82 Key to the System of 



408. Whorls of flowers crowded into a dense broadly 



bracteate spike. 



Perennial herbs; leaves comparatively large; calyx streaked 

 by ten longitudinal venules, finally closed, producing 

 three upper denticles and two lower lobes. Brunella. 1674 



Cymous whorls of flowers often racemose or paniculate. 



Herbs or half -shrubs ; leaves comparatively large ; calyx 

 producing often an upper entire broad lobe and four 

 narrow and pointed lower lobes. Plectranthus. 1675 



409. Stamens two. 



Perennial herbs ; leaves comparatively large ; flowers all in 

 axillary whorls; calyx-lobes five, rarely four; rudimentary 

 stamens present or absent. Lycopus. 1676 



Stamens four ... ... ... ... ... ... 410 



410. Leaves in whorls, generally rigid, always entire. 



Always shrubs; leaves comparatively small; calyx streaked 

 by usually ten longitudinal venules ; anthers of the lower 

 stamens two-celled and sterile, anthers of the upper 

 stamens one-celled and pollen-bearing. Westringia. 1677 



Leaves simply opposite, generally flaccid, often inden- 

 ted 411 



411. Anthers of all four stamens with two parallel cells. 



Herbs or half-shrubs, very odorous ; flowers in axillary or 

 almost spicate whorls ; calyx streaked by ten longitudinal 

 venules; tube of the corolla hardly longer than the calyx; 

 all four anthers pollen-bearing. " Mint " or " Ment." 



Mentha. 1681 



Anthers of all four stamens with two divergent but 

 confluent cells, thus almost unilocular ... ... 412 



412. Upper lobes of the corolla much abbreviated, almost 



or quite connate, much surpassed by the three lower 

 lobes. 



Herbs or seldom half-shrubs, generally dwarf ; leaves often 

 incised ; calyx streaked by usually ten longitudinal 

 venules ; corolla long-persistent ; tube of the corolla 

 inside often annular-bearded ; stamens hardly exserted ; 

 all four anthers pollen-bearing. " Bugle." Ajllga. 1684 



