ABSTRACT

Isoetes brochonii has possibly been subject to more taxonomic designations over the last century than any other European quillwort and most commonly has been put into synonymy with the widespread I. lacustris. Investigations of herbarium and living material in the present study, however, indicate it to be a sterile (aborted spored) hybrid, I. ×brochonii (pro sp.), confined to high elevation lakes of the Pyrenees mountains in France, Spain and Andorra. This represents the first uniquely European Isoetes hybrid to be described. Putative parents are diploid I. echinospora and dodecaploid I. creussensis, probably a hybridogenic Pyrenean endemic. The speciation of I. creussensis may well have occurred in Pyrenean refugia during Quaternary glacial-interglacial fluctuations. We found no convincing evidence for the occurrences of decaploid I. lacustris in the Pyrenees where it appears to have been confused with I. creussensis. A comparative table of the distinguishing morphological characteristics of I. creussensis and I. lacustris is provided, with megaspore ornamentation and microspore size indicated as being particularly important indicators.

摘要

水韭brochonii 有可能受到更多的分类名称在上个世纪比任何其他欧洲quillwort和最常用已投入同义与广泛的一湖生。在本研究植物标本和生活材料的调查，但是，指示它是一个无菌的（中止有孢子的）混合，我。× brochonii（pro sp。），局限于法国，西班牙和安道尔的比利牛斯山脉的高海拔湖泊。这代表了第一独特的欧洲水韭将要描述的混合体。假定的父母是二倍体一棘和dodecaploid一creussensis ，可能是比利牛斯山的地方病。在第四纪冰川-冰川间的波动期间，比利牛斯山脉的庇护区很可能已经发生了克雷索菌的形成。我们没有发现令人信服的证据表明在比利牛斯山出现十倍体湖生I. lacustris，那里似乎已将其与克雷索斯I. creussensis混淆。提供了比较I. creussensis和I. lacustris形态特征的对照表，其中大孢子纹饰和小孢子大小被指示为特别重要的指标。