Freshwater Plants: Phragmites, Juncus and Typha

פורסם: February 15th, 2008 | עודכן: 16/01/15

[Phragmites australis] (common reed) is a cosmopolitan plant growing near fresh water all over Israel and in the neighbouring countries. Its tall stems may reach 10 m when growing conditions are good. Today, however, finding it does not automatically justify the call “we are saved.” This reed may prosper in highly polluted sites. Sewage water “springs” and “streams” are common in urban areas and one has to bear the danger in mind. The height of the reed plants (Fig. 4.2.1) indicates the point where growth conditions are best. This feature should be taken into consideration if one intends to dig for water below the reed. The inflorescence is very hairy (Fig. 4.2.1 right); most hairs help the diaspores to be carried by the wind.

The production of plenty of wind-borne seeds is a very common syndrome in plants growing near water. Such a mode of seed dispersal assures “seed rain” over large areas and the germination of new plants in habitats to which the plant has become adapted. Hence, large areas covered by [Phragmites australis] can be seen in the Arava Valley east of the border line with Jordan, in sites with a high water-table (Fig. 4.2.3).

Fig. 4.2.1: A clump or tuft of Phragmites australis. The wealth of flowering canes and their height indicate plenty of water. Unfortunately, in the vicinity of Bet Shemesh this is sewage water.

Fig. 4.2.2: A wadi in the western Negev where water flows in summer as well.

Species of [Juncus] accompany [“Phragmites australis” P. australis] in sites where underground water is present close to the surface of the soil. Various [Juncus] species are shown in Figures 4.2.3 through 4.2.7. Some of them may grow in slightly saline water while others are confined to fresh water.

Fig. 4.2.3: A small spring in the north eastern Arava Valley (in Jordan), discernable from a distance, thanks to the continuous reed population with Juncus plants on its outskirts.

Fig. 4.2.4: Many Juncus plants have a dark green color. Its Arabic and Hebrew name (samar) is derived from the Arabic root – asmar = dark-colored.

Fig. 4.2.5: Many Juncus species grow in sites where water is available in summer as well. Sometimes the water is brackish.

Fig. 4.2.6: See Fig. 4.2.5.

Fig. 4.2.7: See Fig. 4.2.5.

Species of [Typha] (cattail) are adapted to fresh water as well, but being resistant to sewage water this indicator also calls for great care. However, if I am in the Arava Valley in Jordan, under extreme desert conditions (Fig. 4.2.8) I am willing to endanger myself by digging and searching for potable water under the cattail plants. Walking in Wadi Fidan, which drains huge quantities of water from Edom mountains, brought me to several streams of fresh water flowing among the [Typha] plants (Fig. 4.2.9). The most common cattail species in Israel is [Typha domingensis]. Being cosmopolitan, it resembles the common reed in its distribution. Additional species are shown in Figs. 4.2.9-4.2.12.

Fig. 4.2.8: A small spring in the north eastern Arava Valley (in Jordan) where Typha, Phragmites and Juncus prosper together.

Fig. 4.2.9: Typha growing on a small spring of fresh water of ‘Ain Fidan, north eastern Arava Valley (in Jordan.)

Fig. 4.2.10: Typha blooms. If you pick up a black inflorescence and keep it at home, be prepared for a nasty experience on a hot, dry day: the inflorescence will deteriorate into thousands of small hairy seeds.

Fig. 4.2.11: ‘En ‘Avdat (left) and cattail at the front. ‘En ‘Akrabim (right) shows palms, indicating deep water, and cattail, indicating a spring.

Fig. 4.2.12: Typha latifolia may be recognized by its almost black inflorescences.