212 ESSENTIAL OEGANS — STAMENS. 



organs are not present. The name of hermaphrodite or bisexual is 

 given to flowers in which both these organs are found ; that of uni- 

 sexual (one sex), or diclinous (dig, twice, and xKhri, a bed), to those in 

 which only one of these organs appears, — those bearing stamens only 

 being- staminiferous (stamen, a stamen, fero, I bear), or male ; those 

 having the pistil only, pistilliferous (pistillum, a pistil, fero, I bear), or 

 female. 



The absence of one of the organs is due to abortion or non-develop- 

 ment. When in the same plant there are unisexual flowers, both male 

 and female, the plant is said to be monoecious or monoicous (/jiovog, one, 

 and olxlov, habitation), as in the Hazel and Castor-oU plant ; when 

 the male and female flowers of a species are found on separate plants, 

 the term dicecious or dioicous (dig, twice) is' applied, as in Mercurialis 

 and Hemp ; and when a species has male, female, and hermaphrodite 

 flowers on the same or difierent plants, as in Parietaria, it is poly- 

 gamous (voXxig, many, and yajj^og, marriage). The term agamous (a, 

 privative, and ydfiog, marriage) has sometimes been applied to Crypto- 

 gamic plants, from the supposed absence of any bodies truly represent- 

 ing the stamens and pistil. 



Flowers of the same species of plant sometimes present different 

 forms as regards stamens and pistil. Thus, in the same species of 

 Primula and Linum there are differences in the size and development 

 of the stamens and pistil, one flower having long stamens and a pistil 

 with a short style, the other having short stamens and a pistil with 

 a long style. The former occur in what are called thumb-eyed prim- 

 roses, the latter in those called piu-eyed. Such plants are called 

 dimorphic (dig, twice, and A">^pil, form). These plants, and many others, 

 have thus two kinds of hermaphrodite flowers on distinct individuals. 

 In some plants the stamens are perfected before the pistil ; these are 

 called protandrous (rgStrog, first, avri^, male or stamen). Examples of 

 these are Ranunculus repens. Lychnis Flos-cuculi, Silene maritima, 

 Geranium pratense and sylvaticum, Digitalis purpurea. Campanula 

 rotundifolia, and Zea Mais. In other plants the pistil is perfected 

 before the stamens, as in Potentilla argentea, Plantago major, lanceo- 

 lata, and maritima, Lonicera Periclymenum, and Coix Lachryma. 

 These are called protogynous plants (orgSiroj, first, ymr\, female or pistil). 



Stamens. — The stamens (stamina) arise from the thalamus or 

 torus within the petals, with which they alternate, forming one or 

 more verticils or whorls which collectively constitute the andrcecium 

 (Mi§, male, oixloii, habitation), or the male organs of the plant, as 

 distinguished from the gyncecium (yuvri, female, olxiov, habitation), 

 or female organs of the plant. Their normal position is below 

 the inner whorl or the pistil, and when they are so placed (fig. 337 e), 

 they are hypogynous (i-ro, under, yuv^, female or pistil). Sometimes 

 they become united to the petals, or are epipetalous (kvl, upon, and 



