anonymous 1931. — Contributions to the Flora of Siam. Addita-
mentum XXXII.Bulletin of Miscellaneous Information (Royal Botanic
Gardens, Kew) (9): 441-448. https://doi.org/10.2307/4102478
bachman s. p., moat J., hill a., de la toRRe J. & scott b.
2011. — Supporting Red List threat assessments with GeoCAT:
geospatial conservation assessment tool. ZooKeys 150: 117-126.
https://doi.org/10.3897/zookeys.150.2109
beentJe h. 2016. — The Kew Plant Glossary: an Illustration Dic-
tionary of Plant Terms. Kew publishing, Royal Botanic Gardens,
Kew, Surrey, 184 p.
chen t. & tayloR c. m. 2011. — Urophyllum, in Wu Z. y., RaVen
p. h. & hong d. y. (eds), Flora of China. Vol. 19. Science Press,
Beijing and Missouri Botanical Garden Press, St. Louis: 353, 354.
claRKe J. e. 2000a. — Biodiversity and Protected Areas – Cambo-
dia: Regional Environmental Technical Assistance 5771 – Poverty
Reduction & Environmental Management in Remote Greater
Mekong Subregion (GMS) Watersheds Project (Phase I).
claRKe J. e. 2000b. — Biodiversity and Protected Areas – Laos
P.D.R.: Regional Environmental Technical Assistance 5771 –
Poverty Reduction & Environmental Management in Remote
Greater Mekong Subregion (GMS) Watersheds Project (Phase I).
claRKe J. e. 2000c. — Biodiversity and Protected Areas – Viet
Nam: Regional Environmental Technical Assistance 5771 –
Poverty Reduction & Environmental Management in Remote
Greater Mekong Subregion (GMS) Watersheds Project (Phase I).
cRaib W. g. 1932. — Florae Siamensis Enumeratio. W. H. Mundie,
The Bangkok Times Press, Bangkok, 166 p.
goVaeRts R., R uhsam m., andeRsson l., R obbRecht e., bRid-
son d., daVis a., schanZeR i. & sonK b. 2020. — World
Checklist of Rubiaceae: Facilitated by the Royal Botanic Gardens,
Kew (Published on the Internet). https://wcsp.science.kew.org
hicKey l. J. 1979. — A revised classification of the architecture of
dicotyledonous leaves, in metcalfe c. R. & chalK L. (eds),
Anatomy of the Dicotyledons. Vol. 1. Clarendon Press, Oxford: 25-39.
hooKeR J. d. 1880. — Order LXXV. Rubiaceae, in hooKeR J. D.
(ed.), The Flora of British India. Vol. 3. L. Reeve & Co., London:
17-210. https://www.biodiversitylibrary.org/page/455613
iucn 2012. — IUCN Red List Categories and Criteria, Version 3.1.
Gland and Cambridge, 32 p.
iucn 2019. — Guidelines for Using the IUCN Red List Categories
and Criteria. Version 14. Prepared by the Standards and Petitions
Committee.
leaf-aRchitectuRe-WoRKing-gRoup 1999. — Manual of Leaf
Architecture – Morphological Description and Categorization of
Dicotyledonous and Net-Veined Monocotyledonous Angiosperms.
Leaf Architecture Working Group.
metcalfe d. J., gRubb p. J. & tuRneR i. m. 1998. — The ecology
of very small-seeded shade-tolerant trees and shrubs in lowland
rain forest in Singapore. Plant Ecology 134 (2): 131-149.https://
doi.org/10.1023/A:1009789922595
nagahama a., tagane s., ngoc n. V., binh h. t., cuong t. Q.,
toyama h., nagamasu h., tsuchiya K., Zhang m., suyama
y., moRitsuKa e., thu n. t. a., thinh n. c., matsuo a.,
hiRota s., naiKi a., son l. V., nhan p. h. & yahaRa t.
2019. — A Picture Guide for the Flora of Bidoup-Nui Ba National
Park I: Mt. Langbian . Center for Asian Conservation Ecology,
Kyushu University, Fukuoka, 134 p.
pham h. h. 2000. — Cây cỏ Việt Nam : an Illustrated Flora of
Vietnam. Volume 2, Part 3. Youth Publishing House, Ho Chi
Minh City, 1020 p.
pham g. t. 2019. — Soil Properties Mapping and Land Evaluation
for Potential Agricultural Land Use Types in A Luoi District, Thua
Thien Hue Province, Central Vietnam. PhD Thesis, Georg-Au-
gust-Universität Göttingen, 154 p.
pitaRd J. 1923. — Rubiacées, in lecomte h., humbeRt h. &
gagnepain F. (eds), Flore générale de l’Indo-Chine. Vol. 3. Mas-
son et Cie, Paris: 20-442. https://www.biodiversitylibrary.org/
page/27562437
puff c., chayamaRit K. & chamchumRoon V. 2005. — Rubi-
aceae of Thailand: a Pictorial Guide to Indigenous and Cultivated
Genera. The Forest Herbarium, Department of National Parks,
Wildlife and Plant Conservation, Bangkok, 245 p.
R coRe team 2019. — R: A Language and Environment for Statisti-
cal Computing. Vienna, R Foundation for Statistical Computing.
Available online at https://www.R-project.org/
R oxbuRgh W. 1824. — Urophyllum Wall., in caRey W. (ed.),
Flora Indica. Vol. 2. The Mission Press, Serampore: 184-186.
schmidt J. 1902. — Flora of Koh Chang: contributions to the
knowledge of the vegetation in the Gulf of Siam. Part VI: Ru-
biaceae. Botanisk Tidsskrift 24: 329-367. https://www.biodiver-
sitylibrary.org/page/44723470
stafleu f. a. & coWan R. s. 1983. — Taxonomic Literature.
A Selective Guide to Botanical Publications and Collections with
Dates, Commentaries and Types . Second edition. Volume IV:
P-Sak. Bohn, Scheltema & Holkema; Dr. W. Junk b.v., Utrecht/
Antwerpen; The Hague/Boston, 1214 p.
tan h. t. W., chua K. s. & tuRneR i. m. 1995. — Rubiaceae
of the Bukit Timah Nature Reserve, in chin s. c., coRlett R.
t., W ee y. c. & gee S. Y. (eds), Rain Forest in the City: Bukit
Timah Nature Reserve Singapore. Garden’s Bulletin Singapore.
Supplement 3: 29-61.
tayloR c. m., ehRendoRfeR f., lantZ h., funston a. m. &
puff c. 2011. — Rubiaceae, in W u Z. y., R aVen p. h. &
hong D. Y. (eds), Flora of China . Vol. 19 (Cucurbitaceae
through Valerianaceae, with Annonaceae and Berberidaceae).
Science Press & Missouri Botanical Garden Press, Beijing, St.
Louis: 57-368.
unep-Wcmc & iucn 2020. — Protected Planet: the World
Database on Protected Areas (WDPA). UNEP-WCMC & IUCN,
Cambridge.
W ong K. m., tuRneR i. m., W ang R. J., haRWood R., seah
W. W., ng x. y., lim R. c. J., lua h. K. & mahyuni R.
2019. — Rubiaceae, in middleton d. J., lindsay s. & leong-
ŠKoRni čKoVá J. (eds), Flora of Singapore. Vol. 13 (Gentianales).
National Parks Board Singapore: 1-358.
yoopRaseRt s. 2021. —Taxonomy and Systematics of Urophyllum
(Rubiaceae) in Thailand and Indochina. PhD Thesis, University
of Reading (unpublished thesis), 244 p.