Trachyphyllum A. Gepp, Cat. Afr. Pl.

Linis, V. C. & Logatoc, E. L., 2024, The genus Trachyphyllum (Sematophyllaceae s. l., Bryophyta) in the Philippines, with a new species record for Malesia, Arctoa 33 (2), pp. 160-165 : 160-161

Trachyphyllum A. Gepp, Cat. Afr. Pl. 2(2): 298. 1901.

Type species: Trachyphyllum gastrodes (Welw. & Duby) A. Gepp designated by Buck (1979); Trachyphyllum inflexum (Harv.) A. Gepp designated by Chen (1978) (Tropicos, Missouri Botanical Garden. 03 September 2024. Trachyphyllum A. Gepp. Available at https:// tropicos.org/name/35001313).

Descriptions: Gepp (1901), Buck (1979; 1980).

Notes: Historically, Gepp (1901) initially classified Trachyphyllum within the Entodontaceae —citing the numerous alar cells in its leaves and its morphological similarities to Erythrodontium Hampe. However, Buck (1979) proposed reclassifying the genus as part of the Thuidiaceae , based on both gametophytic and sporophytic characteristics; aligning it more closely with Heterocla-

1 – School of Multidisciplinary Studies , De La Salle-College of Saint Benilde , 2544 Taft Avenue, Malate, Manila 0922, the Philippines; email: [e-mail], [e-mail]. ORCID : 0000-0001-6940-8627

2 – Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines Los Baсos, College 4031, Laguna, the Philippines; email: [e-mail]. ORCID: 0000-0002-7005-7307.

dium Bruch & Schimp. Spence (1997) later reassigned the genus to the Pteryginandraceae, a change that was reflected in the classification system proposed by Goffinet, Buck, & Shaw (2008). In 2014, Carvalho-Silva et al. further reclassified Trachyphyllum into the Pylaisiadelphaceae . Subsequently, Han & Jia (2021) placed the genus under the Sematophyllaceae sensu lato, temporarily within the subfamily Platygyrioideae which included taxa with unstable phylogenetic positions. Most recently, Akiyama et al. (2024) resolved that the genus nested within the Pylaisiadelphaceae —noting, however, the need for further taxon sampling in order to clarify the backbone phylogeny of the family. In light of the unstable systematic position of Trachyphyllum , we opted to follow Han & Jia (2021) and thus treat the genus as a member of the Sematophyllaceae s.l.

In the Philippines, species of Trachyphyllum appear similar to the more widespread Erythrodontium julaceum (Schwägr.) Paris ( Entodontaceae ) but the papillose laminal cells readily distinguishes the former from the latter. Similarly, plants of Macgregorella indica (Broth.) W.R. Buck ( Myriniaceae ) may resemble a minute form of Trachyphyllum in the field but the single costa, short and prorate laminal cells, and the marginal cells of the alar region having thin lateral walls and distinctly thick transverse walls differentiates the former from members of the latter ( Norris & Koponen, 1990). The combination of 1) julaceous habit, 2) characteristic laminal cells papillose at both ends, 3) a well-developed double costa, and 4) numerous quadrate alar cells readily distinguishes Trachyphyllum from genera in the Entodontaceae and Sematophyllaceae s.l. found in the Philippines.

Buck (1979) recognised two subgenera within Trachyphyllum : subg. Trachyphyllum and subg. Carinatum . To date, only members of Trachyphyllum subg. Trachyphyllum have been reported in the Philippines.