Monanthotaxis parvifolia (Oliv.) Verdc.

Hoekstra, P. H., Wieringa, J. J., Maas, P. J. M. & Chatrou, L. W., 2021, Revision of the African species of Monanthotaxis (Annonaceae), Blumea 66 (2), pp. 107-221 : 187

58. Monanthotaxis parvifolia (Oliv.) Verdc. — Fig. 24 ; Map 36

Monanthotaxis parvifolia (Oliv.) Verdc. (1971b) 27. — Unona parvifolia Oliv. (1868) 36. — Popowia parvifolia (Oliv.) Engl. & Diels (1901) 46, nom. illeg. non Kurz (1875), nec Scheff. (1885). — Popowia oliveriana Exell & Mendonça (1937) 24. — Lectotype (designated by Paiva 1966): F.M.J. Welwitsch 760 (lecto LISU not seen; iso BM000553842, BM001125036, BR0000008824080,C10000162,C10000163,COI00004907,G00308295, K000198966,LD1757603,LD1758499,M0107927,M0107928,P00362626, P00362627,PRE0774856-0), Angola, Cuanza Norte,District Gulongo Alto, 305 m, July 1855.

Popowia louisii Boutique (1951b) 114. — Lectotype (designated here): J.L.P. Louis 1213 (lecto consisting of 3 sheets: BR0000008823793 , BR0000008824141 , BR0000008824158 ; iso B100460854 , K000913658 , NY00026228 , P00362646 ), Democratic Republic of the Congo, Orientale, Isangi, île Esali, dans la fleuve, en face de Yangambi, 470 m, 7 Feb. 1936.

Popowia louisii Boutique var. grandifolia Boutique (1951b) 115. — Type: C. Rossignol 9 (holo BR0000008824127 ), Democratic Republic of the Congo, Maniema , Kibombo, Difuma, 8 Mar. 1934.

Shrub or liana, to 4 m long; young branches sparsely to densely covered with appressed to ascending, reddish brown hairs 0.2–0.3 mm long, becoming glabrous; old branches black, blackish brown or reddish brown. Leaves: petiole 2.5–4.5 mm long, 0.5–0.9 mm diam, terete, indument as on branches; lamina elliptic to obovate, 3.2–10.1 by 1.5–4.2 cm, 1.7–2.5 times longer than wide, chartaceous, slightly punctate, glaucous below, above sparsely covered with appressed, white hairs 0.3–0.5 mm long, becoming glabrous, primary vein covered with longer persistent, appressed to ascending, yellow hairs, below sparsely covered with appressed, reddish brown hairs 0.2–0.3 mm long, more densely so with hairs 0.2–0.5 mm long on veins, base rounded or subcordate with slightly thickened black margin, apex obtuse or acute, secondary veins 5–10 per side, slightly curving, tertiary venation percurrent, hardly visible. Inflorescences extra-axillary or leaf-opposed, consisting of solitary flowers; sympodial rachis absent; pedicels 7–11.5 mm long, 0.4–0.5 mm diam, fruiting pedicels 9.5–21(–32) mm long, 0.6–0.8 mm diam, sparsely to densely covered with ascending hairs 0.2–0.3 mm long; lower bract absent; upper bract in the lower half of the pedicel or halfway, ovate to lanceolate, 2.1–2.5 by 0.5–1.2 mm, densely covered with hairs; flower buds globose. Flowers bisexual; sepals free or slightly connate at the base, depressed ovate to almost orbicular, 1.5–3 by 2.3–3.9 mm, apex rounded, sparsely covered with appressed hairs, persistent in fruit; receptacle 1.7–3 mm diam, flat to slightly convex, hairy; petals colour in vivo unknown, 6, in two whorls, outer petals, ovate, 5.5–7 by 3.7–4 mm, outside densely covered with yellowish hairs, near the margins of the inside covered with yellowish hairs <0.1 mm long, inner petals broadly elliptic to ovate, 2.5–4.5 by 2.1–2.5 mm, outside and apical part of the inside densely covered with yellow hairs; stamens 22–24, in three whorls, free, obovoid, 1.4–1.7 mm long, filaments 0.7–1 mm long, thecae latrorse to extrorse, connective truncate, slightly prolonged outward, not hiding thecae, glabrous, staminodes absent; carpels 12, subcylindric, 1.1–1.3 by 0.2–0.4 mm, glabrous except for few hairs at the base, ovules 2–4, lateral, stigma elongate, claviform, 0.3–0.4 mm long, glabrous. Monocarps 2–8, orange to red when ripe, moniliform, each part ellipsoid, 11– 26 by 5– 6 mm, slightly verrucose, glabrous or with a few hairs on the stipe, apex rounded or apiculate, apiculum to 1.5 mm long, stipes 1.5–4 mm long. Seeds 1– 4, ellipsoid, 6.5–10.5 by 4–4.5 mm, ochre-brown, apex apiculate, apiculum to 1 mm long, raphe not visible.

Distribution — Central African Republic, Democratic Republic of the Congo, Republic of the Congo, Burundi, Angola, Zambia.

Habitat & Ecology — In gallery forest and savannas.Altitude: 305–1250 m. Flowering and fruiting all year round.

Preliminary IUCN conservation status — Least concern (LC). EOO: 3 108 335 km 2, AOO: 148 km 2. This species has a wide distribution and occurs in quite some localities and nature reserves.

Notes — 1. Monanthotaxis parvifolia can be recognized by the combination of glabrous carpels, 22– 24 stamens in three whorls and a reddish brown indument on the branches and leaves.

2. It is a highly variable species and the specimens from the Congolean rain forests have much less indument on leaves and branches and slightly shorter hairs than the specimens from the rest in the distribution range. These specimens were formerly placed under Popowia louisii , but besides the sparser indument no other differences could be found with the typical specimens of M. parvifolia .

3. Monanthotaxis parvifolia probably does not occur in West Africa. Most specimens formerly assigned to M. parvifolia have very different flowers and are now described as M. glabra . Another group of specimens from Benin and Togo have the fruits similar to M. parvifolia , however, the phylogenetic analysis ( Fig. 1 ) and vegetative characters indicate that they are related to M. laurentii , see the note under that species. There are 2 specimens from Guinea, which look like M. parvifolia , but without flowers they cannot be assigned with certainty to that species.

Figures

Map 36 Distribution of Monanthotaxis orophila (Boutique) Verdc. (■) and M. parvifolia (Oliv.) Verdc. (●, O means uncertain dets).

Fig. 24 Monanthotaxis parvifolia (Oliv.) Verdc. a. Flowering branch; b. flower, c. longitudinal section of flower; d. stamen, front view; e. stamen, side view; f. carpel; g. longitudinal section of carpel; h. one monocarp; i. longitudinal section of monocarp (based on Louis 12804 and 13119). — Modified from Boutique (1951a) plate 33.

Fig. 1 Bayesian 50 % majority rule consensus tree of the genus Monanthotaxis. Asterisks at nodes indicate node support, i.e., *** Strong node support, ** moderate node support, * weak node support, see Hoekstra et al. (2018). The letters A to K with adjacent black bars indicate the clades. The triangles, circles and squares represent morphological characters of the species which are of some use to distinguis the clades. Green triangles = staminodes absent, red triangles = staminodes present. Green circles = petals in one whorl, red circles = petals in two whorls, yellow circles = petals in bud basally in one whorl, at the top outer petals overlapping the inner ones. Green squares = inflorescences extra-axillary or if cauliflorous also extra-axillary inflorescences present, red squares = inflorescences axillary, supra-axillary or cauliflorous, red and green squares = both extra-axillary and axillary inflorescences present.