1	Spikelets ± compressed; glumes distichous at least on basal part of spikelet		(2)
+	Spikelets terete; glumes spirally imbricate		(11)
2 (1)	Inflorescences reduced to a single spikelet; involucral bracts glumelike		(3)
+	Inflorescences with 2 to several spikelets; involucral bracts leaflike, setaceous, or very rarely glumelike		(4)
3 (2)	Nutlet obovoid, verruculose, stipes less than 0.5 mm; leaf blade 0.5-1 mm wide.		52 F. ovata
+	Nutlet globose, with few verrucae, stipes more than 1 mm; leaf blade ca. 0.5 mm wide.		53 F. longistipitata
4 (2)	Glumes glabrous, not gland-dotted		(5)
+	Glumes hairy or gland-dotted		(7)
5 (4)	Nutlet 1-1.2 mm; spikelets often paired or fascicled, rarely solitary at apex of inflorescence rays.		44 F. nigrobrunnea
+	Nutlet 0.7-0.9 mm; spikelets solitary		(6)
6 (5)	Glumes yellowish brown; spikelets 6-10 mm; basalmost involucral bract less than 2 × as long as spikelet; rhizome short.		45 F. eragrostis
+	Glumes reddish brown; spikelets 3-6 mm; basalmost involucral bract more than 3 × as long as spikelet; rhizome absent.		46 F. disticha
7 (4)	Glumes densely gland-dotted, glabrous; spikelets with 2 or 3 flowers; rays and raylets very slender, glabrous		(8)
+	Glumes not gland-dotted, hairy; spikelets with more than 3 flowers; rays and raylets thicker, hairy		(9)
8 (7)	Leaf blade ca. 1 mm wide, hairy on both surfaces; ligule absent; involucral bracts surpassing inflorescence.		47 F. nanningensis
+	Leaf blade 3-6 mm wide, glabrous; ligule a fringe of short white hairs; involucral bracts shorter than inflorescence.		48 F. cinnamometorum
9 (7)	Glumes awned, awns excurved; stigmas 2.		49 F. kwantungensis
+	Glumes shortly tipped, tips not excurved; stigmas 3		(10)
10 (9)	Perennials; culms 20-40 cm tall; inflorescence a compound anthela; glumes 4-5 mm; nutlet attenuate to base, subsessile; style 4-5 mm.		50 F. fusca
+	Annuals; culms 5-13 cm tall; inflorescence a simple or rarely compound anthela; glumes 2.5-3 mm; nutlet truncate at base, shortly stipitate; style ca. 2 mm.		51 F. fimbristyloides
11 (1)	Spikelet solitary; involucral bracts glumelike; leaves with only a bladeless sheath		(12)
+	Spikelets (1 or)2 to many; involucral bracts not glumelike; leaves with a blade		(15)
12 (11)	Nutlet narrowly oblong, base with a ca. 0.7 mm stipe; culms 4-angled.		40 F. tetragona
+	Nutlet broadly obovoid, subsessile; culms flatly cylindric, subcylindric, or slightly compressed		(13)
13 (13)	Stigmas 3; spikelets narrowly oblong to clavate-oblong, 3.5-4.5 × 1-1.5 mm; glumes pale with short rust-colored lines, oblong to oblong-ovate, apex not mucronate; nutlet white, with sparse verrucae and subhexagonal reticulation		41 F. pauciflora
+	Stigmas 2; spikelets ovoid, narrowly ovoid, ellipsoid, or oblong-ovoid, 5-15 × 2-5 mm; glumes brown with short rust-colored lines or greenish white and sometimes laterally with brown specks, apex mucronate; nutlet yellowish white, with transverse wavy reticulation		(14)
14 (13)	Spikelets slightly nodding; involucral bracts 2-4.5 mm; glumes brown with short rust-colored lines; stamens 3; nutlet margin verruculose.		42 F. nutans
+	Spikelets erect; involucral bract absent; glumes greenish white and sometimes laterally with brown specks; stamens 2; nutlet margin not verruculose.		43 F. acuminata
15 (11)	Stigmas 2; style compressed, apically ciliate		(16)
+	Stigmas (2 or)3; style not compressed or rarely slightly compressed, apically not ciliate		(32)
16 (15)	Spikelets angular because of keeled glumes, 7 mm or less (but to 12 mm in F. gracilenta)		(17)
+	Spikelets terete, at least some to 10 mm or more (but only to 8 mm in F. polytrichoides)		(21)
17 (16)	Style base with sparse long hairs covering nutlet apex.		35 F. squarrosa
+	Style base glabrous		(18)
18 (17)	Glumes brown; nutlet 0.6-0.8 mm		(19)
+	Glumes pale brown; nutlet ca. 1 mm		(20)
19 (18)	Nutlet broadly obovoid, with transverse oblong reticulation; leaf sheath greenish yellow or with rust-colored flecks; leaf blade 0.7-1.5 mm wide.		36 F. bisumbellata
+	Nutlet obovoid, almost smooth but sometimes with very indistinct hexagonal reticulation; leaf sheath brown; leaf blade 0.5-1 mm wide.		37 F. aestivalis
20 (18)	Leaf blade ca. 1 mm wide; spikelet oblong, lanceolate, or linear-lanceolate, 1.5-2 mm wide; rhizomes absent.		38 F. gracilenta
+	Leaf blade 1.5-3 mm wide; spikelet ovate or narrowly ovate, 2-4 mm wide; rhizomes short.		39 F. simaoensis
21 (16)	Spikelets 1-3(-6)		(22)
+	Spikelets several to many (in F. sieboldii sometimes with only 1-3 spikelets, but glumes only 1-veined, and culm base with leafless sheaths)		(25)
22 (21)	Nutlet grayish black, with an extremely short stipe, obovoid, with transversely oblong reticulation and verrucae; growing in sandy places; glumes pale white with short brown lines medially, sometimes slightly yellowish brown apically.		34 F. polytrichoides
+	Nutlet yellowish white or brown, with a distinct stipe, broadly obovoid, with hexagonal reticulation; not growing in sandy places; glumes yellowish white with short brown lines or brown with short rust-colored lines		(23)
23 (22)	Glumes yellowish white, ca. 3 mm; nutlet yellowish white, with a short yellowish white stipe.		31 F. schoenoides
+	Glumes brown, 5-7 mm; nutlet brown or yellowish brown, with a short brown stipe		(24)
24 (23)	Spikelets 1 or 2; bract 1 or absent, longer than inflorescence; rhizomes absent; leaf blade ca. 1 mm wide.		32 F. subbispicata
+	Spikelets 3-6; bract 1, shorter than inflorescence; rhizomes short; leaf blade 1.2-2 mm wide.		33 F. tristachya
25 (21)	Spikelets very narrowly ovoid to linear; nutlet with linear-oblong reticulation; rhizome absent.		30 F. hookeriana
+	Spikelets ovoid, ellipsoid, oblong, oblong-ovoid, narrowly oblong, ovoid- ellipsoid, or narrowly oblong-ovoid; nutlet with subtransverse, oblong, hexagonal, or oblong-hexagonal reticulation or subsmooth; rhizome absent or present		(26)
26 (25)	Plants stoloniferous; nutlet with horizontally oblong reticulation, vertical ribs not obvious.		28 F. stolonifera
+	Plants not stoloniferous; nutlet with hexagonal reticulation (F. dichotoma with oblong reticulation, but vertical ribs obvious; in F. sieboldii reticulation not obvious)		(27)
27 (26)	Culm bases with leafless sheaths; glumes 1-veined, apical part abaxially pubescent; leaf blade ca. 1 mm wide; nutlet almost smooth.		29 F. sieboldii
+	Culm bases without leafless sheaths; glumes with 3 or more veins, abaxially glabrous; leaf blade more than 1 mm wide; nutlet with evident reticulation		(28)
28 (27)	Inflorescences inclined to nodding.		27 F. subinclinata
+	Inflorescences erect		(29)
29 (28)	Rhizomes woody, horizontally elongated.		26 F. rigidula
+	Rhizomes not prominent		(30)
30 (29)	Nutlet with hexagonal reticulation, without obvious vertical ribs, not stipitate.		25 F. longispica
+	Nutlet with transversely oblong reticulation, vertical ribs obvious or not, with a short brown stipe at base		(31)
31 (30)	Nutlet obovoid, with obvious vertical ribs, not verruculose; inflorescences 5-9 cm.		23 F. dichotoma
+	Nutlet ovoid, without vertical ribs, sparsely verruculose; inflorescences 3-4 cm.		24 F. shimadana
32 (15)	Basal part of culms with 1-3 leafless sheaths		(33)
+	Culm leaves all with a leaf blade		(39)
33 (32)	Leaf blade bilaterally compressed, ensiform; leaf sheaths compressed; spikelets spherical or subspherical; glumes 1-1.3 mm.		16 F. littoralis
+	Leaf blade (if present) dorsiventrally flattened but canaliculate, linear; leaf sheaths tubular; spikelets more elongated (but sometimes globose-ellipsoid in F. umbellaris); glumes 1.5-2.7 mm		(34)
34 (33)	Leaves reduced to a bladeless sheath.		18 F. salbundia
+	Leaves with a blade		(35)
35 (34)	Culms 3-angled to subterete.		22 F. umbellaris
+	Culms 4- or 5-angled to subterete		(36)
36 (35)	Anthelae simple or subcompound (rarely reduced to 1 spikelet); glumes without any dark brown lines.		21 F. diphylloides
+	Anthelae usually compound; glumes each with 1 or 2 dark brown lines		(37)
37 (36)	Glume apices obtuse to rounded and not mucronate or apiculate; nutlet 0.6-0.8 mm; spikelets 2.7-7 mm.		17 F. aphylla
+	Glume apices mucronate or apiculate or at least acute; nutlet ca. 0.8 mm (or sometimes longer in F. quinquangularis); spikelets 2-5 mm		(38)
38 (37)	Ligule absent; involucral bracts 4, setaceous; rays 4; nutlet obovoid; stamens 1 or 2.		19 F. quinquangularis
+	Ligule a fringe of pubescence; involucral bracts 5-7, leaflike; rays 5-7; nutlet broadly obovoid; stamens 3.		20 F. chingmaiensis
39 (32)	Culms tufted; rhizomes absent		(40)
+	Culms not tufted; rhizomes short or plants stoloniferous		(44)
40 (39)	Nutlet oblong; glumes white, straw-yellow, or rust-colored		(41)
+	Nutlet obovoid, broadly obovoid, or ellipsoid-obovoid; glumes usually yellowish green		(42)
41 (40)	Glumes white to pale straw-yellow; nutlet papillate laterally but papillae later deciduous; leaf blade 0.2-0.5 mm wide.		1 F. dipsacea
+	Glumes rust-colored; nutlet not papillate; leaf blade 1-2.5 mm wide.		2 F. stauntonii
42 (40)	Stigmas 2; involucral bracts longer or shorter than inflorescence.		5 F. henryi
+	Stigmas 3; involucral bracts shorter than inflorescence		(43)
43 (42)	Spikelets 3-6 × 1-1.5 mm; glumes 2-2.5 mm; nutlet broadly obovoid,. 7-1 mm.		3 F. autumnalis
+	Spikelets 2-3 × 1-1.2 mm; glumes 1-1.2 mm; nutlet obovoid,. 4-0.5 mm.		4 F. microcarya
44 (39)	Nutlet purplish black, grayish black, or blackish purple (not seen for F. psammocola); stigmas 2 or 3		(45)
+	Nutlet white, yellowish white, cream-colored, yellow, or brown; stigmas 3		(48)
45 (44)	Whole plant covered with dense white silky hairs; rhizomes elongated, branched.		12 F. sericea
+	Plant glabrous; rhizomes short, not branched		(46)
46 (45)	Spikelets 10-20 mm; style 3-sided; stigmas 3.		13 F. insignis
+	Spikelets 3-10 mm; style slightly flat or flat; stigmas 2 or 3		(47)
47 (46)	Glumes 1.2-2 mm, apex obtuse; spikelets 3-6 × 1.5-2.5 mm.		11 F. cymosa
+	Glumes 4-5 mm, apex acute; spikelets 6-10 × 2.5-4 mm.		15 F. psammocola
48 (44)	Glumes densely gland-dotted, margin fimbriate-ciliate, apex often emarginate.		14 F. leptoclada
+	Glumes not gland-dotted, margin not fimbriate-ciliate, apex not emarginate		(49)
49 (48)	Plants stoloniferous; involucral bracts subulate or glumelike.		10 F. pierotii
+	Plants not stoloniferous; involucral bracts leaflike		(50)
50 (49)	Leaf sheaths not compressed; glumes 5-7-veined forming an abaxial obtusely angled keel; nutlet ca. 2 mm.		6 F. thomsonii
+	Leaf sheaths compressed; glumes 1-3-veined; nutlet 0.7-1.5 mm		(51)
51 (50)	Ligule absent; involucral bracts longer than inflorescence.		9 F. dura
+	Ligule ciliate; involucral bracts shorter than inflorescence		(52)
52 (51)	Glumes 3-3.5 mm, herbaceous, 1-veined; nutlet 1-1.5 mm.		7 F. complanata
+	Glumes 2-2.5 mm, membranous, 3-veined; nutlet. 7-0.8 mm.		8 F. tainanensis