A genus of grasses with broad leaves and a dense spike of flowers

Usage examples of phalaris.

Phalaris, manner of bending--Results of the exclusion of light from their tips--Effects transmitted beneath the surface of the ground--Lateral illumination of the tip determines the direction of the curvature of the base--Cotyledons of Avena, curvature of basal part due to the illumination of upper part--Similar results with the hypocotyls of Brassica and Beta--Radicles of Sinapis apheliotropic, due to the sensitiveness of their tips--Concluding remarks and summary of chapter--Means by which circumnutation has been converted into heliotropism or apheliotropism.

Distinction between heliotropism and the effects of light on the periodicity of the movements of leaves--Heliotropic movements of Beta, Solanum, Zea, and Avena--Heliotropic movements towards an obscure light in Apios, Brassica, Phalaris, Tropaeolum, and Cassia--Apheliotropic movements of tendrils of Bignonia--Of flowerpeduncles of Cyclamen--Burying of the pods--Heliotropism and apheliotropism modified forms of circumnutation--Steps by which one movement is converted into the other Transversalheliotropismus or diaheliotropism influenced by epinasty, the weight of the part and apogeotropism--Apogeotropism overcome during the middle of the day by diaheliotropism--Effects of the weight of the blades of cotyledons--So called diurnal sleep--Chlorophyll injured by intense light--Movements to avoid intense light.

Brassica oleracea, circumnutation of the radicle, of the arched hypocotyl whilst still buried beneath the ground, whilst rising above the ground and straightening itself, and when erect--Circumnutation of the cotyledons--Rate of movement--Analogous observations on various organs in species of Githago, Gossypium, Oxalis, Tropaeolum, Citrus, Aesculus, of several Leguminous and Cucurbitaceous genera, Opuntia, Helianthus, Primula, Cyclamen, Stapelia, Cerinthe, Nolana, Solanum, Beta, Ricinus, Quercus, Corylus, Pinus, Cycas, Canna, Allium, Asparagus, Phalaris, Zea, Avena, Nephrodium, and Selaginella.

It has already been stated that the cotyledons of Phalaris and Avena, the plumules of Asparagus and the hypocotyls of Brassica, were likewise able to displace the same kind of sand, either whilst simply circumnutating or whilst bending towards a lateral light.

Accordingly, two pots of seedling Phalaris and one pot of seedling Brassica were exposed for 8 h.

Means of observation--Apogeotropism--Cytisus--Verbena--Beta--Gradual conversion of the movement of circumnutation into apogeotropism in Rubus, Lilium, Phalaris, Avena, and Brassica--Apogeotropism retarded by heliotropism--Effected by the aid of joints or pulvini--Movements of flowerpeduncles of Oxalis--General remarks on apogeotropism--Geotropism--Movements of radicles--Burying of seedcapsules--Use of process--Trifolium subterraneum--Arachis--Amphicarpaea--Diageotropism--Conclusion.

Brassica oleracea, circumnutation of the radicle, of the arched hypocotyl whilst still buried beneath the ground, whilst rising above the ground and straightening itself, and when erect--Circumnutation of the cotyledons--Rate of movement--Analogous observations on various organs in species of Githago, Gossypium, Oxalis, Tropaeolum, Citrus, Aesculus, of several Leguminous and Cucurbitaceous genera, Opuntia, Helianthus, Primula, Cyclamen, Stapelia, Cerinthe, Nolana, Solanum, Beta, Ricinus, Quercus, Corylus, Pinus, Cycas, Canna, Allium, Asparagus, Phalaris, Zea, Avena, Nephrodium, and Selaginella.

It has already been stated that the cotyledons of Phalaris and Avena, the plumules of Asparagus and the hypocotyls of Brassica, were likewise able to displace the same kind of sand, either whilst simply circumnutating or whilst bending towards a lateral light.

Phalaris and Avena the first true leaf, which is bright green and no doubt decomposes carbonic acid, exhibits hardly a trace of heliotropism.

Phalaris and Avena, and therefore could not be so easily measured under the microscope.

As the tips of the cotyledons of Phalaris and Avena bend upwards through the action of apogeotropism before the basal part, and as these same tips when excited by a lateral light transmit some influence to the lower part, causing it to bend, we thought that the same rule might hold good with apogeotropism.

When the cotyledons of Phalaris and Avena were covered with grease along one side, the growth of this side was quite stopped or greatly checked, and as the opposite side continued to grow, the cotyledons thus treated became bowed towards the greased side.

In order to observe how long the aftereffects of light lasted, a pot with seedlings of Phalaris, which had germinated in darkness, was placed at 10.

Yet we should remember that the circumnutating sheathlike cotyledons of Phalaris, the hypocotyls of Solanum, and the epicotyls of Asparagus formed round themselves little circular cracks or furrows in a superficial layer of damp argillaceous sand.

We may also conclude from these and the previous observations, that the seedlings of Phalaris in breaking through the surface of the soil circumnutate as much as the surrounding pressure will permit.