Porella takakii S. Hatt.
Creators: name: Zheng, Tian-Xiong
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Plantae
Marchantiophyta
Jungermanniopsida
Porellales
Porellaceae
Porella
Porella takakii

description: 2. Porella takakii S. Hatt., J. Jap. Bot. 28: 181 (1953).   
 ≡ Porella oblongifolia var. takakii (S. Hatt.) Inoue, Bull. Chichibu Mus. Nat. Hist. 6: 28 (1955).   
Original material citation.  
 Type. Japan. Nagano County, Miwa-mura, shaded damp limestone ledge, associated with P. parvistipula, Quercus crispula woods in upper part of Shiroiwa valley, ca. 1300 m alt. July 1952. N. Takaki s. n. (lectotype: NICH 41848, in Hepaticae Japonicae Ser. 5, no. 241, here designated).   
Note 1.  
 Porella takakii was published by Hattori (1953), and is considered to be closely related to P. oblongifolia S. Hatt. but can be distinguished by its teeth-present leaves and leaf-lobules (Hattori 1943, 1953). Later, Inoue (1955) considered the characters variable and reduced P. takakii to a new variety of P. oblongifolia. Hara (1955) could not distinguish between the two species and synonymized P. takakii under P. oblongifolia, which was followed by Hattori (1978).   
 Although Porella takakii has been repeatedly researched, its original citation remains unclear because no specimen number was provided (Hattori 1953; Fig. 3). I investigated the original materials of P. takakii deposited in NICH and found that nine preparations belonging to five gatherings fit the original locality: (1) N. Takaki 327 (NICH 51476, 51477, 51478, 51479, and 51480), (2) N. Takaki 328 (NICH 51534), (3) N. Takaki s. n. (NICH 20909), (4) N. Takaki s. n. (NICH 41848, in Hepaticae Japonicae Ser. 5, no. 241), and (5) N. Takaki s. n. (NICH 60513). The latter three specimens share an absent collection number, but they should be considered separate gatherings because they are neither cross-labelled nor bear a single and original label in common (Art. 8.3; Turland et al. 2018). However, none of these specimens perfectly align with the original ecological data (Fig. 3). For instance, “ N. Takaki 327 ” (NICH 51476, 51477, 51479, and 51480) were collected from a “ shaded, damp ledge of limestone ”, while “ N. Takaki 327 ” (NICH 51478) originated from a “ Quercus crispula forest, on shaded, damp ledge of limestone ”. Similarly, “ N. Takaki 328 ” (NICH 51534) was found in a “ Quercus crispula forest, shady limestone ”, and “ N. Takaki s. n. ” (NICH 20909) from “ associating with P. grandiloba, on shaded, damp ledge of limestone ”; “ N. Takaki s. n. ” (NICH 60513) were collected from “ on calcareous rock under Quercus woods ”. Only “ N. Takaki s. n. ” (NICH 41848, in Hepaticae Japonicae Ser. 5, no. 241) precisely matches the original ecological citation (Hattori 1954). It can be thus inferred that exicattae set contains isosyntypes, implying equal prioritisation of lectotype selection with other specimens listed above according to the Art. 9. 12 (Turland et al. 2018). It is worth noting that Mizutani et al. (2009) regarded “ N. Takaki 328 ” (NICH 51534) as the holotype and “ N. Takaki s. n. ” (NICH 20909) as the isotype of P. takakii; however, this was not the case. All five gatherings noted above were considered syntypes of P. takakii (Art. 9.6; Turland et al. 2018).   
 Due to the difficulty in assessing the condition of distributed exicattae specimens, only “ N. Takaki s. n. ” (NICH 41848) was examined, confirming its alignment with the original description and illustration, particularly in its apically toothed leaves, the most distinguishing characteristic of this species. Consequently, this specimen was designated as the lectotype of P. takakii, despite some plants displaying mechanical damage and lacking intact leaf apices (data not shown).   
 There seems to be an inconsistent issue that Porella takakii was recorded as associating with “ P. parvistipula (Steph.) ” (Probably an orthographic variant of P. parvistipula (Steph.) S. Hatt.) in the protologue (Fig. 3) but occurring with P. grandiloba Lindb. (NICH 20909). Since the former species (P. parvistipula) has been listed as one of the synonyms of the latter (P. grandiloba), both statements are actually the same (Hattori 1978).
description: Published as part of Zheng, Tian-Xiong, 2024, Nomenclatural notes of Frullania auriculata (Frullaniaceae) and lectotypification of Porella takakii (Porellaceae), pp. 215-220 in PhytoKeys 241 on pages 215-220, DOI: 10.3897/phytokeys.241.123013