Pollen morphology supports the transfer of Wendlandia (Rubiaceae) out of Rondeletieae

Abstract

Pollen morphology of 27 species, eight subspecies and one variety of Wendlandia was studied using scanning electron microscopy (SEM). Wendlandia pollen are monads, radiosymmetric, small in size, tricolporate (rarely tetracolporate or bicolporate) and spheroidal (rarely subprolate or suboblate) in equatorial view. The compound aperture consists of ectocolpus, mesoporus and endocolpus. In addition, reticulate sexine and granular nexine were observed. The pollen wall ultrastructure of two Wendlandia spp. was examined by transmission electron microscopy (TEM). The exine consists of the tectum, columellae, foot layer and endexine. The endexine is thickened into a costa around the aperture. The intine forms a protruding oncus at the aperture. The palynological characters show a remarkable uniformity among the Wendlandia spp. Differences with Rondeletia, the main genus of tribe Rondeletieae, exist in the exine pattern, the endoaperture and the pollen wall structure. Our observations indicated that the endoaperture type and the structure of the pollen wall of Wendlandia were similar to those of the Gardenieae-Pavetteae-Coffeeae-Octotropideae clade, which provided palynological evidence for a closer relationship of Wendlandia to subfamily Ixoroideae and the transfer of Wendlandia out of Rondeletieae.

Ethnomedicinal uses, phytochemistry, pharmacology and toxicological aspects of genus Wendlandia: an overview

“…Notably, the original author names, original publication resources, accepted or synonymous plant name and the International Plant Name Index (IPNI) identifier by the plant list (www.theplantlist.org). Raju et al, (2012) reported its tubular flower, evergreen woody trees protect the hilly soil from erosion and similarly useful for pollination by a wide array of pollinators including butterflies, beees, flies, wasps, moth etc (Xie et al, 2010). Because of the similarity of some species of Wendlandia like Wendlandia formosana is closely related to some phytoconstituents derived from Angustifolia (Choze et al, 2010).…”

“…This genus belongs to a widely distributed tropical family called Rubiaceae, encompassing around 13,200 species spread across 615 different genera. Wendlandia has different life forms: trees, shrubs, and herbaceous plants with annual and perennial life cycles (Xie et al, 2010). Approximately 50-70 species of this genus are located in the Indo-Malayan region (Choze et al, 2010).…”