536 THE PRIMROSE FAMILY. 



attached to or immersed in a free central placenta, which is often 

 thick and globular. Style single, with a capitate stigma. 



A widely-spread family, inhabiting chiefly the northern hemisphere, 

 and especially high mountains, often at very great elevations. A few 

 species reappear in the Antarctic regions, and even within the tropics, 

 but the group is there represented chiefly by the Myrsinacece, which 

 scarcely differ, except in their arboreous or shrubby growth. Both 

 these families are chiefly distinguished from other regular-flowered 

 Monopetals by the stamens being opposite to, not alternate with, the 

 lobes of the corolla. This character requires some care in observing 

 it, especially in those species of Lysimachia which have a deeply di- 

 vided, rotate corolla, and the stamens erect in the centre of the flower. 



Aquatic plant, with the leaves all submerged and pinnate, 



with linear lobes I. Hottonia. 



Terrestrial plants, leaves undivided. 



Leaves opposite or ivhorled. Flowers axillary or rarely 

 terminal. 

 Stamens and divisions of the flower in fours .... 8. Centttncttle. 

 Stamens and divisions of the flower in fives. 



No corolla. Calyx pinkish 6. Glaux. 



Both calyx and corolla. 



Capsule opening at the top. Flowers yellow . . 4. Lysimachia. 

 Capsule opening transversely. Flowers blue or red 7. Pimpernel. 

 Leaves alternate or radical, or the upper ones irregularly 

 wJiorled. Flowers terminal. 

 Leaves all radical. Flowers solitary or umbellate, on 

 radical peduncles. Tube of the corolla distinct. 

 Tube of the corolla cylindrical, lobes spreading. No 



tubers 2. Pkimrose. 



Tube of the corolla nearly globular, lobes reflexed. 



Rootstock tuberous 3. Cyclamen. 



Stem leafy. 



Leaves in one terminal whorl, with a few alternate 

 ones below. Peduncles few, terminal, one- 

 flowered. Corolla rotate 5. Trientale. 



Leaves all alternate. Flowers small, white, in a ter- 

 minal raceme 9. Samole. 



The Dodecatheon, or American Cowslip of our gardens, belongs also 

 to the Primrose family. The allied family of Myrsinacece, mentioned 

 above, is represented in our planthouses by a species of Ardisia. 



I. HOTTONIA. HOTTONIA. 



Aquatic herbs, with submerged, pinnatifid leaves, and flowers in 

 whorls forming a terminal raceme ; differing from Primrose in the more 



