2. A preliminary note on Oryza schlechteri

1) International Rice Germplasm Center, IRRI, P. O. Box 933, Manila, Philippines

We report the rediscovery of Oryza schlechteri Pilger. O. schlechteri was first collected in 1907 by R. Schlechter by the Jamu Gorge in the Finisterre mountains, near Bodajim, Papua New Guinea. The species was collected again by A. A. Pulle in Irian Jaya, Indonesia in 1912 along the Van der Sande/Beaufort rivers (van Steenis-Kruseman 1950). This species was not collected again by botanists until 1974 when K. J. White collected the species in Kikori district of Gulf Province, Papua New Guinea. Each of these collections were of herbarium specimens.

In 1990, a collecting mission to Papua New Guinea retraced the collecting route of R. Schlechter and a small population of O. schlechteri was found in presumably the same location as the type population below the Jamu Gorge on the land of Mr. Aro (Fig. 1). Revisiting the area in 1991,.Mr. Aro reported finding a second larger population of this species at higher elevation in the Finisterre mountains. The currently known distribution of O. schlechteri is shown (Fig. 2).

Fig. 2. The known distribution of Oryza schlechteri in Papua New Guinea and Irian Jaya, Indonesia.

O. schlechteri, a creeping stoloniferous plant, was growing on the bank of the river Jamu in partial or complete shade. The habitat was in young mountains with primary forest cover. The river bank where the population was growing was of mixed vegetation including Saccharum and Begonia species. The second population in the Finisterre mountains was reported growing in open moist ground.

Superficially, this species is vegetatively similar to Leersia. It differs from Leersia by its well developed tough sterile lemmas and taxonomists have always aligned this species with the genus Oryza (Duistermaat 1987; Roschevicz 1931; Tateoka 1963). Characteristics which distinguish this species from other Oryza species include its long flagleaf sheath in comparison with its leaf blade length and pubescent culm nodes. Clarification of the biosystematics and botany of this rare and unusual Oryza species will follow.

Duistermaat, H., 1987. A revision of Oryza (Gramineae) in Malaysia and Australia. Blumea 32: 157-193.

Roschevicz, R. J., 1931. A contribution to the knowledge of rice (in Russian). Bull. Appl. Bot. Genet. Plant. Breed. 27(4): 1-133.

Tateoka, T., 1963. Taxonomic studies of Oryza. III. Key to the species and their enumeration. Bot. Mag. Tokyo 76: 165-173.

van Steenis-Kruseman, M. J., 1950. Malaysia plant collectors and collections being a cyclopaedia of botanical exploration in Malaysia and a guide to the concerned literature up to the year 1950. In van Steenis, C.G.G.J. (general editor) Flora Malesiana, vol. 1. 639 p.