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The Calyx in Lycianthes and Some Other Genera
W. G. D'Arcy
Annals of the Missouri Botanical Garden
Vol. 73, No. 1 (1986), pp. 117-127
Published by: Missouri Botanical Garden Press
Stable URL: http://www.jstor.org/stable/2399143
Page Count: 11
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Vasculature and structure of calyces in Lycianthes and some related genera are analyzed to derive more generalized hypotheses on evolutionary trends in similar calyces. The generalized solanaceous calyx is seen as a whorl of five lobes enervated by five primary traces that branch in the lobes to form a pair of lateral veins and minor leaf-like venation. The adjacent laterals fuse basally to form an interconnector vein but are separate distally. There has been a tendency in these genera for the calyx lobes to fuse to higher levels, sometimes right to the top (perfect prefloration). There has been a tendency to fusion of lateral veins to higher levels, which gives rise to ten main traces or ribs in the fused area. The flower must egress from the bud and may do so in several ways. Where calyx prefloration is complete or nearly so, egress must involve stretching or tearing. Thus in Lycianthes, Witheringia, and Capsicum, the calyx becomes thin, with reduced, distorted venation under stretching stresses of floral egress in a region termed the sleeve. A tooth, here meaning any pointed structure accessory to a flower or inflorescence, is nearly ubiquitous in vascular plants, perhaps for protection. When the calyx teeth are completely fused, they no longer function as teeth. In some Solanaceae, this deficiency is remedied by enation of 'secondary' teeth below the sleeve. In Lycianthes they may be enervated by primary traces and fused laterals leading to the ten teeth in two series. These sequences of calyx evolution can be seen in some other families such as the Ericaceae.
Annals of the Missouri Botanical Garden © 1986 Missouri Botanical Garden Press