316 RYDBERG: PHYTOGEOGRAPHICAL NOTES 
of Colorado, and here we find most of the aquatic vegetation. 
The majority of the phaneorgamic plants are found also in the 
plains and prairie regions. To these belong a score of species of 
Potamogeton which here are omitted. Besides these the following 
species are found: 
I. TRANSCONTINENTAL AND EASTERN 
Sparganium angustifolium Persicaria coccinea 
Sparganium minimum Batrachium trichophyllum 
Triglochin palustris Batrachium flaccidum 
Triglochin maritima Batrachium Drouetii 
Alisma brevipes Ranunculus Purshii 
Sagittaria latifolia Sisymbrium Nasturtium- 
Phragmites Phragmites aquaticum 
Catabrosa aquatica Callitriche palustris 
Panicularia grandis Callitriche autumnalis 
Panicularia borealis Hippuris vulgaris 
Panicularia septentrionalis Sium cicutifolium 
Eleocharis palustris Menyanthes trifoliata 
Scirpus validus Veronica americana 
Lemna trisulca Utricularia vulgaris 
Lemna gibba Utricularia minor 
Lemna minor 
2. WESTERN 
Crunocallis Chamissonis Nymphaea polysepala 
3. ENDEMIC 
Panicularia pauciflora Cardamine infaustat 
Agrostis depressat Ranunculus intertextust 
Cardamine cordifoliat 
B. SEDGE BOGS 
The sedge bogs are found where the drainage is poor or in low 
places around lakes, ponds, and streams. In most cases the most 
numerous plants are species of Carex, but many grasses also are 
intermixed, and in some places they are predominant. Of these 
Alopecurus aristulatus and Agrostis alba are the most frequent and, 
in the lower part of the zone, species of Calamagrostis. The com- 
position of the bog vegetation consists of the following plants:— 
