A new species of Friesodielsia (Annonaceae), Friesodielsia formosa, is described from Borneo. A large woody climber of lowland forests, the species has been collected from Sabah, Sarawak and Kalimantan. A new combination in Friesodielsia is made for Oxymitra grandifolia Merr. which is resurrected from the synonymy of Friesodielsia latifolia (Hook.f. & Thomson) Steenis. The name Oxymitra grandifolia is lectotypified.

Pollen and seed characters of 12 Nepalese representatives of the Hedyotis–Oldenlandia–Kohautia complex (Spermacoceae s.l.; Rubiaceae) were investigated morphologically using scanning electron and light microscopy. The members of the complex were found to show remarkable variation in fruit, seed and pollen features. Pollen grains were all colporate with the aperture number varying from 3–4 to occasionally 5. The ectoaperture was a colpus, and the endoaperture was an endocingulum, a lalongate endocolpus or an endocolpus combined with an annulus around the mesoporus. Sexine ornamentation was variable, being perforate, reticulate or microreticulate. Three species were found to have a double reticulum. Supratectal elements were generally absent, but sometimes muri were beset with granules. Seeds were numerous per capsule, small and non-crateriform. Three types of seed were distinguished based on shape: (1) lenticular with a narrow wing-like margin, (2) trigonous, and (3) globose/subglobose. Trigonous seeds exhibited marked variation in colour, size and shape. On the basis of the pollen and seed characters, used in combination with the type of fruit dehiscence, five natural groups are identified for Nepalese taxa. The generic status of Hedyotis, Oldenlandia and Kohautia is maintained but some species are transferred from Hedyotis to Oldenlandia. Pollen and seed morphology, together with the type of fruit dehiscence, proved to be helpful in delimiting supra- and infrageneric groups within the Hedyotis–Oldenlandia–Kohautia complex.

The species of Aeschynanthus Jack (Gesneriaceae) in Cambodia, Laos and Vietnam are revised. Eighteen species are recognised, keys to the species are given, all names are typified, and detailed descriptions of all species are provided. Conservation assessments are given for all species. Aeschynanthus cambodiensis D.J.Middleton, Aeschynanthus jouyi D.J.Middleton and Aeschynanthus pedunculatus D.J.Middleton are newly described.

The genus Clemensiella (Apocynaceae – Asclepiadoideae) is reported to include two species. Clemensiella mariae, a Philippine endemic, is redescribed, illustrated, and lectotypified. Its chromosome number (2n = 22) is reported for the first time. The recently described Hoya viracensis is synonymised with Clemensiella mariae. Clemensiella omlori is described as a new species from Borneo and Sumatra. The taxonomic relationship of Clemensiella to other genera of tribe Marsdenieae is discussed.

Recent studies in the palaeotropics indicate that Rapanea cannot be maintained as a separate genus from Myrsine (Myrsinaceae). Based on the latest evidence from comparative morphology, Papuasian Rapanea are thus transferred to Myrsine. The nomenclatural adjustment provides a foundation for future additions to the enlarged genus, previously represented by only three of the required binomials.

After the establishment of a complete set of Myrsine names for eastern Malesia, M. warrae W.N.Takeuchi & Pipoly is added to the redefined conspectus. The new plant is distinguished by large leaves, rostrate fruits, and an apparent restriction to ultrabasic substrates.

The so-called dithecous leaves with two sheaths (adaxial and abaxial) which occur at branching in species of subfamily Podostemoideae of the aquatic flowering plant family Podostemaceae are enigmatic structures. The fact that in many species the shoot axes and leaves are fused has previously prevented an understanding of the real nature of dithecous leaves. This study reports on the position of the dithecous leaf in Podostemum rutifolium subsp. ricciiforme, the simple shoot structure of which has revealed that the dithecous leaf is the first leaf of the branch and does not arise from the main shoot as previously believed. Accordingly, the two sheaths of the dithecous leaf are interpreted anew: the sheath towards the branch, and its flower bud, is the true (ventral, adaxial) sheath of the dithecous leaf (formerly viewed as an additional new structure), and the other (dorsal, abaxial) sheath towards the flower bud of the main shoot of the branch is a novel structure. Consequently, the branch does not develop from the reverse side of the dithecous leaf in a subfoliar position, but rather is axillary above its subtending leaf. A similar structure was described in a previous paper on Apinagia riedelii, and in both species, and thus in subfamily Podostemoideae, the ramification pattern conforms to the pattern in other angiosperms.