The Yellow Star-of-Bethlehem is one of the first augurs of spring in the flowery meadows of the Donau-Auen National Park. This plant avoids wet locations and is thus more typical of the hardwood riparian forests.
Description
A member of the lily family, the perennial Gagea lutea usually grows from 10 to 30cm high. The first basal leaf is from 5 to 15mm wide, strap-shaped and has a hood-like hook at its very tip. The bottom stem leaf normally does not exceed the height of the inflorescence. Between March and May, the bare, hairless flower stalk carries up to seven yellow flowers. The six petals are shiny yellow-gold on the inside and green on the outside at first, changing later to greenish-yellow with a broad green stripe on the back. They can reach lengths of up to 18mm and are rounded off at the front. The fruit is a small tripartite capsule with few seeds.
Distribution
The Yellow Star-of-Bethlehem's range is huge, encompassing most of Europe and extending to the Himalayas and even Japan. In Austria, the species may be found sporadically to frequently in all provinces. The plant settles in riparian forests with ample herb growth, scrub, and damp meadows, even up to very high Alpine elevations. Prime location for this lily species is deep, nutrient-rich, sandy-loamy soils with (at least occasionally) high ground water levels.
Endangerment and Conservation Status
In the Alps of western Austria, Gagea lutea is considered regionally vulnerable. In Lower Austria, all species of the Gagea genus are protected, at least in part. It is forbidden "to pick more than five specimens of any one species above ground and in total no larger than a small bouquet".
Ecological Characteristics
The Yellow Star-of Bethlehem blooms very early in the year. Like its deciduous leaves, the outwardly green petals are capable of carrying out photosynthesis and thus make a contribution to the energy supply of the plant. In inclement weather such as rain, snowfall and cold, or after being plucked, the flowers quickly close to become completely inconspicuous. Using their bright colour as a signal, the scentless flowers invite pollinating insects to land and reward such visits with nectar. Should such welcome visitors be discouraged by cold or otherwise inclement weather, the plant may resort to self-pollination by folding its flowers inward. Its seeds feature a special attachment – a so-called elaiosome – catering to ants, who are attracted to this prize, remove it from the plant and thus help disperse the seeds. In addition to this type of reproduction, the Yellow Star-of-Bethlehem may also reproduce by vegetative means, using the bulbil in the axil of the basal leaf. Yet another type of reproduction via root suckers has also been documented. As a spring bloomer, the Gagea lutea exploits the extra sun available in the season before the deciduous trees foliate. Energy stored in the bulb enables the plant to form leaves quickly and thus ideally utilize the extra light available on the woodland floor during this brief period. Before the other plants have flowered and the woodland turns shady, this species has already blossomed and managed to store enough reserves in its bulb for the next season!
Special Characteristics
There are over fifty different sub-species of the Gagea genus, most of which are found in the Mediterranean region and in Asian steppe habitats. In Austria, there are eight sub-species represented, most of which are difficult to differentiate from each other.