1	Culm sheath auricles to 1 cm or wider, or if less than 1 cm then branches arising from lower nodes (sometimes from basal node), or leaf blade abaxially glabrous and culm internodes 20–30 cm		(2)
+	Culm sheath auricles less than 1 cm wide, or if ca. 1 cm, then culm blade base less than 1/3 width of sheath apex		(14)
2 (1)	Culm sheath blade nearly 1/2 width of sheath apex or narrower		(3)
+	Culm sheath blade more than 1/2 width of sheath apex		(5)
3 (2)	Culm sheath auricles unequal; sheaths apically asymmetrical broadly arched, with short, stiff hairs near inner margin.		38 B. rigida
+	Culm sheath auricles subequal; sheaths apically convex and undulate, uniformly hairy		(4)
4 (3)	Culm sheaths with pale brown or white silky hairs; auricles 2.5–3 cm; ligule 7–8 mm; leaf blade abaxially densely pubescent at least when young.		28 B. polymorpha
+	Culm sheaths with stiff, dark brown hairs; auricles 0.8–1 cm; ligule 3–4 mm; leaf blade abaxially glabrous.		41 B. vulgaris
5 (2)	Culm sheath blade joined with auricles for 1–1.3 cm		(6)
+	Culm sheaf blade joined with auricles for 3–7 mm		(9)
6 (5)	Culm sheath apically arched, broadly symmetrically triangular; ligule 1.5–2 mm.		30 B. teres
+	Culm sheath apically asymmetrical, arched or truncate; ligule 3–5 mm		(7)
7 (6)	Culm sheaths broadly triangular, length less than 1/2 basal width, apex very broadly arched-convex or subtruncate; auricles ± horizontal.		29 B. tulda
+	Culm sheaths triangular, length more than 1/2 basal width, apex asymmetrically arched, convex; larger auricle slanted downward along sheath margin		(8)
8 (7)	Culm internodes subsolid; culm sheath blade broadly lanceolate to triangular-ovate, ligule entire, white ciliolate; leaf blade abaxially glaucous.		31 B. burmanica
+	Culm internodes hollow; culm sheath blade triangular to narrowly triangular, ligule dentate, fimbriate; leaf blade abaxially green.		32 B. eutuldoides
9 (5)	Culm sheath apically subtruncate; ligule 1.5–2 mm.		36 B. subtruncata
+	Culm sheath apically asymmetrical or broadly arched, sometimes obliquely truncate; ligule 3–5 mm		(10)
10 (9)	Culm sheaths ± pubescent		(11)
+	Culm sheaths glabrous		(12)
11 (10)	Larger culm sheath auricle slanted downward along sheath margin, gradually tapering.		33 B. pervariabilis
+	Larger culm sheath auricle not slanted downward, not tapering.		40 B. dolichoclada
12 (10)	Lower culm internodes without colored stripes.		35 B. tuldoides
+	Lower culm internodes with yellow-green or pale green stripes		(13)
13 (12)	Branches arising from basal node up; larger auricle of culm sheath obovate- oblong or oblanceolate, tapering.		33 B. pervariabilis
+	Branches arising from basal 3rd or 4th node up; larger auricle of culm sheath oblong, not tapering.		34 B. longispiculata
14 (1)	Leaf blade abaxially pale and glaucous		(15)
+	Leaf blade abaxially green or pale green		(17)
15 (14)	Culm sheath auricles very small or inconspicuous.		57 B. multiplex
+	Culm sheath auricles well developed		(16)
16 (15)	Culm sheath auricles obviously unequal, usually partially covered by base of blade; sheaths asymmetrical, apex broadly convex.		39 B. boniopsis
+	Culm sheath auricles subequal, not covered by base of blade; sheath apically subtruncate.		46 B. pallida
17 (14)	Culm sheath blade base narrower than 1/2 width of sheath apex		(18)
+	Culm sheath blade base wider than 1/2 width of sheath apex		(19)
18 (17)	Culm sheath auricles extremely unequal, larger to 3.5 × size of smaller; ligules ca. 1 mm; base of culm sheath blade nearly 3/7 width of sheath apex.		53 B. mollis
+	Culm sheath auricles less unequal, larger to 2 × size of smaller; ligules ca. 2 mm; base of culm sheath blade ca. 1/4 width of sheath apex.		54 B. contracta
19 (17)	Culm sheath auricles inconspicuous; sheath apex truncate.		56 B. truncata
+	Culm sheath auricles well developed; sheath apex asymmetrically arched, broadly arched, or shallowly undulate, subtruncate		(20)
20 (19)	Culm sheath apically subtruncate, sometimes also extremely broadly arched		(21)
+	Culm sheath apically asymmetrically arched, broadly arched, or shallowly undulate		(23)
21 (20)	Culm sheaths stiffly hairy near margins and base; auricles subequal; ligules ca. 1 mm.		47 B. duriuscula
+	Culm sheaths stiffly hairy near base or inner margin but not both; auricles obviously unequal, larger at least 2 × size of smaller; ligules 2–3 mm		(22)
22 (21)	Branches usually arising from 1st or 2nd node; culm sheaths pubescent only near base.		43 B. gibboides
+	Branches usually arising from 8th to 10th node; culm sheaths pubescent only near inner margin.		51 B. lenta
23 (20)	Culm sheath ligule ca. 5 mm.		42 B. utilis
+	Culm sheath ligule 1–3 mm		(24)
24 (23)	Culm sheaths substantially pubescent; ligule 0.6–1 mm		(25)
+	Culm sheaths glabrous or pubescent only near margins; ligule (<1–)1–3 mm		(27)
25 (24)	Culm sheaths white pubescent, auricles falcate and cupped.		49 B. amplexicaulis
+	Culm sheaths stiffly brown hairy, auricles not falcate		(26)
26 (25)	Culm sheaths densely and uniformly dull brown hairy; auricles not covered by blade		48 B. pachinensis
+	Culm sheaths ± brown hairy; auricles usually partly covered by blade.		50 B. semitecta
27 (24)	Culm nodes glabrous; usually branching from 7th to 11th node up.		55 B. textilis
+	Basal culm nodes usually with a ring of gray-white silky hairs above sheath scar; usually branching from 4th to 6th (rarely 7th) node up		(28)
28 (27)	Culm sheaths with stiff marginal hairs; ligule 1–1.5 mm.		45 B. albolineata
+	Culm sheaths glabrous; ligule 2–3 mm		(29)
29 (28)	Culm sheath auricles never covered by blade base, the larger oblanceolate and tapering		44 B. piscatorum
+	Culm sheath auricles partly covered by blade base, the larger oblong with rounded ends.		52 B. mutabilis