160 COMMON CANADIAN WILD PLANT&. 



deeply 2-lipped, the upper erect, notched ; the lower spread- 

 ing, 3-parted. Stamens 2, the anther-cells separated. Pod 

 obovate, flat, 4-seeded. 



ORDER LXIII. LABIA'T^. (MINT FAMILY.) 



Herbs with square stems, opposite leaves (mostly aroma- 

 tic), didynamous (or in one or two genera diandrous) 

 stamens, a 2-lipped or irregularly 4- or 5-lobed corolla, and 

 a deeply 4-lobed ovary, forming in fruit 4 nutlets or achenes. 

 (See Part I. , Section 65, for description of a typical plant.) 



Synopsis of the Genera. 



* Stamens 4, curved upwards, parallel, exserted from a deep notch on 



the upper side of the 5-lobed corolla. 



1. Tcu'crium. Calyx 5-toothed. The four upper lobes of the corolla 



nearly equal, with a deep notch between the upper 2 ; the lower 

 lobe much larger. Flowers pale purple. 



2. Isau'lhiis. Calyx bell-shaped, 5-cleft, almost equalling the small 



pale-blue corolla. Lobes of the corolla almost equally spreading. 

 Stamens only slightly exserted. 



* * Stamens 4, the outer or lower pair longer, or only 2 with anthers, 



straight and not converging in pairs I Anthers 2-celled ! 



*- Corolla, almost equally 4-lobed, quite small. 



3. .Men Ilia. Calyx equally 5-toothed. Upper lobe of the corolla 



rather the broadest, and sometimes notched. Stamens 4, of equal 

 length, not convergent. Flowers either in terminal spikes or in 

 head- like whorled clusters, often forming interrupted spikes. 

 Corolla purplish or whitish. 



4. Lye' opus. Calyx-teeth 4 or 5. Stamens 2, the upper pair, if any, 



without anthers. Flowers white, in dense axillary clusters. 



-t- i- Corolla evidently 2-lipped, but the lobes nearly equal in size ; the 

 tube not bearded inside. Stamens with anthers 2. 



5. Hedeo'ma. Calyx 2-lipped, bulging on the lower side of the base, 



hairy in the throat ; 2 stamens with good anthers, and 2 sterile 

 filaments with false anthers. Low odorous plants, with bluish 

 flowers in loose axillary clusters. 



-i- -i- *- Corolla 2-lipped, the lower of the 5 lobes much larger than the 



other 4 ; the tube with a bearded ring inside. Stamens 2 



(occasionally 4), much exserted. 



6. Collinso'nia. Calyx ovate, enlarged and turned down in fruit, 2- 



lipped. Corolla elongated, the lower lip toothed or fringed. 

 Strong-scented plants with yellowish flowers on slender pedicels 

 in terminal panicled racemes. 



