Pavetta quasidigita W.D.Hawth.

First published in Kew Bull. 68: 570 (2013)
This species is accepted
The native range of this species is Ivory Coast. It grows primarily in the wet tropical biome.

Descriptions

Hawthorne, W.D. (2003). Six new Pavetta (Rubiaceae), including three ‘litter-bin’ species from the evergreen forests of Western Africa. Kew Bulletin 68: 559. https://doi.org/10.1007/s12225-013-9484-7

Type
Type: Ivory Coast, Tabou: FC de la Ht Dodo, close to Kouadjokro, alt 150 m, 5°00'N, 7°18'W, 4 May 1999, C. C. H. Jongkind and students of University of Cocody 4486 (holotype WAG (sheet WAG0060448 flowering), isotype WAG (sheet WAG0060449 fruiting)).
Morphology General Habit
Low shrub to 1 m, apparently monocaulous with leaves rather clustered towards tip of stem; short flowering side branches with leaves more or less hidden amongst the leaves of the main stem
Morphology Branches
Branchlet puberulous with dense, short ± appressed hairs at first, or slightly puberulous with age
Morphology Leaves Stipules
Stipule triangular, with dense short hairs outside, acute, c. 4 mm long; base of inner face with a fringe of hairs (or filiform colleters) c. 0.5 – 1 mm long
Morphology Leaves Leaf lamina
Lamina 15 – 37 × 2.5 – 12.5 (– 16) cm; petiole relatively short, 0.1 – 1.5 cm long
Morphology General Indumentum
Very short hairs (<0.1 mm long) or spots dense on young parts; slightly rough to touch on lower leaf surface
Morphology Leaves
Midrib on dried leaves slightly channelled above towards base, and prominent or grooved with several slight channels towards leaf apex. Lateral nerves 12 – 21 main pairs (excluding several, mostly indistinct ones within 2 cm of leaf base) and often with one strong pair of very ascending lateral nerves arising close to leaf base, meeting in a nerve that runs 1 – 4 mm from the margin Leaves papery, oblanceolate to obovate, acuminate, base obtuse to cordate, rounded, or sometimes slightly decurrent Both cave-like domatia and slight tuft domatia, with tufts of hairs up to c. 0.5 mm long, present in the axils between some of the lateral nerves and the midrib. Venation with many (up to 35 on one side of lateral nerve), close, scalariform 3° veins, prominent on both surfaces of dried leaves; with very distinctive 4° and finer nerves, these tending to be run parallel to the tertiary veins forming a ‘flowing’ reticulate, fingerprint-like pattern, very finely prominent on both surfaces of dried leaves and highly anisotropous with c. 30 veins/cm in one orientation and fewer (c. 2 – 10 veins) when ruler more aligned with veins (VDA ≥ 3)
Morphology Reproductive morphology Inflorescences
Inflorescence terminating the stout erect shoots and on short, axillary flowering branchlets 2 – 3 cm long, with a single terminal pair of leaves or a solitary leaf directly subtending the inflorescence; very compact, sessile heads (presumably compact dichasia) c. 1 cm radius, i.e c. 2 cm diam. × 1 cm deep, becoming slightly more open as fruits develop; heads of fruits (including the width of the peripheral fruits) c. 4 cm diam., on c. 1 cm peduncle
Morphology Reproductive morphology Flowers
Flower with stout, glabrous pedicel, almost 1 mm diam. and 0.5 – 2 mm long in bud and flower; outer surface of calyx, corolla and flower bud glabrous; buds ellipsoid, rounded at tip, 6 – 7 × 2 mm just before opening
Morphology Reproductive morphology Flowers Calyx
Calyx almost unlobed, with truncate tube 1 – 1.5 mm long, or with rounded lobes c. 0.3 mm long
Morphology Reproductive morphology Flowers Corolla
Corolla c. 6 mm long just before opening, pale green, drying black; tube 2 mm long; lobes 4 – 5 mm, lanceolate with rounded tip; bearded in throat
Morphology Reproductive morphology Flowers Gynoecium Style
Style densely puberulous, c. 10 mm long becoming exserted by 3 mm, the pollen presenter 1 – 2 mm long, slightly divided to 0.2 – 1 mm at tip
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens 3 – 5 mm long, black with white-edged longitudinal wings
Morphology Reproductive morphology Flowers Pedicel
Pedicels and inflorescence axes in fruit becoming white and rather fleshy (see notes)
Morphology Reproductive morphology Fruits
Fruit shiny, 7 – 10 mm diam., apex slightly impressed with calyx not persistent or at least minute; dark bluish green to black, drying black, 1 – 4 seeded Fruit with pedicels 3 – 7 mm long
Morphology Reproductive morphology Seeds
Seed: varied in shape, c. 5 × 7 mm
Distribution
Africa: SW Ivory Coast (to be expected in SE Liberia).
Ecology
Understorey of Wet Evergreen rain forest of SW Ivory Coast.
Conservation
Endangered (IUCN 2001): a very limited range in SW Ivory Coast (EOO 362 km2, AOO 12 km2 using 2 km grid). A Black Star species (Hawthorne & Abu Juam (1995)).
Phenology
Flowers in May, fruit in August.
Note

The isotype is a fruiting specimen on a separate vertical stem, presumably from a different individual in the same area, as the plant seems to be monocaulous. At least in some cases, the inflorescence axes, including the pedicels, turn white and possibly swell in fruit, contrasting with and therefore helping to advertise the dark ripe fruit, as in Psychotriapeduncularis (Salisb.) Steyerm. The unusual whiteness of the fruiting axes was noted independently on field notes by Hall & Abbiw in 1975, and by the author in 1999 (photograph on p. 592 in Hawthorne & Jongkind2006), but were not noted by Jongkind et al. on their field notes, which do however mention other aspects of the fruit. Although it is therefore unclear how late and reliably this swollen white pedicel develops in fruit, the character is unknown in other Upper Guinean Pavetta .

This distinctive plant is named quasidigita — “as if a finger” — on account of the swirling, fingerprint-like, fine and minutely prominent finer venation on the leaves. The venation is unusual, although similar patterns occur in other Rubiaceae, for example BertierabrevifloraHiern, Rutideadupuisii De Wild., Schizocolealinderi (Hutch. & Dalziel) Bremek. and Vangueriellavanguerioides (Hiern) Verdc.

Differs from all other Pavetta species with the distinctive pattern in the smallest veins and from most by its low habit with short petiole (< 1.5 cm) and long leaves (15 – 38 cm). P. quasidigita is similar to P. ankasensis (below) and P. ixorifolia, but these have much less anisotropic finer venation; it differs from P. ixorifolia in particular by having shorter flowering branchlets with obtuse to rounded leaf-bases on the subsessile leaves, and with white, swollen fruiting pedicels.
[KBu]

Sources

  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2024. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0
  • Kew Bulletin

    • Kew Bulletin
    • http://creativecommons.org/licenses/by-nc-sa/3.0
  • Kew Names and Taxonomic Backbone

    • The International Plant Names Index and World Checklist of Vascular Plants 2024. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 International Plant Names Index and World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0