Pollination and Fertilization 



161 



receive they also split down the centre and spread apart. The 

 fruits formed in these flowers give evidence that the insects 

 have unconsciously brushed off the pollen from the stamens 

 of the outer flowers and delivered it to the inner stigmas. 



Senecios also spread apart the stigmas in the disk flowers. 

 They have a little brush just at 

 the tip. They can curl back far 

 enough to help themselves from 

 neighbouring flowers, and even 

 from the pollen that has adhered 

 to their own styles if no insect 

 pays them a visit. 



Take any Indigo fera. They 

 are usually creeping plants with 

 blue or purplish flowers, belong- 

 ing to the Pea family. 



Botanists state in a matter-of- 

 fact way that the keel, or two 

 boat-shaped petals in front, is 

 provided with a spur or promi- 

 nence at each side near the base. 

 The bees have never had their 

 attention called to this, and are 

 unaware that these prominences 

 are hidden springs, and that this 

 keel contains concealed and 

 loaded weapons. The unsuspect- 

 ing bee poises on the two side 

 petals invitingly offering a resting-place, when, presto ! the 

 springs are set off, the side petals spread apart ; the keel 

 drops, releasing the stamens charged with powder, and up they 

 fly. The range is just right, and the bee is well dusted for the 

 next flower which has its pistil ready to receive it. 



Every one who lives in the Eastern Province knows what 

 is meant by " lighting matches ". The " matches " of Loranthus 

 oleafolius are borne in umbels of three to five flowers, bright 

 red at base, and orange in the upper portion with green tips. 

 The plant, which .is parasitic on Acacia trees, pays for its 

 II 



I. II. 



FIG. 159. The disk flowers of 

 Senecio have stigmas that can 

 coil back and help themselves to 

 pollen. The ray flowers (I.) have 

 no stamens. (From Thome and 

 Bennett's " Structural and Phy- 

 siological Botany".) 



