Thoracostachyum sumatranum

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Thoracostachyum sumatranum


Leaves green or pale green, distinctly reticulate when dry, up to 2 m long, (1-)2-3½ cm wide; Inflorescence globose or ovoid, often dense, (3-)10-20 cm in diam., with 10 to some hundred (according to CLARKE up to 800!) spikelets; Flowers 3-3½ mm long.


Asia-Tropical: Borneo present; Malaya (Peninsular Malaysia present); New Guinea present, Australasia, Danu swamp present, Johore present, Lampongs present, Malacca present, NE. Queensland present, Palau Islands present, Palembang present, S. Sumatra present, SE. Celebes present, W. Java present
Australia (NE. Queensland), Palau Islands (?), in Malesia: S. Sumatra (Palembang, Lampongs), Malay Peninsula (Malacca, Johore), W. Java (Danu swamp), Borneo, SE. Celebes, and New Guinea.


In Sumatra (Palembang) and the Malay Peninsula the leaves are used for making mats. In Sumatra it is sometimes cultivated for this purpose in swamps and inundated fields. The mats are less durable than those made of the leaves of Pandanus spp.


The inflorescence is very variable in size and density. UITTIEN treated T. sumatranum and T. pandanophyllum as specifically distinct on account of the large decompound inflorescence of the latter, and T. heyneanum on account of the less dense inflorescence and the longer spikelets. It is evident that it is impossible to trace dividing lines only with the aid of these characters. The details of flowers and fruits are the same in all three.
In the herbaria T. sumatranum is often confused with Hypolytrum nemorum. It may be distinguished by the creeping stolons covered with long stramineous scales, the much firmer glumes, the 3 stigmas, and the nut abruptly narrowed into the beak.


Ridl. 1925 – In: Fl. Mal. Pen.: 171
SCHEFF. 1874 – In: Nat. Tijd. N. I.: 89
K. SCH. & LAUT. 1900: Fl. Schutzgeb.: 189
KOYAMA 1964 – In: Micronesica: 64
S. T. BLAKE 1947 – In: J. Arn. Arb.: 208
UITTIEN 1936: p. 139. – In: Rec. Trav. Bot. Néerl.: f. 1d.
Miq. 1870: Illustr: 62: t. 24
KERN 1968 – In: Back. & Bakh.f., Fl. Java 3: 455
UITTIEN 1936: p. 138. – In: Rec. Trav. Bot. Néerl.: f. lc & 2c
Clarke 1898 – In: J. Linn. Soc. Bot.: 94
Clarke 1909: Ill. Cyp.: f. 7-10
UITTIEN 1936: p. 136. – In: Rec. Trav. Bot. Néerl.: f. lb & 2b
VALCK. SUR. 1912 – In: Nova Guinea: 710
Ridl. 1907 – In: Mat. Fl. Mal. Pen. (Monoc.): 102
KÜK. 1924 – In: Bot. Jahrb.: 54
Merr. 1921: En. Born.: 66
UITTIEN 1949 – In: Back., Bekn. Fl. Java, (em. ed.), 10: fam. 246, p. 51