Fissidens lagenarius Mitt.

Bruggeman-Nannenga, Maria Alida, 2022, On the peristomes of the corticolous African species of Fissidens Hedw. (Fissidentaceae, Bryophyta), Cryptogamie, Bryologie 20 (2), pp. 9-36 : 23

Fissidens lagenarius Mitt.

( Fig. 11 )

Pantropical, mammillose species with limbidia restricted to the upper leaves of perichaetial stems and ±divided peristomes with a characteristic ornamentation. OPL lamellae in mid teeth with spaced, irregular oblique to vertical ridges in the mid part of the teeth ( Fig. 11A, B ). Rare in Africa, known from two collections, both with rather poor peristomes. Part of the above description is therefore based on Neotropical specimens.

Peristome

±erect when wet, stiff, undivided in the two African specimens (undivided or imperfectly and irregularly divided according Pursell (2007) in his neotropical monograph, teeth 66-200 µm long, tooth base 22-33 µm wide, distal parts papillose, often broken off or rudimentary.

Ornamentation

OPL basal ±3 cells with high, smooth trabeculae and thin lamellae that are wider than the IPL-lamellae, in distal direction the trabeculae gradually become indistinguishable, lamellae from about the 4-th cell onwards with an irregular pattern of spaced, vertical to diagonal ridges ( Fig. 11A, B ), near the apex papillose; IPL in the basal part over a short distance with two columns ( Fig. 11D, F ), sometimes with a single column throughout ( Fig. 11C ); the ±5 basal-most cells with high, papillose trabeculae and ±smooth lamellae, more distal lamellae with close, oblique to horizontal close ridges; filaments papillose on both sides, often broken off; IPL thicker than the OPL ( Fig. 11G ).

Sporophyte

Seta 0.9-1.5 mm, smooth; capsule narrow and long, 0.45- 0.6 × 0.2-0.25mm, exothecial cell columns ±32, the cells oblong, operculum not observed, spores 17.5-20.5 × 16-18.0 µm, finely papillose.

A rather similar peristome is found in the Brazilian Fissidens scindulosus Brugg. -Nann. This species differs from F.lagenarius by scindulose cells with 1-3 scindulae. Scattered or in loose mats, hardly mixed.

Description and illustration

Buck (2003: fig. 10G-I); Pursell (2007: fig. 94); Bruggeman-Nannenga (2011: fig. 26C, E, G, I, J).

Figures

FIG. 11. — Fissidens lagenarius Mitt. A, OPL, note the transparent OPL lamellae protruding beyond the narrower underlaying IPL lamellae (left below); B, OPL; C-F, IPL variations: C, IPL of two teeth, each composed of a single column of half cells (reduced situation); D, three teeth focused on the incrassate lamellar plates; in the middle tooth two columns are clearly recognizable (normal situation); E, IPL of three teeth focused on the trabeculae; F, IPL of single tooth; G, side view of tooth. A-D, G from Brazil, São Paulo, Yano 235, SP, private herbarium Bruggeman-Nannenga; E from Zambia, North-western Province, Mushitu Forest, Townsend 75/135, E, private herbarium Bruggeman-Nannenga; F from Brazil, Yano 560 235, SP, private herbarium Bruggeman-Nannenga. Scale bar: 20 µm.