continuously stigmatic from bases to apices, apices rounded to acute, appendages essentially none. Cypselae usually monomorphic within heads, mostly ellipsoid, obovoid, or ovoid, ± terete, angled, or ± flattened, not beaked, bodies usually ribbed, sometimes winged (often sericeous, tomentulose, or woolly, sometimes glabrous); pappi (sometimes 0) usually persistent, usually of 4–8[–16+] scales in ± 2+ series, sometimes coroniform.

Distribution

Introduced; mostly Old World (especially s Africa), some species widely introduced as horticultural escapes.

Discussion

Genera 16, species ca. 200 (3 genera, 4 species in the flora).

The circumscription for Arctotideae adopted here follows that of K. Bremer (1994) and is narrower than that of N. T. Norlindh (1977[1978]). Arctotideae have been thought to be closely allied to members of Cynareae, chiefly on similarities in styles of some taxa and prickly, thistly habits in some taxa; such a relationship has been rejected by recent workers. J. L. Panero and V. A. Funk (2002) associated Arctotideae with their subfamily Cichorioideae, along with tribes Vernonieae, Liabeae, Cichorieae, and Gundelieae.

Haplocarpha lyrata Harvey (perennials, leaves in basal rosettes, 8–15 cm, blades usually lyrate, abaxially lanate, peduncles scapiform, 10–25+ cm, ray corollas mostly yellow, abaxially green or red) has been noted as established in Florida (www.plantatlas.usf.edu).

Selected References

Funk, V. A., R. Chan, and S. C. Keeley. 2004. Insights into the evolution of the tribe Arctoteae (Compositae: subfamily Cichorioideae s.s.) using trnL-F, ndhF, and ITS. Taxon 53: 637–655.

Norlindh, N. T. 1977[1978]. Arctoteae—systematic review. In: V. H. Heywood et al., eds. 1977[1978]. The Biology and Chemistry of the Compositae. 2 vols. London. Vol. 2, pp. 943–959.

Lower Taxa

Arctotheca, Arctotis, Gazania

Key

1	Phyllaries connate 1/3–3/4 their lengths; laminae of ray corollas 5-nerved, 4-lobed or -toothed.	Gazania
1	Phyllaries distinct; laminae of ray corollas 4-nerved, 3-lobed or -toothed	> 2
2	Ray florets neuter, corollas adaxially yellow (sometimes drying bluish) or ± bluish; pappi of 7–8+ scales ca. 0.5 mm (usually hidden by hairs on cypselae)	Arctotheca
2	Ray florets pistillate, corollas adaxially whitish to purplish, or yellow to orange (then purple at bases); pappi 0 or of 5–8 scales 0.5–4 mm (usually not hidden by hairs on cypselae)	Arctotis