consisted below of the ordinary unchanged glumes, but the remaining paleae as well as the lodicles and stamens were represented by ligulate leaves. The plant, it is stated, was affected by a parasitic fungus. On the other hand, General Munro, in his valuable monograph of the _Bambusaceae_,[292] refers to an ill.u.s.tration in which "the lowest glumes generally, and the lowest paleae occasionally, had the appearance of miniature leaves, with v.a.g.i.n.ae, ligules and cilia, enveloping, however, perfect fertile spiculae; as progress is made towards the top of the spike, the ligule first, then the cilia, and finally, the leaf-like extension disappears, and the uppermost glumes a.s.sume the ordinary shape and form of those organs."

=General remarks on chloranthy and frondescence.=--Moquin remarks with justice that the position of the flowers on the axis is of importance with reference to the existence of chloranthy. Terminal flowers are more subject to it than lateral ones, and if the latter, by accident, become terminal, they seem peculiarly liable to a.s.sume a foliaceous condition.

Kirschleger says, that in _Rubus_ there are two sorts of chloranthy, according as the anomaly affects the ordinary flowering branches, or the leafy shoots of the year, the summits of which, instead of developing in the customary manner, terminate each in one vast and long inflorescence, very loose and indeterminate, and with axillary flowers.[293]

On the whole, taking in consideration cases of partial frondescence, as well as those in which most of the parts of the flower are affected, phyllody would seem to be most common in the petals and carpels, least so in the case of the stamens and sepals. It is more common among polysepalous and polypetalous plants than in those in which the sepals or petals are united together.

The causes a.s.signed for these phenomena are chiefly those of a nature to debilitate or injure the plant; thus it has been frequently observed to follow the puncture of an insect. M. Guillard[294] gives an instance in _Stellaria media_ where the condition appeared to be due to the attacks of an insect _Thrips fasciata_. Still more commonly it arises from the attacks of parasitic fungi, _e.g._ _Uredo candida_, in Crucifers, &c.

In other cases it has been observed when the plants have been growing in very damp places, or in very wet seasons, or in the shade, or where the plant has been much trampled on. This happens frequently with _Trifolium repens_. The frequency with which the change is encountered in this particular species is very remarkable; it is difficult to see why one species should be so much more subject to the kind of change than another of nearly identical conformation.

It might at first be supposed that the same causes that bring about the complete subst.i.tution of leaf-buds for flower-buds (see Heterotaxy) would operate also in the partial subst.i.tution of leaves for other parts of the flower, but it will be seen that the inducing cause, whether similar or not in the two cases respectively, acts at different times; in the one case, it is not brought into play until the rudiments of the flower are already formed, whereas in the other the influence is exerted prior to the formation of the flower. So that while the formation of leaf-buds in place of flower-buds may be and generally is due to an excess of nutrition, inducing over activity of the vegetative organs, the production of phyllomorphic or chloranthic flowers may be owing rather to a perversion of development arising from injury or from some debilitating agency. The discrepancies in the a.s.signed causes for the conditions above mentioned may, therefore, in great measure, be attributed to the different periods at which the causes in question operate.

The following list may serve as a guide to the plants most frequently the subjects of chloranthy, but reference should also be made to preceding and subsequent sections, and to that relating to prolification of the inflorescence.

Aquilegia vulgaris.

Chelidonium majus.

Corydalis aurea.

Nymphaea Lotus!

*Bra.s.sica oleracea!

Bunias.

Hesperis matronalis.

*Sinapis arvensis!

Sisymbrium officinale.

Erucastrum canariense.

Diplotaxis tenuifolia.

Lychnis dioica!

Cerastium glomeratum!

triviale.

Stellaria media.

Poterium polygamum.

Torilis anthriscus.

Seseli, sp.

Selinum caruifolium.

Epilobium hirsutum!

Begonia fuchsioides.

Gomphia, sp.

Scabiosa Columbaria.

Dipsacus fullonum.

Matricaria Parthenium.

Calendula officinalis.

Campanula pyramidalis.

Reseda odorata!

Vitis vinifera.

Dictamnus Fraxinella!

Triumfetta, sp.!

*Tropaeolum majus!

Rhamnus Frangula.

*Trifolium repens!

Lupinus, sp.

Rosa diversifolia!

Potentilla nepalensis.

argentea.

Fragaria vesca!

Geum rivale.

Rubus fruticosus.

caesius.

Saxifraga foliosa.

Verbasc.u.m phlomoides.

Scrophularia nodosa.

aquatica!

*Primula sinensis!

Lysimachia Ephemerum.

Anagallis arvensis.

Webbiana.

Nicotiana rustica.

Anchusa ochroleuca.

Myosotis caespitosa.

Stachys sylvatica.

Gilia capitata.

Euphorbia segetalis.

Rumex arifolius.

scutatus.

Juncus lampocarpus.

uliginosus.

In addition to the publications before cited the following may be named as containing valuable information on the subject of this chapter.

Jaeger, 'Missbild. Gewachs.,' 1814, p. 83, _Trifolium repens_.

For other accounts of similar malformations in the same plant, see Schmitz, 'Linnaea,' xv, p. 268. Unger, 'Flora' (B. Z.) xxv, p. 369. Caspary, 'Schrift. der. Physik. okon. Gesellsch. zu Konigsberg,' 2, 1861, p. 51, tabs. ii, iii. Fleischer, 'Missbilld. verschied. Cult. Pflanz.,' 1862, p. 55, &c., t. v, vii, &c. For _Primula_ see Brongniart, 'Ann. Sc. Nat.,' ser. 2, t. i, p. 308. A. P. and Alph. De Candolle in 'Neue Denkschrift.' Morren, C., 'Bull. Acad. Roy. Belg.,' xix, part 2, p. 539. Molkenboer, 'Tijdschr. voor Natuurl. Geschied.,'

1843, p. 355, tabs. vi, vii. Marchand, 'Adansonia,' iv, p. 167 and p. 159. _Anagallis_, p. 171, _Lonicera_, p. 83, _Juncus_.

For other plants see Fresenius, 'Mus. Senk.,' 2, p. 35, &c.

Norman, 'Ann. Sc. Nat.,' ser. 4, 1858, vol. ix, p. 220. Christ, 'Flora' (B. Z.) 1867, p. 376, tabs. v, vi, _Stachys_. Cramer, 'Bildungsabweich.,' p. 26, &c. Baillon, 'Adansonia,' ii, p.

300. Moquin-Tandon, 'El. Ter. Veg.,' p. 230. Schauer's translation, p. 220. Hallier, 'Phytopathologie,' p. 160.

FOOTNOTES:

[245] Engelmann makes use of the word frondescence in the same cases.

'De Anthol.,' p. 32, -- 38, while Morren adopts the term Phyllomorphy, 'Lobelia,' p. 95.

[246] See Schlechtendal, 'Bot. Zeit.,' vol. xv, 1857, p. 873; also Marchand, 'Adansonia,' iv, p. 156.

[247] For instances of similar changes in _Composites_, see De Candolle, 'Prod.,' t. vi, p. 571, _Centaurea Jacea phyllocephala_. Clos, 'Ann. Sc.

Nat.,' ser. iii, tom. xvi, 1851, p. 41. 'Science Gossip,' 1865, p. 104, &c.

[248] Kickx, 'Bull. Acad. Belg.,' t. xviii, part 2, p. 288.

[249] Weber, 'Verhandl. Nat. Hist. Vereins. f. Preuss.,' &c., 1860, p.

381.