Structure and Development of Cyclanthus bipartitus Poit. (Cyclanthaceae) with Reference to Other Cyclanthaceae. I. Rhizome, Inflorescence, Root, and Symmetry

Abstract

Plants of C. bipartilus produce entirely subterranean rhizome systems or grow as epiphytes up to 2 m above ground level. This species has a stem unit (rhizome) which, outwardly resembling a single monopodial axis, is actually sympodial with renewal shoots having clearly demarcated evicted and non-evicted portions. A developing spadix forms pistillate units and staminate units. Pistillate units produce perianths, staminodes, and carpels and vary greatly in shape. Carpels within a unit are connate basally, free distally. Staminate units generally produce 2 rows of stamens. Also, 2 staminate units or rows thereof develop between 2 vertically adjacent continuous pistillate cycles. Consequently, at maturity 4 rows of stamens normally intervene between such cycles. Rhizomes bear adventitious roots, which may produce persistent root hairs or lack root hairs. Phyllotaxis of adult leaves is spirodistichous. C. bipartitus exhibits a considerable mirror-image symmetry.