(72) 



5. Zannicliellia. Flowers axillary. 3 flower 

 naked, ? flower with, campanulate per- 

 igonium. Ovaries 4, each 1-ovulate. 

 Fruit nutlets. Aquatic. 



6. Callitriche. Flowers axillary, 2-bracteo- 

 late. Ovary 4-celled; cells 1-ovulate. 

 Fruit a 4-coccous schizocarp. Aquatic. 



II. Diandria, 



1. Pinus. Anthers sessile on the bracts of 

 the amentum. Leaves fasciculate in 

 a sheath. Coniferous. 



2. Pseudotsuga. Anthers sessile on the 

 bracts of the $ amentum. Leaves dis- 

 tichous. Branchlets smooth, the leaf 

 scars not being prominent. Coniferous. 



3. Fraxinus. Flowers paniculate. Calyx 

 obsolete, 4-cleft. Fruit a 1-seeded sa- 

 mara. 



III. Triandria. 



1. Typha. $ spike and ? spike cylindrical. 



6 spike above ? spike. Palese 0. 



2. Sparganium. <5 spike and ? glomeru- 

 late. Flowers separated by a palea- 

 ceous perigonium. Aquatic. 



3. Carex. Glumaceous. Spikes unisexual 

 or androgynous. Spikelets 1-flowered. 



$ spikelet an external palea; ? spike- 

 let with 2 palesB, the interior one trans- 

 formed into a utricle including the 

 1-seeded ovary. 



