KEY TO NATURAL ORDERS 59 
Crass I—MONOCOTYLEDONS—PLANTS wiITH SINGLE LOBED OvVULES 
The seeds have a single lobe or cotyledon constituting a rudimentary 
leaf. The leaves of plants of this class are, in general, parallel- 
veined, and in the stem there is no distinction of pith, wood and bark. 
The flower of most of the land plants of this class and of the more 
highly developed of its aquatics, has its parts in 3’s (petals 3 or 6, 
sepals 3 and stamens 3 or 6). In the submersed aquatics and in some 
other water plants of the class, also in some of the grass-like plants, 
the parts of the flower are in 2’s or 4’s or very rarely in 5’s. 
ORDERS OF MONOCOTYLEDONOUS PLANTS IN OUR AREA 
OrpeR I—PANDANALES—Cat-Tart ORDER 
(Page 90) 
Herbs growing in marshes or other wet places. The flowers are 
arranged on the fleshy terminal of the stem in the form known as a 
spadix, but without the leaf-like sheath characteristic of the Arum 
family. The envelope about the floral elements (perianth) is com- 
posed of bristles or chaffy scales and the flowers bearing stamens and 
those bearing pistils are in different groups, one above the other. The 
flowers are arranged in long cylindric groups or in rounded heads. 
7 8 9 10. 
7. Pistillate flower of Cat-tail. 8. Cat-tail. 9. Bur-reed, 10. Pistillate flower of 
Bur-reed. 
OrpveR II—HHELOBIAE 1—WatTerR ork MarsH PLANTS 
(Page 93) 
Plants wholly or partly submersed in water or partly floating. In 
some families the perianth (flower envelope) is wanting or incomplete, 
while in others it is present and conspicuous. The perianth has never 
more than 4 segments in a single series and it is only in the very 
inconspicuous flowers that there are so many. The more conspicuous 
flowers have a calyx of 3 sepals and a corolla of the same number of 
petals. The stamens number from 1 to many. 
a LE ft 
: SKS ‘ 
12. 13. nae ie oa 
it 
4 and 12 Pondweeds. 13. Ruppia. _ 14. Arrowgrass. 15. Duckweed, 16. Arrows 
ead. 
OrpeR III—GLUMIFLORAE—G.LuMacrous PLANTS 
(Page 109) 
Flowers bearing glumes of dry husks, which take the place of the 
.) Helos, marsh; bios, life, 
