190 MANUAL OF BOTANY 



Series 1. — Microsjjeriuce. 



Order 1. Hydrocharidace^, the Hydrocliaris or Frog-bit 

 Order. — C h a r a c t e r. — Aquatic plants. Flowers spathaceous, 

 regular, unisexual or polygamous. Perianth superior, in 1 or 2 

 whorls, each composed of 3 pieces, the inner petaloid. Stamens 

 few or numerous. Ovar?/ inferior, usually 1 — G-celled ; placen- 

 tation parietal. Fruit indehiscent. Seeds numerous, exalbu- 

 minous. 



Distribution, Numbers, andPro2)crties.- — Inhabitants of fresh 

 water in Europe, North America, East Indies, and New Holland. 

 Illustrative Genera : — Anacharis, Bicli. ; Vallisneria, Mich. 

 There are about 25 species. Their properties are unimportant. 



Order 2. Burmanniace^, the Burmannia Order. — Cha- 

 racter. — Herbaceous plants, wiihowiimelediiwes,, or with tufted 

 r'adical ones. Flowers hermaphrodite, regular. Perianth peta- 

 loid, tubular, regular, superior, usually with 6 divisions. Sta- 

 mens distinct, inserted into the tube of the perianth, either 3 

 with introrse anthers, and opposite the inner segments of the 

 perianth, or 6 with extrorse anthers. Ovary inferior, 1- celled 

 with 3 parietal placentas, or 3-celled with axile placentas ; style 

 1 ; stigmas 3. P'ruit capsular, 1 — 3-celled. Seeds numerous, 

 very minute ; embryo solid. 



Distribution and Numhers. — They are principally found in 

 the tropical parts of Asia, Africa, and America. Illustrative 

 Genera : — Burmannia, Linn. ; Thismia, Griff. According to 

 Miers, there are 38 species. Their properties are unimportant, 

 but some are reputed to be bitter and astringent. 



Order 3. Orchidace^, the Orchis Order. — Character. — 

 Herbs or shrubs, terrestrial or epiphytical. Roots fibrous or 

 tuberculated ; no true stem or a pseudo-bulb. Leaves entire 

 generally sheathing. Floivers irregular, solitary or numerous, 

 with a single bract, hermaphrodite. Perianth superior, usually 

 petaloid and composed of six pieces, which are commonly 

 arranged in two whorls ; the outer whorl, s, si, si, formed of 

 three pieces (sejjals), more or less united below or distinct; 

 one, s, being anterior, or when the ovary is twisted posterior, 

 and two, si, si, lateral ; the i^mer whorl usually consists of three 

 pieces (x>etals), (or rarely of but one), alternating with the pieces 

 in the outer whorl ; one (the labellum or lii)) posterior, or by the 

 twisting of the ovary anterior, usually longer and larger than the 

 other pieces, and altogether different from them in form, often 



