Ammannia herbacea W.J.de Wilde & Duyfjes, 2014

5. Ammannia herbacea W.J.de Wilde & Duyfjes View in CoL , sp. nov.

Herba basin pauciramosa, folia basi subauriculata, inflorescentiae subses- siles, (pedunculus c. 0.5 mm longus), petala adsunt, stamina 4, stylus ovario breviore, placenta centralis ut videtur. — Typus: Clason 267 (holo L), Indonesia, E Java .

Erect, annual, glabrous herb, 25– 50 cm tall, few-branched at base, the branches about as long as the main stem; stem 4-angular but angles rounded. Leaves sessile; lamina narrowly elliptic, 1.5–4 by 0.4–1.2 cm, base broadened, subauricu- late, apex blunt (rounded) or acute, 1-nerved. Inflorescences 1–4-flowered (sub)sessile clusters; peduncle up to 0.5 mm long. Flowers 4-merous; pedicel 0.2(–0.5) mm long, (articulate?); calyx tube campanulate, (0.5–) 1 mm long, faintly 8-ribbed, lobes patent, broad-triangular, c. 0.5 mm long, acute, append- ages conspicuous, c. 0.3(–0.5) mm long, acute; petals pale pink, subcircular, c. 0.2 mm diam; stamens 4, included, inserted towards the base of the tube; ovary broad-ellipsoid, c. 0.8 mm long, style c. 0.3 mm long; placenta axile, in fruit showing up as central. Capsules globose, (1.5–) 2 mm diam, for c. 1/3 exserted from calyx; style c. 0.4 mm long. Seeds numerous, yellow-brown, c. 0.3 mm long.

Distribution — E Java (Malang), known only from the type.

Habitat & Ecology — In ripe paddy fields on good soil; alti- tude not indicated. Flowering and fruiting in June.

Collector’s notes — Plant more sappy than other Ammannias, common.

Note — This species, known only from a single gathering, was annotated as common. Possibly it originated as a hybrid, and in that case perhaps with A. baccifera and A. auriculata

2 mm

Fig. 3 Ammannia octandra L.f. a. Habit of plant; b. flower bud; c. flower; d. flower, opened; e. pistil; f. fruit within persistent calyx; g. seed, two views. — Re- produced with permission from Soerjani et al. (1987).

as parents, both species widespread and extremely polymorphic, and both occurring in E Java. Ammannia herbacea with a different general habit (i.e. few-branched at base and more weakly built and juicy) cannot go, however, with either of these species: A. baccifera differs in having leaf lamina attenuate at base (in Asia) and lacking petals, while A. auriculata differs in having peduncled inflorescences and a style longer than the ovary. We checked whether it could be an introduction by consulting regional revisions of Ammannia outside Malesia viz. Qin & Graham (2007) for China, Hewson (1990) for Australia, Fernandes (1970, 1978, 1980) for southern Africa, Immelman (1991) for South Africa and Verdcourt (1994) for E Africa, but the taxon does not fit any of the species accounted for there. Ammannia herbacea was recorded as common, but apparently as yet has not dispersed outside its locality.