Leafy liverworts of Chapada das Mesas National Park: a floristic survey and checklist of the leafy liverworts of Maranhão state, Brazil

Chapada das Mesas National Park (CMNP) is the fourth largest conservation unit in Maranhão state and an important area for the study of bryophytes due to its geomorphological characteristics, predominant vegetation, and water potential. The aim of our study was to investigate the richness and composition of leafy liverwort species in CMNP, discuss the importance of this area in the state, and present an updated checklist of the leafy liverworts for Maranhão. Our botanical material was collected during four excursions to the park. The checklist was mainly based on literature reports. Forty-one species and two varieties in eight families and 20 genera were identified in CMNP. From the state of Maranhão, 106 species and two varieties in nine families and 39 genera are reported. Our survey of bryophytes in CMNP resulted in the first records from Maranhão of 19 species. Lejeunea juruana Gradst. & M.E.Reiner is also newly found in the Northeastern region of Brazil and in the Cerrado domain.

Sequencing of Organellar Genomes of Nowellia curvifolia (Cephaloziaceae Jungermanniales) Revealed the Smallest Plastome with Complete Gene Set and High Intraspecific Variation Suggesting Cryptic Speciation

The leafy liverwort Nowellia curvifolia is a widespread Holarctic species belonging to the family Cephaloziaceae. It is made up of a newly sequenced, assembled and annotated organellar genomes of two European specimens, which revealed the structure typical for liverworts, but also provided new insights into its microevolution. The plastome of N. curvifolia is the second smallest among photosynthetic liverworts, with the shortest known inverted repeats. Moreover, it is the smallest liverwort genome with a complete gene set, since two smaller genomes of Aneura mirabilis and Cololejeunea lanciloba are missing six and four protein-coding genes respectively. The reduction of plastome size in leafy liverworts seems to be mainly impacted by deletion within specific region between psbA and psbD genes. The comparative intraspecific analysis revealed single SNPs difference among European individuals and a low number of 35 mutations differentiating European and North American specimens. However, the genetic resources of Asian specimen enabled to identify 1335 SNPs in plastic protein-coding genes suggesting an advanced cryptic speciation within N. curvifolia or the presence of undescribed morphospecies in Asia. Newly sequenced mitogenomes from European specimens revealed identical gene content and structure to previously published and low intercontinental differentiation limited to one substitution and three indels. The RNA-seq based RNA editing analysis revealed 17 and 127 edited sites in plastome and mitogenome respectively including one non-canonical editing event in plastid chiL gene. The U to C editing is common in non-seed plants, but in liverwort plastome is reported for the first time.

Ramudaria – A New Name for Udaria (Lophocoleaceae, Marchantiophyta)

The leafy liverwort genus Udaria D.K.Singh, S.Majumdar & D.Singh was recently described based on plants from Arunachal Pradesh and Sikkim in India. However, the name is a later homonym of Udaria A.Gupta, a fossil fungal genus discovered in Tertiary sediments of Dagshai and Subathu Formations in Himachal Pradesh, India. Hence, the liverwort genus is renamed here as Ramudaria, nom. nov. honouring the original eponym, Prof. Ram Udar. Its only species, Udaria lamellicaulis D.K.Singh, S.Majumdar & D.Singh is transferred to the newly named genus as Ramudaria lamellicaulis, comb. nov.

Unique shoot architecture in the leafy liverwort Herzogianthus vaginatus (Herzogianthaceae): insights into novel growth patterns in Jungermanniidae

All studied leafy liverworts have shoots with leaf to underleaf ratios of either 2:1 or 1:1. These ratios are the product of growth by either helical or pendular segmentation of the tetrahedral apical cell. Here we report that Herzogianthus vaginatus has a leaf to underleaf ratio approaching 3:1 on primary shoots, and on secondary shoots the ratio is closer to 4:1. These ratios are incompatible with the simple helical or pendular growth patterns found in other leafy liverworts. Further, the sequence of leaves and underleaves on Herzogianthus shoots is not wholly regular, which is previously unrecorded. We assess potential growth models that may explain the leaf to underleaf ratios and architecture of Herzogianthus shoots, including (1) branch modification, (2) merophyte or leaf-initial duplication and (3) changes in segmentation sequences. We compared leaf sequences produced by pendular and helical segmentation and a range of non-standard models, with sequences observed on shoots of Herzogianthus. Structure allows us to discriminate between the many alternative growth models, because each make testable predictions about leaf and underleaf sequences. We propose that Herzogianthus possesses growth processes unique among leafy liverworts, in which the direction of helication periodically and, sometimes irregularly, reverses. This, in combination with the secondary shoots having different growth patterns from primary shoots, emphasizes that Herzogianthus warrants detailed histological study to test our proposition.

Jungermannia exertifolia Steph. - A new bryophyte record from Bangladesh

A leafy liverwort, Jungermannia exertifolia Steph. (Hepaticae, Jungermanniales,) has been reported from the Adampur Forest of Moulvibazar district as a new species record for Bangladesh. Jungermannia exertifolia is characterized by its flattened leaves and rhizoids arising ventrally all along the stem with alternate leaves, which are obliquely inserted and succubous in arrangement. It grows in the shady habitats of Adampur forest on the surface of the hilly rocks. Detailed taxonomy of the newly reported species along with its photographs is provided. Dhaka Univ. J. Biol. Sci. 29(1): 133-136, 2020 (January)