246 ANGIOSPERMAE—DICOTYLEDONES 



2220. P. glaucocalyz Maxim. (Loew, Ber. D. Bot. Ges., Berlin, iv, 1886, 

 pp. 657-8.) — This species, indigenous to East Asia, bears small, whitish flowers, 

 generally provided with four blue spots above their entrance, serving as nectar- 

 guides. The corolla-tube is 3 mm. long, the flowers belonging therefore to class C. 

 In the first stage of anthesis, the style and stamens rest on the lower Up, the 

 stigmatic branches being still apposed. In the second stage, the style moves 

 upwards, the upper and longer stigmatic branch bending upwards rather strongly, 

 while the lower and shorter one remains horizontal. 



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



A. Diptera. (a) Muscidae: 1. Echinomyia fera Z. ; 2. Lucilia caesar L. 

 (b) Stratiomyidae: 3. Chrysomyia formosa Scop, (c) Syrphidae: 4. Eristalis 

 arbustorum L. B. Hymenoptera. Apidae : all skg. : 5. Apis mellifica 5 ; 



6. Halictus cylindricus F.t; 7. H. sexnotatus K. 5. 



2221. P. striatus Benth. (Breitenbach, Kosmos, Stuttgart, xv, 1884.) — 

 Breitenbach says that the flowers of this species are protandrous in the Botanic 

 Gardens at Marburg and Gottingen, and that the upper ones are female. 



700. Lavandula Tourn. 



Protandrous, very fragrant bee flowers. The stamens and the style are enclosed 

 in the bilabiate corolla. Nectar is secreted by the base of the ovary, as usual. 

 Gynodioecious. Medicus and Heckel state that the stigmas of L. dentata, 

 L. latifolia, and L. bicolor are sensitive. 



2222. L. vera DC. (= L. ofiicinalis Chaix). (Herm. Miiller, 'Fertilisation,' 

 pp. 469-70, ' WeiL Beob.,' Ill, pp. 59-60 ; Kirchner, ' Flora v. Stuttgart,' pp. 606-7; 

 Schulz, 'Beitrage,' II, p. 194 ; Knuth, ' Bloemenbiol. Bijdragen.') — The small, blue, 

 aromatic flowers of this species secrete abundant fragrant nectar from the highly 

 developed nectary, and this is stored at the base of the corolla-tube (6 mm. long), 

 and protected from rain by .a ring of hairs. Schulz says that the flowers are 

 gynodioecious. The anthers of the hermaphrodite flowers dehisce at the very 

 beginning of anthesis, and lie on the upper lip, turning their pollen-covered surfaces 

 upwards. At first the style with its immature stigma does not reach to the middle of 

 the coroUa-tube, so that although insects remove pollen, they cannot act as pollinators. 

 As the stamens fade, the style elongates to about i^ times its original length 

 during which process pollen easily clings to the still apposed stigmatic lobes. 

 These then diverge, and cross-pollination is brought about by insect-visits, for the 

 pollen of the same flower has already been removed. Should such visits fail, 

 automatic self-pollination finally takes place, the style elongating until it reaches the 

 two lower anthers. 



Visitors. — Knuth (Kiel Botanic Garden) only saw the honey-bee, freq., skg. 

 Herm. Miiller gives the following list for Thuringia. — 



A. Hymenoptera. Apidae: i. Anthidium manicatum L. 5 and S, freq. 

 especially the S, skg. ; 2. Anthophora quadrimaculata Pz. j and S, freq., skg. ; 3. Apis 

 mellifica L. 5, in great numbers, skg. ; 4. Chelostoma nigricorne Nyl. t>, skg. 

 5. Coelioxys conoidea ///. j, numerous, skg. ; 6. C. rufescens Lep. } and S, do. 



7. Crocisa scutellaris F. 5 and S, do.; 8. Megachile centuncularis L. $, skg. 

 9. M. fasciata Sm. 5 and $, the S numerous, skg. ; 10. M. willughbiella K. 5, ii 



