140 SUMMER FLOWERS. 



with as many alternating stamens ; ovary four-celled, with a 

 single ovule in each cell affixed at the base of the cavity. 



JJ Corollas irregular. 

 Ovary four-lobed. 



49. Labiate plants herbs ; corolla two-lipped ; stamens usually 



four didynamous (2 long, 2 short), or sometimes only two ; 

 lobes of the ovary one-seeded. 



Ovary undivided (i. e. not lobed). 



50. Verbenaceous plants herbs ; stamens four didynamous, 



rarely two ; ovary four-celled, dividing when mature into 

 four one-seeded nuts. 



51. Scrophulariaceous plants herbs ; stamens four, didyna- 



mous ; ovary two-celled, the cells many- seeded ; placentas 

 axile. 



52. Orobanchaceous plants leafless parasitical herbs ; stamens 



four, didynamous ; ovary one-celled, with two or more many- 

 seeded parietal placentas. 



Monoclilamyds : Perianth single (i. e. consisting of a calyx 

 only) , or altogether wanting, and replaced by scaly bracts ; 

 Orders 53 to 59. . 



* Carpels solitary, simple. 

 t Calyx inferior. 



53. Chenopodiaceous plants herbs ; leaves without stipufes ; 



perianth small, the stamens (4-5, rarely 1-2), alternating 

 with its lobes ; cvule 1-celled, with one ovule. 



54. Ceratophyllaceous plants aquatic floating herbs ; leaves 



without stipules ; perianth none ; ovary and fruit 1- seeded, 

 or 4-lobed, with one seed in each lobe. 



55. Urticaceous plants herbs ; leaves with distinct stipules ; 



flowers unisexual ; perianth small, green, the stamens, 

 usually 4, opposite its segments ; styles two, rarely one. 



