108a. A stamen in front of the middle of each petal =PRIMULACEAE=, p. 87.

108b. Stamens located between the petals or lobes of the corolla, or else so far down in the tubular corolla that their position is not easily ascertained --109.

109a. Corolla salver-form, with a very slender tube, and abruptly spreading lobes =POLEMONIACEAE=, p. 92.

109b. Corolla salver-form, with a wide tube and fringed blue petals =GENTIANACEAE=, p. 88.

109c. Corolla rotate, funnel-form, or bell-shape =GENTIANACEAE=, p. 88.

110a. Ovary deeply 4-lobed, appearing like 4 separate ovaries; style 1 =l.a.b.i.aTAE=, p. 95.

110b. Ovary not 4-lobed --111.

111a. Stamens 2 --112.

111b. Stamens 3 =VALERIANACEAE=, p. 111.

111c. Stamens 4 --113.

112a. Flowers in dense heads 1a, in =ACANTHACEAE=, p. 107.

112b. Flowers solitary or in loose cl.u.s.ters =SCROPHULARIACEAE=, p. 101.

113a. Corolla distinctly 2-lipped and irregular --114.

113b. Corolla not distinctly 2-lipped, its 5 lobes all alike or nearly so --115.

114a. Calyx 2-lipped; the upper lip with 3 awl-shape teeth, the lower with 2 short teeth; flowers in slender terminal spikes =PHRYMACEAE=, p. 107.

114b. Calyx not obviously 2-lipped, its teeth equal or nearly so =SCROPHULARIACEAE=, p. 101.

115a. Flowers sessile or nearly so, in spikes --116.

115b. Flowers in nodding pairs at the top of a slender stalk 3a, in =CAPRIFOLIACEAE=, p. 109.

115c. Flowers solitary or in cl.u.s.ters; not in spikes or nodding pairs --117.

116a. Corolla not over 1 cm. long =VERBENACEAE=, p. 99.

116b. Corolla 1.5 cm. long or more =SCROPHULARIACEAE=, p. 101.

117a. Calyx-lobes 15-25 mm. long; flowers blue, 3-5 cm. long; calyx without an obvious tube 2, in =ACANTHACEAE=, p. 107.

117b. Calyx-lobes united below into an obvious calyx-tube =SCROPHULARIACEAE=, p. 101.

--118--

118a. Leaves deeply lobed, compound, or dissected --119.

118b. Leaves simple and not deeply lobed --129.

119a. Leaves once-pinnately compound or lobed --120.

119b. Leaves once-palmately compound or lobed --124.

119c. Leaves dissected or 2-3 times compound --125.

120a. Leaves merely lobed --121.

120b. Leaves actually compound --123.

121a. Flowers axillary; marsh or swamp plants =HALORAGIDACEAE=, p. 79.

121b. Flowers in terminal cl.u.s.ters --122.

122a. Stamens 2-6; taste mustard-like 52b, in =CRUCIFERAE=, p. 46.

122b. Stamens 10 or more =RESEDACEAE=, p. 48.

123a. Leaflets entire =LIMNANTHACEAE=, p. 68.

123b. Leaflets serrate 70a, in =ROSACEAE=, p. 57.

124a. Flowers solitary 31a, in =RANUNCULACEAE=, p. 38.

124b. Flowers in dense terminal umbels or heads =UMBELLIFERAE=, p. 80.

124c. Flowers in terminal racemes 2a, in =COMPOSITAE=, p. 114.

124d. Flowers in axillary spikes or panicles 9b, in =URTICACEAE=, p. 24.

125a. Leaves merely dissected, not truly compound with distinct leaflets --126.

125b. Leaves truly compound, with distinct petiolate leaflets --127.

126a. Flowers in axillary cl.u.s.ters =CHENOPODIACEAE=, p. 28.

126b. Flowers in terminal cl.u.s.ters =COMPOSITAE=, p. 113.

127a. Stamens 5; flowers in umbels --128.

127b. Stamens 6; flowers in small cl.u.s.ters 3b, in =BERBERIDACEAE=, p. 40.

127c. Stamens many; flowers in racemes or panicles =RANUNCULACEAE=, p. 35.

128a. Styles 5 =ARALIACEAE=, p. 80.

128b. Styles 2 =UMBELLIFERAE=, p. 80.