Isoetes jarmaniae D. F. Brunt., G. Kantvilas & M. Garrett 2021, sp. nov

Isoetes jarmaniae D.F.Brunt., G. Kantvilas & M. Garrett, sp. nov. (Figures 1, 4, 5, 6) Diagnosis:— A diminutive species restricted to alkaline seepage areas in Tasmanian buttongrass moorland and most similar to the larger Isoetes drummondii, from which it differs most conspicuously by its strongly recurved leaves, disproportionately large ligules and congested, boldly ornamented regulate-cristate to columnar, slightly triangular megaspores and finely papillate microspores. Type: — AUSTRALIA: Tasmania, Maxwell Valley near Lancelot Hill, 42°31’S 145°55’E, in alkaline pan, 190 m elevation, 26 April 1985, S. J. Jarman (holotype HO 314939!; isotype DFB! [fragment]). Description:— PLANTS: short (leaf rosette above corm en masse. Distribution and Habitat:— In coarse, peaty quartzite/ silica sand substrate in periodically inundated (flowing) seepage areas over limestone bedrock, with sparse associated vegetation; found only in southwestern Tasmania, Australia. Chromosome Number:— Inferred diploid (2 n =2x=22) by spore size conformity with cytologically confirmed diploid Tasmanian taxa: I. drummondii, I. elatior and I. gunnii (Marsden 1979, D.M. Britton pers. comm.). Etymology:— The epithet honours Dr. S. Jean Jarman of Hobart, Tasmania, who first collected this species and recognised it as unique. The vernacular name Limestone Quillwort is suggested, as per Tasmanian State Government (2021). Paratypes: — Tasmania: tributaries of the Giblin River, E of Lawson Range, 42°56’S 145°44’E, J. Jarman (HO 31378!); Maxwell Valley, 42°30’S 145°55’E, 190 m, 26April 1985, S. J. Jarman (HO 314082!); Maxwell River, 42°31’S 145°55’E, 200 m, 26 April 1985, M. J. Brown (HO 531819!); Middle Giblin River basin, 8 km NW of Mt Gaffney, 43°00’S 145°45’E, 30 m, 17 Feb. 1989, J. R. Croft 10114 & M. M. Richardson (AD, CANB, HO!); Alfhild Creek, Giblin River Valley, 43°03’S 145°43’E, Feb. 1989, L. Gilfedder (HO 114427!); Giblin River 43.0156°S 145.7467°E, M. Garrett s.n., 20 February 1994 (DFB!, OAC); Giblin River, 42°57’S 145°46’E, 20 m, 8 Jan 2005, G. Kantvilas & M. Garrett (HO 531818!); Giblin River valley, 42°56’S 145°45’E, 40 m, 18 Aug. 2016, M. Visoiu (HO 591035!); Maxwell River Valley, c. 700 m SW of Prince Rivulet, 42°29’S 145°55’E, 190 m, 12 Dec. 2017, M. F. de Salas 1915 (DFB (fragment)!, HO 590554!); Algonkian Rivulet valley, c. 800 m NW of junction with Ridge Creek, 42°27’S 145°57’E, 210 m, 12 Dec. 2017, M. F. de Salas 1903 (DFB (fragment)!, HO 590544!); Giblin Valley, c. 2.75 km SE of Pass Hill, 42°56’S 145°45’E, 40 m, 21 Mar 2018, M. F. de Salas 2005 (DFB (fragment)!, HO 593072!).