52 VASCULAR PLANTS. 



ting, and the upper lip deciduous. Tube of 

 the corolla exserted; upper lip helmet-shaped 

 with two lateral lobes; lower lip reduced to a 

 single lobe. Stamens didynainous, ascending, 

 parallel; anthers of the lower pair, dimidiate. 



0. 2f. 

 13. Prunella, L. 



Calyx 2-labiate, in fruit closed and flattened. 

 Corolla with a scaly or hairy ring near its base; 

 upper lip concave; lower 3-lobed. Stamens 

 didynamous, ascending; anthers approximate 

 in pairs. U . 



12. Marrubium, L. 



Calyx tubular 5 — 10-dentate, in fruit the 

 teeth spreading. Tube of the corolla included; 

 limb 2-labiate. Stamens didynamous, included; 

 loculi of the anthers divaricate. U . 



13. Stachys, L. 



Limb of the corolla 2-labiate; upper lip erect, 

 concave; lower spreading, 3-lobed; middle lobe 

 longest. Stamens ascending, approximate in 

 pairs, parallel, contorted in withering. 



0. 2f. l>. 



14. Trichostemma, L 



Tube of the corolla slender; limb 5-cleft; 

 lobes oblong, declined. Stamens didynamous, 

 long-exserted ; filaments spiral in the bud. 



0. 2{. 



