276 



ANGIOSPERMAE—DICOTYLEDONES 



Knuth (Kiel Ober-Realschule Garden, 26. 8. '97) — i. the bee Apis mellifica 

 L. 5, occasional, skg. vigorously and effecting crossing ; it obviously could not reach 

 the base of the flower with its short (6 mm.) proboscis, not being able to force its 

 head into the widened part of the corolla-tube; 2. the humble-bee Bombus terrester 

 L. t>, freq., skg., and effecting crossing; its proboscis (7-8 mm.) could reach the 

 nectar-storing base of the flower ; 3. the hover-fly Rhingia rostrata Z., freq., skg., 

 during which its proboscis (lo-ii mm.) was not entirely inserted into the corolla- 

 tube, and was therefore dusted with pollen 2-3 mm. from its base ; the bees, on the 

 other hand, brought the front of their heads into contact with stigma or anthers ; 

 4. and 5. the hover-flies Syritta pipiens L. and Syrphus balteatus Deg., both skg. 

 and effecting either cross- or self-polhnation ; 6. the Thysanopterid Thrips, frequent 

 in the flowers and occasionally effecting autogamy. Loew (Berlin Botanic Garden), 

 3 bees, all skg. — i. Apis mellifica Z. 5 ; 2. Bombus agrorum F.t,; 3. B. terrester. 



713. Horminum L. 



Protandrous bee flowers. Gynodioecism, rarely gynomonoecism. 



2291. H. pyrenaicum L. (Kerner, ' Schutzmittel d. Bliiten,' p. 225 ; Herm. 



Miiller, ' Alpenblumen,' pp. 

 318-19; Schulz, ' Beitrage,' 

 II, pp. 134-6; MacLeod, 

 ' Pyreneenbl.,' pp. 327-31.) — 

 The hermaphrodite flowers of 

 this species are so strongly 

 protandrous that automatic 

 self-pollination is excluded. 

 Schulz says that they vary in 

 size. Besides hermaphrodite 

 flowers there are often to be 

 found smaller female ones with 

 reduced anthers, generally 

 growing on separate stocks, 

 rarely on the same as the 

 others. In the Pyrenees also 

 (according to MacLeod), both 

 protandrous hermaphrodite 

 flowers and smaller, gynomo- 

 noeciously distributed female 

 ones occur ; in fact, those in 

 the lowest verticillaster are 

 generally female and open later 

 than the hermaphrodites situ- 

 ated just above them, 

 observers, and for the localities 



, a hover-fly, a beede, and 2 



Fig. 333. HorrKi num pyrenaicutn. L. (from Herm. Miiller's 

 Alpenblumen'). A Basal half of a llower, after removal of half 



the calyx and corolla, seen from below. B. Terminal hall of do , 



after remo\'al of the lower lip, seen from below ( X 3M. C. Ends 



of the two upper filaments with their proccs-ses, seen from the front 

 (X 7). Z?. Entrance of a flower, seen from the side (x 3 J,). ca, 



calyx; co, corolla ; Ji, filaments ; ^r, style ; «, nectary ; or', ovary ; 

 ^d, nectar-cover. 



Visitors. — The following were recorded by the 

 stated. — 



Herm. MuUer (Alps), 4 bees, 5 humble-bees 



