Paracephaelis longipedicellata De Block, 2022

Block, Petra De, 2022, Monograph of the western Indian Ocean genus Paracephaelis (Rubiaceae - Pavetteae), with description of thirteen new species, European Journal of Taxonomy 801, pp. 1-99 : 48-52

Paracephaelis longipedicellata De Block sp. nov.

urn:lsid:ipni.org:names:77260710-1

Figs 2C , 4A–B, E, G, M–N , 12

Diagnosis

Differing from Paracephaelis sericea by having narrower leaves (1.5–3.5 cm vs 4.5–12 cm wide), shorter petioles (2–5 mm vs 1–3 cm long), longer pedicels (8–20 mm vs 0–2 mm long or rarely up to 5 mm long in case of reduction), shorter calyx tubes (0.75–1 mm vs 2–5 mm long), and smaller, spherical fruits (4–7 mm in diameter vs ovoid or more rarely subspherical, 10–12 × 8–11 mm) with thin fruit walls (vs thick fruit wall with network of anastomosing sclerified vascular bundles).

Etymology

The species epithet is based on the long pedicels.

Type material

MADAGASCAR – Antsiranana Province, Diana Region, Nossi-Be District • Sambirano , forêt de Lokobe , Nossi-Be ; 13–15 Mar. 1964; fl; Capuron 23451-SF; holotype: P [ P04525149 ]; isotypes: BR [ BR0000022757647 ], P [ P04525148 ], TEF .

Other material studied

MADAGASCAR – Antsiranana Province, Diana Region, Ambanja District • Ampasindava, forêt de Betsitsika , à 582 m du point côté 69, au 294°; 65 m a.s.l.; 22 Jan. 2009; fl; Ammann, Madiomanana & Tahinarivony 324; BR, G n.v . • Ampasindava, forêt de Betsitsika , à 375 m du point côté 264, au 274°; 230 m a.s.l.; 17 Nov. 2009; fr; Ammann, Madiomanana & Tahinarivony 358; BR, G n.v . • Antseva, Tsaratanana massif ; 450 m a.s.l.; 9 Apr. 2000; fl; Antilahimena, Ratovoson, Ravelonarivo & Rabenantoandro 458; BR, MO • Bemanevika, Bandrakorony, forêt primaire subhumide de basse altitude de Bandrakorony, près du ruisseau de Betsitsiky sur la presqu’île d’Ampasindava; 272 m a.s.l.; 20 Jan. 2009; fl; Bernard et al. 1298; BR, MO • Sambirano, presqu’île d’Ambato ; 16 Mar. 1964; fl, fr; Capuron 23425-SF; BR, P, TEF • Sambirano, Antsalabe, entre Djangoa (Ambanja) et Ankaramybe; 12 Oct. 1966; fr; Capuron 24838-SF; BR, P, TEF • Bekaka ; 150 m a.s.l.; 20 Mar. 1950; fl; coll. ignot. 3163-SF; P, TAN, TEF • Manongarivo RS , Besinkara , 1 km NW d’Ambalafary, relevé R 70; 300 m a.s.l.; 22 Jun. 1994; fr; Gautier, Chatelin & Derleth 2404; BR, G n.v., K, TAN • Manongarivo RS, Ambahatra, cours supérieur, crête entre les deux bras de l’Ambahatra, 500 m WNW du point côté 1037, relevé TL1; 850 m a.s.l.; 28 Feb. 1999; fl; Gautier, Messmer & Andriatsiferana 3431; BR, G n.v., P online • Ampasindava, forêt de Betsitsika , à 906 m du point côté 69, au 145°; 150 m a.s.l.; 1 Nov. 2009; fr; Gautier, Ammann, Madiomanana & Tahinarivony 5268; BR, G n.v . • massif de Manongarivo ; 800 m a.s.l.; Apr. 1909; fr; Perrier de la Bâthie 3854; P • chaîne de Bekaka; 150 m a.s.l.; s.dat.; fl; Saboureau 59; P • forêt d’Andranomatavy ; 196 m a.s.l.; 26 Sep. 2013; fr; Tahinarivony 736; G n.v., P online, MO n.v., TAN n.v. – Nossi-Be District • Nossi-Be, RNI 6, Lokobe ; 0–30 m a.s.l.; 19 May 1994; fr; Antilahimena 121; BR, K, MO, P • Nossi-Be , Junea, protection zone around RNI 6, Lokobe ; 105 m a.s.l.; 13 Jan. 2007; fl; Groeninckx, Rakotonasolo & De Block 82; BR, MO, TAN • Nossi-Be, forêt de Lokobe ; Mar. 1962; fl; Keraudren 1581; BR, P • Nossi-Be , Andokobe, Lokobe ; 12 Mar. 1956; fl; Lebosaka 9397-RN; BR, P, TEF • Andokobe, Hell-Ville ; 12 Mar. 1957; fl; Lebosaka 9447-RN; P • Nossi-Be ; 1840; fr; Richard 362; P • Nossi-Be ;1840; fr; Richard 643; P • Nossi-Be ; 1848; fr; Richard 2058; P • Marovalia, RNI 6, Lokobe , Nossi-Be ; 2 Mar. 1951; fl; Rakoto 2724-RN; BR, P, TAN . – Sava Region; Vohemar District • forêt d’Analalava , S de la basse Fanambana; 18 Mar. 1967; fl; Capuron 27547-SF; BR, P, TEF • Vohemar-Sambava road, ca 8 km S of Fanambana river and village, 32 km S of Vohemar; 50 m a.s.l.; 28 Jul. 1985; fr; Puff, Igersheim & Rajemisoa 850728-1/3; K, WU • fir. Fanambana, forêt d’Analalava-Antsoha ; 61 m a.s.l.; Apr. 2001; fl; Rabenantoandro, Ranaivojaona & Rakoto 489; BR, K, MO, P online • fir. Tsarabaria, fkt. Manakana, forêt d’Ambondrobe ; 53 m a.s.l.; 15 Jul. 2003; fr; Rabevehitra, Razakamalala & Rakotomamonjy 312; BR, K, MO • fir. Tsarabaria, fkt. Manakana, Ambondrobe ; 26 Oct. 2002; fr; Rabevohitra, McPherson, Rabenantoandro & Ranarivelo 4212; BR, MO, P online • fir. Tsarabaria, fkt. Manakana , forêt sublittorale E d’Ambondrobe ; 2 Mar. 2003; fl; Rabevohitra, Rabenantoandro & Razakamalala 4574; BR, MO, P online • ibid.; 13 Mar. 2004; fl; Razakamalala, Rabevohitra & Faralahy 1009; BR, K, MO • ibid.; 20 May 2004; fr; Razakamalala & Rabehevitra 1322; BR, K, MO, P .

Description

Shrub or tree, 1–10 m tall; pubescence whitish. Young shoots brown or reddish brown, densely covered with appressed to spreading or, more rarely, erect hairs; older branches reddish brown, flaking, glabrescent. Petioles 2–5 mm long, densely covered with appressed or spreading hairs. Leaf blades narrowly elliptic, narrowly ovate, narrowly obovate, elliptic, ovate or obovate, 2.4–11 × 1.5–3.5 cm, papyraceous to subcoriaceous, drying brown, dark brown or, more rarely, greenish above and somewhat paler below, upper surface (somewhat) glossy, sparsely to moderately covered with short ± appressed hairs or glabrous, lower surface densely covered with long, erect hairs (lanate); margin ciliate; base cuneate; tip conspicuously acuminate, acumen narrow, (0.4–) 0.8–1.8 cm long; domatia absent; midrib glabrous or sparsely covered with appressed hairs above, densely covered with appressed hairs below; 5–9 secondary veins on each side of midrib, glabrous or sparsely covered with appressed hairs above, raised and densely covered with appressed hairs below; higher order venation inconspicuous on both surfaces. Stipules triangular with needle-like awn, outer surface densely covered with appressed hairs, inner surface glabrous in basal half but sparsely to moderately covered with appressed hairs higher up and with row of colleters interspaced with long hairs at the base; sheath 1–3 mm long; awn 2–4 mm long. Inflorescences sessile or pedunculate, lax, 2–6 cm × 3–10 cm, with (1–)3–15(–30) flowers; inflorescence parts densely covered with short appressed or spreading hairs; if present, then peduncle up to 3 cm long; first order branching point usually 1–5 mm displaced above subtending bract pair; first order axes 0.4–4.5 cm long; higher order bracts with stipular parts reduced or absent, foliar parts narrowly triangular and vaulted or linear, 2–5 mm long, or rarely leaf-like, up to 10 mm long; bracteoles on pedicel 1–10 mm below ovary, not opposite, stipular parts absent, foliar parts triangular, ≤ 1 mm long, tips acute. Flowers pedicellate, pedicels 8–20 mm long. Calyx densely covered with short erect or spreading hairs outside, inner surface densely covered with short appressed hairs; tube 0.75–1 mm long; lobes quadrangular or shortly oblong, 0.7–1.2 mm long, often somewhat keeled, margins ciliate, tips rounded. Corolla tube 8–10 mm long, inner surface moderately to densely covered with short erect hairs except for 2–3 mm at base; lobes 6–8 mm long, margins ciliate. Stamens inserted ca 1 mm below level of throat; anthers ca 8 mm long, basal part (2–2.5 mm long) included in corolla tube at anthesis, exserted part spirally contorted; filaments up to 1 mm long. Ovary 1.5–2 mm long, longitudinally ribbed (when dried), densely covered with short erect hairs; per locule (2–)4–6 ovules arranged at periphery of placenta attached somewhat above middle of septum. Style and stigma 15–24 mm long, exserted for 7–12 mm; style densely covered with upwardly directed hairs for 5–7 mm below papillate zone; stigmatic lobes 9–11 mm long. Fruits spherical, 0.4–0.7 cm in diam., densely covered with short erect hairs; fruit wall thin, with sclerified vascular bundles; pyrenes hemispherical, ca 6 × 5 mm, membranous adaxially, crustaceous abaxially, with rounded base, shortly acuminate tip, small adaxial opening in the upper half and faint longitudinal central ridge running from the apex to the top of the adaxial opening and continuing into a faint depression below it. Seeds 5–8 per fruit, 3–4 × 2–3 mm.

Distribution

Coastal species, mostly collected from Lokobe on Nossi-Be, but also present in the surroundings of Ambanja and Manongarivo on the west coast and south of Vohemar on the east coast. Present in: Ambanja and Nossi-Be Districts, Diana Region, and Vohemar District, Sava Region (Antsiranana Province) ( Fig. 23C ).

Habitat and phenology

Littoral, sublittoral or low-elevation humid forest; on sandy soil or rocky substrate; elev. 0–450(–850) m. Flowers: (January–)March–April; Fruits: March–November. Flower buds were collected in January (3 specs), February (1 spec.) and March (1 spec.). Anthetic flowers were collected in March (flowering peak) and April (2 specs).

Vernacular names

Balaniry (coll. ignot. 3163-SF); fatora (Gautier et al. 2404); malemisisika (Tahinarivony 736); tembariky (Gautier et al. 2404); tsifolaky (Rakoto 2724-RN).

Provisional IUCN assessment

Vulnerable: VU B1ab(iii) B2ab(iii). This assessment is based on 32 herbarium collections with detailed locality data, collected between 1840 and 2013. The EOO of P. longipedicellata sp. nov. is estimated to be 2200 km 2 (ca 2100 km 2 on the west coast, ca 100 km 2 on the east coast), which complies with the Endangered category under criterion B1. The AOO is 72 km 2, which also complies with the Endangered category under criterion B2. The species occurs in 8 locations, which complies with the Vulnerable category under subcriterion ‘a’ of criterion B2. The species is present in Lokobe National Park and Manongarivo Special Reserve. Manongarivo Special Reserve is threatened by deforestation for slash-and- burn agriculture. Illegal logging for construction wood and firewood takes place, as well as hunting, cattle grazing, and the collection of non-timber forest products, e.g., medicinal plants ( Nicoll & Langrand 1989; BirdLife International 2020b). The same threats occur in Lokobe National Park albeit to a lesser extent ( Nicoll & Langrand 1989). Outside the protected areas, anthropogenic pressure is even more important. Therefore, a reduction in the extent and quality of the habitat of P. longipedicellata sp. nov. is inferred. This fact, in combination with the low AOO and EOO and the low number of locations, qualifies the species for Vulnerable status.

Notes

1. Paracephaelis longipedicellata sp. nov. is easily recognized by the lax inflorescences, the long pedicels with the subopposite bracteoles positioned well below the ovary, the quadrangular or shortly oblong calyx lobes, ± equal in length to the calyx tube, and the small spherical fruits.

2. The species was recognised as new for science by Homolle, who published the name “ Tarenna nossibensis ” ( Homolle 1938) , but gave no description or type specimen. This nomen nudum was also used by Capuron (1973).

3. Prior to the synonymization of Homollliella with Paracephaelis ( De Block et al. 2015) , herbarium specimens were annotated by the author as “ Homolliella longipedicellata ”, a name which was never published.

Figures

Fig. 2. Overview of the placentation in Paracephaelis Baill. A–K. Abaxial views of placenta and ovules. A’. Adaxial view of placenta and ovules with zone of attachment of the placenta indicated. A–C. Typical placentation type of Paracephaelis, with many ovules arranged at the periphery of the placenta.D–E. Idem, with fewer ovules. F–H. Idem, but ovules restricted to the top of the placenta. I. Typical placentation type in P. cinerea (A.Rich. ex DC.) De Block, P. comorensis De Block sp. nov. and P. trichantha (Baker) De Block. J–K. Idem, with fewer ovules. Drawn by Mr A. Fernandez. From Perrier de la Bâthie 13452 (P. tiliacea Baill., A, A’); Pervillé 633 (P. tiliacea Baill., B); Capuron 23451-SF (P. longipedicellata De Block sp. nov., C); McPherson et al. 14875A (P. saxatilis (Scott Elliot) De Block, D); Gautier et al. 4188 (P. gautieri De Block sp. nov., E); De Block et al. 1280 (P. bardotiae De Block sp. nov., F); De Block et al. 1048 (P. russata De Block sp. nov., G–H); Capuron 23073-SF (P. cinerea (A.Rich. ex DC.) De Block, I); Barthelat et al. 732 (P. comorensis De Block sp. nov., J); and Labat & Pascal 2887 (P. comorensis De Block sp. nov., K).

Fig. 4. Pollen of Paracephaelis Baill.; SEM images. A, C. Polar view. B, D. Equatorial view. E–F. Apocolpium. G–I. Mesocolpium. J–K. Ectocolp and mesoaperture. L. Endocolp with annulus. M. End of endocolp, diverging into terminal horns. N–O. Pollen wall. From Lebosaka 9397-RN (P. longipedicellata De Block sp. nov., A–B, E, G, M–N); Dumetz 1230 (P. saxatilis (Scott Elliot) De Block, C–D, F, I, K); and Capuron 20419-SF (P. seyrigii De Block sp. nov., H, J, L, O).

Fig. 12. Paracephaelis longipedicellata De Block sp. nov.A. Flowering branch. B. Stipules. C. Bracteoles, ovary and calyx. D. Corolla, stamens, style and stigma. E. Fruit. Drawn by Mr A. Fernandez. From coll. ignot. 3163-SF (A, C–D), Capuron 23451-SF (B) and Puff et al. 850728-1/3 (E).

Fig. 23. Distribution maps of Malagasy species of Paracephaelis. A. P. aristata De Block sp. nov. (black dot), P. bardotiae De Block sp. nov. (blue dot), P. capitulifera De Block sp. nov. (green dot), P. gautieri De Block sp. nov. (red dot), and P. grandifructa De Block sp. nov. (yellow dot). B. P. cinerea (A.Rich. ex DC.) De Block (black dot). C. P. longipedicellata De Block sp. nov. (black dot), P. orientalis De Block sp. nov. (blue dot), P. pauciflora De Block sp. nov. (green dot), P. ranirisonii De Block sp. nov. (red dot), and P. seyrigii De Block sp. nov. (yellow dot). D. P. russata De Block sp. nov. (black dot), P. sambavensis De Block sp. nov. (blue dot), P. saxatilis (Scott Elliot) De Block (green dot), P. sericea (Arènes) De Block (red dot), and P. tiliacea Baill. (yellow dot).