Rhynchospora rugosa
Content
Description
Perennial, with short rhizome;
Leaves shorter than the stems, rigid, flat or canaliculate, long-acuminate, with strong midrib and scaberulous margins, 2-3(-5) mm wide;
Inflorescence paniculate, narrow, consisting of 3-4(-6) distant, dense to rather loose corymbiform anthelas, the lateral peduncles compressed, often long-exserted from the sheath, solitary or 2 together;
Flowers bisexual, upper one(s) tabescent.
Stamens (1-)2(-3);
Distribution
Asia-Tropical: Borneo present; Malaya (Peninsular Malaysia present); New Guinea present; Philippines (Philippines present); Sulawesi (Sulawesi present); Sumatera (Sumatera present), Banka present, Luzon present, Mindanao present, Riouw Arch present, W. and E. Java present, tropics and subtropics of the whole world present
Widely distributed in the tropics and subtropics of the whole world, in Malesia: Sumatra, Banka, Riouw Arch., Malay Peninsula, W. and E. Java, Borneo, Philippines (Luzon, Mindanao), Celebes, New Guinea.
Notes
As can be expected from a pantropic species, R. rugosa in the wide sense here accepted is extremely polymorphous. Although none of the characters given below can be considered absolute, the Malesian material is fairly well divisible into two groups characterized as follows:
The type of R. rugosa is from America. American material is said (GALE, S. T. BLAKE) to differ from the Old World specimens by the smaller spikelets and smaller pyriform nuts with prominent band-like corrugations. In the scant American material I could examine I found the spikelets not smaller than in group I, and the length of the nut varying between 1¼ and 2 mm. KÜKENTHAL unites group I with the American plants in ascribing to both bristles as long as or shorter than the nut; already VAHL rightly described the bristles of R. rugosa s.s. as longer than the nuts. Also R. lavarum GAUD. from the Hawaiian Islands, and R. griffithii BOECK. and R. sikkimensis C. B. CLARKE from India apparently belong to R. rugosa s.l. If treated as specifically distinct the correct names of the Malesian races are probably R. brownii R. & S. (based on R. laxa R.BR., non VAHL) for group I, and R. japonica MAKINO for group II. However, I agree with KÜKENTHAL that they do not deserve specific rank; subspecific names are not available, but I refrain from coining them as the species is greatly in Néerl of a systematic and nomenclatural study. KÜKENTHAL called the Malesian plants respectively R. glauca VAHL [subsp. glauca] and R. glauca subsp. chinensis (“BOECK.”) C. B. CLARKE. The former name is illegitimate and in the narrower sense only refers to the American race, the latter is nomenclaturally based on R. chinensis NEES, which partly refers to group I, partly to a different plant.
- Spikelets (3-)4-5 mm long, 2-3-flowered, usually maturing only 1 nut. Nut 1½-1¾ by 1-1½ mm. Style-base ⅔-1 mm long, about half as long as the nut. Bristles somewhat shorter to slightly longer than the nut (without style-base), the longest 1½-2 mm. Anthers 1-1½ mm. Epidermal cells of the nut ± pitted. — Sumatra, Java, New Guinea (Celebes, Philippines according to KÜKENTHAL).
- Spikelets 5-6 mm long, 3-4-flowered, usually maturing 2(-3) nuts. Nut 1¾-2 by 1½-1¾ mm. Style-base 1¼-2 mm long, ¾ to about as long as the nut. Bristles almost reaching the top of the style-base or even slightly longer, the longest 2½-4 mm. Anthers 2-2½ mm. Epidermal cells of the nut not or hardly pitted. — Sumatra, Malay Peninsula, Borneo, Philippines (according to CLARKE), New Guinea. (In Japanese material the spikelets and bristles are still longer).
The type of R. rugosa is from America. American material is said (GALE, S. T. BLAKE) to differ from the Old World specimens by the smaller spikelets and smaller pyriform nuts with prominent band-like corrugations. In the scant American material I could examine I found the spikelets not smaller than in group I, and the length of the nut varying between 1¼ and 2 mm. KÜKENTHAL unites group I with the American plants in ascribing to both bristles as long as or shorter than the nut; already VAHL rightly described the bristles of R. rugosa s.s. as longer than the nuts. Also R. lavarum GAUD. from the Hawaiian Islands, and R. griffithii BOECK. and R. sikkimensis C. B. CLARKE from India apparently belong to R. rugosa s.l. If treated as specifically distinct the correct names of the Malesian races are probably R. brownii R. & S. (based on R. laxa R.BR., non VAHL) for group I, and R. japonica MAKINO for group II. However, I agree with KÜKENTHAL that they do not deserve specific rank; subspecific names are not available, but I refrain from coining them as the species is greatly in Néerl of a systematic and nomenclatural study. KÜKENTHAL called the Malesian plants respectively R. glauca VAHL [subsp. glauca] and R. glauca subsp. chinensis (“BOECK.”) C. B. CLARKE. The former name is illegitimate and in the narrower sense only refers to the American race, the latter is nomenclaturally based on R. chinensis NEES, which partly refers to group I, partly to a different plant.
Citation
Merr. 1923 – In: En. Philip.: 130
RENDLE 1917 – In: Gibbs, Arfak: 91
OHWI 1942 – In: Bot. Mag. Tokyo: 205
BOECK. 1873 – In: Linnaea: 586
BOECK. 1873 – In: Linnaea: 581
BOECK. 1873 – In: Linnaea: 585
Merr. 1921: En. Born: 63
Koord. 1911 – In: Exk. Fl. Java: 202
KÜK. 1950: Bot. Jahrb 75: 143
VALCK. SUR. 1912 – In: Nova Guinea: 706
F.-VILL. 1882: NOV. App: 309
Clarke 1907 – In: Philip. J. Sc.: Bot. 102
KERN 1968 – In: Back. & Bakh.f., Fl. Java 3: 484
Miq. 1856 – In: Fl. Ind. Bat.: 337
S. T. BLAKE 1948 – In: J. Arn. Arb.: 102
OHWI 1942 – In: Bot. Mag. Tokyo: 205
Clarke 1909: Ill. Cyp.: f. 8-11
UITTIEN 1949 – In: Back., Bekn. Fl. Java, (em. ed.), 10: fam. 246, p. 6
KÜK. 1938 – In: Bot. Jahrb.: 259
Ridl. 1907 – In: Mat. Fl. Mal. Pen. (Monoc.): 84
KÜK. 1950 – In: Bot. Jahrb.: 148
1843 – In: Act. Ac. Caes. Leop.-Car.: 108
STEEN. 1972: Mt Fl. Java: t 14: 15
Clarke 1893 – In: Fl. Br. Ind.: 671
VAHL 1909: Ill Cyp.: t. 73, f. 7
Miq. 1856 – In: Fl. Ind. Bat.: 336
Ridl. 1925 – In: Fl. Mal. Pen.: 165