LINN^AN CLASS XX. 189 



Order VI.— HEXANDRIA. 



Zizania. See Graminacece, 142. 



Order XIL— POLYANDRIA. 

 a. Ste7ns not woody. 



Myriophyllum. Calyx 4-parted. Petals 4, or none. Stamens 4 — 8. 

 Ovary 4-celled. Fruit of 4 indehiscent carpels. (Aquatic plants.) 

 Onagraceoe, 50. 



Sagittaria. Flowers in whorls ; the upper sterile, the lower fertile 

 Petals 3. Stamens numerous. Carpels numerous, indehiscent, each 1- 

 seeded. AHsmacece, 137. 



Arum. Peltandra. Ariscenia. Flowers on a spadix, naked at the 

 summit ; staminal flowers in the middle ; fertile ones at the base. 

 Perianth none. Fruit 1-celled, many-seeded. Aracece, 138. 



Caladium. Flowers on a spadix; staminate ones at the summit; 

 fertile ones at the base. Perianth none. Stamens numerous. Fruit 1- 

 celled, many-seeded. Aracece, 138. 



b. Stems woody. 

 The genera under this division are included in the Natural Order 

 Amentaceae, No. 115, and Juglandacece, 116. 



Order XV.— MONADELPHIA. 



The running plants of this order belong to the Natural Order Cucur- 

 bitacece, No. 54. 



The erect, herbaceous plants of the order belong to Euphorhlacece, 

 No. 108. 



The woody plants of the order belong to Coniferce, No. 11*7. 



CLASS XX.— DIGECIA. 



Order II.— DIANDRIA. 



Vallisneria. Flowers on a spadix. Spathe 2 — 4-parted. Sepals 3. 

 Stamens 2. Fertile flowers, with a spiral scape. Spathe 2-cleft. Sepals 

 3. Elongated petals 3. Capsule cylindrical, 1-celled, many-seeded, 

 HydrocharidacecB, 121. 



Salix. Sterile flowers, in a cylindrical ament. Scales 1 -flowered, 

 imbricate. Perianth none. Stamens 1 — 5. Fertile flowers in an 

 ament. Scales l-flowered. Capsule 1-celled, many-seeded. Seeds 

 comose. Amentacece, 115. 



Fraxinus. Calyx small, 3 — 4-cleft, or none. Corolla 4-pctaled, or 

 Qone. Samara 2-eelled, compressed, winged at the apex ; by abortion 

 I -seeded. Oleacece, 78. 



Borya. Flowers in spikes. Perianth 4-leaved. Slignia capitate. 

 Fruit i-seeded. Euphorbiacece, 108. 



Ceratiola. Flowers in the axils of the leaves. Perianth consisting 

 of imbricated scales. Fruit a berry, 2-celled, 2-seeded. Empetracece, 

 107. 



Order III.— TRIANDRIA. 



Ficus. Receptacle fleshy, spherical, inclosing the floiets; calyx ad- 

 hering to tho ovary, 3— 5-parted. Artorarpar.r.a', 111. 



