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Key to Hygrophila

Acanthaceae

Hygrophila

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1 Submersed leaves entire or obscurely crenate.
  2 Flowers sessile.
    3 Leaf blades 1-3.5 cm long; calyx segments ca. 2 mm long, pubescent; flowers borne in terminal and axillary spikes
    3 Leaf blades 5-12 cm long; calyx segments ca. 5 mm long, glabrous; flowers borne in axillary clusters.
      4 Corolla purplish with white or yellow markings on the lower lip, (10-) 12-17 mm long; bracteoles lance-ovate to narrowly elliptic to linear, 6-15 mm long, abaxial surface pubescent with eglandular hairs (especially along the midvein; calyx 9-14 mm long at anthesis (to 15 mm long in fruit), the lower surface pubescent with eglandular hairs to 0.6 mm long (some at least of the hairs > 0.2 mm long)
      4 Corolla entirely white, 5.5-9 mm long; bracteoles subulate to lanceolate to linear, 2.2-5.5 (-7) mm long, the abaxial surface glabrous; calyx 5-7 mm long during anthesis (to 9 mm long in fruit), the lower surface glabrous or pubescent with hairs < 0.2 mm long