Kniphofia vandeweghei Eb.Fisch. & Mark.Ackermann, 2019

Fischer, Eberhard & Ackermann, Markus, 2019, A new species of Kniphofia (Asphodelaceae) from Nyungwe National Park, Rwanda, Phytotaxa 391 (1), pp. 39-56 : 40-41

Kniphofia vandeweghei Eb.Fisch. & Mark.Ackermann sp. nov. ( Figs. 1–4 , 5C , 6B , 7C–G , 8 )

Kniphofia princeae affinis sed primo aspectu racema valde densa, gemmis floralibus in apice ± horizontaliter instructis et sub apicem dense pendentibus pedunculum tegentem et obscuratum valde differt. A K. princeae etiam foliis distichis vel spirodistichis latioribus et brevioribus, racema longiore et latiore, floribus luteis vel rare aurantiacis, perigono non vel leviter constricto et non vel leviter curvato et capsulis laevibus ± globosis valde distincta est.

Type:— RWANDA. Western Province: Nyungwe National Park, Rwasenkoko Swamp, 2380 m, 06 January 2018, Fischer & Ackermann 345/18 (holotype BR!, isotypes B!, K!)

Perennial herb. Rhizome up to 1.5 m long, thick, 2–5 cm in diameter, with yellow to brownish roots. Leaves dense, in young plants distichous, when older distichous to spirodistichous, lanceolate to linear-lanceolate, kinked in the upper part, 650–1100 X 30–50 mm wide towards the base. Inflorescence 1–2 m long; peduncle 10–20 mm in diameter; raceme very dense and compact, 250–700(–1100) X 60–90 mm; buds first in ± horizontal arrangement at apex, then bending into a dense pendent arrangement completely covering the peduncle; bracts oblong to lanceolate, 2–4 X 1 mm at the base, apex acute; pedicels 2–4 mm long. Flowers dark orange when young, paler with age and yellow when open, ± straight; perigone-tube 30–37 mm long, not or slightly constricted above ovary, straight or slightly curved, 5–8 mm wide at mouth, lobes 1–2 mm long; stamens slightly exserted for 1–5 mm; style exserted for up to 6 mm in older flowers. Capsules ± globose, smooth, 5–9 X 7–9 mm, rounded at apex.

Distribution and habitat: —Only known from the eastern Democratic Republic of Congo in the mountains west of Lake Kivu and from Rwanda ( Fig. 4 ). The species grows in Afromontane swamps, often in water. Localities are at elevations of 2000–2500 m, with the exception of Mt. Muhi, where it was collected at elevations between 3260 m and 3450 m

Pollination ecology: —In all investigated localities in the Rwasenkoko swamp, only male and female Blueheaded sunbirds [ Cyanomitra alinae (= Nectarinia alinae Jackson 1904: 94 )] have been frequently observed visiting the flowers ( Fig. 3E–I ). Vande weghe & Vande weghe (2011) also observed the Malachite sunbird [ Nectarinia famosa (= Certhia famosa Linnaeus 1766: 187 )] in the same area visiting the flowers.

Etymology: —Dedicated to Jean Pierre Vande weghe who was the first to recognize the status of the new species in the 1980s.

Discussion: — Kniphofia vandeweghei differs from K. princeae in the usually distichous to later spirodistichous leaf arrangement (rosulate in K. princeae ), the much shorter and slightly broader leaves [650–1100 mm vs. 1150– 1800(–2000) mm and 30–50 mm vs. 20–37 mm] ( Fig. 6 ), the very dense flower arrangement in the inflorescence with the buds first in ± horizontal arrangement at the apex, then later bending into a dense pendent arrangement completely covering the peduncle (lax and well-spaced even in the usually ± horizontal buds, where the peduncle is always visible in K. princeae ) ( Fig. 7A, C–D ), the distinctly wider raceme (60–90 mm vs. 40–65 mm), the mainly yellow and rarely orange flowers (orange to bright red, often tipped yellow at mouth in K. princeae ), the flower perigone that is not or only slightly constricted above the ovary and straight or only slightly curved (constricted above the ovary and sometimes strongly curved in K. princeae ), and the smooth and almost globose capsules (verrucose and acutetriangular at apex in K. princeae ) ( Fig. 7B, F–G ; Table 1).

Kniphofia vandeweghei and K. goetzei Engler (1901: 273) share a long rhizome, which is unusual in the genus Kniphofia (compare Fig. 2B and photos of K. goetzei at https://www.inaturalist.org/observations/4516936). However, it differs from K. goetzei in the width of the leaves (30–50 mm vs. 15–25 mm), the shape of the inflorescence (conical to cylindrical vs. narrowly ellipsoid to ovoid), the very dense flower arrangement in K. vandeweghei (vs. lax or moderately dense in K. goetzei ), and the bud arrangement (pendulous vs. erect to spreading). Kniphofia goetzei is only known from Udzungwa Mountains to Rungwe in southern Tanzania.

In contrast to the two previous species, K. paludosa Engler (1901: 274) , another taxon restricted to Afromontane swamps and often growing in water, is characterized by a very short rhizome of 40 mm length ( Whitehouse 2002). Other differential characters to K. vandeweghei are the shorter inflorescence (up to 1.2 m vs. 1–2 m in K. vandeweghei ), a shorter raceme [100–200 mm vs. 250–70(–1100) mm in K. vandeweghei ], longer pedicels (4–8 mm vs. 2–4 mm in K. vandeweghei ), and the bud arrangement being horizontally in K. paludosa and pendulous in K. vandeweghei ( Whitehouse 2002) . Kniphofia paludosa is restricted to the Elton Plateau in southern Tanzania ( Whitehouse 2002).

Herbarium specimens from D.R. Congo, collected at Lubero and on Mt. Muhi, are unfortunately limited, making comparisons with K. vandeweghei difficult. They resemble K. vandeweghei , but even though several of the diagnostic characters are difficult to observe in these specimens, we provisionally include them into this species. Field observations of living plants are required to confirm their status. However, a photograph by Eli Greenbaum (6 January 2011) ( Fig. 5C ) of an inflorescence from the nearby Itombwe Mountains, southwest of Lake Kivu, clearly matches the elongated and dense inflorescence of K. vandeweghei . Unfortunately no herbarium specimen of this plant was made.

Kniphofia vandeweghei usually flower in December and January, occasionally in July at Mt. Muhi.

Additional specimens examined (paratypes):—D.R. CONGO. Lacs Edouard et Kivu. Lubero–Rutshuru , 2700 m, 24 December 1936, Ghesquière 3525 ( BR) ; Kasamolehe, Lubero , 2100 m, 16 December 1957, de Witte 11527 ( BR) ; Mt. Muhi , sommêt, 3450 m, July 1948, Hendrickx 5367 ( BR) ; Kabare, entre la riv. Isale et Mt. Muhi , 3260 m, 28 July 1955, Kinet 16 ( BR) ; Marais près du sommêt du Mt. Muhi, 3350 m, 28 July 1955, Kinet 31 ( BR) ; Montagnes à l’ouest du Lac Kivu, 2000–2400 m, February–March 1929, Humbert 7790 ( BR) ; Itombwe Mountains , 06 January 2011, E. Greenbaum s.n. (Photo BR, no specimen collected) . RWANDA. Lacs Edouard et Kivu. Marais Rwasenkoko ( Muwasenkoko ), km 67 Butare–Cyangugu , 2300 m, 17 December 1971, Bamps 2792 ( BR) ; Marais Rwasenkoko ( Muwasenkoko ), 17 December 1971, Bouxin 1247 ( BR) ; Marais Rwasenkoko ( Muwasenkoko ), 27 December 1971, Bouxin 1277 ( BR) ; km 63 route Astrida (= Butare)– Shangugu (= Rusizi ), 6 August 1957, Reynders 149 ( BR) ; environs de Musagare, au km 80, 2270 m, 24 January 1971, Bouxin 146 ( BR) ; Muragiro , 2000 m, 24 March 1956, Christaensen 1606 (fruit) ( BR) ; swamp at border Western Province to Southern Province at road Nyamagabe–Ruzizi , km 50, 09 January 2018, Fischer & Ackermann 368/18 ( BR) .

Figures

FIGURE 1. Kniphofia vandeweghei A. Habitat at type locality. B–C. Habit. Photographs: E. Fischer & M. Ackermann, Rwanda, Rwasenkoko swamp, 06 January 2018.

FIGURE 2. Kniphofia vandeweghei. A. Habit (with M. Ackermann). B. Plant with very long rhizome (see white arrow). C. Basal leaves showing distichous to spirodistichous leaf arrangement. D. Basal leaves with rhizome.Photographs: E. Fischer & M.Ackermann, Rwanda, Rwasenkoko swamp, 06 January 2018.

FIGURE 3. Kniphofia vandeweghei. A–B. Flowers. C–D. Flowers dissected. E–F, I. Inflorescence visited by female Cyanomitra alinae. G–H. Inflorescence visited by male Cyanomitra alinae. Photographs: E. Fischer & M. Ackermann, Rwanda, Rwasenkoko swamp, 06 January 2018.

FIGURE 4. Known distribution of Kniphofia vandeweghei (yellow dots).

FIGURE 5. Kniphofia princeae.A.Habit.B.Inflorescence.Kniphofia vandeweghei. C. Inflorescence.Photographs:A–B.R.v.Blittersdorf, A. 24 March 2009, B. 14 February 2012, Tanzania, Sumbawanga, Mbizi Forest (see Blittersdorf 2009–2012); C. E. Greenbaum, D.R. Congo, Itombwe, 06 January 2011.

FIGURE 6. Kniphofia princeae. A. Habit. Kniphofia vandeweghei. B. Habit. Photographs: A. R. v. Blittersdorf, Tanzania, Sumbawanga, Mbizi Forest, 24 March 2009 (see Blittersdorf 2009–2012). B. E. Fischer & M. Ackermann, Rwanda, Rwasenkoko swamp, 06 January 2018.

FIGURE 7. Kniphofia princeae. A. Inflorescence. B. Detail of infructescence with mature capsules. Kniphofia vandeweghei. C–D. Inflorescence. E. Peduncle with bracts and pedicels. F. Mature capsule. G. Detail of infructescence. Photographs:A–B. R. v. Blittersdorf, A. 31 March 2009, B. 14 February 2012, Tanzania, Sumbawanga, Mbizi Forest (see Blittersdorf 2009–2012). C–G. E. Fischer & M. Ackermann, Rwanda, Rwasenkoko swamp, 06 January 2018.

FIGURE 8. Known distribution of Kniphofia vandeweghei (yellow dots) and K. princeae (white dots).