ARACEAE. 



61 



Monstera deliciosa Liebm., a vine with large ovate perforated leaves is 

 grown on walls for ornament and for its cylindric- edible fruit. [Philodendron 

 lacentm of H. B. Small.] 



Philodendron giganteum Schott, West Indian, a very large-leaved, half- 

 climbing species, existed in the Victoria Park, Hamilton, 1912. 



A species of Philodendron, climbing to a height of 8, with cordate, ovate, 

 short-acuminate, yellow-mottled leaves about 1 long, was seen at Orange 

 Valley in 1914. 



Several other species of this family are grown in gardens as ornamentals. 



Family 2. LEMNACEAE Dumort. 

 DUCKWEED FAMILY. 



Minute perennial floating aquatic plants, without leaves or with only 

 very rudimentary ones. The plant-body consists of a disk-shaped, elon- 

 gated or irregular thallus, which is loosely cellular, densely chlorophyl- 

 lous and sometimes bears one or more roots. The vegetative growth is by 

 lateral branching, the branches being but slightly connected by slender 

 stalks and soon separating. The inflorescence consists of one or more 

 naked monoecious flowers borne on a slight lateral prominence on the edge 

 or upper surface of the plant. Each flower commonly consists of but a 

 single stamen or a single flask-shaped pistil. The anther is provided with 

 two to four pollen-sacs, containing spherical minutely barbellate grains. 

 The pistil is narrowed to the funnel-shaped scar-like stigmatic apex, and 

 produces 1-6 erect or inverted ovules. The fruit is a 1-6-seeded utricle. 

 The family comprises the smallest of the flowering plants and contains 4 

 genera and about 30 species of wide distribution. 



1. LEMNA L. 



Thallus disk-shaped, usually provided with a central nerve and with or 

 without two or four lateral nerves. Each thallus produces a single root, which 

 is devoid of vascular tissue and is commonly provided with a thin blunt or 

 pointed rootcap. The ovary contains from one to six ovules. Fruit ovoid, 

 more or less ribbed. Endosperm in one or three layers. [Greek, in allusion to 

 the growth of these small plants in swamps.] About 8 species, in temperate 

 and tropical regions. Type species : Lemuel trisulca L. 



1. Lemna cyclostasa (Ell.) Chev. VAL- 

 DIVIA DUCKWEED. (Fig. 88.) Thallus oblong- 

 elliptic, l"-2" long, thin, subfalcate and 

 shortly stalked at the base, provided with 

 numerous stomata, except on the borders, nerve- 

 less ; rootcap blunt ; spathe renif orm ; fruit 

 ovoid-oblong, unsymmetrical ; seed prominently 

 12-29-ribbed. [L. minor cyclostasa Ell.; L. 

 valdiviana Phil. ; L. minor of .Rein, Reade, Le- 

 froy, Moore and Harshberger.] 



Common in ditches and marshes, often cover- 

 ing the surface of water. Native. United States, 

 West Indies and tropical continental America. Its 

 minute flowers are seldom observed. Probably 

 transported to Bermuda on the feet or feathers of 

 birds. 



