Aquatic herbs, with horizontal perennial rootstocks, floating leaves and showy flowers. Sepals 4. Petals , imbricated in few to many series, inserted on the ovary, gradually passing into stamens; stamens ∞, the exterior with large petaloid filaments and short anthers, the interior with linear filaments and elongated anthers. Carpels ∞, united into a compound pistil with radiating linear projecting stigmas. Fruit globose, covered with the bases of the petals, ripening under water. [A spring of Parnassus.]

About 40 species, of wide geographic distribution. Type species: Castalia pudica Salisb.

Flowers 3'-5 1/2' broad, fragrant; leaves orbicular to reniform, purplish beneath.

1.

C. odorata.

Flowers 4'-9' broad, not fragrant; leaves orbicular, green both sides.

2.

C. tuberosa.

Flowers 1'-1 1/2' broad not fragrant; leaves oval.

3.

C. tetragona.

1. Castalia OdorÓta (Dryand.) Woody. & Wood. Sweet-Scented White Water Lily. Pond Lily. Water Nymph. Water Cabbage. Fig;. 1842

Nymphaea odorata Dryand. in Ait. Hort.

Kew. 2: 227. 1789. Castalia pudica Salisb. in Konig. &

Sims, Ann. Bot. 2:72. 1805. Castalia odorata Woody. & Wood in Rees' Cyclop. 6: no. 1. 1806. Nymphaea odorata var. minor Sims, Bot. Mag. pl. 1652. 1814. Nymphaea odorata var. rosea Pursh, Fl.

Am. Sept. 369. 1814.

Rootstock thick, simple or with few branches. Leaves floating, orbicular or nearly so, 4'-12' in diameter, glabrous, green and shining above, purple and more or less pubescent beneath, cordate-cleft or reniform, the sinus open but sometimes narrow; petioles and peduncles slender, with 4 main air-channels; flowers white, or sometimes pink, 3'-6' broad, fragrant; petals numerous, in many rows, narrowly oblong, obtuse; fruit globose, or slightly depressed; seeds stipitate, oblong, snorter than the aril.

In ponds and slow streams, Newfoundland to Manitoba, south to Florida, Louisiana and Kansas. Toad-lily. June-Sept.

1 Castalia Odor Ta Dryand Woody Wood Sweet Scented 1841 Castalia Odor Ta Dryand Woody Wood Sweet Scented 185

2. Castalia Tuber˛sa (Paine) Greene. Tuberous White Water Lily

Fig. 1843

Nymphaea tuberosa Paine, Cat. Pl. Oneida Co., N. Y. 132. 1865. Castalia tuberosa Greene, Bull. Torr. Club 15: 84. 1888.

Rootstock thick, with numerous lateral tuberous-thickened branches, which become detached and propagate the plant. Leaves orbicular, 5'-12' in diameter, floating, sometimes slightly pubescent beneath, green both sides, the veins very prominent on the lower surface; sinus open or closed; petioles stout; flowers pure white, 4'-9' broad, inodorous or very slightly scented; petals oblong, in many cows, broader than those of C. odorata, obtuse; fruit depressed-globose; seeds globose-ovoid, sessile, longer than or about equalling the aril.

Lake Champlain, west through the Great Lakes to Michigan, south to Delaware and eastern Nebraska and Arkansas. Summer.

3. Castalia Tetrag˛na (Georgi) Lawson. Small White Water Lily

Fig. 1844

Nymphaea tetragona Georgi, Reise in Russ.

Reichs, I: 220. 1775. Castalia pygmaea Salisb. Parad. Lond. pl.

68. 1807. C. Leibergii Morong. Bot. Gaz. 13: 134.

1888. Castalia tetragona Lawson, Trans. Roy.

Soc. Canada 6: Sec. IV. 112. 1888.

Leaves floating, oval or oblong, 2'-4' long, 1 1/2' - 3' wide, green above, green or purplish beneath, the basal lobes acute or rounded; sinus open, narrow; petioles and peduncles nearly or quite glabrous; flowers white, inodorous, 1'-2' broad; petals in about 2 rows, faintly striped with purple, obtuse or acutish, oblong or obovate, thin, about the length of the sepals.

In the Misinaibi River, Ontario (R. Bell); in ponds along the Severn River, Keewatin (J. M. Macoun); near Granite Station, northern Idaho (Leiberg). Also in Siberia, Japan and the Himalayas. Summer.

3 Castalia Tetrag Na Georgi Lawson Small White Wat 186