Ochna polyneura Gilg (Gilg 1903: 240)

Shah, Toral, Mashimba, Fandey H., Suleiman, Haji. O., Mbailwa, Yahya S., Savolainen, Vincent, Larridon, Isabel & Darbyshire, Iain, 2023, A taxonomic revision of the ecologically important Ochna holstii (Ochnaceae) complex using molecular and morphological data, Plant Ecology and Evolution 156 (2), pp. 174-200 : 174

5. Ochna polyneura Gilg (Gilg 1903: 240)

Figs 3D , 10

Polyochnella polyneura (Gilg) Tiegh. ( Tieghem 1903: 18) - Type: same as for Ochna polyneura .

Ochna hylophila Gilg ( Gilg 1903: 242; Brenan and Greenway 1949: 383) - Type: TANZANIA • Mampyui road on E Ungoni border; 1900-1901; Busse 732; holotype: B†; lectotype (designated here): G [G00341215], K! photo; isolectotype: EA.

Polyochnella hylophila (Gilg) Tiegh. ( Tieghem 1903: 40) - Type: same as for Ochna hylophila .

Ochna Ochna sp. 42 of Flora of Tropical East Africa ( Verdcourt 2005: 37) - Type: TANZANIA • Uzaramo District, Pande Hill.

Type.

TANZANIA • Mbarangandu region ; Busse 681; lectotype (designated here): EA [EA000002036]; syntype: B † • TANZANIA • Mbarangandu region ; Busse 671; syntype: B†; isosyntype: EA [EA000002037] .

Description.

Shrub or small tree, 2-8 m tall. Bark whitish-grey or brown, corky and sometimes appearing fissured. Stems rusty brown, sometimes grey, more prominently fissured, sometimes with sparse pale lenticels, glabrous; young new growth brown-green, glabrous or sometimes puberulous, often with pale sparse lenticels. Stipules brown, linear, narrow, 1.8-4.5 mm long, deciduous. Leaves green, often drying blue-black; young leaves often rusty brown with a yellow midrib; mostly thin but sometimes slightly coriaceous, glabrous, oblanceolate-lanceolate or sometimes ovate, 5-11.5 cm long, 1.5-4.5 cm wide; leaf base cuneate-attenuate, rounded or rarely acute at apex, margins serrate; lateral veins numerous, ± 20, tertiary vernation reticulate above and below, midrib raised below and above; petiole 1-3 mm; buds brown, up to 1 cm long, bud scales deciduous, up to 9 mm long. Flowers arranged in racemes with 7-10(-13) flowers or in fascicles with 2-5 flowers; rachis up to 3 cm long; pedicel 2-3.5 cm long, articulated at or near the base, or up to 13 mm, brown-green, sometimes drying blue-black, often puberulous below articulation or glabrous. Sepals green to red-brown, oblong-elliptic, 7.5-10 mm long, 3.5-6 mm wide in flower, turning red in fruit, 9-11 mm long, 5-6 mm wide. Petals yellow, orbicular, long-clawed, 6-15 mm long, 5-12 mm wide. Anthers dehiscing by longitudinal slits, 1.2-2 mm long; filaments 3-4.5 mm long. Carpels 5; style capitate at apex with lobes, 3-6 mm long. Drupelets black, ellipsoid, 6-9 mm long, 5-8.5 mm wide, attached at the base.

Distribution.

Tanzania, Malawi, Zimbabwe, and Mozambique (Fig. 10 ).

Habitat.

Miombo woodland, wooded grassland, open thicket. Altitude: 23-1880 m.

Phenology.

Flowering and fruiting from October to January, which coincides with early rainfall.

Preliminary IUCN conservation assessment.

Ochna polyneura occurs in miombo woodland across eastern and southern Africa and has an estimated EOO of 940,865 km2 and AOO of 92 km2. Even though the AOO falls within the threshold for the Endangered category under criterion B, the species occurs in 15 locations and 14 occurring within protected areas. Although there are some localised declines in individuals due to firewood harvesting, extensive areas are still intact within its large range. For this reason, the species is assessed as Least Concern (LC).

Additional material examined.

TANZANIA - Morogoro District • 5 Jan. 1932; fr.; Wallace 255; K [K001082494] • Morogoro, 9 miles NE of Kingolwira station; 7 Jan. 1955; fr.; Welch 266; EA, K [K001082496] • Morogoro, Near Kingolwira Station ; 17 Nov. 1956; fl.; Welch 336; EA, K [K001082497] . - Songea District • Forest near Songea on Songea-Tunduru road; Nov. 1951; fl.; Eggeling 6360; EA, K [K001082507] • About 12 km E of Songea by Nonganonga stream; 990 m; 27 Dec. 1955; Milne-Redhead & Taylor 7915; EA, K [K001082506, K001082505] • About 12 km E of Songea by Nonganonga stream; 990 m; 21 Jan. 1956; Milne-Redhead & Taylor 7915a; EA, K [K001082504] . - Bagamoyo District • Bana Forest Reserve; Dec. 1964; Proctor 2804; EA, K [K001082493] • Bana Forest Reserve ; 28 Oct. 1965; fl.; Mgaza 757; K [K001082490] . - Mbeya District • Pande Hill ; 6°42'S, 39°05'E; 22 Nov. 1969; Harris et al. BJH3619; K [K001271417] . - Rufiji District • Selous Game Reserve, ca 17 km SW of Kingupira; 8°36'S, 38°28'E; 175 m; 9 Jan. 1977; fr.; Vollesen 4298; K [K001271383] • Selous GR, Lodge-Kivuko Hill ; 7°47'S, 38°08'E; 80 m; 13 Dec. 1989; fr.; Luke & Luke 5609; EA, K [K001082491] . - Sumbawanga District • Muva Mbizi FR; 1880 m; 21 Nov. 1987; fr.; Ruffo & Kisena 2778; K [K001082559] . - Kisarawe District • Tamburu Forest Reserve, off the main Dar es Salaam-Lindi Road , before reaching Somanga , near Kiwanga village ; 8°16 ’47.42” S, 39°12 ’16.45” E; 23 m; 9 Jan. 2020; Shah TS 65; K [K001271507] . - Kilwa District • Miruba / Mandawa, Ngarama Forest Reserve North ; 9°24 ’32.69” S, 39°22 ’36.44” E; 281 m; 11 Jan. 2020; Shah TS 69; K [K001271508] • Miruba/Mandawa, Ngarama Forest Reserve North; 9°24 ’32.69” S, 39°22 ’36.44” E; 281 m; 11 Jan. 2020; Shah TS 70; K [K001271509] . - Newala District • Above Ndanda mission station, on dirt road close to the plateau of Makonde escarpment, near the village at the top; 10°19 ’39.76” S, 39°2 ’27.92” E; 880 m; 15 Jan. 2020; Shah TS 82; K [K001271510] . - Mtwara District • Liganga, Rondo Plateau on general land/village land outside of the nature reserve boundaries; 10°11 ’33.83” S, 39°9 ’17.10” E; 676 m; 16 Jan. 2020; fr.; Shah TS 86; K [K001271511] .

MALAWI - Mzimba District • 4 mi. E of Mzambazi ; 30 Dec. 1975; fr.; Pawek 10659; K [K001271408] . - Chitipa District • Mt Mulanje low down the Likhubula valley ; 860 m; 7 Nov. 1987; fl.; Chapman & Chapman 8926; E [E01123514], K [K001387306] .

Bibliography.

Brenan and Greenway (1949: 383); Robson (1963: 242); Vollesen (1980: 25); Verdcourt (2005: 25).

Notes.

Ochna polyneura is easily recognised by its leaves drying blue-black, racemose inflorescences, and somewhat exfoliating bark. It closely resembles O. puberula but it differs by having exactly 5 carpels, whereas the latter has 5-9 carpels, and a largely accrescent calyx in fruit. In general, O. puberula is a smaller plant with smaller leaves and flowers. Molecular results have placed the undescribed species O. sp. 42 from FTEA ( Verdcourt 2005) as sister to all samples O. polyneura. In this study, we have included the specimen within the delimitation of O. polyneura , given that it shares morphological similarities with other individuals of the species, such as having a corky fissured bark, similar leaf shape and size, drying blue-black. However, it is likely that Verdcourt (2005) kept this specimen separate as it has paired flowers, which differs from typical O. polyneura , which has 7-10 flowers in a raceme. Additional specimens from Pande Hill, Uzaramo District are required for a more thorough study as it may prove to be a distinct species or infraspecific taxon.

Figures

Figure 3. Species of Ochna, habit and leaf margin. A. Ochna maguirei (from Story 5935). B. Ochna puberula (from Fanshawe 2648). C. Ochna afzelioides (from Richards 13726). D. Ochna polyneura (from Vollesen 4298). Drawn by Andrew Brown.

Figure 10. Distribution map of Ochna polyneura in Tanzania, Malawi, and Mozambique.