1	Plicae reduced to a small tooth or auricle on side of lobe, less than 1 mm.		(2)
+	Plicae usually wider and/or longer than 1 mm.		(3)
2 (1)	Corolla lobes as long as or longer than tube		I Otophora
+	Corolla lobes shorter than tube (in G. prainii)		XI Sect. Chondrophyllae
3 (1)	Corolla throat with a ring of multicellular hairs (not to be confused with fringed plicae between corolla lobes)		XII Sect. Fimbricorona
+	Corolla throat naked.		(4)
4 (3)	Style almost as long as or longer than ovary; calyx winged or sharply angled or if terete then stems, leaves, and calyces densely covered with purple and white pilosity.		(5)
+	Style usually much shorter than ovary (about as long as ovary in some species of sects. Isomeria and Microspermae); calyx not winged, usually terete.		(6)
5 (4)	Plants 5-12 cm tall, densely branched from base and toward stem apex; stem leaves ± crowded toward apex, leaf blades lanceolate; stamens straight; seed coat alveolate		VIII Microsperma
+	Plants (5-)10-50 cm tall, not densely branched; stem leaves widely separated, leaf blades ovate-lanceolate, ovate, or cordate; stamens decurved; seed coat minutely to coarsely reticulate		IX Stenogyne
6 (4)	Stigma lobes connate or contiguous, expanded into a discoid or funnelform structure; calyx completely enveloped by upper pair of broad obovate leaves		VI Phyllocalyx
+	Stigma lobes free, recurved, linear to oblong; calyx usually not concealed by upper leaves or leaves narrower.		(7)
7 (6)	Stamens unequal and plants perennial; flowers 4merous or if 5merous then corollas 3-4.5 cm …		III Kudoa
+	Stamens equal or if unequal then plants annuals with solitary flowers (flowers of G. picta and G. yunnanensis in clusters) and corollas 0.6-2.5 mm; flowers 5-merous.		(8)
8 (7)	Perennials; basal leaves persistent at flowering time, blades (excluding petiole) mostly over 3 cm and much larger than stem leaves or vegetative rosettes present along with flowering stems and their leaves distinctly larger than those of flowering stems.		(9)
+	Annuals or if perennials then without conspicuously larger basal or rosette leaves (largest leaves at flowering time usually well above base of stem), and/or with all basal leaves less than 1.5 cm.		(13)
9 (8)	Flowering stems arising singly from slender stolons, often creeping and rooting at lower nodes, without a well-developed caudex or stout rhizome and without a stout persistent taproot; larger leaves generally distinctly pseudopetiolate, with blades less than 1.8 cm, spatulate, elliptic, ovate-elliptic, obovate, or suborbicular, base obtuse, rounded, or truncate, only midvein prominent; flowers solitary or to 8 in terminal clusters, sessile		VII Sect. Isomeria
+	Flowering stems arising from a ± stout erect caudex, often with a well-developed ± stout taproot and/or in a dense tuft (sometimes also stoloniferous); leaves and inflorescences diverse but above combination of characters generally not present.		(10)
10 (9)	Remains of old leaf bases fibrous and conspicuous on caudex; seed coat reticulate, usually minutely so (also winged at 1 end in G. waltonii)		II Cruciata
+	Remains of old leaf bases at base of current season's growth absent or membranous, not distinctly fibrous or if somewhat fibrous then with stem leaves numerous, closely spaced, less than 5 mm wide, and with flowers solitary; seed coat with membranous lamellae forming spongy complex hexagonal pits.		(11)
11 (10)	Stems several to many, ± tufted, strongly decumbent; stem leaves opposite or whorled, numerous, closely spaced (9 or more pairs or whorls per stem and/or upper leaves exceeding internodes)		III Kudoa
+	Stems 1 to several, decumbent or erect; stem leaves opposite, usually fewer than 9 pairs per stem, closely spaced only basally and on short stems.		(12)
12 (11)	Sepals 3-9 mm, ± erect, 2 conspicuously larger than other three; base of current season's growth without blackish membranous remains of old leaf bases		III Kudoa
+	Sepals smaller, often recurved or if over 3 mm then sepals subequal and/or base of current season's growth covered with blackish membranous remains of old leaf bases		IV Sect. Frigida
13 (8)	Perennials, without a stout caudex; flowers solitary.		(14)
+	Annuals or if perennial then with a stout caudex and clustered flowers; flowers solitary or clustered.		(15)
14 (13)	Corolla over 2.5 cm, often much larger; capsule wingless		III Kudoa
+	Corolla usually to 1.5 cm (2.3-3 cm in G. qiujiangensis and G. jamesii); capsule winged along sutures toward apex		XI Sect. Chondrophyllae
15 (13)	Perennials; stems usually over 20 cm, from a stout caudex; larger stem leaf blades usually over 3.5 cm; flowers clustered.		(16)
+	Annuals; stems usually shorter than 20 cm, caudex none; all stem leaf blades usually less than 3 cm; flowers solitary or clustered.		(17)
16 (15)	Calyx lobes subequal or irregularly unequal, linear to narrowly triangular, base not or scarcely narrowed; calyx tube often split along 1 side (except in G. manshurica); lowermost stem leaves scalelike; seed coat coarsely reticulate, winged at ends		V Pneumonanthe
+	Calyx lobes dimorphic, 2 larger than other 3, lanceolate to spatulate, base distinctly narrowed; calyx tube entire; lowermost stem leaves larger or scalelike; seed coat alveolate, not winged		III Kudoa
17 (15)	Seed coat alveolate, with hexagonal pits; flowers solitary or clustered in axillary or terminal inflorescences, if clustered then with corollas over 1.5 cm and/or with calyx lobes each with distinct blade and petiole		VIII Microsperma
+	Seed coat finely reticulate, without hexagonal pits; flowers usually solitary, if ± clustered in terminal inflorescences then with corolla 0.7-1.1 cm and calyx lobes without petiole.		(18)
18 (17)	Capsule conspicuously winged along sutures at apex		XI Sect. Chondrophyllae
+	Capsule not winged		X Sect. Dolichocarpa