Taxonomy Nymphaea amazonum. 201 



N. integrifolia, Salzmann MS., Ad. specimens coll. Salzmann, 1830, at Bahia. 



N. foetida, Gardner MS., fid. specimen coll. Gardner, No. 2477, Aug., 1839, in the Li.ke of Parana- 



gua, in hb. Berlin. 

 AT. nocturna, March MS. (Ad. Hooker, 1. c), 



Description. Flower floating, 10 to 12 cm. across, opening two nights. The 

 first night, the bud stands with its base about 1 cm. or more immersed in the water, 

 and begins to open about 3 o'clock a. m. ; it spreads gradually until 4.15 a. m., when 

 the sepals stand out at about 45 and the petals are loosened, leaving an aperture 1.3 

 cm. wiJ-3 into the center of the flower. At 4.45 a. m. it begins to close, being com- 

 pletely closed about 6 a. m. The second night the bud has risen till its base is just 

 out of the water, and begins to loosen at the apex at 6.30 p. m. ; the sepals spread 

 out rapidly to a horizontal position, followed by the outermost series of petals, which 

 reach nearly the horizontal position; the second series also open slightly from the 

 tip of the bud (about 1 cm.) ; this phase is completed by 8 p. m., a tight creamy- 

 white acute bud being left in the center of the flower. The flower remains thus until 

 about 3.30 a. m., when the parts begin to open out more fully, the process being com- 

 pleted about 4.45 a. m. At this time the sepals and outermost petals are horizontal in 

 position, the inner petals standing at all angles up to about 40 above the hori- 

 zontal; the outermost stamens lie against the innermost petals; from this position the 

 stamens stand at all angles up to the innermost which bend over the stigma. All of 

 the stamens have now dehisced, the flower is warmer than the surrounding air, and 

 has a very faint sweetish odor with a suggestion of peaches. Closure of the flower 

 begins about 5 a. m., and is led by the stamens and petals; these, with exception of 

 1 or 2 outermost petals, are united into a tight bud at 5.30 a. m., while the sepals are 

 only io to 15 above the horizontal. By 6 o'clock complete closure is effected, and 

 the flower is retreating below the water, where it becomes completely covered before 

 the middle of the succeeding afternoon, i. e., in eight hours or less. From 7 to 7.30 

 p. m. and from 4 to 4.30 a. m. the movements of the petals and sepals on the second 

 night is very rapid and may easily be seen; the apex of the organ rotates about its 

 base, moving about 1.3 cm. in three minutes; the aperture at the apex of the bud 

 therefore enlarges at twice this rate. In one observation the inmost petals were closed 

 over the stamens at 4 a. m. ; at 4.06 their apices stood 5 cm. apart ! The closure of 

 the flower after its full maturity is almost as rapid. Bud 5.4 to 7.3 cm. long by 2.7 to 

 3.8 cm. in diameter, conical-ovate, broad at base, acuminate above, more or less obtuse, 

 abruptly contracted below to the petiole. Peduncle 40 to 50 cm. long, 0.6 to 0.8 cm. 

 in diameter, terete, brownish-green, lighter at base, smooth, with 3 minute central air- 

 canals, 6 to 7 main canals and 12 to 14 outer canals, separated by extremely thin par- 

 titions. Receptacle round, pure dark brown, nearly horizontal, distinctly bounded 

 from the sepals at the margins. Sepals 4, fleshy, ovate, rounded at apex, carinate on 

 back in upper part, the ridge vanishing about two-thirds of the length from the tip. 

 Outer surface dark green above, paler below, the lower quarter being greenish-white ; 

 whole surface marked with strong purplish-black lines and dots, the lines becoming 

 bright red on the lower quarter of the sepal. Inner surface apple green above, shading 

 to greenish-white at base, with a few dull brownish spots and streaks on margins in 

 upper half. Innermost (posterior) sepal deeply hooded at apex, i. e., the fleshy tip is 



