2o6 ANGIOSPERMAE—DICOTYLEDONES 



weather, and then automatic self-pollination takes place as a result of the pseudo- 

 cleistogamy. 



According to Warnstorf (Verh. bot. Ver., Berlin, xxxviii. 1896), the diameter 

 of the flower may be as much as 8 mm. ; the petals have black marginal glands. 

 The pollen is yellow, ovoid, delicately tuberculated, about 31 /x long and 

 15 /A broad. 



Visitors. — In Dumfriesshire, several Muscidae have been recorded (Scott-Elliot, 

 'Flora of Dumfriesshire,' p. 33). 



515. H. Elodes Huds. (=Elodes palustris Spach). (MacLeod, Bot. Jaarb. 

 Dodonaea, Ghent, vi, 1894, pp. 226-7.) — The base of each yellow petal bears a 

 split scale, which perhaps secretes nectar. Above these scales, between the staminal 

 bundles, there are small liguliform bifid glands (? modified stamens) which are 

 applied to the ovary, and perhaps also secrete nectar. 



Visitors. — In Dumfriesshire, a Muscid has been observed (Scott-Elliot, ' Flora 

 of Dumfriesshire,' p. 34). 



XX. ORDER MALVACEAE R. BR. 



Literature. — Knuth, 'Grundriss d. Bliitenbiol.,' p. 32. 



The bright colour of the large corolla, and often also of the pyramid of stamens, 

 renders the flower conspicuous. Nectar is secreted between the bases of the petals, 

 or at the bottom of the calyx. Many species, therefore, belong to the flower class C. 

 Individual genera (Hibiscus) include nectarless species, which consequently belong 

 to class Po. Almost all the Malvaceae are markedly protandrous. The South 

 Brazilian species of Abutilon are pollinated by humming-birds, which discharge 

 their function so actively that the possibility of autogamy has been lost (Herm. Miiller, 

 'Fertilisation,' p. 146). 



147. Malva L. 



Flowers protandrous, with concealed nectar, secreted as above described. 



516. M. sylvestris. (Sprengel, ' Entd. Geh.,' pp. 347-50 ; Herm. Miiller, 

 'Fertilisation,' pp. 142-4, ' Weit. Beob.,' II, p. 221; Knuth, ' Bl. u. Insekt. a. d. 

 nordfr. Ins.,' pp. 47-8, 152 ; Kirchner, 'Flora v. Stuttgart,' p. 331.) — The red petals 

 are marked with dark circles, which serve as nectar-guides, and above the secre- 

 tion are ciliary hairs serving as a protection. In the first stage of anthesis the 

 anthers meet in the form of a pyramid above the filaments — which are united below — 

 completely covering the still immature stigmatic branches enclosed in the staminal 

 tube, so that the mature anthers alone occupy the middle of the flower. After they 

 have dehisced the stamens curve downwards, while the stigmatic branches develop, 

 and spread out so that the papillae on their inner surfaces now occupy the place 

 where the anthers were at first situated. Insects visiting the flower must, therefore, 

 regularly effect crossing. Automatic self-pollination is excluded, and is unnecessary, 

 owing to the large number of insect visitors. 



Visitors. — Herm. Miiller (H. M.) and myself (Kn.) in Central and North 

 Germany have observed the following). — 



