Octoblepharum peristomiruptum Salazar Allen & Gudino, 2020

Allen, Noris Salazar & Gudino, Jose A., 2020, Octoblepharum peristomiruptum (Octoblepharaceae) a new species from the Neotropics, PhytoKeys 164, pp. 1-9 : 1

Octoblepharum peristomiruptum Salazar Allen & Gudino sp. nov. Figs 1 , 2 , 3 , 4

Diagnosis.

Octoblepharum peristomiruptum is distinguished by its reddish to dark-purple coloured leaf bases, containing purple-coloured chlorocysts, with hyaline lamina 8-14 cells wide, unequally wide on each side of the costa, with purple cell walls, the exserted cylindrical capsule with long rostrate operculum and eight strongly vertically striate-reticulate teeth with the two rows of cells forming each tooth frequently separated at base.

Type.

Panama. Coclé: Distrito de Penonomé, above Chiguirí Arriba, Mariposario Cerro La Vieja, 8°39.88'N, 80°12.07'W, 360 m alt., 1 Jan 2019, J.A. Gudiño L. 3519 (holotype: PMA!; isotypes H!, NY!).

Description.

Plants (2.3-)3.5-5.0 cm tall. Stems erect, lacking a central strand of differentiated cells and thick-walled border cells, slightly tomentose at base, branching monopodial (pseudodichotomous), innovations arising early, during development of sporophyte. Rhizoids dark orange-red, arising from stem and leaves. Leaves ligulate, dentate in distal half, smooth at base, erect to slightly reflexed in upper third, (4.0-)5.5-6.7(-8.0) mm long, (0.4-)0.5-1.2 mm wide at base, including hyaline lamina ; apex apiculate, ending in an elongate cell flanked by 2 hexagonal cells; margins of leaf slightly undulate due to swollen hyalocysts, these single or in groups of 2-3 cells. Limbidium extending from leaf apex to mid-leaf, 2(-3) cells wide, thinner at base. Hyaline lamina adpressed to stem, unistratose, composed of thin-walled pitted hyalocysts, the hyalocysts long and hexagonal at apex, hexagonal to pentagonal at mid- lamina next to costa and rectangular, quadrate and short pentagonal basally. Costa in cross-section composed of ventral and dorsal porose hyalocysts supporting a unistratose, median network of small, thick-walled chlorocysts, in cross-section chlorocysts forming an irregularly zig-zag row, quadrate to triangular at base and triangular to tear-shaped above; the chlorocysts at leaf base, below hyaline lamina , surrounded by one layer of porose hyalocysts ventrally and three layers dorsally, at hyaline lamina hyalocysts in 1-2 rows ventrally and 4 rows dorsally, at mid-leaf in 3 layers ventrally and 3-4 layers dorsally, near apex 2 layers ventrally and two dorsally. Autoicous, perigonia axillary in short branches below the archegonia, antheridia surrounded by 5-7 small, mostly hyaline leaves (in some, only the central area of the leaf with chlorocysts), paraphyses 4-5 cells long with 1-2 brown basal cells, perichaetia terminal, archegonia with paraphyses to 10 cells long and with 1-2 short brown basal cells. Setae dark orange-red, smooth, sinistrorse, 4-5 mm long. Capsules dark red when mature, cylindrical (1.3-)1.6-2.0 mm long, the exothecial cells at mouth of capsule quadrate, dark red with slightly thickened transversal walls, at mid-capsule rectangular and quadrate with dark orange, thick longitudinal walls and thin transversal walls, (56-)80-92(-115) µm, becoming shorter towards mouth of capsule (26-)32-44 µm, phaneroporous stomata present at base of capsule. Prostome present. Peristome of eight elongate triangular teeth, inserted in mouth of capsule, each tooth composed of 2 rows of cells, basally fenestrate, strongly striate vertically, sometimes striations horizontally orientated at base and fading or absent in areas where separation of the rows of cells composing the tooth occurs. Operculum conic, long - rostrate, slightly curved. Calyptra cucullate, apex dark red, beige below. Spores brown, spheroid, densely gemmate, 14-16 µm.

Additional specimens examined (paratypes).

Brazil. Pará: Belem, Museu Goeldi, 29 Aug 1927, P. Occhioni 668 (H), Belem, 13 Aug 1923, J.G. Kulmann s.n. (HBR-H), 1½ hr. upstream from Lageira airstrip, on Rio Maicuru, 0°55'S, 54°26'W, 243.84 m alt., 23 Jul 1981, J.J. Strudwick & G.L. Sobel 3443 (NY); Matto Grosso: Pacca Nova, affl. do Mamoré, 23 Sept 1923, J.G. Kulmann 516 (HBR-H).

Habitat, distribution and phenology.

Octoblepharum peristomiruptum was found on the cortex of a shrub, at 2 m above soil level in a private butterfly garden in the Coclé Province, Panama. The site is on the edge of the road. The climate in this area is characterised by average temperatures ranging from 23-30 °C (http://www.accuweather.com, accessed Jan 2020). In Brazil, the plant was found in three sites, on a living tree trunk in the "Museu Goeldi" reserve in Belem ( Pará), on the trunk of a palm tree in a forested area in Matto Grosso and on a living tree trunk in a seasonally-flooded (varzea) forest. It is distributed in southern and northern Brazil and Central America (Panama). Plants with sporophytes were collected in Panama in January and, in Brazil in July, August and September.

Eponymy.

The species name refers to the character of the peristome teeth that rupture at base separating the two rows of cells that compose each tooth.

Conservation status.

The new species has been found in Coclé Province, Panama in a private conservation site and in the State of Pará, Brazil, on trees in the garden of the "Museu Goeldi" that is considered a reserve site. The conservation status of the other collection sites in Brazil is unknown. It is most probable that the species also occurs in other Central and South American countries. Given the limited knowledge of the current state of the sites where collections were made, the conservation status cannot be properly assessed. Thus, this new species is temporarily considered Data Deficient (DD).

Figures

Figure 1. Octoblepharum peristomiruptum Salazar Allen & Gudino. Photographs A habit in its natural environment B enlarged group of plants. Microphotographs C cross section of stem with young leaf (lf) D apex of leaf E chlorocysts near apex of leaf F chlorocysts at base of leaf (note the strong reddish-purple colouration) G enlarged hyalocysts on leaf border H rhizoids originating from border of leaf chlorocysts I rhizoids at apex of leaf. All from Gudino 3519 (PMA).

Figure 2. Octoblepharum peristomiruptum Salazar Allen & Gudino. Microphotographs A leaf, hyaline lamina B-D cross sections of leaf B near apex C at mid-leaf D at base E androecium F-I male bracts J antheridium and paraphysis K paraphyses of gynoecium A taken from Kulhmann 1621 (NY), B-K taken from Gudino 3519 (PMA).

Figure 3. Octoblepharum peristomiruptum Salazar Allen & Gudino. Microphotographs A four peristome teeth B dorsal view of peristome teeth with the two vertical rows of cells composing the teeth separating at base C two teeth with early and late separation of the two rows of cells D border and upper exothecial cells of capsule. A, B, D taken from Occhioni 668 (H), C taken from Gudino 3519 (PMA).

Figure 4. Octoblepharum peristomiruptum Salazar Allen & Gudino. Scanning electron microscopy micrographs A sporophyte B peristome teeth dorsal view C close-up of rupturing wall D ventral view of two teeth E ventral view at base of two teeth F spore A-C, E, F taken from Gudino 3519 (PMA), D taken from Strudwick & Sobel 3443 (NY).