KEY. 253 



Flowers with only 1 set of perianth, sometimes with 

 hood-shaped, petal-like staminodia, or glumaceous, or naked. 



809 



800, Herbs with leaves 801 



Herbs leafless, beset with small, scattered scales, 

 purplish- or yellowish-brown, much branched ; the simple or 

 spicate branches flower-bearing their whole length — the upper 

 flowers sterile, the lower fertile (with scattered perfect ones). 

 Parasite on the roots of the beech. 



(323) Epiphegus Virginica, Bart. 



801. I. Corolla in both sorts of flowers of 2 or 3 pe- 

 tals, or tubular, and 2- to 3-lobed. Stemless, scape-bearing 

 marsh or aquatic herbs 802 



H. Corolla (at least of the staminate flowers) 4-pe- 

 talled or parted 804 



in. Corolla (at least of the staminate flowers) 5- to 

 6-petalled or parted. Calyx 5-toothed. Stamens 5 805 



803. Both kinds of flowers on the same receptacle (form- 

 ing a head). Ovary 2- to 3-celled, its cells 1-seeded. Fruit 

 a pod. Leaves grass-like, flat, clustered at the base of the 



slender, simple, 1-headed, fluted scape 803 



Each kind separate, and not in heads. Flowers of 

 3 sepals and 3 petals, commonly whorled in threes ; the ste- 

 rile occupying the upper part of the scape. Leaves, if pres- 

 ent (the blade is sometimes obscure), arrow-shaped, or lan- 

 ceolate, with longitudinal nerves and cross- veinlets. 



Sagittaria (884). 



803. Stamens, petals and sepals 3. Stigmas in the fer- 

 tile flowers 3. Scape 5-ribbed, puberulent. Leaves linear, 

 bristle-like. Fsepalanthus flavidus, Kunth. 



Stamens 4 or 6. Petals 2 or 3 (distinct in the fer- 

 tile, united in the sterile flowers). Sepals 3. Fertile flowers 

 in the margin; style 1 ; stigmas 2 or 3. Scape 7- to 12-rib- 

 bed. Leaves sword-shaped or subulate. Eriocaulon. 



804. Submersed aquatics. Leaves, usually whorled in 

 3's, 4's, or 5's, parted into capillary segments. Sessile stig- 

 mas 4, pubescent. Some of the flowers perfect. Calyx 4- 

 lobed. Petals 4 (sometimes wanting). Stamens 4-8. Fruit 



