The Star-of-Bethlehem (Ornithogalum umbellatum) is a bulbous perennial flowering plant in the family Asparagaceae, prized for its clusters of star-shaped white flowers that bloom in late spring to early summer.
The common name derives from the flower's resemblance to the Star of Bethlehem described in the biblical account of the Nativity. Each flower has six white tepals with a distinctive green stripe on the outer surface, creating a striking star pattern.
• Genus name Ornithogalum comes from the Greek words "ornis" (bird) and "gala" (milk), possibly referring to the white color of the flowers
• Species epithet "umbellatum" refers to the umbel-like inflorescence
• Also commonly known as "nap-at-noon" or "eleven-o'clock lady" because flowers open around midday and close in the evening or on cloudy days
• Has been cultivated as an ornamental garden plant since at least the 16th century
Taxonomie
• Native range includes the Mediterranean basin, extending from Portugal and Morocco eastwards to Turkey and the Caucasus
• Has been widely naturalized in North America, where it was introduced as a garden ornamental in the 17th–18th centuries
• Now considered an invasive species in parts of the eastern United States and Canada, where it colonizes lawns, meadows, roadsides, and disturbed areas
• The genus Ornithogalum comprises approximately 150–200 species, with the greatest diversity in southern Africa
Bulb & Roots:
• Bulb is ovoid, 1.5–3 cm in diameter, covered with a thin membranous tunic
• Produces offsets (small bulblets) around the parent bulb, enabling vegetative spread
• Roots are fibrous and contractile, which help pull the bulb deeper into the soil
Leaves:
• Basal rosette of 4–8 linear leaves emerging directly from the bulb
• Leaves are narrow, 10–30 cm long and 3–8 mm wide, with a prominent pale midrib
• Glaucous green to dark green; typically wither by the time flowers fully open
Inflorescence & Flowers:
• Erect, leafless scape (flowering stem) 10–30 cm tall
• Terminal corymbose raceme (appearing umbel-like) bearing 6–20 flowers
• Each flower is 1.5–2.5 cm across with 6 white tepals
• Outer surface of each tepals bears a conspicuous green stripe; inner surface is pure white
• Flowers are actinomorphic (radially symmetrical) and hermaphroditic
• 6 stamens with yellow anthers; superior ovary
Fruit & Seeds:
• Fruit is a three-lobed ovoid capsule (~1 cm long)
• Seeds are black, rounded, and approximately 2 mm in diameter
• Seeds are dispersed by wind and gravity; also spread through soil disturbance
• Commonly found in meadows, grasslands, roadsides, woodland edges, and disturbed ground
• Prefers well-drained, loamy or sandy soils but tolerates a range of soil types
• Blooms from April to June depending on latitude and climate
• Flowers open around midday in sunny conditions and close in the evening or on overcast days — a behavior known as photonasty
• Pollinated by generalist insects including bees and hoverflies
• In its invasive range (e.g., eastern North America), it can form dense colonies that displace native spring ephemerals
• Emerges early in spring, flowers, and completes its above-ground growth cycle by early summer, then enters dormancy — a strategy typical of spring ephemerals adapted to deciduous woodland and meadow environments
• Contains cardiac glycosides (including convallatoxin and convalloside) and ornithogalin
• Ingestion can cause nausea, vomiting, diarrhea, abdominal pain, and in severe cases, cardiac arrhythmias
• The bulb is the most toxic part and can be mistaken for edible alliums (wild onions or garlic) by foragers
• Livestock poisoning has been reported when animals graze in heavily infested pastures
• Skin contact with the sap may cause dermatitis in sensitive individuals
Light:
• Full sun to partial shade; performs best with at least 4–6 hours of direct sunlight
Soil:
• Well-drained, moderately fertile soil; tolerates sandy, loamy, or clay-loam soils
• pH range: 6.0–7.5 (slightly acidic to neutral)
• Does not tolerate waterlogged conditions, which cause bulb rot
Planting:
• Plant bulbs in autumn (September–November) at a depth of 5–8 cm
• Space bulbs 5–10 cm apart for naturalized drifts
• Once established, bulbs multiply readily by offsets and self-seeding
Watering:
• Moderate watering during active growth in spring
• Reduce watering after foliage yellows and dies back in summer
• Dormant bulbs are drought-tolerant
Temperature:
• Hardy in USDA zones 4–9
• Tolerates winter temperatures down to approximately -30°C when dormant
• Requires a period of winter chilling for optimal flowering
Propagation:
• By bulb offsets (division) in late summer or autumn
• By seed sown in autumn; seedlings typically take 3–4 years to reach flowering size
Common Problems:
• Generally pest- and disease-free
• Bulb rot can occur in poorly drained soils
• Can become invasive in favorable conditions — consider planting in contained areas or where spread can be managed
Anecdote
The Star-of-Bethlehem's midday flowering behavior has fascinated botanists for centuries: • The flowers exhibit photonasty — they open in response to bright light and close in darkness or dim conditions, typically between approximately 10 a.m. and 4 p.m. • This behavior led to its folk name "nap-at-noon" in parts of Europe, as the flowers appear to "take a nap" in the afternoon • The green stripes on the outer tepals are thought to serve as nectar guides for pollinators, visible in ultraviolet light • In the language of flowers (floriage), Star-of-Bethlehem symbolizes purity, hope, and reconciliation • Despite its toxicity, the plant was used in traditional European folk medicine in carefully controlled preparations, though such use is strongly discouraged today • In its invasive range in North America, a single bulb can produce dozens of offsets over several years, forming dense mats that are extremely difficult to eradicate — making it a cautionary tale about introducing non-native ornamental plants
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