Neostenanthera neurosericea (Diels) Exell, J. Bot. 73 (Suppl.): 6, 1935

Couvreur, Thomas L. P., Dagallier, Leo-Paul M. J., Crozier, Francoise, Ghogue, Jean-Paul, Hoekstra, Paul H., Kamdem, Narcisse G., Johnson, David M., Murray, Nancy A. & Sonke, Bonaventure, 2022, Flora of Cameroon - Annonaceae Vol 45, PhytoKeys 207, pp. 1-532 : 270-274

Neostenanthera neurosericea (Diels) Exell, J. Bot. 73 (Suppl.): 6, 1935

Figs 82 , 83 ; Map 10F

≡ Stenanthera neurosericea Diels, Bot. Jahrb. Syst. 39. 483, 1907.

= Neostenanthera platypetala (Engl. & Diels) Pellegr., Bull. Soc. Bot. France Mém. 1949: 56. 1950; ≡ Stenanthera platypetala Engl. & Diels, Bot. Jahrb. Syst. 39. 482, 1907. ≡ Boutiquea platypetala (Engl. & Diels) Le Thomas. Adansonia sér. 2, 5: 532, 1965. Syn. nov. Type. Cameroon. South Region; Bipindi, Zenker G.A. 2877, Mar 1904: lectotype, sheet here designated: B[B 10 0154069]; isotypes: B[B 10 0154071]; BM[BM000546878]; K[K000199036].

= Stenanthera macrantha Mildbr. & Diels, Bot. Jahrb. Syst. 1111. 445, 1915. Type. Cameroon. South Region, Kribi, Mildbraed G.W.J. 5886, Jul 1911: holotype: B[B 10 0154070]; isotype: HBG[HBG502540].

Type.

Cameroon. South Region; Bipindi, Zenker G.A. 3105, 1904: lectotype, sheet here designated: B[B 10 0154067]; isotypes: B[B 10 0390251]; BR[BR0000008824059]; GOET[GOET005682]; G[G00014887, G00014888]; L[L0038043]; LISC[LISC000393]; HBG[HBG502533]; MO[MO-216971]; M[M0107916]; P[P00363312]; S[S07-13457]; WAG[WAG0000096] .

Description.

Tree to shrub, up to 7 m tall, d.b.h. 3-6 cm; stilt roots or buttresses absent. Indumentum of simple hairs; old leafless branches sparsely pubescent, young foliate branches densely pubescent. Leaves: petiole 4-5 mm long, ca. 1 mm in diameter, densely pubescent, grooved, blade inserted on top of the petiole; blade 15-21 cm long, 5-8 cm wide, ovate to elliptic, apex acuminate, acumen 1-2 cm long, base rounded, papyraceous, below densely pubescent with erect slight curly hairs when young and old, densely pubescent when old, above glabrous when young and old, concolorous or discolorous, whitish below; midrib sunken or flat, above glabrous when young and old, below densely pubescent when young, densely pubescent when old; secondary veins 15 to 21 pairs, glabrous below; tertiary venation percurrent. Individuals bisexual; inflorescences cauliflorous or ramiflorous on old leafless or young foliate branches, leaf opposed or extra axillary. Flowers with 9 perianth parts in 3 whorls, 1 to 2 per inflorescence; peduncule ca. 2 mm long, unbranched; pedicel 10-30 mm long, ca. 1 mm in diameter, densely pubescent; in fruit 20-30 mm long, 2-3 mm in diameter, densely pubescent; bract 1, basal, ca. 1 mm long, ca. 1 mm wide; sepals 3, valvate, free, 2-3 mm long, 1-2 mm wide, triangular, apex acute, base truncate, green, densely pubescent outside, glabrous inside, margins flat; petals free, outer petals longer than inner; outer petals 3, 15-33 mm long, 8-15 mm wide, thick, elliptic, apex acute, base narrowed and concave, light green to light yellow to cream, margins flat, pubescent outside, pubescent inside; inner petals 3, valvate, 10-15 mm long, 3-5 mm wide, triangular, apex acute, base broad and concave, light green to cream, margins flat, pubescent outside, glabrous inside; stamens 30 to 40, in 5 to 6 rows, 2-3 mm long, linear; connective tongue shaped, glabrous, red; staminodes absent; carpels free, 20 to 25, ovary ca. 2 mm long, stigma cylindrical, glabrous. Monocarps sessile, 7 to 15, 20-30 mm long, ca. 20 mm in diameter, ellipsoid, apex apiculate, pyramidal in shape, pubescent, wrinkled, brown when ripe; seed 1 per monocarp, 11-14 mm long, 10-11 mm in diameter, ellipsoid; aril absent.

Distribution.

From Cameroon to Gabon; in Cameroon known from the South, Central Littoral and South-West regions.

Habitat.

A common species when present; in primary or old secondary rain forests, non-inundated soils. Altitude 200-600 m a.s.l.

Local and common names known in Cameroon.

None recorded.

IUCN conservation status.

Least Concern (LC) ( Cheek 2014a) (as Boutiquea platypetala ).

Uses in Cameroon.

None reported.

Notes.

This species is closely related to N. myristicifolia but differs by having densely pubescent young foliate branches and sessile and pyramidal monocarps (versus clearly stipitate and ellipsoid monocarps).

We transfer Boutiquea platypetala (Engl. & Diels) Le Thomas back into the genus Neostenanthera . This species was initially described in the genus Stenanthera ( Diels 1907), then transferred to Neostenanthera ( Pellegrin 1949) until Le Thomas (1965b) erected the genus Boutiquea to accommodate it mainly because of its characteristic sessile monocarps (versus long-stipitate in Neostenanthera s.str.). Besides that, all other morphological characters are common with Neostenanthera ( Fero et al. 2014), such as overall flower morphology (e.g. broad and concave inner petal bases), septate anthers, carpels with single ovules and consequently single seeded monocarps (rare in Cameroonian Annonaceae , but a character of the tree genus Annickia too). In the latest revision of the genus Neostenanthera , Fero et al. (2014) didn’t consider Boutiquea as congeneric with Neostenanthera . However, recent molecular data ( Guo et al. 2017a; Couvreur et al. 2019) revealed that B. platypetala is phylogenetically very close to Neostenanthera , which is coherent with morphology. The occurrence of species with stipitate and sessile monocarps in the same genus is not uncommon in Annonaceae , for example in Artabotrys or Uvaria , and this character thus does not appear sufficient to warrant the separate generic status suggested by Le Thomas (1965b).

In addition, we also consider the name Neostenanthera platypetala as a synonym of Neostenanthera neurosericea the latter being the older name and thus takes precedence. Both names have already been tentatively suggested to be conspecific based on morphological similarities ( Diels 1907; Fero et al. 2014). A close examination of the material of N. neurosericea (only known from the flowering type collection) and N. platypetala reveals no major differences, in particular the dense pubescence of young foliate branches, the shape of the leaves (rounded at base, clearly acuminate at apex and obovate in shape), the solitary flowers borne on the branches, and the shape and size of the petals are similar.

Specimens examined.

Central Region: Bank Nyong River near the new bridge ca 65 km SSW of Eséka, 3.53°N, 10.41°E, 16 July 1964, de Wilde W.J.J.O 2840 (WAG); 16 km SSW d’Eséka, 3.65°N, 10.78°E, 02 January 1974, Letouzey R. 12550 (P,WAG,YA); Route Vetere ( Likouk-Lokoundji ), 3.48°N, 10.32°E, 14 January 1974, Mezili P. 251 (P,YA). Littoral Region : Ebo Bekob abandoned village CRES research station, 4.36°N, 10.41°E, 21 April 2005, Etuge M. 6447 (K). South Region : Campo Ma an National Park 5 km after main entrance, 2.34°N, 10.25°E, 15 February 2012, Couvreur T.L.P. 384 (WAG,YA); Campo Ma an National Park 5 km after main entrance, 2.35°N, 10.25°E, 15 February 2012, Couvreur T.L.P. 386 (WAG,YA); Entre Fenda (60 km ESE de Kribi et riviere Kienke ), 2.8°N, 10.4°E, 22 January 1962, Letouzey R. 4092 (K,P,YA); Elom ( Kribi ), 2.78°N, 10.25°E, 25 April 1968, Letouzey R. 9436 (P); 55 km ESE de Kribi 2 km W du village, 3.21°N, 10.06°E, 12 March 1963, Raynal A. 10389 (P,YA); Assok ( Nyabessan ), 2.77°N, 10.47°E, 18 February 1965, Raynal A. 13457 (P,YA); 44 km N de Nyabesssan Réserve forestière de Kienké-sud 500 m N de la route, 2.78°N, 10.37°E, 18 February 1965, Raynal A. 13472 (P,YA); Campo-Ma’an area Bibambivoto, 2.24°N, 10.26°E, 23 August 2000, Tchouto Mbatchou G.P. 2986 (KRIBI,WAG,YA); Campo-Ma’an area Mvini, 2.33°N, 10.20°E, 25 August 2002, Tchouto Mbatchou G.P. CORIX_3 (WAG); Campo-Ma’an area Mvini, 2.27°N, 10.18°E, 14 September 2000, Tchouto Mbatchou G.P. 3035 (KRIBI,WAG); Campo-Ma’an area Bifa, 2.65°N, 10.28°E, 12 October 2001, Tchouto Mbatchou G.P. 3298 (KRIBI,WAG); Korup National Park Primary rain forest, 5.03°N, 8.833°E, 01 March 1987, Thomas D.W. 6891 (MO); Bipindi, 3.08°N, 10.42°E, 1898, Zenker G.A. 1904 (K); Bipindi, 3.08°N, 10.42°E, 20 June 1904, Zenker G.A. 2877 (B; Bipindi, 3.08°N, 10.42°E, 01 January 1918, Zenker G.A. 29 (P); Bipindi, 3.08°N, 10.42°E, 01 January 1904, Zenker G.A. 3105 (L,P,WAG); Bipindi, 3.08°N, 10.42°E, 01 January 1908, Zenker G.A. 3749 (L,P); Bipindi, 3.08°N, 10.42°E, 01 January 1909, Zenker G.A. 3819 (E,L,M); Bipindi, 3.08°N, 10.41°E, Zenker G.A. 3897 (K); Bipindi, 3.08°N, 10.41°E, 01 December 1913, Zenker G.A. 440 (P); Bipindi, 3.08°N, 10.41°E, 01 November 1913, Zenker G.A. 440 (P,U,WAG); Bipindi, 3.08°N, 10.41°E, 01 January 1912, Zenker G.A. 4402 (L). South-West Region : Ekundu Kundu, 5.12°N, 8.895°E, 27 April 1996, Cable S. 2279 (K,YA); Mundemba, 5.05°N, 8.883°E, 05 March 1993, Gereau R.E. 5185 (MO,WAG); Between Ikenge ad Esukutang ca 6 km W of Ikenge, 5.27°N, 9.1°E, 03 April 1988, Thomas D.W. 7554 (MO,P,WAG,YA); Korup National Park, 5.33°N, 8.9°E, 22 May 1988, Thomas D.W. 7809 (MO,P) .

Figures

Map 10. A Monodora myristica B Monodora tenuifolia C Monodora undulata D Monodora zenkeri E Neostenanthera myristicifolia F Neostenanthera neurosericea G Neostenanthera robsonii H Piptostigma calophyllum I Piptostigma fugax. White borders represent region limits in Cameroon; green patches represent protected areas (see methods and Suppl. material 1: Fig. S 1).

Figure 82. Neostenanthera neurosericea A flowering branch B detail of pubescence of leaves, lower side C detail of receptacle, 1 outer and 2 inner petals removed D inner petals, inner and outer views E outer petals, inner and outer views F carpel, side view and detail of single basal ovule G stamen, front and back views, note septate anthers H fruiting branch I longitudinal section of a single monocarp showing single seed J transversal section of seed A-C, I, J from Letouzey 4092 C-G from Raynal 10389. Drawings by Helene Lamourdedieu, Publications Scientifiques du Museum national d'Histoire naturelle, Paris; modified from Le Thomas (1965 b, pl. 1, p. 533), originally under Boutiquea platypetala.

Figure 83. Neostenanthera neurosericea A trunk with flowers B base of leaf blade, upper side C base of leaf blade, lower side D flower, one inner petal folded showing the red staens and yellow carpels E flower, side view F fruits, note sessile and pyramidal monocarps. Neostenanthera robsonii G trunk with fruits H base of leaf blade, upper side I base of leaf blade, lower side J fruit with numerous monocarps, one monocarp longitudinally sectionned revealing single seed A-F Couvreur 603, Gabon G Couvreur 678, Campo Ma'an, Cameroon H-J Couvreur 1077, Gabon. Photos Thomas L. P. Couvreur.