Abstract

Salvia (sage) is a species rich and medicinally important genus. Species-level identification is usually very difficult, particularly in closely related species. Here, we investigated nutlet micromorphological characteristics of 51 taxa belonging to S. subg. Salvia, S. subg. Sclarea and Salvia verticillata clade (S. subg. Heterosphace) by stereo binocular microscopy and scanning electron microscopy to show their taxonomic and phylogenetic value. The present study is the most comprehensive nutlet micromorphological study based on the number of taxa studied in the genus so far. The size of nutlets varies from 1.61 mm (S. verticillata subsp. verticillata) to 8.44 mm (S. albimaculata) in length, 1.02 mm (S. verticillata subsp. verticillata) to 4.20 mm (S. macrochlamys) in width. Nutlet length/width ratio ranges from 1.02 (S. bracteata and S. indica) to 3.06 (S. albimaculata). The basic shape of nutlets is elliptic, widely elliptic, circular, ovate or obovate. Five nutlet sculpturing patterns are present namely colliculate, reticulate, verrucate, rugose and foveate. The variation of surface sculpturing, nutlet shape, size, and exocarp cell shape provide useful diagnostic properties at species and subgenus level. However, nutlet micromorphological characters are of low phylogenetic value in studied Salvia species.

摘要

鼠尾草（鼠尾草）是一种丰富且具有药用价值的属。物种级别的鉴定通常非常困难，特别是在密切相关的物种中。在这里，我们研究了属于S. subg 的 51 个分类群的小坚果微形态特征。丹参，S. subg。Sclarea和Salvia verticillata clade ( S. subg. Heterosphace ) 通过立体双目显微镜和扫描电子显微镜显示它们的分类学和系统发育价值。本研究是迄今为止基于该属研究的分类群数量的最全面的小坚果微形态学研究。小坚果的大小从 1.61 毫米不等 ( S. verticillata亚种 verticillata ) 到 8.44 毫米 ( S. albimaculata ) 的长度，1.02 毫米 ( S. verticillata subsp . verticillata ) 到 4.20 毫米 ( S. macrochlamys ) 的宽度。小坚果长宽比范围为 1.02 ( S. bracteata和S. indica ) 到 3.06 ( S. albimaculata）。小坚果的基本形状为椭圆形、宽椭圆形、圆形、卵形或倒卵形。小坚果的雕刻纹样有五种，即丛状、网状、曲状、皱纹状和中央凹状。表面雕刻、小坚果形状、大小和外果皮细胞形状的变化在物种和亚属水平上提供了有用的诊断特性。然而，小坚果微形态特征在所研究的鼠尾草物种中的系统发育价值较低。