Description :

• Glabrous or pubescent annual herbs
• Leaves alternate, variously pinnatisect
• Capitula radiate or discoid, solitary or in corymbs, pedunculate
• Involucre subglobose; bracts in several rows, apically obtuse or acute, with scarious margins, with or without central resin canal
• Receptacle flat, convex or conical-globose, epaleate
• Ray florets , if present, female, fertile, strap-shaped; corolla white
• Disc florets bisexual; corolla always 4-lobed; lobes often cucullate; tube conspicuously swollen and of thick and brittle texture; limb campanulate and partly enervate
• Anthers ecalcarate and ecaudate
• Style branches with or without central resin canal
• Cypselas yellowish brown, ± terete but tapering at base, 4-ribbed, with abaxial entire or toothed rim, glandular between ribs especially on adaxial side; pericarp very thin; epicarpic cells ± sclerenchymatous, elongated with narrow lumina; testa epidermis cells with thick, sinuate walls
• Pappus 0
• x = 9 (aneuploids, B-chromosomes)

Nomenclature:

• Oncosiphon Källersjö
  • Källersjö: 310 (1988)
  • Bremer & Humphries: 152 (1993)
  • Bremer: 476 (1994)
• Matricaria L.
  • Linnaeus: 891 (1753), in part excluding type.
• Pentzia Thunb.
  • Thundberg: 145 (1800), in part excluding type

Distribution & Notes:

• Southern Africa : Species 8, endemic, mainly Namibia, Northern and Western Cape, 1 species extending to North-West, Gauteng, Mpumalanga, Free State, Lesotho and Eastern Cape