Abstract：
Agaricus is a species-rich genus with more than 600 species around the world. In this work, three new species, Agaricus cacainus, A. baiyunensis, and A. praeclarefibrillosus are described from the specimens collected at Baiyun Mountain, Guangzhou, China, a subtropical area with a monsoon maritime climate, based on phylogenetic analyses and morphological examinations of internal transcribed spacer (ITS1-5.8S-ITS2 = ITS), D1/D2 domains of the large subunit of ribosomal DNA (28S), and a part of translation elongation factor 1-alpha (TEF1). Agaricus cacainus in A. sect. Amoeni is characterized by a parabolic to applanate, slightly depressed pileus covered with chocolate brown, appressed, triangular squamules against white background, a white, furfuraceous stipe, an unchanging context when cut, a fragile and evanescent annulus, usually 4- or 2-spored basidia, and mostly pyriform cheilocystidia. Agaricus baiyunensis in A. sect. Minores has a pileus with a slightly truncate top covered with light brown, downy-wooly fibrillose scales and a light yellowish stipe with membranous annulus. Agaricus praeclarefibrillosus in A. sect. Brunneopicti is characterized by a pileus surface with brownish, triangular, recurved scales and longitudinally splitting lines toward margin, a cottony stipe with white, tiny, recurved fibrils, a single annulus, and variously shaped cheilocystidia, with sparsely ornamented basidiospores. The detailed comparison of their morphological characteristics with closely related species is provided.
摘要：
蘑菇属是一个物种丰富的属，在世界各地有600多种。在这项工作中,三个新物种,姬松茸,A.白云，从白云山收集的标本中描述了praeclarefibrlosus，广州,中国,季风海洋性气候的亚热带地区，基于内部转录间隔区的系统发育分析和形态学检查（ITS1-5.8S-ITS2=ITS），核糖体DNA（28S）大亚基的D1/D2结构域，和翻译延伸因子1-α(TEF1)的一部分。A.教派中的姬松茸。Amoeni的特征是抛物线，略带沮丧的比目鱼，上面覆盖着巧克力棕色，Pressed,白色背景的三角形小方块，一个白色的,糠醛柄，剪切时不变的上下文，一个脆弱的消逝的环，通常是4或2孢子的基底，主要是梨状叶囊虫。白云蘑菇。Minores有一个pleeus，顶部略带截断，上面覆盖着浅棕色，绒毛羊毛状纤丝鳞片和浅黄色柄具膜质环。A.sect中的姬松茸。Brunneopicti的特征是具有褐色的绒毛表面，三角形,递归刻度和纵向分裂线朝向边距，白色的棉柄，微小，弯曲的原纤维，一个环，和不同形状的智囊团，带有稀疏装饰的担子孢子。提供了它们与密切相关物种的形态特征的详细比较。
