Innovations in organismal botany - a tribute to the pioneering studies of Donald A. Eggert
Tomlinson, P. Barry. .
Carboniferous arborescents in relation to the architecture of modern trees.
Don Eggert's interpretation of Carboniferous lepidendroids was innovative because, faced with the reconstruction of such tall trees from scattered fragments, he produced a result that emphasized developmental dynamics, encapsulated in the concepts of epidogenesis and apoxogenesis, with an ultimate suggestion of determinate growth. This anticipated in an essentially pioneering fashion the later concept of "tree architecture" based on the study of modern trees, in which "deterministic" and "opportunistic" processes combine to produce a tree's canopy within a forest environment. Given this, we can ask the question - did early tree forms demonstrate the process of "reiteration"?; i.e., the partial or total repetition of a tree's architecture, as when subject to some disturbance within a biological environment. Simply put, how did a lepidodendroid tree respond to branch breakage, bearing in mind that its branches developed by stem apical dichotomy. The paleobotanical literature says little about this, so maybe early trees did not reiterate. If so, how did later trees gain this ability? A possible explanation is because they developed axillary branching, which seems correlated with the development of the megaphyll (providing the leaf axil) and the presence of secondary growth from a bifacial vascular cambium (which permits the development of the attachment of a branch to the parent axis). We will explore this idea with reference to unusual examples in modern trees which in turn raises the question of why the leaf axil is almost always the site of branching in modern trees, but in highly diverse, but little studied ways.
Log in to add this item to your schedule
1 - National Tropical Botanical Garden, The Kampong, 4013 Douglas Rd, Miami, FL, 33133, USA
Presentation Type: Symposium or Colloquium Presentation
Location: Lindell D/Chase Park Plaza
Date: Tuesday, July 12th, 2011
Time: 2:30 PM