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Four O'Clock Flower
Mirabilis jalapa
オシロイバナ
A perennial herb native to South America (treated as an annual in Japan), naturalized along roadsides and vacant lots from summer to autumn. Its English name 'Four O'Clock' derives from its habit of opening flowers around 4 PM. The Japanese name 'Oshiroibana' (face-powder flower) comes from the white powdery endosperm inside the black seeds, once used as face powder.
Identification Points
- ✓Flowers open in the evening and close by morning
- ✓Flower colors are diverse—red, yellow, white, pink, etc. (multiple colors may appear on one plant)
- ✓Black spherical fruits contain white powdery endosperm
Habitat
Roadsides, vacant lots, and gardens (cultivated and naturalized)
Season
June–November (flowers)
Morphological TraitsAI-estimated, needs verification
Growth form
Herb
Flowering season
Summer
Habitat
Roadside
Leaf type
Simple
Venation
Pinnate
Petal count
3 petals
Petal fusion
Fused
Stipules
Absent
Leaf dissection
Undivided
Flower symmetry
Actinomorphic
Ovary position
Superior
Stamen count
3-4
Phylogenetic Positionオシロイバナ科 →
Phylogenetic Position
Angiosperms > Eudicots > Core Eudicots > Caryophyllales > Nyctaginaceae
Divergence Era
Paleogene (ca. 55 million years ago)
Evolution Notes
Nyctaginaceae belongs to the betalain-producing clade within Caryophyllales. The showy structures are petaloid sepals rather than true petals. Nocturnal flowering is an adaptation to attract hawkmoths.
View on evolution timeline →Sources & References
AI-generated, needs verification