412 MANUAL OF NATURAL HISTOBY. 



inflorescence cymose, flowers often in verti- 

 cillasters ; corolla bilabiate, the upper lip 

 entire or bifid, lower layer, 3-lobed ; stamens 

 four ; ovary free, deeply 4-lobed ; ovules four ; 

 stigma bifid ; fruit 1 to 4 small achaenia, 

 enclosed within the persistent calyx ; seeds 

 erect ; cotyledons flat ; radicle inferior. Na- 

 tives chiefly of temperate countries. Among 

 the more important species, are Peppermint 

 (Mentha piperita), Spearmint (M. viridis), 

 Pennyroyal (M. Pulegium), Lavender (La- 

 vandula vera), Rosemary (Rosmarinus offici- 

 nalis), Wild-Marjoram (Origanum vulgare), 

 Sweet-Marjoram (Melissa officinalis), White- 

 Horehound (Marrubium vulgare), Sage 

 (Salvia officinalis, S. grandifiora), Thyme 

 (Thymus), and Kretan-Dittany (Origanum 

 Dictammus). (Labiatce, Jussieu.) 



II. SUB-ORDER. — Symmetrical-Echials (Boragmanse), 



Flowers regular, symmetrical. 

 5. Family. — Brunoniads (Brunoniaceas). Serbs, 

 stemless, with simple glandless hairs ; leaves 

 radical, exstipulate ; flowers capitate, on 

 scapes, surrounded by an involucre of en- 

 larged bracts, blue ; calyx free ; corolla 

 almost regular ; aestivation valvate ; stamens 

 five ; stigma enclosed in an indusium ; fruit 

 a membranous utricle ; seed solitary, erect, 

 exalbuminous ; radicle inferior. Australian 

 species. 



