Fruit differentiation, palynology, and systematics in Pterocephalus and Pterocephalodes, gen. nov. (Dipsacaceae).

Veronika Mayer, Friedrich Ehrendorfer

    Veröffentlichungen: Beitrag in FachzeitschriftArtikelPeer Reviewed

    Abstract

    The single-seeded fruits of the Dipsacaceae are enclosed by four fused bracts forming an epicalyx. A detailed study of the epicalyx morphology and anatomy of nearly all of the approximately 30 species of Pterocephalus s.l., together with other floral, palynological and karyological data, suggest only loose relationships and convergent similarities (homoplasies) between the core of the taxa (Pterocephalus s.s.), ranging from south-west and central Asia (P. gedrosiacus, P. afghanicus) to Macaronesia (e.g. P. dumetorum) east Africa (P. frutescens) and southeast Asia (P. hookeri, P. bretschneideri and P. siamensis). The latter are separated as a new genus: Pterocephalodes. Pterocephalus s.s. lacks floral bracts, has numerous feathery calyx bristles and 5-merous corollas, and is apparently monophyletic. Its species demonstrate the gradual development of a hyaline corona, a diaphragma and other specialized epicalyx structures. These and other features allows the recognition of a relatively plesiomorphic, very widespread and paraphyletic basal group of perennial species (epicalyx type I), two more apomorphic perennial groups (epicalyx types II and III), and two most advanced groups (epicalyx types IV and V) with one perennial and two annual species. Pterocephalodes has floral bracts and 4-merous corollas, also appears to be monophyletic, and is limited to the eastern Himalaya and south-west China. It shares with Pseudoscabiosa the lack of a diaphragma in some of its species as well as the origin of a feathery pappus and of a corona. Thus, all three genera allow an insight into the evolutionary processes of fruit differentiation in the Dipsacaceae family.
    OriginalspracheEnglisch
    Seiten (von - bis)247-278
    Seitenumfang32
    FachzeitschriftBotanical Journal of the Linnean Society
    Jahrgang132
    PublikationsstatusVeröffentlicht - 2000

    ÖFOS 2012

    • 106008 Botanik

    Fingerprint

    Untersuchen Sie die Forschungsthemen von „Fruit differentiation, palynology, and systematics in Pterocephalus and Pterocephalodes, gen. nov. (Dipsacaceae).“. Zusammen bilden sie einen einzigartigen Fingerprint.

    Zitationsweisen