Champluvier (1988) lists three species for Rwanda, of which only Aframomum angustifolium is correctly identified. The specimens assigned to Aframomum mildbraedii Loes. are probably Aframomum spiroligulatum A.D.Poulsen & Lock (Poulsen and Lock 1997: 608), but we could not retrieve any of the cited specimens. The specimen Bouxin 1146, identified as Aframomum zambesiacum (Baker) K.Schum. (Schumann 1904: 206) represents the recently described Aframomum wuerthii Dhetchuvi & Eb.Fisch. (Dhetchuvi and Fischer 2006: 241). The highest diversity of Aframomum in Rwanda is found in Nyungwe National Park where numerous endemic species occur (e.g. Impatiens nyungwensis Eb.Fisch., Dhetchuvi & Ntaganda; Fischer et al. 2003: 91).

RWANDA – Northern Province • along road between Gakenke and Bushwati; 01°38’37.40”S, 29°46’34.77”E; 1760 m; 26 Oct. 2004; Fischer & Dhetchuvi 559/2004; KOBL. – Southern Province • Butare, Arboretum Ruhande; 2°36’48.74”S, 29°45’00.79”E; 1714 m; 29 Nov. 2006; Fischer 1344/2006; KOBL. – Eastern Province • Ibanda-Makera gallery forest; 02°06’37.17”S, 30°50’59.76”E; 1311 m; 24 Sep. 2021; Fischer 656/2021; KOBL.

For further localities in Rwanda see Harris and Wortley (2018).

New record for Rwanda.

RWANDA – Western Province • Nyungwe National Park, Cyamudongo Forest; 02°32’27.45”S, 28°59’20.20”E; 1945 m; 19 Oct. 2004; Fischer 495/2004; KOBL • ibid.; 26 Mar. 2006; Fischer 571/2006; KOBL • Forest edge close to WCS-guesthouse at Gisakura; 02°26’25.33”S, 29°05’36.44”E; 1906 m; 15 Oct. 2004; Fischer 411/2004; KOBL.

The species was already illustrated by Fischer and Killmann (2008).

New record for Rwanda.

RWANDA – Western Province • Nyungwe National Park, Cyamudongo Forest; 02°33’31.44”S, 28°59’02.36”E; 1993 m; 20 Dec. 2007; Fischer 986/2007; KOBL • Kamiranzovu Swamp, 2000 m; 02°29’04.08”S, 29°09’56.42”E; 2114 m; 15 Oct. 2004; Fischer 401/2004; KOBL • Road Pindura–Bweyeye km 7; 02°32’15.56”S, 29°14’23.15”E; 1860 m; 14 Oct. 2004; Fischer 389/2004; KOBL • Road Pindura–Bweyeye km 25; 02°36’21.75”S, 29°19’56.71”E; 1768 m; 14 Oct. 2004; Fischer 395/2004; KOBL.

The species was confused with Aframomum mala (K.Schum.) K.Schum. by Poulsen and Lock (1997) and Fischer and Killmann (2008). The identification of some East African collections was corrected by Harris and Wortley (2018).

RWANDA – Western Province • Nyungwe National Park, between Karamba and Gisakura: 02°28’20.65”S, 29°06’24.39”E; 1941 m; 19 Oct. 2004; Fischer 475/2004; KOBL.

This is the second known locality of this species in Rwanda. Rangiro, which is also situated in Nyungwe National Park, was already cited in the protologue. The species has been illustrated by Fischer and Killmann (2008).

RWANDA – Western Province • Nyungwe National Park, edge of Kamiranzovu swamp; 02°29’04.75”S, 29°09’04.68”E; 1952 m; 11 Dec. 2018; Fischer 1143/2018; KOBL, NHR.

Only known from the type locality where it was most recently observed in December 2021. The specimen Bouxin 1146 (BR0000024589918), also collected at this locality, was misidentified as Aframomum zambesiacum by Champluvier (1988) (see also Bouxin 1974).

New record for Rwanda.

RWANDA – Western Province • Nyungwe National Park, Cyamudongo Forest; 02°33’29.90”S, 28°59’13.23”E; 1954 m; 26 Sep. 2011; Fischer 644/2011; KOBL • Forest edge close to WCS-guesthouse at Gisakura; 02°26’25.33”S, 29°05’36.44”E; 1906 m; 20 Oct. 2004; Fischer 521/2004; KOBL • Road Pindura–Bweyeye km 6; 02°31’45.81”S, 29°18’53.82”E; 1987 m; 16 Oct. 2004; Fischer 463/2004; KOBL.

The species has already been illustrated by Fischer and Killmann (2008). Dhetchuvi (1996) cites a specimen of Aframomum zambesiacum from Rwanda, Eastern Province, Parc National de la Kagera, colline Rurama, 3 Nov. 1958, Troupin 8698 (BR0000024588621) but this proved to be Aframomum angustifolium.

The genus Renealmia comprises 82 species (POWO 2023), 26 of which are found in tropical Africa. While a modern treatment for tropical America (Maas 1977) and subsequent descriptions of new taxa (Maas 1979; Maas and Maas 1987, 1990; Ospina and Pozner 2013) and revisions of critical groups (Lima et al. 2018) are available, the African species are still in need of a revision (Lock 1985). Important contributions have been the treatments for Flore du Cameroun (Koechlin 1965) and Flore du Gabon (Koechlin 1964). Dhetchuvi (1996) proposes six new species of Renealmia in his PhD thesis, which will be validated in a paper on the genus in Central Africa (Fischer and Dhetchuvi unpubl. data). Another six new species have subsequently been discovered during intensive research in the field and in major herbaria. One of these taxa, R. timmiorum, was collected on a joint field trip by the first author and the last author in Rwanda and thus the description could be written in more detail. A second new species was collected by the first author in the isolated Cyamudongo Forest. The four remaining species will be described in a forthcoming paper. Champluvier (1988) only lists R. congolana De Wild. & T.Durand (De Wildeman and Durand 1899: 144) from Rwanda. However, this species differs from Renealmia susannae-katziae and R. timmiorum in the partial inflorescences (cincinni) with at least 4–8 flowers and the distinctly pubescent rachis. Renealmia congolana is now considered as a synonym of R. africana Benth. ex Hook.f. (Hooker 1883: 24) (Fischer and Dhetchuvi unpubl. data). This taxon has not yet been recorded for Rwanda and the specimens cited by Champluvier (1988) represent mostly R. timmiorum. The majority of collections available consists of fruiting material, including the majority of species already proposed by Dhetchuvi (1996). However, their description will point out the existence of these taxa and may help to collect further material and to assess the conservation status. Important characters used in the description of Renealmia species are the leaves, the number of flowers in a cincinnus, the shape of the bracteole, the shape of the calyx and the fruit (including number of seeds). Generally, the flowers are rarely available and flower characters are therefore difficult to apply for comparison with other species. The two new species proposed in the present paper have fortunately been observed with flowers and their characters are included in the descriptions. The majority of Renealmia species in Africa is restricted to lowland rainforest. The two new taxa from Rwanda represent species of the genus that are occurring at the highest known elevations of up to 2003 and 2267 m.

BURUNDI – Bubanza Province • Mugomero (Rugazi); 03°13’33.65”S, 29°31’21.89”E; 2167 m; 2 May 1981; Reekmans 10045; holotype: BR [BR0000020218539].

The new species resembles Renealmia africana and R. dewevrei De Wild. & T.Durand. It differs, however, in the partial inflorescences (cincinni) with 1–2(–4) flowers (vs 1–7 in R. africana and 4–8 in R. dewevrei), the glabrous calyx and fruit (vs pubescent in R. africana and R. dewevrei), the subglobose capsules, and the 2–3 seeds per locule (vs 11–13 in R. africana and 9 in R. dewevrei).

Perennial herb forming a dense clump. Leafy shoots 100 to 200 cm tall, covered at base with imbricate leafless sheaths. Leaves with sulcate sheaths surrounding the stem, with reticulately anastomosing venation and numerous brownish glands between the reticulations. Ligule obtuse, up to 2 mm long. Petiole 4–6(–10) cm long. Lamina narrowly obovate, attenuate at base and decurrent along petiole, caudate-acuminate at apex, about 60 cm long and 10 cm wide, greyish-green at lower surface, lateral veins visible at both surfaces. Inflorescence thyrsic, arising at base of leafy shoots, 20–40 cm long. Peduncle about 30 cm long, with up to 5 leafless glabrescent sheaths of about 5–10 cm length, ciliate near margin, internodes glabrous; rachis about 1/2 of inflorescence, glabrous, red. Bracts caducous, membranaceous, pubescent with persistent hairs, ciliate at margin, about 1 cm long. Bracteoles caducous, membranaceous, tubular, abaxially shortly incised, pubescent with persistent hairs, ciliate at margin, about 5 mm long. Partial inflorescences (cincinni) subsessile, with 1 to 2(–4) flowers. Pedicels red-orange, sparsely pubescent, with minute hairs, about 3–15 mm long, regularly enlarged at apex. Calyx persistent, accrescent in fruit, tubular apex with acuminate lobes, glabrous except for ciliate margin, purple, about 6 mm, 1 cm long in fruit. Corolla yellowish with purplish to violaceous marks; dorsal lobe rounded, 5 mm long, tinged with mauve; lateral lobes purplish 5 mm long; labellum yellowish with purple; claw 3.7 mm long; limb about 8 mm in diameter, the free portion 3-lobed. Stamen with 1 bilocular theca, about 2 mm long; lateral staminodes ovate, acuminate, 1 mm long. Ovary 2–3 × 1–2 mm, glabrescent, greenish-yellowish tinged with purple; epigynous glands rectangular, 1 mm long; style 8 mm long; stigma bilobed, 0.7 × 1.1 mm. Fruits subglobose, glabrous, shining black at maturity, 10 × 5–8 mm. Seeds globose-polygonal to irregular, 3 mm in diameter, 2–3 per locule.

Only known from Nyungwe National Park, Rwanda, and western Burundi (Fig. 9).

The new species grows close to a small stream with Carapa grandiflora, Tabernaemontana stapfiana, Lepidotrichilia volkensii, Alangium chinense, Myrianthus holstii in the tree layer, Scepocarpus hypselodendron and Illigera vespertilio as lianas, and Fagopyrum snowdenii, Uvariopsis congensis (juvenile), Ptisana africana, Blotiella bouxiniana, Impatiens erecticornis, Antrophyum mannianum, Culcasia falcifolia, and Polystachya cultriformis in the herb layer or as stem epiphytes. A specimen was collected near the road passing through Cyamudongo Forest to Nyakabuye in a forest with Newtonia buchananii, Entandrophragma excelsum, Myrianthus holstii, Polyscias fulva, Maesa latifolia, Neoboutonia macrocalyx, Xymalos monospora, Astropanax abyssinicus, and Tabernaemontana stapfiana in the tree layer. The species occurs from 1240 to 2267 m.

Dedicated to Mrs Susanne Katz on the occasion of her 50^th birthday for her generous financial support of taxonomic research.

Karuzi and Mabayi are now densely and heavily populated area. The location of Kihofi is likely lost due to a large sugarcane plantation and a factory which are installed there. The collecting sites in Burundi are located outside protected areas where the species’ habitat is rapidly degrading due to agriculture and urbanization expansion. By considering the loss of habitat, the number of locations is 4 or 5. Two are located within protected areas (Nyungwe National Park). Several adverse factors are affecting the extent and quality of habitat of this species like logging and agriculture. The calculated EOO is 6680 km² and the AOO is 54 km². Based on the above observations, it is assessed as Endangered: EN B1 ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v).

RWANDA – Western Province • Nyungwe National Park, Cyamudongo Forest, near Riv. Nyamabuye: 02°33’10.015”S, 28°59’31.46”E; 1755 m; 1 Apr. 2004; Fischer 156/2004, KOBL, NHR • Cyamudongo Forest, along road to Nyakabuye; 02°33’30”S, 28°59’01”E; 1978 m; 18 Oct. 2004; Dhetchuvi & Fischer 1990; KOBL • ibid.; 10 Dec. 2018; Fischer 1137/2018; KOBL • 23 km on road Pindura–frontière Burundi; 02°34’45.38”S, 29°12’13.35”E; 1720 m; 13 Aug. 1974; Auquier 3742; BR [BR0000020218010].

BURUNDI – Bubanza Province • Bubanza; 19 Dec. 1970; Lewalle 5101; BR [BR0000014516139] • Bubanza, Mabayi, route vers Cibitoke; 02°42’36.15”S, 29°17’20.15”E; 2267 m; 22 Jun. 1969; Lewalle 3799; BR [BR0000020218003] • Bubanza, Muyebe, Rugazi; 03°12’54.72”S, 29°31’10.34”E; 1845 m; 16 Oct. 1974; Reekmans 3839; BR [BR0000020218591] • Bubanza, Cibitoke-Mabayi, vallée Nyamagana; 2 Mar. 1969; Lewalle 3285; BR [BR0000020218607]. – Rutana Province • Kiofi, Mosso; 04°02’S, 30°07’E; 1240 m; 15 Mar. 1952; Michel & Reed 1371; BR [BR0000020218546]. – Karuzi Province • Kitega, Chefferie Bweru, environs de Karuzi; 03°08’33.22”S, 30°05’38.16”E; 1758 m; 21 Jan. 1959; Van der Ben 2446; BR [BR0000020218027].

RWANDA – Western Province • Nyungwe National Park, crête au Sud-Ouest du Kamiranzovu; 02°28’27.11”S, 29°07’36.31”E; 2003 m; 5 Aug. 1976; Troupin 15842; holotype: BR [BR0000020217891].

The new species resembles Renealmia cincinnata and R. cabrae in the lax inflorescence but differs in the hyaline bracts, the elliptic lamina that is decurrent on the petiole, the pubescent and much shorter inflorescence with partial inflorescences (cincinni) bearing 1–3 flowers, and the fruits with 2–3 seeds per locule.

Perennial herb usually with few single shoots closely adjacent. Leafy shoots 40 to 100 cm tall, covered at base with imbricate leafless sheaths, the upper sheath sometimes with a reduced lamina. Leaves with sulcate sheaths surrounding the stem, with reticulately anastomosing venation and densely pubescent between the reticulations, with numerous simple and bifid hairs, margin membranaceous, reddish. Ligule very short, up to 2 mm long. Petiole 3–7 cm long, with reticulation and hairs within the furrows. Lamina elliptic, distinctly and progressively attenuate at base and decurrent at apex of petiole, acuminate to acute at apex, 19–25 cm long and 3.5–4 cm wide, median vein reticulate and glabrous, dark green at upper surface, greyish-green at lower surface, lateral veins visible only at lower surface, acumen at apex about 1 cm long. Inflorescence thyrsic, arising at base of leafy shoots, 14–25 cm long, entirely pubescent, with flowers and fruits horizontally arranged or bent upwards, in spiral arrangement. Peduncle about 10–20 cm long, up to 7 internodes reaching 8.5 cm of length, longer than the sheaths, with basal leafless sheaths short and dense, upper sheaths longer, of about 7 cm length, with bifid and caducous hairs at outer surface; rachis 5–10 cm long, entirely purple, with minute simple and caducous hairs, glabrescent. Bracts coriaceous to membranaceous, persistent, lanceolate, basal bract 2.5–3 cm long, the upper bracts shorter, glabrous with membranaceous ciliate margin, bracts of secondary axes lanceolate, with membranaceous ciliate margin, 1–2 cm long. Bracteoles tubular, with short abaxial slit, membranaceous, about 6–8 mm long, glabrescent. Partial inflorescences (cincinni) subsessile, with 1 to 3 flowers; peduncle about 2 mm long. Pedicels purple, becoming orange in fruit, glabrescent, about 5–20 mm long. Calyx persistent, accrescent in fruit, tubular, apex with acuminate lobes, glabrous except for ciliate margin, purple, about 6 mm, 1 cm long in fruit. Corolla white with purplish to violaceous marks; dorsal lobe rounded, 4.5–5 mm long, tinged with mauve; lateral lobes purplish, 4.5–5.1 mm long; labellum white with purple; claw 3.8 mm long; limb 6.3 × 7 mm, obtusely 3-lobed, mid-lobe deeply emarginate. Stamen with 1 bilocular theca, about 3.8 × 2 mm; lateral staminodes acuminate, ovate-lanceolate, 1 mm long. Ovary 2–3 × 1–2 mm, glabrescent, greenish-yellowish tinged with purple; epigynous glands rectangular, 1 mm long; style 8 mm long; stigma bilobed. Fruits elliptic, glabrous, about 1.5 cm long and 5 mm wide, red-orange, shining black at maturity. Seeds red-orange, surrounded by a yellowish aril, 2–3 per locule.

Montane forests of western Rwanda (Fig. 9).

The new species is found at the type locality in a montane rainforest with Pentadesma reyndersii, Newtonia buchananii, Carapa wohllebenii, Parinari excelsa, and Strombosia scheffleri dominant in the tree layer. Other abundant species in the shrub and herb layer are Mimulopsis arborescens, Alchornea hirtella, Blotiella bouxiniana, Cincinnobotrys speciosum, Selaginella lewalleana, Saintpauliopsis lebrunii, and Scadoxus multiflorus. Other habitats mentioned on the specimens studied include Parinari excelsa-forest, forest with Pentadesma lebrunii, and relict transition forest. It occurs from 1580 to 2003 m.

Dedicated to the family Timm from Germany for their generous financial support of taxonomic research.

Using a 3 × 3 km² grid cell size, the EOO is estimated at 41.3 km² which falls within the limits for the Vulnerable category; the AOO is estimated at 27 km² which falls within the limits for the Endangered category. As all locations are situated in a protected area (Nyungwe National Park), the species is assessed as Least Concern (LC).

RWANDA – Western Province • Nyungwe National Park, Ntendezi; 02°27’07.43”S, 29°03’27.43”E; 1580 m; Habiyaremye s.n.; BRLU, NHR • Rangiro; 02°27’36.41”S, 29°10’51.50”E; Bridson 379; BR [BR0000020217877], K • Rangiro, forêt dense près pépinière de Rutabanzogera; 02°27’13.61”S, 29°11’44.52”E; 1967 m; 12 Jun. 1978; Raynal 20486; P [P00072226], WAG [WAG0364620] • Rangiro; 02°27’36.41”S, 29°10’51.50”E; Troupin 16051; BR [BR0000020217884] • Gisakura, near waterfalls; 02°25’51.95”S, 29°07’02.92”E; 1933 m; 19 Oct. 2004; Dhetchuvi & Fischer 1991; KOBL, NHR • ibid.; 10 Dec. 2018; Fischer 1125/2018; KOBL, NHR • Site Gisakura/Karamba; 6 Jul. 1999; Liengola IBL 406; GIS • Gisakura; 6 Jul. 1999; Liengola IBL 407; GIS • Forêt de Nyungwe, village Gasumo, sous-bois de la forêt primaire de montagne; 02°31’00.09”S, 29°04’28.19”E; 1680 m; 6 Jul.1999; Liengola IBL 412; GIS • Cyangugu, commune de Kagano, forêt de Gisakura, forêt à Pentadesma reyndersii et Syzygium guineense; 02°27’06.31”S, 29°06’46.86”E; 1966 m; 10 Apr. 2000; Ewango & Boniface 2247; BR [BR0000009718661].

Renealmia montana sensu Dhetchuvi (1996) comprises R. timmiorum and another undescribed taxon from eastern D.R. Congo found at lower elevations (850–1000 m) that will be validated in a future paper.