The Chusquea meyeriana informal group within Chusquea subg. Chusquea is endemic to the Atlantic forests of southeastern Brazil and includes seven described species (C. anelythra, C. anelytroides, C. attenuata, C. clemirae, C. longispiculata, C. meyeriana and C. parviligulata). Work on the treatment of Chusquea for the Flora do Brasil allowed us to confirm the presence of another unnamed species belonging to this group, which we here describe as Chusquea cordata. We compared its morphology with that of the partially sympatric C. longispiculata. Chusquea cordata is distinguished based on its cordate culm leaf blades, unique within this informal group, and smaller synflorescences and spikelets than in C. longispiculata, among other characters. In addition to line illustrations of the new species, a map of its geographical distribution and a key to the species of the C. meyeriana informal group based on vegetative characters, we illustrate the foliar micromorphology and anatomy of C. cordata and C. longispiculata to highlight both similarities and differences. Because the C. meyeriana informal group has been defined by differing combinations of vegetative and reproductive characters by various authors, we propose an updated combination of diagnostic features including a new character. This informal group is now diagnosed by: the presence of a white waxy infranodal band; culm leaves with at least a slight corky ridge at the juncture of the girdle and sheath; at least initially infravaginal branching; synflorescences subtended by 1–4 spatheate bracts; the lower two primary synflorescence branches strongly reflexed; and spikelets with very reduced glumes I and II. With this new species, Chusquea comprises 198 described species, of which 49 occur in Brazil, with 45 of them endemic.

Chusquea subg内的Chusquea meyeriana非正式小组。Chusquea是巴西东南部大西洋森林的特有种，包括七种已描述的物种（C. anelythra、C . anelytroides、C . attenuata、C . clemirae、C . longispiculata、C . meyeriana和C. parviligulata ）。Chusquea的治疗工作对于巴西植物群，我们能够确认属于该组的另一种未命名物种的存在，我们在这里将其描述为Chusquea cordata。我们将其形态与部分同域的C进行了比较。长刺 Chusquea cordata因其心形的秆叶片而区别开来，在这个非正式组中是独一无二的，并且比C更小的合花序和小穗。longispiculata等字符。除了新物种的线条插图，其地理分布图和C. meyeriana物种的关键基于植物性状的非正式组，我们说明了C的叶面微形态和解剖结构。cordata和C . longispiculata以突出相同点和不同点。因为C . 梅耶里亚纳非正式组已由不同作者通过植物和生殖特征的不同组合来定义，我们提出了包括新特征在内的诊断特征的更新组合。这个非正式组现在被诊断为： 存在白色蜡状下节带；在带和鞘的接合处具有至少一个轻微的软木脊的秆叶；至少最初是阴道下分支；花序被 1-4 苞片包围；下部的两个初级合花枝强烈反折；和颖片 I 和 II 非常减少的小穗。有了这个新物种，Chusquea包括 198 个已描述的物种，其中 49 个出现在巴西，其中 45 个是地方性的。