FLORA OF THE DISTRICT OF COLUMBIA. 33 



Fruit a capsule; leaves toothed or with toothed lobes; flowers blue or white; 

 petals present. 

 Juice orange; leaves thick and succulent; petals regular, white; capsule 



acute Sanguinaria (p. 162). 



Juice colorless; leaves thin; petals irregular, blue or white; capsule 



obtuse Viola (p. 206). 



Leaves entire, eometimes cordate at the base. 



Blades of the leaves broadly kidney-shaped, as broad as long or broader. 

 Fruit a capsule. 

 Leaves pubescent; flowers brownish purple; plants of woodlands. 



Asarum (p. 143). 

 Leaves glabrous; flowers blue or white; plants of muddy shores. 



Heteranthera (p. 116). 



Blades of the leaves not kidney-shaped, longer than broad, usually narrow 



but sometimes oval or triangular. 



Flowers crowded in a spike, this surrounded by a corolla-like spathe, the 



whole inflorescence appearing like a single flower; fruit a berry, 



fleshy, with 1 or few seeds ARACEAE (p. 113). 



Flowers not crowded in a spike surrounded by a spathe; fruit a capsule, or 

 fleshy and with numerous seeds. 

 Leaves deeply cordate, more than 15 cm. wide; fruit fleshy. Flowers 



yellow Nymphaea (p. 155). 



Leaves not cordate, less than 10 cm. wide; fruit a dry capsule. 

 Flowers very irregular; leaves sometimes ovate or oval. 



ORCHIDACEAE (p. 127). 

 Flowers regular; leaves narrow. 

 Leaves 2-ranked; flowers blue IRIDACEAE (p. 126). 



Leaves not 2-ranked; flowers white or yellow. 



Erythronium (p. 122). 



G. 



Green plants with leafy stems, the leaves rarely reduced to scales, the stems some- 

 times bearing only a single leaf or pair of leaves, but this borne far below the inflo- 

 rescence; leaves evidently parallel-veined; parts of the flower in 3's or 6'8. 



Flowers sessile in very dense heads or spikes, without a perianth, or the perianth 

 represented by 3 or 6 minute green scales. Plants growing in or at the edge of 

 water; leaves linear. 

 Flowers in long, brown or green spikp=; plants about a meter high. 



TYPHACEAE (p. 62). 

 Flowers in green spheric heads; plants rarely half a meter high. 



SPARGANIACEAE (p. 62). 

 Flowers not sessile in dense spikes or heads; perianth present, usually conspicuously 

 colored. 

 Petals irregular; flowers sometimes inclosed in a spathe. Fruit a capsule. 

 Flowers blue, inclosed in a spathe; stems much jointed; leaves ovate or lanceolate. 



Commelina (p. 116). 



Flowers never blue, not inclosed in a spathe; stems not jointed 



ORCHIDACEAE (p. 127). 

 Petals regular; flowers not inclosed in a spathe. 

 Leaves 2-ranked; fruit a capsule. 

 Flovrers in racemes, whitish, very small; inflorescence glandular-pubescent. 



Tofieldia (p. 119). 

 Flowers not in racemes, usually blue or orange and large; plants without 



glandular pubescence IRIDACEAE (p. 126). 



69289—19 3 



