Anthophyte clade

Angiosperms and their gymnosperm sister groups

Diversity

  • The proposed anthophyte clade includes the glossopterids, pentoxylales, bennettitaleans, gnetophytes, caytoniales, and angiosperms (Doyle & Donoghue 1987)

  • This is a debated clade and molecular studies tend not to support the anthophyte clade hypothesis

    • Many research articles have rejected the inclusion of gnetophytes in this clade (Goremykin et al. 1996; Chaw et al. 1997; Hansen et al. 1999; Qiu et al. 1999; Samigullin et al. 1999; Chaw et al. 2000; Sanderson et al. 2000; Magallon & Sanderson 2002; Hajibabaei et al. 2006)

    • Although, some research that includes fossil taxa possibly supports the Gnetales in the Anthophyte clade (Rothwell et al. 2009)

Features

Synapomorphies for the anthophyte clade include:

  • Scalariform pitting in secondary xylem

  • Once-pinnate microsporophylls

  • Single ovule per cupule

  • Derived non-saccate pollen with granular exine structure

  • Syndetocheilic stomata

    • Guard cell mother cell gives rise to a pair of guard cells

    • One or more pairs of subsidiary cells

  • Aggregate reproductive structures into flower-like structures

    • Commonly bisexual

Geologic Age

Above: Anthophyte clade, with representatives: cross-section of a stem of the Pentoxylon (left), Nilssonia, a Bennettitalean leaf (middle), and the flower of an angiosperm, Akebia (right)