118 



STRUCTURAL BOTANY. 



sessile flowers either scattered, clustered, or crowded upon it, 

 as Plantain, Mullein, Vervain. The so-called spikes of the 



435, Spiranthes cernua flowers in a twisted spike. 436, Orontium aquaticura flowers on a naked 

 spadix. 437, Betula lenta flowers in ameuts. 



Grasses, as Wheat, Timothy, are in fact compound spikes, bear- 

 ing little spikes or spikelets in place of single flowers (440). 



438, Andromeda racemosa flowers in a secund raceme. 439, Vwbascum Rlattaria raceme. 440 

 Loliuin perenne a compound spike or a spike of spikelets. 441 Dipsacus sylvestris head with an In 

 volucre t{ leaves. 442. Osmorhiza longistylis a compound umbel. 443. Its fruit. 



