KEY. 187 



448. Calyx 5-parted, or cleft 449 



Calyx 4-toothed ; segments shorter, than the very 



unequal corolla-lips. Upper lip of the corolla very short, 

 entire; the lower 3-lobed, the middle lobe largest and 

 spreading. A scale at the base of each filament. Herb a 

 few inches long, branched. Leaves roundish-ovate, obscure- 

 ly 3-nerved, sessile, crowded. Flowers minute, sessile, axil- 

 lary, white. Micranthemum micrantha, Rich. 

 (Hemianthus micranthemoides^ Nutt.) 



449. The cells of each anther placed one lower down 

 than the other. Pod 4-seeded. Leaves ensiform. Spikes 

 oblong, dense, long-peduncled. Flowers purplish. Herbs 

 erect, 2-3 feet high, with an angular, smooth stem. Bor- 

 ders of streams and ponds. Dianthera Americana, L. 



[Ehytiglossa xjedunculosa^ Nees.) 

 Anther-cells parallel, or divergent. Pod many- 

 seeded 450 



450. Flowers very large. Corolla gibbous, bell-shaped, 

 5-lobed, somew^hat 2-lipped, pale dull yellow, spotted with 

 brownish purple. Fertile stamens 2, or 4. Pod fleshy, ter- 

 minated by a long, incurved beak, 4-celled. Low, branching 

 herbs, clammy-pubescent, with an unj^leasant scent. Leaves 

 cordate, entire or wavy. Seeds wingless. 



(323) Martynia proboscidea, Mx. 



Flowers smaller. Pods not beaked 451 



451. Flowers white or yellow. Sterile filaments short, 

 or none. Upper lip of the corolla entire or slightly bifid, 

 the lower 3-cleft. Leaves not clasping. The 1-flowered 

 pedicels usually with 2 bractlets, near the calyx. 



Gratiola. 



Flowers purple. Sterile filaments exserted, forked, 



one of the forks glandular, or rarely with half an anther. 



Upper lip of the corolla short, erect, 2-lobed, the lower 



longer and spreading, 3-cleft. Upper leaves partly clasping. 



Ilysanthes gratioloides, Benth. 



45^. (437.) Ovary entire 453 



Ovary deeply 4-lobed, forming in fruit 4 achenia. 



481 



