470 



ILLUSTRATIONS OF Til IC NATURAL ORDKRS. 



more ovaries, separate or somewhat united, with one or more ovules 

 in each. — Ex. Saururus, Ilottuynia : a small group. 



1138 113 



906. Ord. Ccratophyllaceac {Hornwort Family) consists of the single 

 genus Ceratophyllum (growing in ponds and streams in many parts 

 of the world) ; distinguished by the whorled and dissected leaves 

 with filiform segments ; the flowers moncecious and sessile in the 

 axil of the leaves ; the stamens indefinite, with sessile anthers ; and 

 the simple one-celled ovary, which forms a beaked achenium in fruit, 

 containing an orthotropous suspended seed, with four cotyledons ! 

 and a manifest plumule. 



907. Ord. CallitrichacefC (Water- Starwort Family), formed of the 

 genus Callitriche ; aquatic annuals, with opposite entire leaves ; the 

 axillary flowers (either perfect or monoecious) with a two-leaved 



FIG. 1127. Saururus cernuus. 1128 A separate flower with its bract and a part of the 

 axis magnified 1129 A more magnified anther, discharging its pollen from one cell. 1130 

 Cross-section of the ovary. 1131 A'ertical section of one of the carpels in fruit, and of the 

 contained seed, with the sac at the extremity of the albumen, containing the minute embryo. 

 1132 A seed. 11C3 Same, with the outer integument (testa) removed, showing the vitellus. 

 1134 The latter, Highly magnified. 1135 Section of the same, showing the enclosed heart- 

 shaped cnibrj o. 



