PRIMULACEAE 



75 



1829. P. saccharata Mill. — 



Visitors. — Loew observed the bee Anthophora pilipes F. i, skg., in the Berlin 

 Botanic Garden. 



1830. P, sinensis Sabine. (Ljungstrom, Bot. Not., Lund, 1884, pp. 17 1-4.) — 

 Ljungstrom observed cleistogamous flowers on plants of this species cultivated under 

 glass. These possessed a bell-shaped calyx, and a short closed tubular corolla, with 

 faint indications of lobes, and of a pale yellowish green colour. The anthers were 

 very small, and also the pollen-grains, these being only 14 /x long, while those of the 

 long- and short-styled chasmogamous flowers were respectively 32 /a and 24 /x in 

 length. One plant was long-styled, with the style bent in the middle and enclosed 

 in the corolla. In short-styled flowers the st^le was straight. Fruits and seeds were 

 not observed. 



544. Hottonia Boerh. 



Flowers heterostylous dimorphous, with concealed nectar, secreted at the base of 

 the ovary and stored up in the corolla-tube. Sometimes cleistogamy. 



1831. H. palustris L. (Darwin, 'Forms of Flowers,' pp. 50, 52, 252, 254; 

 Sprengel, ' Entd. Geh.,' p. 103; John Scott, J. Linn. Soc, Bot., London, viii, 1865; 

 Herm. MuUer, 'Fertilisation,' pp. 386-9, ' Weit. Beob.,' IH, p. 65; Knuth, ' Bloe- 



FlG. 246, Hottonia palustris, L. (after Henu. Miiller). (i) Long-stylcd flower. (2) Stigmatic 

 papillas of do. (3) Short-styled flower. (4) Stiftnatic papillae of do., enlarged to same scale as (2). 



menbiol. Bijdragen ' ; MacLeod, Bot. Jaarb. Dodonaea, Ghent, v, 1893, pp. 446-7.)— 

 Sprengel discovered heterostyly in this species, about which he makes the following 

 remarks (loc. cit.) : 



' Some plants only bear flowers with stamens inside the corolla-tube but the 

 style projecting from it, and others only flowers with the style shorter and the stamens 

 longer than the tube. I do not believe that this is accidental, but an arrangement of 

 Nature, though I am unable to explain its meaning.' 



The corolla-tube of the white or reddish flowers is 4-5 mm. long, and the 

 shorter reproductive organs are placed in its opening, while the longer ones project 

 3-4 mm. from it. Insect visitors when probing for nectar touch the two kinds of 

 organ with different parts of their bodies, and thus regularly effect legitimate crossing. 



