Euryale ferox (Nymphaeaceae).--Professor Caspary informs me that this plant is highly self-fertile when insects are excluded. He remarks in the paper before referred to, that his plants (as well as those of the Victoria regia) produce only one flower at a time; and that as this species is an annual, and was introduced in 1809, it must have been self-fertilised for the last fifty-six generations; but Dr. Hooker assures me that to his knowledge it has been repeatedly introduced, and that at Kew the same plant both of the Euryale and of the Victoria produce several flowers at the same time.
Nymphaea (Nymphaeaceae).--Some species, as I am informed by Professor Caspary, are quite self-fertile when insects are excluded.
Adonis aestivalis (Ranunculaceae).--Produces, according to Professor H. Hoffmann ('Speciesfrage' page 11), plenty of seeds when protected from insects.
Ranunculus acris (Ranunculaceae).--Produces plenty of seeds under a net.
Papaver somniferum (Papaveraceae).--Thirty capsules from uncovered plants yielded 15.6 grains weight of seed, and thirty capsules from covered-up plants, growing in the same bed, yielded 16.5 grains weight; so that the latter plants were more productive than the uncovered. Professor H. Hoffmann ('Speciesfrage' 1875 page 53) also found this species self-fertile when protected from insects.
Papaver vagum.--Produced late in the summer plenty of seeds, which germinated well.
Papaver argemonoides.--According to Hildebrand ('Jahrbuch fur w. Bot.' B.7 page 466), spontaneously self-fertilised flowers are by no means sterile.
Glaucium luteum (Papaveraceae).--According to Hildebrand ('Jahrbuch fur w. Bot.' B.7 page 466), spontaneously self-fertilised flowers are by no means sterile.
Argemone ochroleuca (Papaveraceae).--According to Hildebrand ('Jahrbuch fur w. Bot.' B.7 page 466), spontaneously self-fertilised flowers are by no means sterile.
Adlumia cirrhosa (Fumariaceae).--Sets an abundance of capsules.
Hypecoum procumbens (Fumariaceae).--Hildebrand says (idem), with respect to protected flowers, that "eine gute Fruchtbildung eintrete."
Fumaria officinalis (Fumariaceae).--Covered-up and unprotected plants apparently produced an equal number of capsules, and the seeds of the former seemed to the eye equally good. I have often watched this plant, and so has Hildebrand, and we have never seen an insect visit the flowers. Hermann Muller has likewise been struck with the rarity of the visits of insects to it, though he has sometimes seen hive-bees at work. The flowers may perhaps be visited by small moths, as is probably the case with the following species.
Fumaria capreolata.--Several large beds of this plant growing wild were watched by me during many days, but the flowers were never visited by any insects, though a humble-bee was once seen closely to inspect them. Nevertheless, as the nectary contains much nectar, especially in the evening, I felt convinced that they were visited, probably by moths. The petals do not naturally separate or open in the least; but they had been opened by some means in a certain proportion of the flowers, in the same manner as follows when a thick bristle is pushed into the nectary; so that in this respect they resemble the flowers of Corydalis lutea. Thirty-four heads, each including many flowers, were examined, and twenty of them had from one to four flowers, whilst fourteen had not a single flower thus opened. It is therefore clear that some of the flowers had been visited by insects, while the majority had not; yet almost all produced capsules.
Linum usitatissimum (Linaceae).--Appears to be quite fertile. H. Hoffmann 'Botanische Zeitung' 1876 page 566.
Impatiens barbigerum (Balsaminaceae).--The flowers, though excellently adapted for cross-fertilisation by the bees which freely visit them, set abundantly under a net.
Impatiens noli-me-tangere (Balsaminaceae).--This species produces cleistogene and perfect flowers. A plant was covered with a net, and some perfect flowers, marked with threads, produced eleven spontaneously self-fertilised capsules, which contained on an average 3.45 seeds.