THALAMIFLOR^ 



187 



and the stamens are monadelphous (fig. 157). P. 

 persicaricsfolia is a handsome herb met with in 

 Shillong. Xanthophyllum flavescens (gundhi) is a 

 large tree of DarjiHng and hilly parts of Chittagong 

 with yellow and pink panicles. 



Nat. Order 17. CaryophyllacecB.— This is mostly an 

 Order of temperate regions, represented by the com- 

 mon garden annual Pink {Dian- 

 thus chinensis), with grass- like 

 opposite glabrous leaves, swollen 

 nodes, syncarpous ovary, free 

 styles, and free central placenta- 

 tion. The flowers of Pink are 

 protandrous and typical butter- 

 fly-flowers, the nectar being se- 

 creted and concealed at the bottom 

 of the corolla -tube, which is 

 formed by the long claws of the 

 free petals held together like a 

 tube by the gamosepalous calyx 

 and stiff bracts. Pink is typical 

 of the Order. Gypsophila ceras- 

 tioides is a common season flower 

 of gardens. In cool climates, 



like those of Darjiling and Shillong, species of Sper- 

 gula (fig. 158), Arenaria, and Drymaria occur com- 

 monly as weeds. Cymose dichotomy or dichasium 

 is the common form of inflorescence in this Order, 

 and 2 to 5 free-styled flowers and free-central placen- 

 tation are characteristic. 



Closely allied to it is the Nat. Order Elatinacece, 

 which are minute marsh or water plants with bisexual 

 flowers and 3 to 5 styles. 



Nat. Order 18. Portulacacece. — Herbs. Leaves 

 usually succulent. Flowers regular. Sepals usually 



Fig. 158. — Spei'gtda arvensis 



