Rubiaceae

Neonauclea Merr.

First published in J. Washington Acad. Sci. 5: 538 (1915)
This genus is accepted
The native range of this genus is Tropical & Subtropical Asia to S. Pacific.

Descriptions

Timothy M. A. Utteridge and Laura V. S. Jennings (2022). Trees of New Guinea. Kew Publishing. Royal Botanic Gardens, Kew

Distribution
A genus of 68 species distributed in tropical and subtropical Asia through to the South Pacific with 22 species in New Guinea including the Bismark Archipelago (13 endemics) and two species in the Solomon Islands.
Morphology General Habit
Shrubs or trees to c. 45 m; branch internodes occasionally ant-inhabited
Morphology General Buds
Terminal bud often flattened
Morphology General
Raphides absent
Morphology Leaves Stipules
Stipules pressed flat together or conical at apex, ligulate to elliptic or obvovate, caducous
Morphology Reproductive morphology Inflorescences
Inflorescences terminal; stipule-like bracts enclosing immature inflorescence, caducous; 1–3(–9) globular heads, arrangement dichasial or thyrsoid; bracteoles present or absent
Morphology Reproductive morphology Flowers
Flowers 5-merous, ±subsessile, free but aggregated around receptacle; calyx apex often modified and caducous; corolla imbricate, narrowly funnel- to salver-shaped, inside ±glabrous; stamens adnate to upper part of tube, filaments short, exserted or slightly so; style exserted, stigma globose to obovoid; ovary 2-locular, ovules pendulous, many per locule
Morphology Reproductive morphology Fruits
Fruits aggregated around common receptacle, free, capsular, dehiscing loculicidally and septicidally from base, valves detaching, ovary septum semi-persistent on receptacle
Morphology Reproductive morphology Seeds
Seeds small, numerous, flattened, ends shortly winged.
Ecology
The genus Neonauclea may have ants inhabiting the branches and are sometimes rheophytic.
Recognition
The inflorescences are in ball-like heads and the upper portion of the calyx lobes are caducous (look for the fallen portion of the calyces in amongst other parts of the inflorescence, where they are often caught). The fruiting head is also distinctive: the individual fruits are free (rather than syncarpous) and the septae of each ovary persists for some time after the locules of the fruit have fallen, giving a temporary ‘spiny’ appearance (similar to Adina but the whole calyx, rather than just the base, is persistent in Adina).
[TONG]

Sources

  • Herbarium Catalogue Specimens

    • 'The Herbarium Catalogue, Royal Botanic Gardens, Kew. Published on the Internet http://www.kew.org/herbcat [accessed on Day Month Year]'. Please enter the date on which you consulted the system.

  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2025. 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 Names and Taxonomic Backbone

    • The International Plant Names Index and World Checklist of Vascular Plants 2025. 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

  • Trees of New Guinea

    • Trees of New Guinea
    • http://creativecommons.org/licenses/by-nc-sa/3.0