Order 81.— BUTTERWORTS. 257 



ARME'RIA vulga'ris, Thrift, is another sea-coast plant, sometimes cultivated, bav- 

 in"? a tult of linear leaves at base, and a bunch of rose-coloved flwwers at top of the 

 ecape. 



PLUMBA'GrO Capen'is, Leadwort, has pale blue fls. resembling Phlox. Cultivated. 



Oeder LXXXI. LENTIBULACE^. Butterworts. 



Serbs growing in water or w^et places with bilabiate flowers on scapes ; 

 calyx of 2 or 3 se[)als. Corolla with a spur behind, throat bearded ; 

 itamens 2, included. Styles, 2, ovary free, capsule many-seeded. 



Analysis of the Genera. 

 § Leaves broad, entire. Corolla throat open. Calyx 5-parted. Growing 



in wet rocky places, chiefly South. Butterwort, Pinguicula. 



§ Leaves finely dissected, sometimes 0. Corolla throat closed. Utricularia. 1 



1. UTRICULA'RIA. Bladderwort. 

 Calyx 2-parted. Corolla irregularly bilabiate, spurred. Stamens 2. 

 Stigma 2-lipped. Pod round, 1-celled. Plants loosely floating or fixed in 

 the mud. Leaves mostly present, furnished with little sacks (utricles) filled 

 with air which floats them. Scape eract. Summer. (Fig. 98.) 



* Flowers purple Nos. 1, 2 



* Flowers yellow (a) 



a Plants rooting in the mud Nos. 3-5 



a Planrs floating in the water . . . (b) 



b Plants buoyed by a whorl of inflated petioles No. 6 



b Plants buoyed by air-bladders on special branchlets Nos. 7, 8 



b Plants buoyed by air-bladders on the leaves (c) 



c Flowers of 2 kinds, the liple-^s down on the stems No. 9 



c Flowers all alike and borne on the scapes. . . .(d) 



d Flower-stalks 2-12, nodding in fruit, on each scape Nos. 10, 11 



d Flower-stalks 1-5, erect in fruit ou each scape Nos. 12-15 



1 U. purpu'rea. Leaves whorled, on the long floating stems, Fls. 6" broad. Ponds. 



2 U. resupina'ta. Leaves scattered on the creeping stems. Flowers 4". Muddy shores. 



3 U. cornu'ta. Scape tall (8-12'), scaly, 2-5-flowered. Fls. large, spur decurved. 



4 U. subula'ta. Scape 2-5' high, very slender, flowers few, small. Spur inflexed. 



5 U. biparti'ta. Scape 2-3', flowers 1-3, on slender pedicels. Lower lip of the cor- 



olla entire. South. 

 6 U. infla'ta. Floating stem long. Scape 6-10' high, flowers 4 or 5, 8" broad. 



7 U. interme'dia. Leaves crowded, in 2 rows, rigid. Fls. 2 or 3, spur conical. 



8 U. Robbin'sii. Leaves alternate, thread-like. Fls. 4-7, spur fusiform. 



9 U. clandesti'na. Stem-flowers soUtary, bud-like. Scape with 2 or 3 fls. seldom seea. 



10 U. vulga'ris. Scape with 5-12 fls. Corolla throat closed. Spur couiail. 



11 U. minor. Scape with 3-6 fls. Corolla throat open. Spur blunt, very short. 



