1 48 Lemnaceae — Aracese. 



ORDER 83. — Lemnaceae. 



Flowers monoecious 2 in a spathe. Perianth none. Stamens i — 2. Ovary 

 i-celled. Style short. Stigma simple. Plants with floating fronds, without 

 distinction of stem and leaf. 



l.—LEMNA. 

 Fronds with roots, flowers in marginal clefts of the frond. 

 Root single, 559 



Roots many, L. polyrhiza. 



559 Frond lanceolate, L. trisulca. 



559 Frond orbicular, 560 



560 Fronds concave, L. gibba. 



560 Fronds flat, L. minor, 



LEM'NA MI'NOR (105). Common Duckweed. 7—8. Frond |—i in. 



(1466) obovate or oblong, slightly convex below. Stagnant water. 



LEM'NA TRISUL'CA (70). 6—7. Frond thin \—l in. obovate 

 (1465) lanceolate, usually 3 together at right angles with a single root-fibre. 



Lem'na gib'ba (50). Frond opaque \ — \ in orbicular hemispherical, 3 or 



(1467) 4 together with a single root to each. [F, Eg. CI. 



LEM'NA POLYRHIZ'A (54). Frond flat \-~^ in. broadly obovate with 



(1468) many roots. Ponds and ditches. 



ORDER 84. — Araceae 



Flowers monoecious on a spadix within a spathe. Perianth hypogynous or 

 wanting. Stamens few or many, filaments very short or none. Ovary 

 superior, i- (rarely 3-) celled. Fruit a berry. 



Leaves hastate, Arum I 



Leaves ensiform, . Acorus II. 



\.—ARUM. 



AR'UM MACULA'TUM (80). Cuckoo-pint, Lords and Ladies. 3—4. 



(1462) Leaves radical hastate spotted with long petioles sheathing at the base, 

 spathe twice as long as the spadix, termination of the spadix club- 

 shaped purple, berries crowded scarlet. Woods and hedges. Fig. p. 170. 



l\.— ACORUS. 



A'CORUS CALAMUS (31). Sweet Flag. 6—7. Leaves radical 3— 6 ft. 



(1464) ensiform, spathe long continuous with the scape 2-edged, spadix lateral 

 narrowed upwards 3 — 4 in. curved thickly studded with flowers, 

 perianth-segments 6 free membranous, stamens 6. fW. C. 



