Forked Fimbry

Fimbrstylis bisumbellata is a greyish-green annual herb that reaches up to (3-) 10-35 cm long and forms small tufts. Culms are terete, and glabrous. Leaf sheaths are villous in upper parts, and bladeless in the lower parts. Leaves are 0.5-1 mm wide, flat, adaxially glabrous, and abaxiall villous especially in the proximal parts, with scabrous margins towards the apex. The inflorescence with 15-30 narrowly ellipsoid, acute, light brown to greyish-brown mostly solitary spikelets that reach up to 3.5-4.5 x 1.3-1.5 mm. Glumes are 1.3-1.8 x c. 1 mm, ovate, glabrous or slightly hirsute, keeled, with a prominent mid-vein, with scarious margins. The fruit is a yellowish to almost white biconvex, broadly obovoid nutlet.

Nile Valley North of Nubia (Location: Delta), Nile Valley North of Nubia, Nubia, Mareotic Sector, Isthmic Desert, Galala Desert, Arabian Desert (Location: Wadi Allaqi).

Canary Islands, Mauritania, Mediterranean Europe from Spain to Greece, Egypt, Palestine, Lebanon, Syria, Turkey, Caucasus, Iran, Turkmenistan, Afghanistan, Pakistan, tropical Africa, Madagascar, Malaysia, Australia, New Zealand.

Marshy places, Nile and canal banks, ditches, rice fields.

Annual

Height: (3-) 10-35 cm

Fimbristylis dichotoma is found in temperate to tropical regions worldwide. It is one of the most widespread and weedy species of Fimbristylis, unquestionably with many races and forms. The two commonest forms in the United States often occur in mixed populations, one sort with inflorescence branches more ascending, inflorescence dense, habit lower, and leaves broader; the other sort usually taller, inflorescence more sparse, branches more widely spreading, and leaves more ascending and narrower. The abundance of such plants both in regions where rice originated and in regions where rice is, or was, introduced, indicates an Asian origin for such weeds.

The name is applied here in corrected sense (Fischer, Notes on the Flora of Madras: Part X, Kew Bull.: 149. 1935, see following species). F. dichotoma is restricted to monsoon areas.

Plants perennial, cespitose, (10–) 20–80 cm, base thickened, not bulbous; rhizomes absent. Leaves nearly distichous, spreading to ascending, 1/2 length of culms; sheaths distally ciliate, backs mostly glabrous; ligule line of short hairs; blades narrowly linear, 2–3 mm wide, flat to broadly involute, scabrid ciliate, adaxially smooth or hirtellous. Inflorescences: anthelae compound, dense or open, ascending-branched, longer than broad; scapes slender, 1 mm wide, slightly compressed distally; proximalmost involucral bract exceeding anthela. Spikelets pale drab brown to chestnut brown, ovoid-lanceoloid, 4–8 mm; fertile scales broadly oblong or ovate, 2 mm, acute to obtuse angled, glabrous, midrib reaching scale tip or excurrent, finely mucronate. Flowers: stamens 1–2; styles 2-fid, flat, fimbriate. Achenes white to brownish, lenticular, obovoid, 1–1.2 mm, cancellate, each face longitudinally with (5–)10–12 ribs, connected by vertical rows of horizontally rectangular pits. 2n = 20, 30.

Greyish green, caespitose perennial, 30-60 cm. Stem 0.7-1.2 mm diam., deeply grooved, glabrous. Leaves to c. half of stem length; sheaths open, scarious side slightly villose, mouth margin ciliate; ligule a dense fringe of hairs; blades 1-3 mm wide, flat, sometimes slightly incurved, midrib not prominent, margins scabrous, esp. towards apex. Inflorescence 2-6 cm diam., with 6-50, mostly solitary, occasionally geminate spikes; lowest bract leaf-like, as long as or longer than inflorescence. Spikes 4.5-8 x 2.5-3.5 mm, ovoid, terete, acute, light brown to brown; glumes coriaceous, widely ovate, occasionally slightly keeled, apiculate, apical parts glabrous, brown; rachis castaneous, narrowly winged. Stamens 1; filaments more than 2 mm long, c. 0.2 mm wide, flat, colourless; anthers c. 0.8 mm, connective tip mucronate; style c. 1 x 0.2 mm, deciduous, flat, brown, margins colourless, ciliate; stigmas 2, c. 0.5 mm, flat, basal parts ciliate. Nut 1-1.2 x c. 0.8 mm, lenticular, trabeculate, yellowish, sometimes whitish.

Distribution: Weed probably in all tropical and subtropical areas.

Fl. Per.: August-October.

Grasslands along rivers, also as a weed.

Fruiting summer–fall, into winter southward. Moist, usually sandy waste areas, roadsides, low fields, and savannas; 0–200 m (to 2000 m, tropics); introduced; Ala., Fla., Ga., La., Miss., N.C., S.C., Tex.; Mexico; West Indies; Bermuda; Central America; South America; Eurasia; Africa; Atlantic Islands; Indian Ocean Islands; Pacific Islands; Australia.

Scirpus dichotomus L., Sp. Pl. 1: 50. 1753; Kral, Sida 4: Pl. 37a (1971). U. Scholz, in H. Scholz & U. Scholz, Fl. descr. Graminées & Cypéracées Togo: fig. 11. 1988.

Scirpus dichotomus Linnaeus, Sp. Pl. 1: 50. 1753; Fimbristylis annua (Allioni) Roemer & Schultes var. diphylla (Retzius) Kükenthal; F. brizoides Nees & Meyen; F. diphylla (Retzius) Vahl subsp. diffusa D. B. Ward; F. glauca Vahl; F. polymorpha Boeckeler; Scirpus diphyllus Retzius

Fimbristylis dichotoma (L.) Vahl, Enum. 2: 287. 1805
Scirpus dichotomus L. Sp. PI. 50. 1753.
Scirpus anniius All. Fl. Ped. 2: 277. 1785. (Italy.)
Scirpus diphyllus Retz. Obs. 5: 15. 1789. (India.)
Fimbristylis serratulum Vahl, Enum. 2: 285. 1805. (South America.)
Fimbristylis hirtellum Vahl, Enum. 2: 286. 1805. (South America.)
Fimbristylis glaucum Vahl, Enum. 2: 288. 1805. (India.)
Fimbristylis tomentosum Vahl, Enum. 2 : 290. 1805. (India. )_
Fimbristylis laxum Vahl, Enum. 2: 292. 1805. (South America.)
Scirpus sulcatus Ell. Bot. S. C. & Ga. 1: 86. 1816. [Savannah, Georgia {Baldwin).1 Not S.
sulcatus Petit-Thouars, 1811. Fimbristylis annua R. & S. Syst. 2; 95. 1817. Scirpus pubescens Link, Jahrb. Gewachsk. 1^: 80. 1820. {Willdenow 1269; lapsus calami for
Scirpus pallescens.) Scirpus nitidulus Link, Jahrb. Gewachsk. P
(Humboldt). 1 Scirpus fuscescens Link, Jahrb. Gewachsk. 1^
(Humboldt) .'i Scirpus Balduinianus Schultes in R. & S. Syst. Veg. Mant. 2 : Scirpus Elliottii Spreng. Syst. 4^ 28. 1827. Fimbristylis Humboldtii Presl, Rel. Haenk. 1 : 190. 1828. Fimbristylis verrucosa Presl, Rel. Haenk. 1 : 190. 1828. Fimbristylis Baldwiniana Torr. Ann. Lye. N. Y. 3 : 344. 1836. Scirpus depauperatus Muhl. ; Kunth, Enum. PI. 2 : 233, as syn.
Pennsylvania.) Fimbristylis brizoides Nees & Meyen ; Nees in Mart. Fl. Bras. 2* ;

Fimbristylis dichotoma, commonly known as forked fimbry or eight day grass, is a sedge of the family Cyperaceae that is native to tropical areas.