 |
| Monoon kalimantanense Nurmawati
in Nurmawati, Ariyanti, Chikmawati & Kessler, 2020.
|
During the study of Monoon Miquel (1865: 15) in western Malesia, we found two individuals of this genus cultivated in the Bogor Botanic Garden. According to the catalogue An alphabetical list of plant species cultivated in the Bogor Botanic Gardens, these plants were collected from South Kalimantan in 1977 (Sari et al. 2010). Leaves and aggregate fruits of these plants indicated that they are a species of Monoon (Annonaceae). The leaves exhibit eucamptodromous venation, decurrent insertion of secondary veins, and scalariform tertiary veins. The aggregate fruits consist of many one-seeded, stalked monocarps. However, other characters indicated that they differ from already known Monoon species. We consider these plants, therefore as new to science.
This new species shares characters with M. lateriflorum (Blume) Miquel (1865: 19), previously Guatteria lateriflora Blume (1825: 20) and M. sclerophyllum (Hook. & Thomson) Xue & Saunders in Xue et al. (2012: 1033), previously Polyalthia sclerophylla Hooker & Thomson (1872: 65), in having ramiflorous, fasciculate inflorescences, many-flowered fascicles, oblong petals slightly constricted basally and many-stipitate monocarps (ca. 30) in aggregate fruits. However, other characters of leaves, flowers, and monocarps indicate that this new material differs from M. lateriflorum, and M. sclerophyllum (Table 1).
Keywords: plant taxonomy, taxonomic revision, Annonaceae, Monoon, Magnoliids
 |
| FIGURE 1. Monoon kalimantanense. A. Plant habit. B. Spreading branches with mature leaves. C. Glossy young leaves. D. Abaxial and adaxial surfaces of the lamina. E. Decurrent secondary veins. F. Ramiflorous inflorescences. G–H. Flowers in fascicles. I. Flower with stamens and carpels arranged on the torus. J. Inner (i) and outer (o) petals removed from the torus. K. Sepal. L. Stamens arrangement on the torus. M. Fruit. N–O. Monocarps and seeds.
Labels: se = sepal, st = stamen. Scale bars, K–L = 1 mm.
Photos by S. Nurmawati from Bogor Botanic Gardens, block XX.D.122a.
|
 |
| FIGURE 2. Monoon kalimantanense. A. Leaves on twig. B. Lamina base, lamina apex, and scalariform tertiary vein. C. Flower. D. Pedicellate flower with a bracteole. E. Outer petals. F. Inner petals. G. Stamen. H. Ovary. I. Fruit. J. Stipitate monocarp. K. Seed. Illustration by Wahyu Santoso. |
Monoon kalimantanense Nurmawati, sp. nov.
Small trees, leaves 35–49 cm long. Inflorescences ramiflorous, with many flowers, stigma surface densely curly hairy. Inflorescences position and monocarp of Monoon kalimantanense is similar to M. lateriflorum and M. sclerophyllum but differs in having larger leaves with a rounded base, green pedicels, broadly triangular and densely hairy sepals, shorter oblong petals and monocarps slightly asymmetrically attached on the stipe.
Distribution, habitat, and ecology:— Known only from the Bogor Botanical Garden, most probably originally in South Kalimantan, Meratus Mts, near Muara Uja, Jaro Dam. The plants cultivated in the Garden have full exposure to sunlight with an average rainfall of 3000 to 4000 mm annually.
Etymology:— Referring to its provenance in South Kalimantan.
Subekti Nurmawati, Nunik Sri Ariyanti, Tatik Chikmawati and Paul J. A. Kessler. 2020. Monoon kalimantanense (Annonaceae), A New Species from Kalimantan, Borneo, Indonesia. Phytotaxa. 446(1); 1–5. DOI: 10.11646/phytotaxa.446.1.1
