Paracephaelis orientalis 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 : 52-55

Paracephaelis orientalis De Block sp. nov.

urn:lsid:ipni.org:names:77260711-1

Fig. 13

Diagnosis

Differing from Paracephaelis sericea by having shorter stipules (2.5–5 mm vs 8–30 mm long), smaller leaves (4.5–10.5 × 1–4 cm vs 7–21 × 4.5–12 cm), glabrous upper leaf surfaces (vs moderately to densely covered with short erect hairs or, rarely, blade glabrous but midrib and sometimes secondary veins pubescent), usually glabrous lower leaf surfaces (vs densely covered with short erect hairs), shorter calyx tubes (1.5–2 mm long in flowering stage and ca 3 mm long in fruiting stage vs 2–5 mm long), shorter corolla tubes (ca 7 mm long vs 6–17 mm long), longer filaments (2–2.5 mm vs 1–1.5 mm long), and sparsely pubescent connectives (vs connectives glabrous).

Etymology

The species epithet is based on the distribution of the species along the east coast of Madagascar.

Type material

MADAGASCAR – Fianarantsoa Province, Atsimo-Atsinanana Region, Midongy-Atsimo District • Manombo; 30 m a.s.l.; 4 Feb. 2006; fl; Tosh, De Block & Rakotonasolo 341B; holotype: BR [ BR0000022757555 ]; isotypes: BR[BR0000022757562], BR[BR0000022757692], E, G, K, MO, NY, P, UPS, TAN, TEF, WAG .

Other material studied

MADAGASCAR – Toamasina Province, Analanjirofo Region, Fenoarivo Atsinanana District • fir. Ampasimaningoro , fkt. Tampolo , forêt littorale de Tampolo (forêt classée) ; 0 m a.s.l.; 4 Jul. 2001; fl; Rabenantoandro, Razakamalala, Razafindrainibe & Ludovic 559; BR, K, MO. – Maroantsetra District • commune Rantabe , Beanana ; 175 m a.s.l.; 27 Feb. 2002; fr; Antilahimena, David & Rajao 943; BR, MO. – Soanierana Ivongo District • Manompana , fkt. Tanambao Ambodimanga , forêt de Menagisy ; 26 May 2010; fr; Lehavana & Zackarie 700; MO n.v., P online, TAN n.v . • commune Manompana , village le plus proche Tanambao-Maritaina , forêt de Menagisy-Pointalare [Pointe à Larrée] , 3 km vol d’oiseau S de Tanambao-Ambodimanga; 52 m a.s.l.; 12 Apr. 2011; fr; Randrianaivo, Rakotonandrasana, Razafindrabeaza, Olivier, Tsivakia & Odon Sanga 1836; BR, CNARP n.v., MO, P, TAN. – Atsinanana Region, Vatomandry District • commune Ambalabe , fkt. Ambinanindrano II , forêt de Vohibe à Antenanala, 4 heures de marche d’Ambalabe; 671 m a.s.l.; 16 May 2011; fl, fr; Randrianaivo, Razanatsima, Rakotondrajaona, Randrianasolo, Mamy, Dedesy, Kôtsy & Dimby 1861; BR, CNARP n.v., MO, P, TAN • Ambalabe , Ambinanindrano II, E de Toby Foara ; 590 m a.s.l.; 12 May 2006; fr; Razanatsima 110; MO n.v., P online, TAN n.v . • Ambalabe , Ambinanindrano II , forêt de Vohibe , direction NW du Toby Foara; 637 m a.s.l.; 21 Aug. 2015; fr; Razanatsima 1394; MO n.v., P online, TAN n.v. – Toliara Province. Anosy Region. Taolagnaro District • ca 117 km N of Fort Dauphin, ca 7 km N of Manantenina forest remnant called Analalava; 50 m a.s.l.; 8 Nov. 1989; fr; McPherson 14410; K, MO, P, TAN, TEF • Iabakoho , Antsotso ; 25 May 2006; fl; Rajoharison, Antilahimena, Ramisy & Maharavo 207; BR, MO, P, TAN .

Description

Tree, up to 20 m tall, dbh up to 30 cm; pubescence tawny or whitish. Young shoots brown or reddish brown, glabrous to densely covered with short appressed hairs; older branches brown or reddish brown, flaking, glabrous. Petioles 2–12 mm long, glabrous to densely covered with short appressed hairs. Leaf blades obovate or narrowly obovate, 4.5–10.5 × (1–) 1.5–4 cm, coriaceous, drying brown or dark brown and hardly discolorous, upper surface glossy and glabrous, lower surface densely covered with minute erect hairs all over (Tosh et al. 341B) or glabrous and then sometimes with midrib sparsely to moderately covered with short appressed hairs; base attenuate; tip acuminate with acumen 0.4–1.2 cm long; hair tuft domatia often present; 5–10 secondary veins on each side of midrib, raised below; higher order venation inconspicuous on both surfaces. Stipules caducous, triangular, 2.5–5 mm long, gradually tapering into an acute tip or with short awn ≤ 1 mm long, outer surface of youngest stipule pairs moderately to densely covered with short appressed hairs, inner surface glabrous with 1–3 rows of colleters at the base. Inflorescences sessile, 1.5–4 × 2–5 cm, with 12–60 flowers, partial inflorescences compact; inflorescence parts densely covered with short appressed hairs; first order axes 0.5–3 cm long; higher order bracts with stipular parts reduced or absent and foliar parts triangular, 2–4 mm long, tips acute; bracteoles at base of ovary, opposite, stipular parts absent, foliar parts triangular, 1.5–2 mm long, tips acute or obtuse. Flowers sessile. Calyx densely covered with short appressed hairs outside; tube 1.5–2 mm long in flowering stage, ca 3 mm long in fruiting stage, inner surface densely covered with long appressed hairs in basal half, upper half densely covered with appressed hairs in the region of the sinuses, glabrous or sparsely covered with appressed hairs below the lobes; lobes quadrangular, somewhat keeled, 1.– 1.5 mm long, inner surface glabrous or sparsely covered with short appressed hairs, margins ciliate, tips rounded. Corolla tube ca 7 mm long, inner surface moderately to densely covered with spreading hairs in upper half; lobes 5.5–6.5 mm long, margins ciliate. Anthers 4–5 mm long, completely exserted from corolla tube at anthesis; filaments 2–2.5 mm long; connective sparsely covered with appressed hairs (filament not pubescent). Ovary 1.5–2 mm long, longitudinally ribbed (when dried), densely covered with short appressed or spreading hairs; per locule 4–7 ovules arranged at periphery of placenta attached to upper half of septum. Style and stigma 12–19 mm long, exserted for 5–12 mm; style densely covered with long spreading hairs for 3–5 mm below papillate zone; stigmatic lobes 8–9 mm long. Fruits spherical, 0.8–1 cm in diam., faintly ribbed longitudinally (when dried), moderately covered with short appressed or spreading hairs; fruit wall thin, with sclerified vascular bundles; mature pyrenes and seeds unknown.

Distribution

Occurring along the east coast from south of the Masoala Peninsula to Taolagnaro. Present in: Amparafaravola District, Alaotra-Mangoro Region, Soanierana Ivongo and Fenoarivo Atsinanana Districts, Analanjirofo Region, and, Vatomandry District, Atsinanana Region (Toamasina Province); Midongy-Atsimo District, Atsimo-Atsinanana Region (Fianarantsoa Province); Taolagnaro District, Anosy Region (Toliara Province) ( Fig. 23C ).

Habitat and phenology

Littoral or low-elevation humid forest; on sandy soil; elev. 0– 700 m. Flowers: November (Taolagnaro: McPherson 14410, buds), February (Atsimo-Atsinanana: Tosh et al. 341B), May (Taolagnaro: Rajoharison et al. 207); Fruits: February–August.

Vernacular names

Maraintsiatoraka (Rajoharison et al. 207); mentalady (Antilahimena et al. 943); oditrovy (Razanatsima 1394).

Provisional IUCN assessment

Vulnerable: VU B2ab(iii). This assessment is based on 10 herbarium collections, all collected after 1989. GeoCAT calculates the EOO of P. orientalis sp. nov. as 30 125 km 2, exceeding the upper limit for the Vulnerable category under criterion B1. However, this must be considered an overestimation since most littoral and low-elevation humid forest along the east coast has already been destroyed ( Green & Sussman 1990; Consiglio et al. 2006; Moat & Smith 2007). The AOO is 32 km 2, which complies with the Endangered category under criterion B2. The species occurs in 7 locations, which complies with the Vulnerable category under subcriterion ‘a’ of criterion B2. Paracephaelis orientalis sp. nov. occurs in Manombo Special Reserve and Tampolo Protected Area.All along the east coast, littoral and low-elevation humid forest is under high anthropogenic pressure ( Green & Sussman 1990; Consiglio et al. 2006; Moat & Smith 2007). To a lesser extent, this is also the case for forests within protected areas. Manombo suffers from slash-and-burn agriculture, bushfires, logging, hunting, and unsustainable use of non-timber forest products ( Nicoll & Langrand 1989; Ralainasolo et al. 2008). Tampolo is mostly affected by logging for timber, firewood and the production of charcoal, the collection of non-timber forest products such as Pandanus leaves for making mats, hunting, and fishing ( Ratsirarson & Ranaivonasy 2002). Because of the above-mentioned facts, a reduction in the extent and quality of the habitat of P. orientalis sp. nov. is inferred. This threat, in combination with the low AOO and the low number of locations, qualifies P. orientalis sp. nov. as Vulnerable.

Note

This is the only species in the genus currently known to have a sparsely ciliate connective. It should be noted, though, that mature flowers were unavailable for study in several species.

Figures

Fig. 13. Paracephaelis orientalis De Block sp. nov.A. Flowering branch. B. Stipule. C. Bracteole, ovary and calyx. D. Corolla, stamens, style and stigma. E. Fruit. Drawn by Mr A. Fernandez. From Tosh et al. 341B (A–D) and Randrianaivo et al. 1836 (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).