GERANIACEAE 229 



call attention to the differences between the two varieties of this species as regards 

 pollination. He distinguishes between them as follows. 



(a) Genuimim. The petals of this, the common variety, are generally of a 

 uniform red, and equal in size, though the upper ones are sometimes rather shorter 

 and of a darker tint than the others. The nectaries are all equally developed, 

 as in Geranium. The flowers are homogamous or slightly protogynous. The three 

 upper anthers, while dehiscing, lie close to the stigmatic branches, as do the two 

 lower ones subsequently, so that automatic self-pollination is inevitable. This is 

 effected an hour after the flower opens, which is at 7 o'clock in the morning. 

 By midday the flowers have shed their petals. This variety is perfectly fertile 

 with its own pollen. 



(b) Pimpinellifoliiim Willd. This variety is markedly entomophilous. The 

 flowers are as a rule relatively large, and the two upper petals smaller, broader, 

 and of a brighter red than the three lower ones. The latter are elongated, and 

 serve as an alighting-place for visitors. Each upper petal generally has a dark 

 nectar-guide, but this may be absent, and some or all of the other petals may be 

 similarly provided. The deeper parts of the flower are at first so blocked up by 

 the stamens that no insects can penetrate into them. The upper sepal and petals 

 are so far remote from the upper stamens that the dark posterior nectaries become 

 visible, while the lower ones are almost hidden by the hairs of the petals. The 

 latter are distinctly smaller than the former, and secrete much less nectar. When 

 the flower opens the style is still short and undeveloped, and the anthers are at 

 some distance from it. First the upper anthers, and afterwards the lower ones, 

 dehisce introrsely. The stamens soon curve completely outwards, and usually shed 

 their anthers before the stigmatic branches open and expand, which is generally 

 on the second day of anthesis. Only occasionally, especially when the nectar-guides 

 are not very conspicuous, do the stamens bend back again to the stigma in such 

 a way as to make automatic self-pollination possible as a last resort ; but this is 

 effective only to a slight extent. The petals usually fall off on the second day. 

 The nectar-guides are frequently wanting, or only slightly developed, in the smaller 

 female flowers that occur in addition to the hermaphrodite ones, either on the same 

 or on different stocks. 



The variety pimpinellifolium, however, does not always exhibit the characteristics 

 described by Ludtoig 1 . Schulz, in various parts of Germany and the Tyrol, has 

 studied the varieties of Erodium cicutarium for several years. The chief variety 

 (genuinum), according to him, occurs e. g. at Halle in two different oecological 

 forms. 



I. Flowers of a uniform red, in many cases quite radially symmetrical (actino- 

 morphous), and with a diameter of about 8 to 13 mm. Sometimes the two upper 

 petals are short and broad, sometimes they are also more deeply coloured than 

 the upper ones, and may exhibit one or several greyish-white patches, occasionally 

 streaked with red. Such flowers are almost always homogamous, less often slightly 



1 Ludwig described gemiinum from the neighbourhood of Greiz, and pimpinellifolium from 

 Schmalkalden, Schleusingen, &c. 



