Pavetta curalicola J.E.Burrows

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation

Predicted extinction risk: threatened. Confidence: confident

Burrows, J.E. 2009. Tarenna pembensis and Pavetta curalicola, two new species of Rubiaceae from northern Mozambique. Kew Bulletin 64: 689. DOI: https://doi.org/10.1007/s12225-009-9160-0

Type

Mozambique, Nampula Province, Naçala Distr., Quissimajulo Beach, 22 Dec. 2006. J. E. Burrows & S. M. Burrows 9751 (holotypus PRE!).

Morphology General Habit

Deciduous shrub, 1 – 1.5 m high, bark pale grey-beige, thin, somewhat flaking, branching monopodial or sympodial, the branchlets characteristically thickened and club-shaped terminally

Morphology Leaves

Leaves borne in terminal clusters, sessile or petiolate to 3 mm long, obovate, occasionally sub-elliptic, glabrous, drying blackish, 28 – 55 × 13 – 28 mm, apex rounded to broadly acute, often shortly mucronate, base cuneate to attenuate, margins finely revolute, domatia absent, bacterial nodules absent or few, elliptic, set against the midrib, lateral veins 7 – 10 pairs

Morphology Leaves Stipules

Stipules broadly triangular, c. 2.5 × 5 mm, with a winged acumen 1.5 – 2 mm long, inner surface sericeous

Morphology Reproductive morphology Inflorescences

Inflorescences in dense terminal hemispherical clusters c. 45 mm across (excluding styles), subtended by 1 or 2 pairs of leaves, primary inflorescence branches 1 – 2 mm long, secondary inflorescence branching absent, bracts stipule-like

Morphology Reproductive morphology Flowers

Flowers 4-merous, pedicels 3 – 4 mm long; calyx glabrous, tube 0.5 – 1 mm long, lobes 4, linear-subulate, 6 – 8 mm long; corolla tube 10 – 12 mm long, white, lobes 4 – 5 × 1 – 1.5 mm, apices mucronate, style exserted 14 – 20 mm

Morphology Reproductive morphology Fruits

Fruit (immature) 6 mm across, green, shiny, calyx eventually caducous

Morphology Reproductive morphology Seeds

Seeds c. 4 mm wide, very finely rugulose on convex face, brownish

Distribution

Africa: Mozambique.

Ecology

Pavetta curalicola is unusual in the genus in that it appears to grow exclusively on coral rock, probably mostly in a distinctive thicket formation which develops on coral rag, although in some localities, such as at Pangane, the thicket has largely been destroyed. The type collection was from a shrub growing about 1 km from the sea, on jagged coral rock in short (3 – 4 m high) semi-deciduous thicket, with its roots growing into crevices. The Matibane collection is stated to grow on calcareous sands and rocky (coral?) ground. Since these coral rag formations are numerous along the coast of Nampula and Cabo Delgado provinces, it is likely that P. curalicola is more widespread than the few collections would suggest. It is also possible that this species occurs on coral formations in the Lindi Distr. of south-eastern Tanzania.

Conservation

Although few collections of this species exist, its favoured habitat of coral rag thicket is fairly widespread and is not seriously threatened by rural settlement. A status of Least Concern (LC) is recommended.

Note

The specific epithet is from the Latin curalium, coral; and —cola, dwelling on, referring to this species’ distinct preference for coral rock (‘coral rag’). Suggested English common name: Coral Brides-bush. Bridson (loc. cit.) states that this taxon is similar to the Tanzanian PavettacrebrifoliaHiern which has 5 – 6 pairs of lateral veins, petioles up to 20 mm long, and scattered bacterial nodules (see diagnoses for further details). Since she had only seen a single fruiting collection, Bridson was reluctant to describe it. However, now that we have seen three flowering collections, it is realised that this is a distinct species deserving of specific rank.