DOI: 10.5061/dryad.pnvx0k6jj
title: Data from: Nutlet morphology in the tribe Elsholtzieae (Lamiaceae)

description: A comprehensive study on nutlet morphology on 46 taxa from the tribe
 Elsholtzieae was conducted using stereomicroscopy, light microscopy, and
 scanning electron microscopy. The objectives were to evaluate the nutlet
 characteristics in a systematics context and to provide additional
 evidence for taxon delimitation. The nutlet shape varied from elliptical,
 widely elliptical, spheroidal, and ovate to pyriform. The size ranged from
 0.50 to 2.70 mm in length and 0.34 to 2.65 mm in width. The three types of
 trichomes included simple non-glandular trichomes (Collinsonia punctata),
 clavate non-glandular trichomes (Elsholtzia cephalantha), and peltate
 glandular trichomes (Mosla grosseserrata and M. chinensis). We also report
 the presence of mucilaginous reaction in nine species of the genus
 Elsholtzia in Elsholtzieae. Four types (undulate, papillae-like
 projection, thorn-like pattern, and reticulate) and three subtypes
 (reticulate, reticulate-cellular, and supra-reticulate) of nutlet surface
 patterns in the mid-ventral region were recognized in Elsholtzieae based
 on the differences in cell outline, outer periclinal walls, and dentations
 of the anticlinal walls. These nutlet micromorphological results may serve
 as a reference for future hypotheses on the classification of the tribe
 Elsholtzieae.
description: A total of 68
 specimens from 46 taxa (44 species and 2 varieties) from 6 genera
 (<i>Collinsonia</i> 4 spp.; <i>Elsholtzia</i> 25
 spp.; <i>Keiskea</i> 3 spp.; <i>Mosla</i> 8
 species and 1 variety; <i>Perilla</i> 3 spp. and 1 variety;
 <i>Perillula</i> 1 sp.; Table 2, Suppl. Table S1) in
 Elsholtzieae were sampled from the collections of the following herbaria:
 GH, KB, KH, KHUS, MO, NY, S, TNM, and UPS (herbarium abbreviations
 according to Thiers 2020, and continuously updated). All data, including
 species authorship, collector, and herbarium acronyms from the list of all
 of the taxa and specimens investigated, are summarized in Supplementary
 material Table S1. Although the nutlets of <i>Ombrocharis
 dulcis</i> Hand.-Mazz., which is natively distributed in Hunan
 Province in central China (Li and Hedge 1994, Wu et al. 2007, Manchester
 et al. 2009), were not sampled from herbarium collections, we nevertheless
 decided to include nutlet morphological data of this species for
 comparison (Table 2) from the previously published data by Chen et al.
 (2016). Nutlet morphological observations focused primarily on the general
 shape following the overall plane or two-dimensional shape (Simpson 2010),
 size (length and width), mucilage production (Ryding 1992a), and the
 features of the exocarp, involving general sculpturing patterns,
 projections of the outer periclinal walls, and dentations of the
 anticlinal walls (Moon et al. 2009a). The minimum-maximum range and mean
 nutlet size were measured on at least 10 randomly chosen individuals from
 each taxon. The terminology for nutlet sculpturing patterns and pericarp
 structure was mostly adopted from Ryding (1992a), Budantsev and Lobova
 (1997), and Moon et al. (2009a). Fully matured
 nutlets were directly mounted onto aluminum stubs with double adhesive
 tape and coated using an ion-sputtering device (JEOL, JFC-1100E, Japan)
 prior to observation using a scanning electron microscope (JEOL, JSM-5200,
 Japan) at 20 kV. To check for the absence and presence of myxocarpy, one
 to five nutlets were treated with distilled water and first examined using
 a light microscope (Olympus, BX-41, Japan). Production of mucilage was
 noted and classified as functionally non-myxocarpic (&lt;0.01 mm) and
 strongly myxocarpic (&gt;0.5 mm) following Ryding (2001) and Moon et
 al. (2009a). One-way analysis of variance (ANOVA) and Tukey's HSD test were used to compare the differences in nutlet morphological measurements among studied taxa at the sectional or generic level. All statistical analyses were performed using the statistical program R (version 3.5.0, 2018).