Tar. 8108. 
PONTEDERIA CORDATA, var. LANCIFOLTA. 
Temperate America. 
PoNTEDERIACER. 
Ponreperta, Linn.: Benth. et Hook. f. Gen. Plant. vol. iii. p. 837; Solms in 
DC. Monogr. vol. iv. p. 531. 
Pontederia cordata, Linz., var. lancifolia, Morong, in Mem. Torr. Bot. 
Club, vol. v. p. 105 ; a typo foliis lanceolatis recedit. 
Herba aquatica, 1-2 ped. alta. Rhizoma horizontale vel ascendens, abbre- 
viatum, inferne radicibus dense obtectum. Caules florifert erecti, inter- 
nodiis duobus superioribus elongatis. Folia longe petiolata, petiolis 
inferne vaginantibus; lamina lanceolata, obtusa, basi rotundata vel 
obtusa, 3-1 ped. longa, 1-24 poll. lata, glabra. Spatha angusta, tubulosa. 
Panicula densa, spiciformis, 2-4 poll. longa. Perigonium czruleum, 
glanduloso-pilosum, circiter 4 poll. longum; tubus antice fenestratus ; 
lobi ovato-oblongi, tubo breviores; lobus medianus posticus macula flavo- 
virente notatus. Achenium ovatum, leve, breviter apiculatum.—P. lan- 
eifolia, Muhl. Cat. p. 34; Ell. Sketch, vol. i. p. 382. P. lanceolata, Nutt. 
Gen. Am. vol. i. p. 216. 
The small family of the Pontederiacex contains but five 
genera, of which three have been figured in this Magazine, 
namely :—Pontederia (t. 1156), in which two of the cells 
of the ovary are abortive, and only a single ovule is 
developed in the third cell; Hichhornia (t. 2932, sub Pon- 
tederia, & tt. 5020, 6487), which differs from Pontederia in 
having all three cells developed and containing many 
ovules; and Heteranthera (t. 6192), which is noteworthy, 
on account of having only three stamens. 
One of the best known species is the ‘* Water hyacinth,” 
Fichhornia speciosa, a native of Tropical South America, 
which was introduced into the St. John’s River, Florida, 
about 1890, and increased so rapidly as to become a serious 
menace to navigation in 1897. A fullaccount of its spread 
is given in the U.S. Department of Agriculture, Division 
of Botany, Bull. No.18. It is figured at t. 2932 under the 
name Pontederia azurea. 
The plant now figured was regarded as a distinct 
species by Muhlenberg and Nuttall, but has been reduced 
by more recent botanists, including Solms, who mono- 
graphed the family, to a variety or form of P. cordata ; 
the typical form of the latter is figured in t. 1156. The 
DecemBeEr Ist, 1906. 
