180 THE WATERLILIES. 



scented, opening early (6 a. m.) ; sepals usually purplish-green or purple (pure green 

 in var. gigantca). Seed of medium size. 



Nymphaca odorata, Alton 1789, fid. original specimen in hb. British Museum, from Kew Garden 

 (excluding Siberian plant); 1811. Willdenow 1797; 1816. Sims 18056. Andrews tab. 297. 

 Pursh 1814. Nuttall 1818. Smith 1819. DeCandolle 1821 b; 1824. Rafinesque 1830. Planchon 

 18536. London 1855. Caspary 1855; 1865. Meehan 1880. Wood 1880. Gray 1889. Gray, 

 etc., 1895. Tricker 1897. Conard 1901 a. 



N. alba, Linnaeus 1753 (the North American plant). Walter 1788. Michatix 1803, fid. specimen 

 from lib. Michx., in hb. Paiis. 



N. alba canadcnsis, Graham in Jameson Edinb. rev. str. 1. journ., vol. 8, p. 386, 1826 (not seen). 



N. alba flore flaw odorata, Gronovius 1762. 



Castalia fudica, Salisbury 1806 a. Britten 1888 a. 



C. odorata, Woodville & Wood 1806. Greene 1888. Branner & Coville 1888. Lawson 1889. Brit- 

 ton 1889 a. Britton, etc., 1894. Britton & Brown 1897. 



DESCRIPTION. Floivcrs usually floating, 7 to 12 or 15 cm. across, opening on 3 

 or 4 successive days from 6 a. m. to 12 m., with a strong, sweet, characteristic odor. 

 Ends of two forms, the one slender, conical, rounded at apex, the other ovoid. 

 Peduncle terete, greenish-purple, usually slender and weak (0.3 to 0.5 cm. in diameter) ; 

 in the case of strong crowded plants in shallow water (30 cm. or less), the peduncles 

 may be rigid and bear the flowers 15 cm. above the water (Sugar Hollow Pond, Dan- 

 bury, Conn.). In fruit the peduncle coils into a close spiral (or loose if peduncle is 

 very stout), bent to right or left, or both ways in one peduncle; coils 5 to 9, about 2.5 

 cm. in diameter. Air-canals as in Sec. Castalia. Receptacle short, round, scarcely evi- 

 dent, horizontal. Sepals 4, ovate to lance-ovate, rounded at apex, narrowed at base, 

 putrescent after flowering. Outside green, more or less shaded with reddish-brown or 

 red, covered margins nearly white ; veinless ; inside greenish-white. Petals 23 to 32 

 (average 27), smaller than the sepals; outer ones ovate to elliptic-lanceolate, slightly 

 concave, apex obtuse or rounded, narrowed at base, pure white, spreading out as much 

 as 15 below the horizontal. Median petal slightly obovate, obtuse at apex, wedge- 

 shaped at base. Inner petal broadly ob-lanceolate, obtuse, sides curved and tapering at 

 base. Outermost staminode ob-lanceolate, acute, with one short anther cell. Stamens 

 55 to 106 (average 79) inserted in direct series with the petals; innermost ripen first, 

 outermost last. Filaments of all dimensions from staminodes to filiform threads, the 

 innermost being more slender than their anthers, which are bent inward at right 

 angles. Anthers curved, concave outward, placed obliquely so that the apex stands 

 over the point of attachment or nearer the center of the flower; anthers largest in 

 intermediate stamens. Pollen grains spherical, thickly beset with longer and shorter 

 rods and lumps, alike from all the stamens, rupturing in germination by a large cir- 

 cular cap which is rough like the other parts of the grain. Carpels 13 to 25 (average 

 17), with short linear styles, 0.64 cm. long by 0.16 cm. wide, which are erect on the 

 first clay of opening, later strongly incurved over the stigmatic disc. The latter is 

 basin-shaped, shallow, but of varying depth. Stigmatic surface continued out on the 

 styles one-half of their length or less, then narrowed suddenly and finally ending 

 acuminately. Axile process nearly spherical, pointed at top, much narrowed at point 

 of attachment. Ovules many, small. Seed ovoid, of medium size, 0.23 cm. long by 

 0.16 cm. in diameter, dark olive color, smooth, shining; aril one-fourth longer than the 

 seed. 



