Coffea rizetiana Stoff. & M. Noirot 2021, sp. nov.
Creators: name: Stoffelen, Piet
name: Anthony, François
name: Janssens, Steven
name: Noirot, Michel
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Gentianales
Rubiaceae
Coffea
Coffea rizetiana

description: Coffea rizetiana Stoff. & M.Noirot, sp. nov.
(Figs 1-3)
The new species C. rizetiana Stoff. & M.Noirot, sp. nov. is related to C. montekupensis Stoff. and C. liberica Bull. ex Hiern, but it differs from C. montekupensis by having: elliptic vs obovate leaves; larger leaves (14)20-24(26) cm long and (5)6-9(10) cm wide vs 7-18(19) cm long and (2)2.5-5(6.5) cm wide; fewer secondary veins (8-10 pairs vs 12-13 pairs); longer corolla tube (4-7 mm vs 2.5-4 mm) and larger black fruits vs smaller red fruits and larger seeds (14-20 mm long × 8-13 mm vs 11-15 mm × 8-9 mm). It differs from C. liberica by having: shorter petioles (less than 1 cm vs 1-1.5 cm); acuminate leaf tips (vs apiculate or obtuse in C. liberica); a cuneate leaf base (vs rounded or rarely cuneate); a thinner leaf blade; shorter corolla tube; longer corolla lobes; and, black fruit (vs red or rarely yellowish or blackish; Fig. 3) with a thicker fleshy pericarp.
INFORMAL NAMES USED IN LITERATURE. — Coffea sp.: ‘Koto’ in Hamon et al. (2009, 2015), Razafinarivo et al. (2012), Noirot et al. (2016), Hamon et al. (2017).
Coffea liberica ‘Koto’: in Noirot et al. (1993), Cros et al. (1994), Anthony et al. (1997), Dussert et al. (1997a, 1997b), Lashermes et al. (1996, 1997), Stoffelen (1998: 102, 103, 110, 125), Stoffelen et al. (1999), Fernandez & Lashermes (2002), Noirot et al. (2003), Campa et al. (2004, 2005a, 2005 b, 2008), Dubreuil-Tranchant et al. (2011).
TYPE SPECIMEN. — Stoffelen 2045 (holo-, BR [BR0000026083674V]; iso-, P, YA), 15.IV.2016 collected in the greenhouses of Meise Botanic Garden, Belgium; grown from material collected in 1983 in Cameroon, south of the Mouyouka-Kompina forest, 4°22N, 9°34E, a forest road, to the left of the Penda-Mboko asphalt road, after 2.6 km leads to the population.
OTHER LIQUID PRESERVED SPECIMENS STUDIED. — Noirot EC66a, 3.XII.2012, flowering (BR, WAG); Noirot EC66b, 31.III.2013, fruiting (BR); Noirot EC54, 31. I.2013, flowering (BR, WAG); Noirot EC 52 (BR), sterile; Noirot EC 61, sterile (BR); Noirot EC63, sterile (BR, WAG); Noirot EC66, 30.X.2012. All these specimens were collected in the germplasm collection in the Bassin Martin coffee collection.
DISTRIBUTION. — Cameroon, only known from one population at the south of the Mouyouka-Kompina forest, N 4°22, E 9°34. A forest road, on the left of the Penda-Mboko asphalt road, leads to the population after 2.6 km.
HABITAT. — Understory of secondary rain forest, forest at 60 m above sea level, sympatric with C. canephora.
ETYMOLOGY. — This species is dedicated to the Professor Georges Rizet, Geneticist at the Orsay University Paris XI. Scientific adviser to the ORSTOM Director, he was central to the survey and genetic studies of the wild coffee genetic resources collected by IRD (ex-ORSTOM), Cirad and MNHN from 1966 to 1984.
DESCRIPTION
Small tree up to 6 m tall, young branchlets glabrous. Leafblades elliptic, (14)20-24(26) cm long, (5)6-9(10) cm wide, tip acuminate, acumen c. 1 cm, with rounded tip; small pit domatia at the junction of the midrib and the secondary veins, glabrous; 8-10 secondary veins at either side of the midrib. Petiole 0.5-1(1.3) cm long. Stipules 0.2-0.4 cm long, truncated to slightly obtuse, in young stage covered with exudate.
1-2(3) inflorescence per axil, each with 1(2) flowers and supported by two truncate bracteal cups, lower cup with 2 small reduced leaves-like appendages, 1-1.5 mm long; inflorescence stalk and peduncle in total c. 4 mm long.
Flowers 6 (7)-merous. Calyx reduced to a small rim, truncate. Corolla white; tube 4-7 mm long; lobes 15- 17 mm long, 5-7 mm broad; anthers 7-12 mm long, filament 2-5 mm long; ovary glabrous, not surrounded by the bracteal cups; disc c. 1 mm high.
Infructescence 1-2 per axil. Fruit 1 per infructescence. Fruit black to dark maroon-brown, fleshy pericarp (Fig. 3). Short peduncle c. 5 mm. Fruit almost spherical, somewhat truncate at top, (1.5) 2-3 cm long, 1.6-2.3 wide along the septum and 2-2.6 cm perpendicular to the septum. Disk and calyx reduced, small and not accrescent. Seeds small elliptic to elliptic, 14-20 mm long, 8-13 mm wide and c. 5-7 mm thick. Habitus, fruits and flowers are illustrated in Fig. 2.
description: Published as part of Stoffelen, Piet, Anthony, François, Janssens, Steven & Noirot, Michel, 2021, A new coffee species from South-West Cameroon, the principal hotspot of diversity for Coffea L. (Coffeeae, Ixoroideae, Rubiaceae) in Africa, pp. 277-285 in Adansonia (3) (3) 43 (26) on page 281, DOI: 10.5252/adansonia2021v43a26, http://zenodo.org/record/5817109