In music, a fourth is an interval spanning four staff positions in the musical notation common in Western culture.
Specific fourth intervals include:
- Perfect fourth, the fourth spanning five semitones
- Diminished fourth, a perfect fourth narrowed by a chromatic semitone, thus spanning four semitones
- Augmented fourth or tritone, an interval of three adjacent whole tones (six semitones)
In addition, fourth in music may refer to:
- Quartal harmony, harmonic structures built from the perfect fourth, the augmented fourth and the diminished fourth
- Subdominant, the fourth tonal degree of the diatonic scale
Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction