Many of the plants that bloom in late summer and early autumn, such as the Crocus and the Pancratium are bulbous, allowing them to flower without leaves. The Muscari blooms slightly earlier, just after the first rain, when its leaves sprout. Thus, it blossoms at the expense of reserves from the previous year. At this time of year there are few insects and many of the flowering plants have especially large blossoms – the Crocus and the Pancratium can be seen from afar while the Muscari is less attractive and can develop seeds without pollination. All three of these bulbous plants are potentially readily available sources of food for animals The bulbs of all three species contain toxic compounds which protect them from preying.
White flowers are rare among the species that grow in the desert sands. The Pancratium sickenbergeri has white blossoms and a weak scent that is relatively unpleasant in comparison to the similar Sea Daffodil. It attracts both nocturnal and diurnal insects. The plant has narrow curly leaves that appear only after it blooms, so it is a harbinger of the rains. The seeds of this species are spongy and suited to dispersal by the sea waves. Some think that it evolved from the Sea Daffodil, which has similar seeds that can float in seawater.
Although the passage says: “I am a rose of Sharon, a lily of the valleys” (Song of Songs 2:1) it is not certain that this is the plant to which it refers.
The Pancratium sickenbergeri’s bulb serves as a food source and allows it to blossom at the end of summer with no leaves. The desert gazelles eat both the bulb and the flowers. It was discovered that under conditions of abundant grazing, the plants developed shorter flowering stalks because the gazelles prefer to eat the taller ones. Thus the shorter flowers have a greater chance of survival.
The stage presence of certain flowers simply cannot be ignored, even if it just a single blossom. It was not for naught that poet Lea Zehavi called this species “an astonishing yellow flower”.
In the spring, when there is stiff competition for pollination, the size of the flower can be linked to the amount of nectar it offers. Visitors have learned that large flowers offer larger reward, thus those flowers compete more for pollination services. In the autumn, when there are not many flowers or visitors, it is more important for the “advertisement” to be visible from afar than for the reward to be great. There is no concern that the pollinators will seek a better source since there are few flowers in the habitat during this season.
The Sternbergia clusiana can be pollinated by different insects. Bees that land on its smooth perianth slide inside and suck the nectar that is secreted at the bottom of the flower. On their way out they climb onto the stamens, collect the pollen and sometimes also touch the stigma and pollinate it as well. The bees fly straight toward the flower, thus it seems that the color is the main attracting signal. Close observation reveals that on the ends of the flower’s perianth there are small additions measuring 3-4 millimeters. These “tips” are the glands that excrete a scent and a small amount of nectar to attract hoverflies. The hoverflies fly toward these tips in a zigzag manner, indicating that they are attracted by the scent particles which are carried in the wind, and thus occasionally change direction.
The blossoming of this species depends on a decrease in temperature. That is why it blooms first at higher mountain altitudes and only later in lower locations. The difference can be as much as an entire month during the same season.
Many know this plant by its common name “rain bells” (which is also common to the Autumn Squill). This is due to the shape of the flower and its appearance at the start of the rainy season. The light blue flowers are slanted downward and protected from rain damage. The upper flowers are small and sterile and serve only for “advertising”. Although the flowers have nectar and a sweet scent, visitors are surprisingly rare and it produces seeds infrequently. Its blossoming season is short and illusive and may be difficult to recognize due to the small number of flowers. When these flowers are gently squeezed, they make a sound similar to a buzzing fly. Some believe this is the origin of its name Muscari, which means “fly”.
Most of the plant’s reproduction is achieved by creating many bulbils near the mother plant. Every such bulblet is equipped with a juicy thick retractable root that grows horizontally. After growing sideways for a few centimeters it retracts, pulling the new bulbil away from the mother plant, thus preventing inter-generational competition. Over time large dense colonies are created.
Professor Emeritus Department of Evolutionary and Environmental Biology, Haifa University