Soledad Jimenez

Background and aim: Bryophytes are an important group of plants in forest ecosystems that act as primary colonizers, moisture regulators and nutrient fixers. Due to their sensitivity to disturbance, they are used as bioindicators in impact studies. Nevertheless, there are extensive areas poorly studied that currently are undergoing significant changes due to agricultural and livestock practices, as is the case in Chaco. As part of a major project which aims to determine the impact on land-use change on the bryophyte diversity in Chaco, samples collected in the region have been analyzed with the aim of updating knowledge of the bryophyte flora in the province. M&M: Samples from preserved and non-preserved areas from Chaco were studied according to the traditional techniques for bryophytes and mounted in water-glycerin-phenol or Hoyer´s solution. Results: As a result, 26 species distributed in 19 genera and 13 families, are newly recorded to Chaco province. Conclusions: The results improved our understanding of a poorly explored flora in a region with unique characteristics. These findings reinforce the value of floristic studies to collect data about poorly known species and their distribution, and to provide a basis for applied studies. In Argentina, despite efforts made in recent decades, there is still a lack of understanding regarding bryophyte diversity. This, combined with rapid changes in land use, may lead to the alteration or disappearance of bryophyte communities before they are even studied.

Background and aim: Herbarium specimens were reviewed as part of broader project that deals with the diversity of bryophytes from the Chaco province (Argentina). One of the samples matched the description of Timmiella acaulon, a species poorly known. The aim of this work is to record T. acaulon as new to Chaco Province and to describe morphologically and illustrate in detail this remarkable species. M&M: Herbarium samples were analyzed with standard techniques for bryophytes. Examination with scanning electron microscope was made using samples mounted directly on double-sided tape and coated in gold-palladium. Results: Timmiella acaulon is newly registered for Chaco province. A complete and detailed morphological description, and illustrations are here presented. Conclusions: Due to the rediscovery of the species more than 100 years after its original description, the distribution range of T. acaulon is extended to northeastern Argentina, and details of morphological characters of systematic value are provided.

The genus Anaschisma includes four species in America, of which, A. lilliputanum is recorded for the first time to the Argentina. The specimens were analyzed morphologically using conventional techniques for Pottiaceae (Bryophyta). A distribution map of the genus, description and illustration in SEM and LM of the species are provided. Comments and differences between this taxon and A. schiavoneae from Argentina are presented.

The study of the type specimen of Bartranda minuta Taylor, a species described based on Ecuadorian samples that predates the recently resurrected Chilean Philonotis brevifolia Herzog shows that both names displayed the same set of diagnostic characters. In this contribution, P. minuta is proposed as the correct name of this taxon, a lectotype is selected, and its distribution is extended to North America, based on samples collected in California.

The knowledge of the bryoflora of Uruguay is poor and restricted to a few studies, principally in Montevideo (^{Matteri 2004}). Additionally, new mosses and liverworts have been recently recorded in different areas of the country (^{Ellis et al. 2011}, 2012a, 2012b, ^{Flores & Suárez 2014}, ^{Suárez & Schiavone 2013}, ^{Suárez et al. 2014}), which highlights the floristic importance and the singularity of its flora.

As part of a study of the bryophytes of South America, some samples collected in Paraguay were identified as Gertrudiella uncinicoma, a species of Pottiaceae characterized by the presence of a well-developed central strand and a thick-walled hyalodermis on the stem, lanceolate leaves, laminal cells ventrally mammillose, and several rows of guides cells at the transverse section of the costae. This work represents the first record of the genus from Paraguay. A complete description, ecological comments, illustrations in optical and scanning electron microscopy, and a distribution map are presented.

Philonotis polymorpha (Müller 1883: 79) Kindberg (1889: 79) is a circumsubantarctic species recorded for almost all subantarctic islands, central and southern Chile and Argentina (Ochyra et al., 2008; Müller, 2009; Bednarek-Ochyra, 2014). It was first described as Bartramia polymorpha Müll. Hal. based on specimens collected on Îles Kerguelen by Naumann in 1874, and subsequently transferred to Philonotis (Bridel 1827: 15) by Kindberg (1889). It is a medium sized plant, yellowish-green to reddish-brown below, commonly found growing sterile on wet rocks or soil in forests, near rivers and waterfalls. Diagnostic characters of this species are the dimorphic leaves, ovate to oblong-lanceolate, the abruptly short-acuminate apex, margins plane, serrate at the apex, entire at the base, the excurrent, robust and well defined costae, ending in a mucro, and the papillae projecting at proximal angles of laminal cells. The variability in the leaf morphology led to the description for many taxa along the history (Ochyra et al., 2008). Recently, Bednarek-Ochyra (2014) proposed Philonotis tenella Kaalaas (1912: 109) from Îles Crozet, as a new synonym of P. polymorpha, completing with these results the range of this species in the subantarctic islands.

As part of the revision of Philonotis in South America, a sample collected in Chile perfectly matched the type specimen of P. brevifolia Herzog. This species described from Chile was considered conspecific with P. krausei (Müll. Hal.) Broth. by Seki, but is resurrected here on the basis of the shape, apex, margin of the leaves, the shape of the laminal cells and the position of the papillae on these cells. A lectotype is designated for P. brevifolia, and a detailed and illustrated description is provided, including the traits of new discovered male plants, amending the original description. Dans le cadre d'une révision du genre Philonotis en Amérique du Sud, un échantillon récolté au Chili correspond parfaitement au type de P. brevifolia Herzog. Cette espèce décrite du Chili était considérée conspécifique avec P. krausei (Müll. Hal.) Broth. par Seki, mais elle est ici considérée comme distincte sur base de la forme, de l'apex et des marges de la feuille, de la forme des cellulaires laminaires, et de la position de papilles sur ces cellules. Un lectotype est désigné pour P. brevifolia, et une description détaillée et illustrée sont présentées, dont les caractères des plantes mâles nouvellement découvertes, complétant ainsi la description originale.

1. Bartramia patens Brid.Contributors: R. Ochyra and M. LebouvierÎles Crozet, Île de la Possession: (1) Baie du Marin, steep cliff overlooking Crique du Navire, north-east of the Alfred Faure Stati...