PL end, ph. 6. FLUVIAT. 26. Potamogit. 37 



14-. Potamogilon pusiUum. Dwarf riverweed. 



Leaves linear, opposite and alternate, distant, spreading 

 at the base, narrower than the stipulae ; stem round, very 

 slender, branchy ; peduncles axillary : spike many flowered. 



Pot. pusillnm, gramineo folio, caule tereti, Raii Syn. 150, 15. 

 Potamogetoii pusillum, Lin. S. P. 184. 



Ditches and ponds on a clay bottom; perennial; July. 



Plant sunk, e.Kcept the spike when in flower; stipulce 

 embracing the stem ; peduncles solitary, longer than the 

 spike ; spike ovate, small. 



IV. 27. ZOSTERA. Linnaeus. Grasswrack. 



Flower monoicous or dioicous, resting on a one-sided 

 leaflike spadix; perigonium none; anther round; pollen 

 connected by fibres ; style 2-cut ; capside membranaceous, 

 1 -seeded. — Root fibrous; stem round, decumbent, rooting 

 at the joints, leafy; leaves flat, linear, alternate, grasslike; 

 spadix flat, from a cleft in the leaflike, sessile spatha. 



Zostera marina. Sea grasswrack. 



Leaves not nicked, slightly 3-nerved ; stem roundish. 



Alga, Ger. em. 1569 ; Raii Syn. 5?, 1. 

 A. marina {(ramina minor, Raii Syn. 52,2. 



A. marina gra-aiinea angustifolia seminifera ramosior, Raii Syn. 52, 3. 

 Alga q. Potamogeiton marinum in atriculis epiphyllospermon minus 

 Doody, Raii Syn. 53,4. 



A. angHstifolia vitriariorum, Raii Syn. 53, 5. 



Fucus marinus sive Alga marina graminea. Park. 1242. 



Zostera marina, Lin.S. P. 13T4. 



Sea-shores, saltwater ditches; perennial; August. 



Stem smooth, kneed; leaves opening a little above the 

 base with a longitudinal slit, exserting a linear spadix 

 bearing flowers on one side ; anther single, sessile, at the 

 side of the germen ; germen oblong, sessile ; stigmata two, 

 linear ; capsule elliptic, hanging. 



The scaly hairs at the base of this plant, being detached 

 and felted into balls by the action of the waves of the sea, 

 and roasted to blackness, are used in diseases of the lym- 

 phatic system, in the same manner and with the same in- 

 tent as burnt sponge. 



(3. latifolia. Leaves broad, very evidently 3-ribbed. 



II. 7. AROIDE^, Jussieu ; Pipen/amw par^, Lin. 



Flowers monoicous, sessile, round a simple spadix ; in- 

 volucrum a one-leafed spatha; perigonium none; stamens 

 numerous, aggregated round the spadix ; anthers inverse ; 



