676 



OBDEB 135. ALISMACE^E. 



COHORT 6, FLORIDE^. 



Endogenous plants with the Flowers usually perfect and 

 complete, the perianth double, 3-parted, the outer often, and 

 sometimes both, green. 



ORDER CXXXV. ALISMACEJE. WATER PLANTAINS. 



Marsh herbs, with parallel- veined, petiolate leaves and branching peduncles. 

 Ftotuers perfect or monoecious, with a regular double perianth. Sepals 3, green ; 

 petals 3, colored or green ; stamens hypogynous. Ovaries 3 or more, separating 

 into as many 1 -seeded achenia. 



Genera 9, species 70, distributed in all parts of the world, more common in temperate 

 climates. One species of Sagittaria is cultivated for food in China (S. Sinensis). (Our specimens 

 were revised by Dr. Engelman.) 



SUBORDERS AND GENERA. 



I. ALISMEJ3. Petals white, with a green calyx. 



Embryo curved. Leaves rush-like, with no 

 lamina, (a) ( Stam 6. AI.ISMA. 1. 



a Fls. all perfect. 1 Stam. 9. 24. ECIIIX. 2. 



a Fls. diclinous. Stam. oo ...SAGITTARIA. 3 



II. JUNCAGINE^E. Petal? greenish, like the sepals. 



Embryo straight. Leaves mostly expanded 



to a lamina, (b) 



b Anthers oval. Lv?. radical... TRiGLOCiiijX. 4 

 b Anth. linear. Lvs. cauline.ScnEUCiizEiiiA. 5 



FIG. 712. Inflorescence of a Sagittaria, leaf 

 and flowers, a, One of the pistils enlarged, fr, The pis- 

 til of Alisma cut open, showing the seed and curved em- 

 bryo. 



1. ALIS'MA, L. WATER PLANTAIN. 

 (Celtic alls, water 1) Flowers ; sepals 

 3, persistent ; petals 3, aestivation involute ; stamens 6 ; ovaries and 

 styles numerous, arranged in a circle, forming as many flattened ach- 

 enia. It Acaulescent, marsh herbs, with mostly expanded leaves, and 

 with panicled flowers. 



A. plantago L. Lvs. all radical, ovate or oval, subcordate, abruptly acuminate ; 

 scape many-flowered; fls. verticillate in the panicle; carpels 15 to 20 r ribbed on 

 the back, forming an obtusely triangular whorl. A common, smooth, handsome 

 inhabitant of pools and ditches. Lvs. resembling those of the common plantain, 

 with about 5 veins running from end to end, connected by cross veinlets. Peti- 

 oles 8 12' long. Panicle a scape, 1 2f high, with numerous, small, rose- white 

 flowers. JX, Aug. (A. trivialis and parviflora Ph.) 



2. ECHINODCTRUS, Richard, Engelm. (Gr. i%lvos the sea-urchin, 

 dopog, a sack ; alluding to the head of carpels bristly with the persistent 

 styles.) Flowers $ ; sepals 3, persistent ; petals 3, aestivation imbri- 

 cate ; slam. 6 oo ; ovaries and styles co, imbricated in a head, form- 

 ing as many flattened, beaked achenia. Scape creeping or erect, flow- 

 ers verticillate. 

 1 E. radicans Engelm. Leaves ample, ovate, obtuse, cordate, about 7-veined, on 



long petioles ; scape prostrate, running and rooting at the proliferous joints ; fls. 



