Pollen morphology of the tribeHemimerideae: possible evidence of ancestral pollen types and parallel evolution in the basalmost clade ofScrophulariaceaes.str.

Sergei L. Mosyakin,Zoya M. Tsymbalyuk

doi:10.3372/wi.47.47102

Sergei L. Mosyakin, Zoya M. Tsymbalyuk

Open Access

https://doi.org/10.3372/wi.47.47102

Copy DOI

Abstract

Abstract: Pollen morphology of nine species belonging to six genera of tribe Hemimerideae (representing the basalmost clade of Scrophulariaceae s.str.) was studied and illustrated with light microscopy (LM) and scanning electron microscopy (SEM). Pollen grains in Hemimerideae are 3- or 6–8-colpate or 3- or 5–8-colporate, prolate, spheroidal or oblate-spheroidal in shape; they are mainly medium-sized or occasionally small. The outline in polar view is 3-lobed, rounded-3-lobed or 5–8-lobed; the outline in equatorial view is elliptic or orbicular. Exine sculpture is rough, rough-foveolate, foveolate, microreticulate, rugulate, rugulate-foveolate or rugulate-microreticulate. Four major pollen types are recognized, based on original data: 3-colpate (Alonsoa), 6–8-colpate (Diclis, Hemimeris), 3-colporate (Colpias) and 5–8-colporate (Diascia, Nemesia). Within two of these pollen types, two subtypes can be further distinguished based on pollen size, exine sculpture, details of the colpi and endoapertures. Based o...

Highlights

Current opinions on taxonomy and phylogeny of Hemimerideae and some other early-branching clades of Scrophulariaceae s.str.According to recent studies, the tribe Hemimerideae Benth. is the earliest-branching phylogenetic lineage of Scrophulariaceae s.str
The tribe was established in the new series of Ed wards’s Botanical Register continued by Lindley (1835), who explicitly credited the authorship to Bentham: “For this valuable contribution we are indebted to George Bentham, Esq. the learned author of the Genera and Species Labiatarum.”
Kholodny Institute of Botany of the National Academy of Sciences of Ukraine, Kyiv (Kiev), Ukraine (KW; herbarium codes according to Thiers 2016+)

Summary

Introduction

Current opinions on taxonomy and phylogeny of Hemimerideae and some other early-branching clades of Scrophulariaceae s.str.According to recent studies, the tribe Hemimerideae Benth. is the earliest-branching phylogenetic lineage of Scrophulariaceae s.str. Current opinions on taxonomy and phylogeny of Hemimerideae and some other early-branching clades of Scrophulariaceae s.str. The tribe, as currently outlined, includes Alonsoa Ruiz & Pav. 16 species, tropical America and S Africa), Colpias E. 72 species, according to Steiner 2009), Diclis Benth. Ten species, tropical and S Africa and Madagascar), Hemimeris L. f. Olmstead (2012) included Schistanthe Kunze (authorship erroneously cited as “Kuntze”) in Hemimerideae, with a question mark (probably better placed in Alonsoa: see Roux 1986). Mey. ex Benth. (one species, S Africa), Diascia Link & Otto (c. 38 species, S Africa; or c. 72 species, according to Steiner 2009), Diclis Benth. (c. ten species, tropical and S Africa and Madagascar), Hemimeris L. f. (four species, S Africa) and Nemesia Vent. (c. 65 species, tropical and S Africa) (Olmstead & al. 2001; Oxelman & al. 2005; Tank & al. 2006; Datson & al. 2008; Steiner 2009; Olmstead 2012). Olmstead (2012) included Schistanthe Kunze (authorship erroneously cited as “Kuntze”) in Hemimerideae, with a question mark (probably better placed in Alonsoa: see Roux 1986).

Methods

Results

Discussion

Conclusion