Acrobolbus mashpianus Burghardt 2022, sp. nov.
Creators: name: Burghardt, Michael
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Marchantiophyta
Jungermanniopsida
Jungermanniales
Acrobolbaceae
Acrobolbus
Acrobolbus mashpianus

description: Acrobolbus mashpianus Burghardt, sp. nov. (Fig. 1)
Diagnosis:— Acrobolbus mashpianus is similar to Acrobolbus setaceus in its toothed leaf margins but differs by the strongly asymmetrically bilobed leaves that are more deeply bifid (1/2–4/5 vs. 1/4–1/3) and the longer teeth of the leaf margin (5-8 cells vs. 1-3 cells long).
Type:— ECUADOR. Pichincha: Metropolitan District of Quito, Parrish Pacto, Mashpi Ecological Reserve, Jungle Swing trail, elev. 913 m, 0°09’58.13’’N 78°52’50.36’’W, 22 February 2019, M. Burghardt MB 11033 (holotype: QCNE!).
Plants prostrate, scattered among other bryophytes; soft-textured, whitish green, turning brownish in the herbarium. Shoots small, up to 1.5 cm long and 1.3–1.5 mm wide with leaves; microphyllous stoloniferous base lacking. Stems light brown, slightly dorsoventrally flattened; near base ca. 85–140 × 60–100 µm thick, in cross-section about 4–6 cells high; differentiation in cortex and medulla lacking, cells thin-walled, ca. 10–23 × 11–17 µm, without trigones or only tiny ones; stem surface papillose to striate-papillose. Branching sparse, lateral-intercalary of the Plagiochila - type; rhizoids scattered along the stem. Shoots with contiguous to subimbricate foliation. Leaves succubous, obliquely to widely spreading, plane; ventral leaf margin not decurrent; dorsal margin not to shortly decurrent by few cells; leaves cuneate to occasionally subrectangular, widest above the middle, asymmetrically bilobed to 4/5, occasionally only to 1/2, with the dorsal lobe distinctly smaller than the ventral lobe; ca. 450–720 × 270–400 µm, 1.5–2.4 times as long as wide; lobes elongate triangular to lanceolate, acuminate, margins plane and crenulated, especially towards the (2–)4– 7(–8)-celled uniseriate lobe tips; lobes usually widely diverging, sometimes subparallel to somewhat connivent. Leaf margins beset with one to four elongate triangular to more commonly ciliate teeth, teeth 5–8 cells long, consisting of a short 2-celled base and a 4–7 cell long uniseriate tip. Leaf areolation ± regular; cells in the center of the ventral leaf lobe isodiametric to distinctly elongated with scattered cells shorter than wide, (30–)35–42(–52) × (29–)30–38(–47) µm, (0.9–)1.1–1.4(–1.8) times as long as wide; cells of the lobe tips (uniseriate part) slightly elongated, (29–)30–35(– 40) × (20–)22–24(–26) µm, (1.1–)1.2–1.5(–1.7) times as long as wide; cell walls thin, trigones small, triangular with convex sides, intermediate thickenings absent, leaf surfaces striate-papillose with some papillae rounded. Oil bodies of the Jungermannia - type, brown, 4–6 per cell, ellipsoidal to sometimes globose, surface granular. Underleaves vestigial, one-to-two-celled. Asexual reproduction possibly by fragmenting leaf lobes and teeth.
Male and female plants were not seen.
Habitat and distribution:— Acrobolbus mashpianus is only known from the type collection from the Mashpi Ecological Reserve in the Province of Pichincha. For a detailed description of the locality see Burghardt (2020). The holotype was collected in a humid evergreen premontane forest, where it grew on a tree trunk in appressed mats of a rich liverwort community. Associated species include Ceratolejeunea cornuta (Lindenberg 1829: 23) Stephani (1895: 65), Leptoscyphus trapezoïdeus (Montagne 1843: 251) Söderström (2013: 27), Plagiochila rudischusteri Robinson (1988: 199), Prionolejeunea aemula (Gottsche 1845: 338) Evans (1904: 219), P. muricatoserrulata (Spruce 1884: 155) Stephani (1913: 223), and P. trachyodes (Spruce 1895: 338) Stephani (1913: 215).
Etymology: — The name of the new species refers to the type locality.
description: Published as part of Burghardt, Michael, 2022, Acrobolbus mashpianus (Acrobolbaceae, Marchantiophyta) sp. nov. from the Northern Andes of Ecuador-Notes on the Bryophytes of Ecuador VII, pp. 133-138 in Phytotaxa 577 (1) on pages 133-134, DOI: 10.11646/phytotaxa.577.1.7, http://zenodo.org/record/7517605