ORCHIDACE^ 



401 



long. Some foreign species have more than one kind of 

 flower. The above diagram (Fig. 328) illustrates the 

 structure of an orchid flower. The seeds are numerous, 

 and very minute. 



In some species the ovules are undeveloped or very 

 rudimentary when the plant is in flower. According to 

 Hildebrand/ in Dendrobium the formation of the ovules 

 has not yet commenced, even the placentae are not 

 fully developed, and it is not till four m-onths after the 

 deposition of the pollen that the formation of the embryo 

 begins. 



Orchis 



Of this genus we have ten species, of which Orchis 

 masGula (Early Purple Orchis, Fig. 329) is perhaps the 

 commonest, and I have therefore taken it as the type. 

 It occurs in Southern and Central Europe as far as South 

 Scandinavia. It is sometimes, 

 but not always, scented. The 

 leaves are spotted and broad. 

 The flowers vary from pinkish 

 purple to flesh-colour, sometimes 

 pale or even white. They form 

 a loose spike 3 to 6 inches long. 

 Fig. 330 represents the side view 

 of a flower from which all the 

 petals and sepals have been re- 

 moved, except the lip (/), half of 

 which has been cut away, as 

 well as the upper portion of the 

 near side of the nectary (n). The 

 pollen forms two masses (Figs. 

 331, a, and 332), each attached 

 to a tapering stalk, which gives 

 the whole an elongated pear-like form, and is attached 

 to a round sticky disk (Fig. 332, d), which lies loosely 

 in a cup -shaped envelope, the rostellum (r). This 

 envelope is at first continuous, but the slightest touch 



' "On the Impregnation in Orchids," Ann, of Nat. Sist. xii. (1863). 



2 D 



Fig, 329. — Orchis mascula. 



