282 ANGIOSPERMAEDICOTYLEDONES 



718. Pycnanthemiun Michx. 



2304. P. muticum Pers. (= P. pilosum Nutt.). (Loew, Ber. D. bot. Ges., 

 Berlin, iv, 1886, pp. 126-7.) This species is indigenous to North America. The 

 numerous crowded, spotted white flowers are protandrous. The corolla-tube is 

 about 6 mm. long. The spots indicate fly visitors. 



2305. P. lanceolatum Pursh. (Loew, op. cit., iv, 1886, pp. 127-8.) The 

 plant of this species cultivated in the Berlin Botanic Garden bears only purely 

 female flowers. 



719. Loptianthus Benth. 



2306. L. nigosus Fisch. et. Mey. (Loew, op. cit., iv, 1886, pp. 125-6.) 

 Loew describes this species as feebly protandrous. The numerous, crowded, strongly 

 aromatic flowers attract large numbers of visitors. 



Visitors. Loew observed the following in the Berlin Botanic Garden. 



A. Diptera. Syrphidae : i. Eristalis tenax Z. ; 2. Syritta pipiens Z. B. Hy- 

 menoptera. Apidae : all skg. : 3. Apis mellifica Z. 5 ; 4. Bombus agrorum F. 5 ; 

 5. B. pratorum Z. 5 ; 6. Psithyrus vestalis Fourcr. J. 



2307. L. chinensis (= Nepeta lophantha Fisch. et Mey.). 

 Visitors. Loew observed the following in the Berlin Botanic Garden. 



A. Diptera. Syrphidae: i. Syrphus balteatus Beg. B. Hymenoptera. 



Apidae : 2. Bombus agrorum F, S, skg. ; 3. Halictus sexnotaius K. $, po-cltg. ; 

 4. Psithyrus vestalis Fourcr. S, skg. C. Lepidoptera. Rhopalocera : 5. Pieris 

 brassicae Z., skg. 



2308. L. anisatus Benth. 



Visitors. Loew (Berlin Botanic Garden) observed the humble-bee Bombus 

 agrorum $, skg. 



2309. L. scrophulariaefolius Benth. 



Visitors. Loew (Berlin Botanic Garden) observed the humble-bee Bombusj 

 agrorum F. $, steadily skg., and 2 bugs Corizus parumpunctatus SchilL, anc 

 Sehirus biguttatus Z. 



720. Ziziphora L. 



2310. Z. capitata L. (Willis, J. Linn. Soc., Bot., London, xxx, 1895.) TW 

 small inconspicuous flowers of this species are regularly self-pollinated in England.! 

 The length of the corolla-tube (9 mm.) adapts them to bees or hover-flies. 



721. Melittis L. 



Protandrous revolver flowers belonging to class Hhb or Lm. 



2311. M. Melissophyllum L. (Herm. Miiller, ' Weit. Beob.,' Ill, p. 52 ^ 

 Stadler, ' Beitrage,' pp. 12-16; Schulz, ' Beiirage,' II, pp. 136-8; Bonnier,] 

 ' Etudes anat. et physiol. d. nectaires,' pp. 31, 64 ; Kerner, ' Nat. Hist. PL.'Eng. Ed. 

 1, II, p. 569.) Kerner says that the flowers of this species are always white in thfl 



