CARPEL DEVELOPMENT IN DRIMYS LANCEOLATA

Abstract

The dissimilar carpels of representatives of the Tasmannia and Wintera sections of the genus Drimys have been investigated developmentally with particular attention to the presence of peltation. In Drimys winteri of the Wintera section peltation results from an active adaxial meristem, but in D. lanceolata of the Tasmannia section the adaxial “cross‐zone” meristem is weakly developed and contributes little to the carpel. The form of the carpels also shows contrasts; the carpel of D. lanceolata begins growth as paired ridges separated by a cleft extending over the summit. Allometric growth reorients the cleft and it eventually extends from the ventral base of the carpel up over the summit. The cleft elongates greatly, together with the main part of the carpel. In D. winteri, growth is concentrated below the level of the cleft, and the carpel grows as an elongating cylinder. The cleft remains short, not extending with the carpel. In both species, early growth involves subsurface initials: subapical, adaxial (although weak in D. lanceolata), and submarginal. The presence of a disc encircling the base of the solitary carpel is reported for the first time for D. lanceolata.