SAPINDACEAE 255 



625. A. carnea Willd. In this species again, according to Martelli (op. cit.), 

 the flowers are not all fertile. Such are to be found, singly or in pairs, among 

 sterile ones on the same inflorescence. And as before, only the lower part of the 

 whole inflorescence is fertile. Sterile flowers occur in A. flava, but the great 

 majority are fertile. There is no difference between the parts of the entire in- 

 florescence, or its component branches. Focke (Abh. natw. Ver., Bremen, xiv, 1897, 

 p. 302) states that the species of Aesculus (Pavia), cultivated in Germany, are andro- 

 monoecious, like the horse-chestnut. For the production of fruit, cross-pollination 

 (by humble-bees) is generally necessary. 



626. A. Pavia L. ( = Pavia rubra Link). (Warnstorf, Schr. natw. Ver., Werni- 

 gerode, xi, 1896.) In this species the lower flowers of the branches of the panicle 

 are hermaphrodite and fertile, and the next above them pseudo-hermaphrodite; or 

 all the flowers may be pseudo-hermaphrodite. The two posterior and larger petals 

 possess a yellow nectar-guide, which later on assumes an intensely red colour. The 

 stamens are about as long as these petals. The pollen-grains are vermilion in 

 colour, ellipsoidal, with longitudinal furrows; on an average they are 25-30 p broad 

 and 42 fi long. 



Visitors. Alfken observed the following Apidae at Bremen. 1. Apis mellifica 

 L. ^ ; 2. Bombus hortorum L. o. ; 3. B. lucorum Z. 5; 4. B. muscorum F. 5 ; 5. B. 

 ruderatus F. <j>; 6. Psithyrus barbutellus K. 5, skg. ; 7. P. vestalis Fourcr. 1-5 skg. 

 and po-cltg. 



627. A. rubicunda Lodd. ('D. Geschlechts-Vert. b. d. Pfl.,' pp. 26-7.) The 

 species is andromonoecious with protogynous hermaphrodite flowers. While Hilde- 

 brand found all the earliest flowers of the panicle to be purely male, Kirchner (' Neue 

 Beob. u. d. Bestaubungseinricht. einheim. Pfl./ p. 31) says they are hermaphrodite, 

 occurring chiefly in the lower part of the inflorescence, where male flowers greatly 

 predominate as a rule. 



628. A. flava Ait. Martelli found most of the flowers to be fertile in this 

 species (cf. A. carnea). Focke saw many blossoms that had been perforated by 

 Bombus terrester. 



629. A. macrostachya Michx. (Kirchner, ' Beitr'age,' p. 30 ; Knuth, ' Bloe- 

 menbiol. Bijdragen.') The species is andromonoecious, with protandrous hermaphro- 

 dite blossoms, which are perhaps moth flowers. They are horizontal, white in colour 

 except for the red anthers, and exhale an odour of lilies. Nectar is secreted outside 

 the bases of the upper stamens. The tubular gamosepalous calyx is 7-8 mm. long. 

 The petals are slender, with long claws, and at first 12 mm. in length. To begin 

 with, the stamens are of the same length, but afterwards project 20-25 mm - out 

 of the corolla, when their anthers dehisce successively. After these have shed their 

 pollen, withered, and curved downwards, the stigma becomes fully mature, and at 

 this stage the style is over 30 mm. long. In male flowers the pistil is vestigial. 



Visitors. Kirchner observed the honey-bee, but supposes from the structure, 

 colour, and odour of the flowers, that nocturnal hawk-moths are the real pollinators. 

 In the Kiel Botanic Garden I too saw the honey-bee, skg., and also Bombus hortorum 

 L. 5. These two insects did not fly, but crept from flower to flower. 



