Periodic phenomena

Flowers, also known as blossoms and blooms, are the reproductive structures of flowering plants. Typically, they are structured in four circular levels around the end of a stalk. These include: sepals, which are modified leaves that support the flower; petals, often designed to attract pollinators; male stamens, where pollen is presented; and female gynoecia, where pollen is received and its movement is facilitated to the egg. When flowers are arranged in a group, they are known collectively as an inflorescence.

right|thumb|Variation of orbital eccentricity    

A decade (from , , ) is a period of 10 years. It may also be called a decennium (from , ). Decades may describe any ten-year period, such as those of a person's life, or refer to specific groupings of calendar years.

a type of ovulation cycle where the endometrium is shed if pregnancy does not occur

In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, after flowering; and to the shedding of ripe fruit. The antonym of deciduous in the botanical sense is evergreen.

periodic changes in the orbital movements of the earth

Phenology is the study of periodic events in biological life cycles and how these are influenced by seasonal and interannual variations in climate, as well as habitat factors (such as elevation).

part of the day during which traffic congestion on roads and crowding on public transport is at its highest

period of very close to 19 years that is nearly a common multiple of the solar year and the synodic (lunar) month

periodic change in the Sun's activity

philosophical concept regarding infinite continuance of the universe

genus of insect of eastern North America

plot device in science fiction

collective behaviour of a large number of (usually) self-propelled entities of similar size

purported correlation between the lunar cycle and behavior and physiological changes in living beings on Earth, including humans

purported menstrual cycle synchronization in women who live together

small deviation in the Earth's axis of rotation relative to the solid earth

Wikimedia list article

Phenomenon in bamboo

thumb|250px|Flowering bamboo Mautâm () is a cyclic ecological phenomenon that occurs every 48–50 years in the northeastern Indian states of Tripura, Mizoram and Manipur, as well as in many places of Assam which are 30% covered by wild bamboo forests, and Chin State in Myanmar, particularly Hakha, Thantlang, Falam, Paletwa and Matupi Townships. It begins with a rat population boom, which in turn creates a widespread famine in those areas.