Scrophulariaceae, Bacopa, stem anatomy, druse crystals
About 20 vertical air passages occur in each internode, separated at each node by a solid diaphragm of parenchyma, in which leaf traces depart. Air passages are schizogenous and begin to form just below the shoot apex. This may be the first report of druse crystals in Scrophulariaceae. Druses become visible in the second nodal plate below the shoot apex. In the mature stem, druses are more common in nodes, but they also occur in internodes. The stele appears to be an ectophloic siphonostele, without separate vascular bundles at any stage of development. This appears to be a good species for further study by electron microscopy.
Proceedings of the Iowa Academy of Science
©1975 Iowa Academy of Science, Inc.
Lersten, Nels R. and Gunning, James L.
"Development of Air Passages, and Crystal Distribution, in the Stem of Bacopa caroliniana (Scrophulariaceae),"
Proceedings of the Iowa Academy of Science, 82(2), 109-112.
Available at: https://scholarworks.uni.edu/pias/vol82/iss2/9