taxonID	type	description	language	source
DA03091AD62E7C49FCC1B962589A2303.taxon	description	Description — Megaspores c. 480 × 460 – 480 µm; proximal face trilete, densely pustulate, pustules 20 – 50 µm in diam., not anastomosing, sometime tuberculate, tubercles thin in between, 7.5 – 15 µm in diam., waxes with threads slightly felty, ridges c. 50 µm wide and c. 20 µm high; distal face clavate with distant projections up to 60 µm high and 40 – 50 µm in diam. and small tubercles 20 – 24 µm in diam. in between, densely covered by short threads, clavate projections above with short or lacking threads. – Fig. 2.	en	Fischer, Eberhard, Lobin, Wolfram (2022): The genus Isoetes (Isoetaceae) in Central Africa (Democratic Republic of the Congo, Rwanda, Burundi) with the description of three new species. Willdenowia 52 (3): 315-334, DOI: 10.3372/wi.52.52303, URL: https://doi.org/10.3372/wi.52.52303
DA03091AD62E7C49FCC1BF225F5D2123.taxon	description	Description — Megaspores 400 – 520 × 480 – 520 µm; proximal face trilete, densely tuberculate-pustulate, with large projections 30 – 60 µm in diam. and up to 20 µm high, and smaller projections 19 – 22 µm in diam., with dense threads covering tubercles and most of pustules, ridges up to 30 µm wide and up to 40 µm high; distal face with few large and distant pustules 40 – 60 µm in diam. and up to 20 µm high, and small tubercles 20 – 30 µm in diam., tubercles with short and dense threads, pustules free of waxes. – Fig. 3.	en	Fischer, Eberhard, Lobin, Wolfram (2022): The genus Isoetes (Isoetaceae) in Central Africa (Democratic Republic of the Congo, Rwanda, Burundi) with the description of three new species. Willdenowia 52 (3): 315-334, DOI: 10.3372/wi.52.52303, URL: https://doi.org/10.3372/wi.52.52303
DA03091AD62E7C5BFCC1BDC25A0B25C3.taxon	description	Description — Megaspores (360 –) 440 – 520 × (360 –) 440 – 520 µm; proximal face trilete, laevigate or with up to 3 flat tubercles c. 22.5 µm high and up to 15 µm in diam. per areole, covered with dense threads, ridges c. 60 µm wide and 20 – 30 µm high, free of waxes; distal face with dense to distant pustules 20 – 40 µm in diam., partly smaller, anastomosing, larger pustules 80 – 100 µm in diam., all covered with dense threads. – Fig. 4 – 6. Additional specimens studied — BENIN: ATAKORA: Matéti, SE of Dassari, along RNIE (Route Nationale) 3, 10 ° 48.3 ' N, 01 ° 09.3 ' E, dried up rice fields, 22 Nov 1999, Van der Maesen, Akoegniaou, Yédomonhau & Agbani 7203 (BR 0000015469366). — TANZANIA (T 4): TABORA: 21 km on Tabora – Urambo road, 05 ° 05 ' S, 32 ° 39 ' E, 1025 m, 11 Jun 2008, Bidgood, Leloyo & Vollesen 7304 (K 001291892).	en	Fischer, Eberhard, Lobin, Wolfram (2022): The genus Isoetes (Isoetaceae) in Central Africa (Democratic Republic of the Congo, Rwanda, Burundi) with the description of three new species. Willdenowia 52 (3): 315-334, DOI: 10.3372/wi.52.52303, URL: https://doi.org/10.3372/wi.52.52303
DA03091AD63C7C5BFF3CBCC258BC20C3.taxon	materials_examined	Holotype: D. R. Congo, Bas-Congo, Zongo, Kasangulu, chutes, 8 Apr 1971, Hallé 1922 (BR 0000015460486). Diagnosis — The new species resembles Isoetes alstonii and I. schweinfurthii but differs from both in the stouter habit and much shorter leaves (20 – 25 mm vs 150 – 400 [– 600] mm). The megaspores are slightly larger (c. 560 × 480 µm vs 400 – 520 × 480 – 520 µm in I. alstonii and 360 – 520 × 360 – 520 µm in I. schweinfurthii). The proximal face is densely pustulate with larger and smaller pustules, sometimes anastomosing, whereas in I. alstonii the proximal face is densely tuberculate-pustulate, with larger and smaller projections, never anastomosing, and in I. schweinfurthii the proximal face is laevigate or bears 3 tubercles at most. Description — Corm 3 - lobed, 5 – 13 mm wide, bud scales absent. Leaves 12 – 38, 20 – 25 mm long, c. 3 mm wide at base, 0.9 – 1 mm wide at apex, tapering gradually to a slender point. Ligule not seen. Velum rudimentary to absent. Megasporangia c. 5 × 2.5 mm, ovate, sporangial wall pale. Megaspores c. 560 × 480 µm; proximal face trilete, densely pustulate, with densely large and small pustules, sometimes anastomosing, 48 – 60 µm in diam., wax-like structures sometimes rodlet-like and filiform threads on pustules and dense threads between pustules, larger pustules partly anastomosing, ridges also partly pustulate, up to 60 µm wide and 60 µm high; distal face densely pustulate with large and smaller intermixed pustules, large pustules 45 – 57 µm in diam., partly anastomosing, small pustules 30 – 38 µm in diam., pustules almost completely covered with dense threads, sometimes rodlet-like. Microspores not seen. Distribution — Known only from the type locality in western D. R. Congo (Fig. 14 A). Habitat — On wet rocks in waterfalls, probably perennial, c. 320 m. IUCN conservation assessment (preliminary) — Critically Endangered: CR B 2 ab (iii). Isoetes hallei is known only from the type locality. The last two collections were made c. 50 years ago. The estimated AOO is 4 km ² (assuming a 4 km ² grid cell size). The habitat, a waterfall, is actually not protected, but there seem to be no immediate threats. Etymology — Named after Francis Hallé (born 1938), who first collected the new species. Additional specimens studied — D. R. CONGO: BAS-CONGO: chutes de Zongo, dans une pente rocheuse mouillée d’embruns, 21 Feb 1971, F. Hallé 1900 (P 01590086).	en	Fischer, Eberhard, Lobin, Wolfram (2022): The genus Isoetes (Isoetaceae) in Central Africa (Democratic Republic of the Congo, Rwanda, Burundi) with the description of three new species. Willdenowia 52 (3): 315-334, DOI: 10.3372/wi.52.52303, URL: https://doi.org/10.3372/wi.52.52303
DA03091AD63C7C5BFF3CB9E25AD8201D.taxon	description	Description — Megaspores c. 400 × 400 – 440 µm; proximal face trilete, with scattered and large and distant pustules 20 – 30 µm high and 30 – 40 µm in diam., and small tubercles 10 – 20 µm in diam. in between and toward ridges, with sparse threads, ridges free of waxes; distal face with large pustules up to 40 µm high and 30 – 40 µm in diam., partly anastomosing, and with small tubercles 16 – 20 µm in diam. toward margin, with sparse threads. – Fig. 7. Note — Welwitsch wrote on the Kew specimen in ink: “ Obs Omnia specimina a me visa habitu et statura pusilla inter se perfecte aequalia! ” Taxonomic treatment	en	Fischer, Eberhard, Lobin, Wolfram (2022): The genus Isoetes (Isoetaceae) in Central Africa (Democratic Republic of the Congo, Rwanda, Burundi) with the description of three new species. Willdenowia 52 (3): 315-334, DOI: 10.3372/wi.52.52303, URL: https://doi.org/10.3372/wi.52.52303
DA03091AD63C7C5AFCBEBCE25FF521A3.taxon	materials_examined	Holotype: Burundi, Bubanza district, Rusizi plain, km 14, 800 m, temporary swamp, 16 Mar 1975, Reekmans 4400 (K 001291890). Diagnosis — The new species differs from Isoetes abyssinica in the much longer leaves (240 – 460 mm vs 114 – 188 mm) and in the megaspore micromorphology. The megaspores are smaller (c. 400 × 400 µm vs c. 480 × proximal face trilete, bearing spaced tubercles 7 – 11 per areole, 11.25 – 22.5 µm in diam., with dense threads in between, only a small apex free of waxes, ridges c. 50 µm wide and c. 20 µm high, almost free of waxes; distal face with spaced larger and smaller pustules, 30 – 45 µm in diam., partly anastomosing, c. 26.25 × 15 µm, with dense threads between pustules, large apex of pustules free of waxes. Microspores not seen. Distribution — Known only from the type locality in the Rusizi plain of W Burundi (Fig. 14 B). The above cited collections were already mentioned as Isoetes abyssinica Chiov. by Pichi Sermolli (1983, 1985). Habitat — Amphibious, in seasonally waterlogged depressions in palm savanna, 780 – 850 m. IUCN conservation assessment (preliminary) — Critically Endangered: CR B 2 ab (iii). Isoetes pichisermollii is known only from the type locality and its immediate surroundings. The last collections were made c. 50 years ago. The estimated AOO is 4 km ² (assuming a 4 km ² grid cell size). The habitat, a seasonally waterlogged depres- sion in palm savanna, is under high pressure by agriculture (see Ntore & al. 2018). Because a part of the Rusizi plain is situated in eastern D. R. Congo, the species may well also occur in that country. Fig. 14. A: distribution map of Isoetes hallei (black circle). – B: distribution map of I. rwandensis (yellow circles) and I. pichisermollii (red circles). – Red Etymology — Named after Rodolfo Emilio lines indicate country borders, blue lines and surfaces rivers and lakes. – Scale bars: A = 1500 km; B = 100 km. Guiseppe Pichi Sermolli (1912 – 2005), a famous Italian pteridologist, who first mentioned the taxon from Burundi. 460 – 480 µm in I. abyssinica). The distal face in the new species has spaced larger and smaller pustules, where- Taxonomic notes — Verdcourt (2005: 3) stated, withas in I. abyssinica the distal face is clavate with distant out having seen the spores, that “ these Burundi speciprojections and small tubercles in between. The new mens [of Isoetes abyssinica] seem too robust ”. Isoetes species also differs from I. schweinfurthii, which has a abyssinica s. str. was placed into synonymy of I. welsimilar leaf length, in the megaspore micromorphology. witschii by Verdcourt (2005), but there are sufficient dif- The megaspores are smaller (c. 400 × 400 µm vs (360 –) ferences, e. g. in megaspore micromorphology, to keep 440 – 520 × (360 –) 440 – 525 µm in I. schweinfurthii). The both taxa as separate species. The specimen Reekmans proximal face bears spaced tubercles 7 – 11 per trilete sur- 4400, which we have chosen as the holotype, bears a face, whereas in I. schweinfurthii it is laevigate or bears pencil annotation by Henk Beentje who identified it as 3 tubercles at most. I. schweinfurthii. Description — Corm 3 - lobed, 10 – 20 mm wide, bud scales c. 9 × 4 mm, cuspidate, blackish. Leaves (6 –) 10 or 11, 240 – 400 (– 460) mm long, 4 – 5 mm wide at base, c. 1 mm wide at apex, tapering gradually to a slender apex. Ligule not seen. Velum absent. Megasporangia c. 5 × 3 mm, sporangial wall pale. Megaspores c. 400 × 400 µm; Additional specimens studied — BURUNDI: BUJUM- BURA: vallée Mugegi, km 14, 13 Mar 1971, Reekmans 91 (BR 0000015460400). — BUBANZA: plaine de la Rusizi, 19 Feb 1971, Lewalle 5192 (BR 0000013164775); plaine Rusizi km 14, 18 May 1974, Reekmans 3451 (BR 0000015460424, K 001291891).	en	Fischer, Eberhard, Lobin, Wolfram (2022): The genus Isoetes (Isoetaceae) in Central Africa (Democratic Republic of the Congo, Rwanda, Burundi) with the description of three new species. Willdenowia 52 (3): 315-334, DOI: 10.3372/wi.52.52303, URL: https://doi.org/10.3372/wi.52.52303
DA03091AD63E7C59FF3CBA825E702783.taxon	materials_examined	Holotype: Rwanda, Eastern Province, Bugesera, Nyamata, 02 ° 07 ' 00.91 '' S, 30 ° 04 ' 07.67 '' E, 1415 m, seasonal shallow ponds on ferricretes, 9 Jan 2012, Fischer 66 / 2012 (BR 0000015253576 V). Diagnosis — The new species differs from Isoetes abyssinica and I. welwitschii in the shorter leaves (55 – 62 mm vs 114 – 185 mm in I. abyssinica and 50 – 200 mm in I. welwitschii). It differs in the colour of the megasporangium wall (dark brownish to blackish vs pale in I. abyssinica and I. welwitschii). The megaspores are smaller (c. 400 × 400 µm vs c. 480 × 460 – 480 µm in I. abyssinica). The distal face is densely pustulate-tuberculate with larger, rounded pustules intermixed with smaller tubercles, sometimes anastomosing, whereas in I. abyssinica the distal face is clavate with distant projections and small tubercles in between, and I. welwitschii has a distal face with large pustules, partly anastomosing and with small tubercles intermixed. Description — Corm 3 - lobed, up to 5 mm wide, bud scales 2 – 2.5 × c. 1.5 mm, cuspidate, pale green. Leaves 15 – 21, 55 – 62 mm long, 1.2 – 1.6 mm wide at base, 0.4 – 0.6 mm wide at apex, tapering gradually to an acute apex. Ligule not seen. Velum absent. Megasporangia 2.2 – 2.6 × 1.2 – 1.4 mm, sporangium wall dark brownish to blackish. Megaspores c. 400 × 400 µm; proximal face trilete, evenly tuberculate with small and dense tubercles 28 – 30 µm in diam., ridges c. 50 µm wide and c. 33 µm high, areoles and ridges with dense threads; distal face densely pustulate-tuberculate with larger, rounded pustules 39.9 – 60 µm in diam. intermixed with smaller tubercles, sometimes anastomosing, up to 26 µm in diam., larger pustules sometimes anastomosing, dense threads between pustules, only apex of pustules ± free of waxes. Microspores not seen. Distribution — Known only from the type locality and one additional locality in Eastern Province of Rwanda (Fig. 14 B). Habitat — In small, temporary pools on ferricretes (Fig. 12 A) along with Callitriche oreophila Schotsman, Cyperus species, Lindernia parviflora (Roxb.) Haines, Marsilea minuta L. and Rotala tenella (Guill. & Perr.) Hiern (see Fischer & Hinkel 1992). IUCN conservation assessment (preliminary) — Critically Endangered: CR B 2 ab (iii). Isoetes rwandensis is now known only from one locality. The type locality near Nyamata was destroyed during road work in 2021 by covering the ferricrete with more than 1 m of soil. The estimated AOO is therefore 4 km ² (assuming a 4 km ² grid cell size). At the second location, there is a potential threat of house construction and road work. Etymology — Named after the country of Rwanda, where the new species is probably endemic. Additional specimens studied — RWANDA: EASTERN PROVINCE: Mpanga, entrance of Ranch Mpanga between Lac Cyambwe and Lac Mpanga, 02 ° 04 ' 56.65 '' S, 30 ° 46 ' 39.96 '' E, 1310 m, seasonal shallow ponds on ferricretes, 30 Mar 1987, Fischer 110 (KOBL).	en	Fischer, Eberhard, Lobin, Wolfram (2022): The genus Isoetes (Isoetaceae) in Central Africa (Democratic Republic of the Congo, Rwanda, Burundi) with the description of three new species. Willdenowia 52 (3): 315-334, DOI: 10.3372/wi.52.52303, URL: https://doi.org/10.3372/wi.52.52303
