3418 



UTRICULARIA 



UTRICULARIA 



Utricularia comprises plants with numerous slender 

 wiry scapes bearing one or many fls. : calyx large, 2- 

 parted or 2-lobed; corolla with a spur which is usually 

 long and curved under the fl. ; posterior lip erect, entire, 

 emarginate or 2-fid; anterior lip often large, broad, and 

 showy, spreading or reflexed, entire, crenate or 3-lobed, 

 or the middle lobe various: lys. of the aquatic species 

 much dissected, sometimes disappearing at flowering- 

 time, very delicate: plant floating or rooting in the 

 mud, the Ivs., branches, and sometimes the roots bear- 

 ing minute bladders; Ivs. of terrestrial species linear or 

 spatulate and rosulate at base of plant. The bladders 

 trap small aquatic animals. These bladders have a 

 valve-like door through which the animals enter when 



3888. Utricularia longifolia. ( X M) 



looking for food or when trying to escape from other 

 creatures; they are most numerous and effective in the 

 species which float in stagnant water. They are fewer in 

 the marsh-inhabiting species. The terrestrial kinds 

 often have minute deformed and useless bladders; 

 these kinds are common in the tropics and are charac- 

 terized by erect foliage of the ordinary type. These 

 often form little tubers by which they may be propa- 

 gated. The native aquatic species propagate themselves 

 by seeds and also by winter buds. (A winter bud of 

 another aquatic plant is figured under Elodea, p. 1110). 

 Some of the utricularias are epiphytic in a way. Those 

 who are familiar with bromeliaceous plants know how 

 the water gathers in the axils of the Ivs. These brome- 

 liads are themselves often epiphytic, perching on high 

 trees in moisture-laden tropical jungles. In the minia- 

 ture ponds supplied by the If .-axils of Vriesia and other 

 bromeliads live certain utricularias with fully developed 

 and effective bladders. Occasionally they send out a 

 long "feeler" or runner-like shoot which finds another 

 bromeliad and propagates another bladderwort. 



The aquatic utricularias are sometimes cultivated in 

 aquaria, but their flowers are not showy, nor are those 

 of any of the hardy kinds. A number of them are native 

 in lakes and ponds in the United States and Canada. 

 The showy species are the terrestrial and epiphytic 

 kinds of the tropics. These, for complexity of floral 



structure, beauty of color and lasting qualities, vie with 

 certain orchids. In fact, they are usually grown by 

 orchid-lovers in orchid-houses. Perhaps the most 

 desirable of the genus are U. montana, U. Endresii, and 

 U. longifolia, each of which represents a different color. 

 Well-grown baskets of these plants have numerous 

 scapes a foot or so high bearing five to twenty flowers, 

 each 1 }/2 to 2 inches across. In general, such plants are 

 grown in warmhouses, U. Endresii requiring a stove 

 temperature, while some of the others may thrive in an 

 intermediate house. As a class they are grown in bas- 

 kets, near the light, using a compost of fibrous peat 

 and sand. The plants are kept constantly wet during 

 the growing season and until the flowers are gone. Dur- 

 ing the winter they are rested, being kept in a cooler 

 place and given just enough water to keep the tubers 

 from shriveling. 



americana, 1. 

 bifida, 4. 

 Endresii, 8. 

 Forgetiana, 9. 

 Humboldtii, 7. 



janthina, 5. 

 latifolia, 9. 

 longifolia, 9. 

 macrorhiza, 1. 

 major, 8. 



montana, 3. 

 prehensilis, 2. 

 reniformis, 6. 

 vulgaris, 1. 



A. Habit aquatic. 



B. Foliage dissected into numerous thread-like segms.; Ivs. 

 floating. 



1. vulgaris, Linn. Hardy aquatic: sts. a few inches to 

 3 ft. long, with crowded 2-3 pinnately divided floating 

 Ivs. }/2-l in. long, provided with numerous bladders and 

 yellow fls. 3/in. long or more, borne in few-fld. racemes: 

 scapes 6-8 in. high: corolla closed, with reflexed sides 

 and a conical blunt spur. Eurasia, in ponds and chan- 

 nels. Gn. 28, p. 403. ^Sometimes listed among aquatic 

 plants. What is considered by some to be the same 

 species occurs far northward in N. Amer.; represented 

 in the U. S. by var. americana, Gray, with a more slen- 

 der and rather acute spur. Some authors consider the 

 American plant to be distinct, and it then takes the 

 name U. macrorhiza, LeConte, distinguished from the 

 Eurasian material by longer sts., shape and direction of 

 spur and reduced or rudimentary stolons. Sometimes 

 collected for aquaria. 



BB. Foliage ribbon-like. 



2. prehensilis, E. Mey. An aquatic plant with fl.- 

 shoots twining above the water : Ivs. (often disappeared 

 at flowering-time) linear-lanceolate to Ungulate, obtuse, 

 sometimes nearly 1 in. long, narrowed into a slender 

 petiole: bladders numerous on the Ivs. and rhizoids, 

 with the mouth near the stalk, nearly or quite globose, 

 almost y% line in diam. : fls. yellow, 1-6; upper lip of 

 corolla broadly oblong-spatulate; palate erect, crested; 

 spur straight and acute, descending, Min. or more long. 

 Trop. Afr. G.C. III. 48 : 447. A rapid grower and pro- 

 fuse bloomer in cult. Annual. 



AA. Habit terrestrial or epiphytic: foliage entire, erect. 

 B. Color of fls. white, with a yellow palate. 



3. montana, Jacq. Tropical American epiphyte, with 

 clusters of tubers }4-%in. long, minute, deformed, use- 

 less bladders and large white fls. with a yellow palate, 

 the fls. 1-4 on a scape, each 1J^ in. across: Ivs. 4-6 in. 

 long, elliptic-lanceolate. Trunks of trees, W. Indies and 

 S. Amer. B.M. 5923. F.S. 19:1942. I.H. 18:64. G.C. 

 III. 49:405. G. 29:251. G.W. 2, p. 414; 3, p. 518; 15, 

 p. 301. A lovely species. 



BB. Color of fls. yellow, with an orange palate. 



4. bifida, Linn. Terrestrial species from Trop. Asia, 

 with minute bladders and small fls. resembling a 

 diminutive linaria: Ivs. densely matted, erect, thread- 

 like, 1-2 in. long: fls. yellow, with an orange palate, 

 j^gin. long, 5-8 in a raceme: pedicels drooping in fr. : 

 scape about 6 in. or less high. India, Malaya, China, 

 Japan, Philippines. B.M. 6689. 



