SCROPHULARINEAE 



20I) 



2149, P. recutita L. (Herm. Miiller, ' Alpenblumen,' pp. 293-5 ; Kerner, 

 'Nat. Hist. PI.,' Engl. Ed. i, II, pp. 272-3.) — The lower lip of the red corolla of 

 this species is symmetrically disposed, and only a small part of its base is apposed to 

 the upper one. It possesses a median groove which, according to Hermann Mailer, 

 conveniently guides the proboscis of a humble-bee to the nectar in the base of the 

 flower, though Lindman says it is too narrow for this purpose. Humble-bees with 

 a proboscis 8-9 mm. long can suck all the nectar. Kerner speaks as follows of the 

 way in which pollen is discharged (op. cit., pp. 272-3). — 



' The anthers in the flowers of this plant are borne on elastic filaments, and are 

 regularly squeezed between the lateral walls of the helmet-shaped upper lip. No 

 separation of the anther-valves is possible unless this lip expands and becomes 

 laterally inflated. This is brought about in a very curious manner. When a humble- 

 bee alights it seizes the projecting upper lip and bends it down through an angle 

 of about 30°, this action being facilitated by the presence of strong ribs at the base of 



Fig. 306. Pedicularis recutita, L. (after Henn. Miiller). A, Flower just before opening, seen 

 from the side. B. Upper part of do., after opening. C Mature flower, seen from the side. D. Upper 

 part of do., from the front. B. Uppermost part of the corolla, the left half having been cut through 

 and bent down. F. Ovary and nectary. G. Cross-section of upper lip on xy in C(x 5). a, anthers ; 

 f;r, style; /, /, fold and thickening on side of upper lip; n, nectary; ov, ovary; r, reflexed edge of 

 upper lip; st, stigma; «, groove on lower lip; w, folds bounding do. 



the helmet on either side of the throat of the corolla, which act like levers, and 

 communicate their motion to the entire upper lip. In consequence of the inclination 

 of this lip, the sides of the helmet, which up to this time are tightly stretched, bulge 

 out laterally ; secondly, the filaments bend in the same sense as the bulging sides of 

 the helmet ; and thirdly, the anthers themselves come apart pouring the pollen-dust 

 on to the insect's back. In order that this complicated machinery may do its work 

 successfully, the insect must insert its proboscis at a certain definite spot through a 

 little groove in the under lip, and for this reason all other spots where entrance into 

 the flower might be effected are barricaded. The margin of the upper lip, for 

 instance, is thickly furnished with short-pointed prickles which the insects take care 

 not to touch.' 



