104 IRIDACEAE. 



narrow, 3-10 cm. long; pedicels very short; perianth spreading, the segments 

 oblong, 2 mm. long, as long as the ovary; filaments subulate, longer than the 

 perianth; style about as long as the ovary. 

 On rich wooded banks. 



Vagnera sessilifolia (Baker) Greene. Rootstocks slender; stems 30-60 

 cm. tall, smooth; leaves broadly lanceolate, acuminate, flat, sessile, pubescent 

 beneath, 10-15 cm. long; raceme open, 2-5 cm. long, 5-10-flowered; pedicels 

 4-12 mm. long; perianth segments spreading, lanceolate, 4 mm. long; stamens 

 shorter than the styles. 



In moist wooded copses. 



128. UNIFOLIUM. 



Perennial herbs with creeping rootstocks; leaves 2 or 3, ovate 

 to lanceolate, cordate; flowers solitary or fascicled in a simple 

 raceme; perianth 4-parted; stamens 4; stigma 2-lobed; ovary 

 2-celled; fruit a 2-celled berry with 2 seeds in each cell. 



Unifolium bifolium kamtschaticum (Gmel.) Piper. Basal leaves ovate- 

 reniform, acute or acuminate, 5-10 cm. broad; cauline leaves usually 2, cordate 

 to sagittate, 5-10 cm. long; perianth segments 2-3 mm. long, becoming reflexed. 



Moist places, very common. 



Family 23. IRIDACEAE. IRIS FAMILY. 



Perennial herbs; leaves narrow, equitant, 2-ranked; flowers 

 perfect, regular or irregular, mostly clustered, subtended by 

 bracts; perianth of 6 segments or 6-lobed, its tube adnate to 

 the ovary, the segments or lobes in 2 series; stamens 3, inserted 

 on the perianth opposite its outer series of segments or lobes; 

 ovary inferior, mostly 3-celled; ovules mostly numerous in each 

 cell; style 3-cleft, its branches sometimes divided. 



Flowers very large; styles petal-like. 129. IRIS, 104. 



Flowers moderate in size; styles filiform. 



Filaments united to the top; flowers usually blue. 130. SISYRINCHIUM, 105. 

 Filaments not united to the top; flowers not 



blue. 

 Filaments united only at the base; flowers 



reddish-purple. 131. OLSYNIUM, 106. 



Filaments united for more than half their 



length; flowers yellow. 132. HYDASTYLUS, 106. 



129. IRIS. 



Herbs with creeping or horizontal, often woody and sometimes 

 tuber-bearing rootstocks; stems erect; leaves erect or ascending, 

 equitant; flowers large, regular, terminal, solitary or clustered; 

 perianth of 6 clawed segments united below into a tube, the three 

 outer dilated, spreading or reflexed, the three inner narrower, 

 smaller, usually erect or in some species about as large as the 



