Ramat Bet Hakerem: Geophytes

פורסם: August 8th, 2010 | עודכן: 15/01/15

1.12. Plants with bulb or corm (geophytes)

One of the successful life forms suited to Mediterranean conditions is the geophytes. These plants have underground food and water reserves stored in a bulb, corm, rhizome or even in thick roots. [Urginea maritima] is one of the most prominent geophytes of Israel. It has a peculiar life cycle; it develops a rosette of large leaves and when the rainy season ends its leaves dry out. The apical meristem of a bulb, which is large enough to bloom, changes during the summer and becomes a minute inflorescence hidden within the bulb. As the days become shorter, during August-September, the [“Urginea maritima” U. maritime] blooms (Figs. 2.1.46, 2.1.47). Such an inflorescence terminates the activity of the stem, the leaves of which developed at the beginning of winter. When sprouting, the young leaves looked like the stone-cutter’s chisel (Fig. 2.1.48) and this is the meaning of the name. The perennial bulb is the organ which enables blooming during the driest season of the year. When the fruits ripen, they open and the black seeds (Fig. 2.1.47) are seen, and become available for seed dispersal by the wind. When wetted, the fruit valves close and resemble [Phagnalon rupestre] in this strategy– both disperse seeds by wind but retain them when wetted.

Fig. 2.1.46: Urginea maritime was a very common plant growing among the rocks of Ramat Bet HaKerem but with urbanization it has become almost extinct in that area. Even today, people unaware of the importance of the plant to the general public, harm it during blooming or after.

Fig. 2.1.47: The Urginea fruits, as those of the rest of the family, have three cells and open in three sutures when ripe.

Fig. 2.1.48: A short while after blooming the fruits develop and ripen. Each capsule opens by three sutures (left) and the light, black seeds (right) are distributed by the wind.

Fig. 2.1.49: Urginea leaves sprout at the beginning of winter.

[Narcissus tazetta] once grew in the rock crevices of Ramat Bet HaKerem, but is not growing there any more. Such [“Narcissus tazetta” N. tazetta] plants were growing 10-20 years ago in similar rocks in Givat Ram and near the Science Museum but they too are not found there any more. Wild plants have difficulty surviving in urban areas. [“Narcissus tazetta” N. tazetta] has a bulb in which internal changes take place before the rainy season starts, so there is a population of them blooming two weeks after the first effective rain of the winter.

[Cyclamen persicum] is one of the most significant plants of Ramat Bet HaKerem. The landscape seen from a bridge ([localvegb1 Fig. 2.1.5]) was populated with cyclamens blooming before leaf development (Fig. 2.1.50). Like the [Urginea], [Cyclamen], has a corm storing enough food and fluids to enable flowering at the beginning of the season, even before leaves develop. Another population of such cyclamens grows on cliffs of Gey Ben-Hinom. In addition there are many cyclamens at the rock reserve which bloom with well developed leaves. They have not become extinct.

Fig. 2.1.50: Cyclamen persicum blooming before leaf sprouting. A population of this form was present in Ramat Bet HaKerem (see also Fig. 2.1.5) and appears to have become extinct there.

[Sternbergia clusiana] grew on Ramat Bet HaKerem in the 1980s. I remember the last days of the last [“Sternbergia clusiana” S. clusiana] which was blooming on a Friday when I visited. Arriving at the same location the next day, I saw only a small hole in the soil. This plant carries the name of Bet HaKerem in its common name in Hebrew. In my childhood we called it “karmit” but it is now extinct in the natural habitats around Bet HaKerem. When soil removing or “landscape development” activity (as authorities prefer to call such a process) took place in the valley between Bet HaKerem and Givat Ram, I transferred [Sternbergia] bulbs from that valley to the Botanical Garden where they continue to grow today.

[Allium daninianum] is one of the plants “decorating” soil pockets in the rocks (Fig. 2.1.51). It develops small cylindrical leaves in winter and bears modest bell-shaped flowers in spring. The Sicilian botanist Brullo visited Israel and named this plant after the Israeli botanist who accompanied him.

Fig. 2.1.51: Allium daninianum, in summer, at the entrance to a tiny cave.

Fig. 2.1.52: Allium daninianum flowers with extending anthers.

In addition to the species mentioned above there are many more geophytes in the rock reserve. [Scilla autumnalis] blooms before the rainy season and develops another inflorescence after the first rains. The following species bloom in winter and in spring: [Arisarum vulgare], [Arum palaestinum], [Asphodelus ramosus], [Anemone coronaria] and [Ranunculus asiaticus].

Fig. 2.1.53: Colchicum stevenii blooms after the first rain.