Gaertnera vaginans (DC) Merr., En. Born. (1921)
Latin for 'sheath', referring to the sheath-like stipule that completely encloses the twig.

Synonyms
Gaertnera acuminata Benth., Gaertnera acuminata var. montana Ridl., Gaertnera acuminata var. oxyphylla (Benth.) Ridl., Gaertnera borneensis Val., Gaertnera brevistylis Ridl., Gaertnera caudata Ridl., Gaertnera junghuhniana Miq., Gaertnera koenigii (Arn.) Wight, Gaertnera koenigii var. oxyphylla (Benth.) Clarke, Gaertnera koenigii var. thyrsiflora (Arn.) Thw., Gaertnera longevaginalis (Hiern) Petit, Gaertnera oxyphylla Benth., Gaertnera pedicellata Ridl., Gaertnera ramosa Ridl., Gaertnera sessiflora Ridl., Gaertnera sralensis (Pitard) Kerr, Gaertnera taiensis Kerr, Gaertnera thyrsiflora (Arn.) Blume, Gaertnrea zollingeriana Miq., Ophioxylon arboreum Koenig, Psychotria longevaginalis Schweinf. ex Hiern, Psychotria oxyphylla Wall., Psychotria sralensis Pierre, Psychotria vaginans DC, Sykesia acuminata (Benth.) O.K., Sykesia junghuhniana (Miq.) O.K., Sykesia koenigii Arn., Sykesia oxyphylla (Benth.) O.K., Sykesia thyrsiflora Arn., Sykesia vaginans (DC) O.K., Sykesia zollingeriana (Miq.) O.K., Uragoga sralensis Pierre ex Pitard

Note
The synonym Gaertnera junghuhniana Miq., might turn out to be a separate species, in which case all specimens from Borneo belong to this species since the true Gaertnera vaginans (without this synonym) only occurs in Tropical Africa, Madagascar and Sri Lanka.

Description
Shrub up to 6 m tall and 11 cm dbh. Stipules fused, forming a tube around the stem, ca. 9 mm long, often with pointed tips. Leaves opposite, simple, penni-veined, rarely hairy. Flowers ca. 5 mm diameter, white, with long corolla tube, flowers placed in panicles. Fruits ca. 6 mm diameter, blue-purple, berries.

Ecology
In undisturbed to slightly disturbed (open) mixed dipterocarp, keranga, (peat)-swamp and sub-montane forests up to 1000 m altitude. Mostly on hillsides and ridges, but also on alluvial sites and along rivers and streams. Usually on poor sandy soils, but also on clay, limestone and ultrabasic. In secondary forests usually present as a pre-disturbance remnant.

Distribution
Tropical Africa, Madagascar, Sri Lanka, Indo-China, Thailand, Peninsular Malaysia, Sumatra, Borneo (throughout the island).

Local names in Borneo
Alad sadik, Api-api, Baruas, Enduropis, Enteburok, Jambu hutan, Jampari, Kopi-kopi, kupi-kupi, Labuk, Lehek bini, Lilingan, Madang, Masintan, Mengkuan hutan, Merpisang, Olah puteh, Peleket, Plekit, Pingan-pingan, Pitaling, Sabar bubu, Sakai, Santan hutan, Sawar bubu, Supat, Supot, Tambar dimidua.