210 FOUNDATIONS OF BOTANY 



4. V. vulgaris, L. Greater Bladderwokt. Stems submerged, 

 leafy, 1-3 ft. long. Leaves spreading, pianately cut into very many 

 thread-like segments ■which bear many bladders. Scapes 6-12 in. 

 long, 5-12-flowered, pedicels bent down after flowering. CoroUa J-| 

 in. long, yellow, upper lip broad and short, palate prominent ; spur 

 conical, pressed close to the under lip. Ponds and slowly flowing 

 streams. 



93. ACANTHACE.ffi. Acanthus Family. 



Herbs or shrubs. Leaves opposite or whorled, mtliout 

 stipules. Mowers irregular, usually with large bracts. Calyx 

 of 4 or 5 unequal segments which considerably orerlap each 

 other. Corolla 4-5-parted and usually more or less 2-lipped. 

 Stamens usually 2 long and 2 short, sometimes only 2. Oyary 

 free from the calyx. Fruit usually a, capsule. Seeds not 

 winged. A large family, mostly tropical, with only a few 

 insignificant wild species in the northern United States. 



I. RITELLIA, Plumier. 



Perennial herbs ; stems swollen at the joints and often 

 between them, somewhat 4-angled. Leaves sessile or short- 

 petioled, mostly entire. Mowers axillary, solitary or clustered, 

 showy, white, blue, or purple. Calyx 2-bracted, 6-parted, the 

 divisions linear and awl-shaped. Corolla-tube slender, often 

 much elongated, the limb spreading, nearly equally 5-lobed. 

 Stamens 4, 2 long and 2 short, Lacluded or slightly projecting. 

 Style slender. Capside slender, narrowed below, 4-12-seeded.* 



1. R. strepens, L. Smooth Ruellia. Stem erect, slender, 

 usually simple, smooth or hairy, 1-3 ft. high. Leaves ovate to 

 oblong, acute at the apex, narrowed below into a short petiole. 

 Flowers solitary or in small clusters, sessile or short-peduncled. 

 Calyx-lobes shorter than the tube of the corolla, downy or fringed. 

 Corolla blue, the tube 1^-2 in. long, the limb 1-1 J in. wide. Cap- 

 sule usually longer than the calyx, smooth, 8-12-seeded. The later 

 flowers often without a corolla. On rich, dry soil.* 



2. R. ciliosa, Pursh. Hairy Ruellia. Stem erect, rather stout, 

 often few-branched above, covered with white hairs, 4-30 in. high. 

 Leaves oblong to ovate, acute or obtuse at the apex, narrowed and 



