452 PlCKEliEL WEED FAMILY. 



CXX. PONTEDERIACRffi, PICKEREL WEED FA.MILY. 



A few water plants, with perfect and more or less irregular 

 flowers from a spathe, the perianth with 6 petal-like divisions 

 and free from the 3-celled ovary ; stamens 3 or 6, unequal or 

 dissimilar, inserted in the throat of the perianth; style 1, the 

 stigma 3- or 6-lobed or toothed. 



* stamens 6 ; perianth funnel-form. 



1. PONTEDERIA. Flowers in a terminal spike. Perianth of 6 divisions irregularly united 



below in a tube, the 3 most united forming an upper lip of 3 lobes, the others more 

 spreading and with more or less separate or lightly cohering claws forming the lower 

 lip, open only for a day, rolling up from the apex downwards as it closes ; the 6-ribbe(l 

 base thickening, turning green, and inclosing the fruit. Stamens 6, the 3 lower in the 

 throat, \rtth incurved filaments ; the 3 upper lower down and shorter, often imperfect. 

 Ovary 3-celled, 2 cells empty, one with a hanging ovule. Fruit a 1 -celled 1 -seeded 

 utricle. 



2. EICHHORNIA. Differs in having the flowers spicate-racemose or paniculate, the 3 



cells of the ovary all developing and each many-ovuled, the upper stamens Included 

 and the lo^iver ones exserted. Plant (in ours) floating free. 



» * Stamens 3 : perianth salver-form. 



3. HETEUANTHEEA. Flowers 1-few from a spathe which bursts from the sheathing 



side or base of a petiole. Perianth tube slender, the limb nearly equally parted and 

 ephemeral. Capsule 1-celled or incompletely 3-celled, many-seeded. 



1. PONTEDERIA, PICKEREL WEED. (J. Pontedera, an early 



Italian botanist.) 



P. cordata, Linn. Common P. Everywhere in shallow water ; stem 

 l°-2° high, naked below, above bearing a single, petioled, heart-shaped 

 and oblong or lance-arrow-shaped, obtuse leaf, and a spike of purplish- 

 blue, small liowers ; upper lobe with a conspicuous yellowish-green spot ; 

 flowers all summer. 21 



2 EICHHORNIA. (./. A. F. Eichhorn, a German.) 



£. specidsa, Kunth. (E. crAssipes, PoNXEoiiRiA AztjREA). From S. 

 Amer., now frequent in greenhouses, and in lily ponds in summer ; leaf 

 blade nearly orbicular, shining green, the petiole terete and swollen mid- 

 way into a hollow bladder; flower large (1^' long), violet, several in a 

 raceme ; roots feather-like and purplish, free in the water. 



3. HETERANTHERA, MUD PLANTAIN. (Greek: unlike anthers.) 



* Stamens unequal, the two posterior with ovate yellow anthers, the other 

 longer loith an oblong or sagittate greenish anther. 



H. renifdrmis, Ruiz. & Pav. In mud or shallow water. Conn., S. and 

 W.; with floating, round-kidney-shaped leaves on long petioles, and 3-5 

 ephemeral white flowers, their perianth with a slender tube, bearing 6 

 nearly equal divisions. 



H. Iim6sa, Vahl. In mud, Va., S. and W.; distinguished by its oblong 

 or lance-oblong leaves, and solitary, larger, blue flower. 



* « Stamens all alike, with sagittate anthers. 



H. (or Schollera) gramlnea, Vahl. Water Star Grass. A grass- 

 like weed growing under water in streams, from N. Eng., W. and S., with 



