AOA, MBIOTAXY IN 
corolla is developed as usual. his deficiency of the 
corolla is frequently, but not invariably, associated 
with an increased fertility. Thus, in some violets the 
flowers produced in summer, and in which the petals 
are either entirely suppressed or are more or less 
atrophied, are always fertile, while the blossoms deve- 
loped in spring, and in which the petals are always 
present, are much less fertile. In Ozalis Acetosella 
there are two forms of flower, the one with, the other 
without, petals, but both seem equally fertile. Linné 
remarks that many plants which, in warm latitudes, 
produce a corolla, do not do so when grown in colder 
chmates. Thus, certain species of Helianthemwm are 
apetalous in Lapland. In the Pyrenees, according to 
Bentham, the flowers of Ajuga wa are constantly de- 
prived of their corolla.' 
Apetalous flowers have been noted most frequently 
in the following plants : 
Aconitum, sp. pl. ! Crategus ! 
Cardamine impatiens. Medicago lupulina. 
Cheiranthus Cheiri! Melilotus officinalis. 
Viola odorata! Ononis minutissima. 
Cerastium vulgatum ! Saxifraga longifolia. 
Alsine media. Verbascum Thapsus. 
Stellaria. Ajuga iva. 
Lychnis dioica ! Teucrium Botrys. 
Dianthus barbatus, and other Lamium purpureum ! 
Caryophyllez. amplexicaule. 
Helianthemum, sp. ! Polemonium cxruleum, 
Oxalis Acetosella. Campanula, sp. pl.! 
Balsaminez. Ruellia clandestina. 
Malpighiacez. Lonicera Periclymenum ! 
Rosa centifolia. Tradescantia, sp.! 
arvensis! Hymenocallis. 
The following references apply some to apetalous and others to dimor- 
phic flowers, but it must be remembered that the latter plants are not 
necessarily wanting in petals or stamens, &c., though the functional 
activity of the parts may be impaired : 
A. de Jussieu, ‘Monogr. Malpigh.,’ pp. 82, 354. Torrey, ‘Fl. New 
York,’ i, p. 428. Hooker and Thomson, ‘Journ. Linn. Soe.,’ ui, p. 7, 
Guillemin, ‘Archiv de Botan.,’ i, p. 412. Michalet, ‘Bull. Soc. Bot. 
Fr.,’ vii, p. 465. Miller, ‘ Bot. Zeit.,’ 1857, p. 729. ‘ Natural History 
Review,’ July, 1862, p. 235. 
i 


1 *Cat. Plant. Pyr,’ p. 58. 
