Classification of trichome types within species of the water fern Salvinia, and ontogeny of the egg-beater trichomes

Abstract

Species of the water fern Salvinia are well known for their extremely water-repellent floating leaves. The architecture of Salvinia surfaces is of great interest for biomimetic applications, because submersed in water, they retain air films for a long period. Knowledge of these surfaces is also important for pest control, since one species ( Salvinia molesta D.S. Mitch.) is a pantropic invasive aquatic weed. The micromorphology of the leaf surfaces of six representative species has been characterized by scanning electron microscopy. Based on their morphology, the trichomes are classified in four types, named after the typical species. Among the species examined, numbers, distribution, and sizes of the trichome types vary significantly. The simplest types, the Cucullata trichomes, are multicellular, uniseriate, and up to 800 µm high. Groups of two multicellular, uniseriate trichomes are described as the Oblongifolia trichomes. The Natans trichomes are grouped as four multicellular, uniseriate trichomes. The Molesta trichomes are composed of four trichomes, which are connected by the second last apical cells of the trichome. The ontogeny of the Molesta trichome groups was puzzling and resulted in various names being applied to them (“Krönchenhaare,” “egg-beater,” or “coroniform” hairs). Their unique development from four solitary uniseriate trichomes to groups of four connected trichomes is described in detail.

Applying Methods from Differential Geometry to Devise Stable and Persistent Air Layers Attached to Objects Immersed in Water

“…It is to be expected that in both cases an interface stretches from pillar to pillar like a tent's roof, similar to that in Fig. 7 which represents already an abstraction of the leaf surface of the floating fern Salvinia [7] .…”

Superhydrophobic hierarchically structured surfaces in biology: evolution, structural principles and biomimetic applications

“…Persistent air layers under water (Salvinia effect) are discussed in [14,15,[53][54][55][56][57][58][59][60][61][62].…”

“…Thus, we find many examples of biological surface compartmentation; the dimensions vary from the microscopic in Eschscholtzia or Aeginetia seeds (figures 18a and 24) to the much larger units the entire leaf of Salvinia cucullata ( figure 18b,c). The margins of the compartments show an elaborated architecture [53], a particular 'edge effect' preventing the escape of air [60]. These biological construction details provide important information for biomimetic technical surfaces ( §9).…”

<i>Camellia</i> (Theaceae) classification with support vector machines based on fractal parameters and Red, Green, and Blue intensity of leaves

“…Traditionally, leaf traits such as shape (Ming, 2000), morphology research (Barthlott et al, 2009), and leaf anatomy Jiang et al, 2010) have been used for classification. Recently, several researchers have used fractal parameters for plant identification (Mancuso et al, 2003;Azzarello et al, 2009;Pandolfi et al, 2009).…”