206 



PONTEDERACEyE. 



[Endogens. 



Order LXIII. PONTEDERACE^E.— Pontederads. 



Pontedereae, Kxinth in Humb. et Bonpl. N. G. 1. 211. (1815) ; Agardh Aph. 

 Ach. Rich. Nvuv. Elim. ed. 4. 427. (1828) ; Eiidl. Gen. liv, Meisn. Gen. p. 



). (1823).— Pontederaceae, 

 J. Kunth Enum. 4. 119. 



Diagnosis. — Lilial Endogens with a naked perianth, circinate when withering, anthers 

 turned inwards, and mealy albumen. 



Aquatic or marsh-plants. Leaves sheathing at tlie base, ^A^th parallel veins, in the 

 larger species arrow-headed, cordate or dilated. Flowers 

 either soUtary or in spikes or umbels, spathaceous, fre- 

 quently blue, sometimes yellow. Perianth tubular, colom'ed, 

 (5-parted, more or less irregular, with a circinate aestivation. 

 Stamens arising from the calyx, 6, or 3 opposite the petals; 

 anthers turned inwards, opening lengthwise. Ovary free, 

 more or less completely 3-celled, many-seeded ; style 1 ; stig- 

 ma simple; o\'ules anatropal. Capsule 3-celled, occasionally 

 acquiring an adliesioi^ to the perianth, 3-valved, ^vith loculi- 

 cidal dehiscence. Seeds indefinite, attached to a central 

 axis, ascending ; hilum small ; embryo with its radicle rather 

 enlarged, orthotropal, in the axis of somewhat mealy albu- 

 men. 



The aquatic plants comprehended under this name are 

 essentially distinguished by the divisions of then* flowers 

 being rolled inwards after flowering, to which may be added 

 mealy albumen, and an indefinite number of seeds. For 

 this reason a plant called Reussia, which seems to want the 

 first and last characters, appears to have no business among 

 them. They were referred to Spiderworts by SaUsbury, 

 and are considered nearly related to that Order by AchUle 

 Richard, who, however, separates them, suggestmg their 

 being referable to LilyAVorts. There can be no doubt of theii' 

 close relation to the latter Order, from which they are 

 principally kno^vn by their u'regular flowers, mealy albumen, 

 and perianth rolhng inwards after expansion. Leptanthus, 

 however, if it is really one of the Order, has all the habit of 

 aPotamogeton, and establishes a connection with the Arrow- 

 grasses. Hooker, who has given an excellent figure of 

 Eichhornia speciosa {B. M. t. 2932), states that each fibre of 

 the roots has a calyptrate covering at the extremity, similar 

 to that found on the roots of the Duck-weed. 



Water-plants found exclusively m North and South 

 America, the East Indies, and tropical Africa. 



Very little is known of their uses. Monochoria vaginalis 

 is employed in Indian pharaiacy ui hver-complaints and 

 disorders of the stomach. Rubbed down in butter and 

 drank, it is thought to remove redness of the eyes ; pow- 

 dered and mixed with sugar it is administered in asthma ; 

 and when chewed, is said to relieve toothache 

 milk it is given in fever ; and, finally, when 



Fig. CXXXIX. 



brayed with 

 •ovmg, is eaten as a potherb. — Endlicher. 



Heteranthera, Ruiz et Pav. 

 Buchozia, Flor. Plum. 

 Heterandra, Palis. 



GENERA. 



Leptanthus, L. C. Rich. 



Schollera, Willd. 

 Eichhornia, Kth. 



Numbers. Gen. G. Sp. 30. 



Pontedeiia, Linn. 

 Unisema, Rafin. 

 Monochoria," Presl. 



PoSITION.- 



Jwicaginaceoe. 

 PoNTEDERACE.^. — LiUacece . 

 Mayacece 1 



Fig. CXXXIX.— Eichhornia .speciosa ; 1. pistil ; 2. transverse section of the ovarv.— ^ooAvr. 



