Asparagus aphyllus and Asparagus horridus
When spring comes, the Asparagus species produce new stems that sprout vertically from the horizontal underground stems – the rhizomes. These stems are conically tipped, not branched, and are juicy, soft and tasty – at least in their tips (Fig. 4.9.2). Many people are fond of this natural food. Walking in maquis areas where A. aphyllus grows or in the sandy soils of the coastal plain where A. horridus (Fig. 4.9.3) grows, it may be difficult to find stems resembling those in Fig. 4.9.1. It is highly likely that people who came there earlier ate the good tips. Naturally, we shall remember these plants when we reach the chapter on palatable plants. When we arrive there we shall recall the delicacies of young pickled A. horridus stems that were constantly seen on Mr. G. Hadjikyriakou's table in Cyprus.
Sour plants with a warning
Many people, and especially children, like to bite the stems, peduncles, leaves and petioles of Oxalis and Rumex (Figs. 4.9.4-4.9.5). These plants contain oxalic acid which, when consumed in small quantities, would appear to be harmless. One may consider this an excellent combination – water with an acidic addition in one mouthful. Do not eat Rumex or Oxalis – it may harm you. Soldiers in a special unit were taught that they may eat Rumex. Evidently their instructors did not warn them against eating large quantities of the plant. In the course of their training they had to navigate by foot in small units in a desert area, without a sufficient supply of water. Many soldiers reached the end of the exercise complaining that their urine was reddish. When they were examined, it was found that they had consumed large quantities of Rumex cyprius or R. vesicarius (Figs. 4.9.6-4.9.7). The soldiers did not know that when the oxalic acid present in this plant meets calcium ions in their blood, calcium oxalate crystals develop. The latter resemble needles that wound blood capillaries in the urinary tract, leading to the "red urine" situation. Please, do not eat Rumex or Oxalis – it may harm you!
Leaves or their parts
It is hard to find leaves ready for direct consumption; many of them contain chemicals that function as "herbivore repellents". There are plants that do not have such a sharp taste at certain stages in their growth and can be used as a source of water. One of these is Eryngium creticum (Fig. 4.9.8), whose leaf petioles have a taste resembling that of cultivated parsley (Petroselinum crispum). As the season proceeds, according to the "Eryngium calendar", pungent leaves develop, the petioles are not as juicy as they were in the younger and softer leaves, and they are not worth the effort of collecting them (Fig. 4.9.9).
Beware of poisonous plants
When parsley is mentioned there is a danger that someone will think he has found “wild parsley” growing in natural areas of Israel and will endanger himself or others with him. In Israel, parsley grows only in cultivated areas but there are a few wild plants that resemble it. The most dangerous one is the poisonous Conium maculatum (Fig. 4.9.10), which may confuse the non-professional at the beginning of winter (Fig. 4.9.11). This plant was used to poison Socrates and it is important to be careful. In other words – do not touch any wild plant that looks like parsley.
A plant that has leaves slightly resembling those of Foeniculum vulgare, is Ferula communis. Young cows, who do not know the poisonous nature of this plant eat it and may die. The photos may help (Fig. 4.9.12) and one has to remember the "aniseed” (or Arak) smell of fennel in contrast to the bad smell of the Ferula.
My late teacher and commander, Nogah HaReuveni, used to recommend using Opuntia ficus-barbarica (Fig. 4.9.13; erroneously called O. ficus-indica in many floras dealing with the Medierranean area) to obtain the water it stores. The inner part of the flat stems of this succulent (Fig. 4.9.14) is water-storing tissue; however, the water "comes" with mucus and light acids. You may not like this combination, but if it means saving your life the recommendation is clear.
Distillation of water from stems, leaves, and wet soil
Books published by the American Air Force dedicate many pages to teaching techniques of obtaining water in ways that resembles distillation. The basic idea used here is the "greenhouse principle" and here are the details. Dig a pit in an area well-exposed to solar radiation throughout the day. The pit should be round, half a meter deep and one meter in diameter. Place a mug or a big glass or other container for the drinking water, on a stable stone with a flat upper surface. Collect plant material that does not smell or stink, is not covered with salt or much dust, and is not poisonous. The layer of "green" material should be some 40 cm thick – not to over-fill the pit. Cover the pit with a sheet of transparent polyethylene and seal the edges with the soil that was taken out of the pit. Put a stone on the center of the sheath, causing the lowest part of the polyethylene cone to be over the mug. The solar rays will penetrate the transparent plastic, but the heat radiation cannot be reflected out (the "greenhouse principle") and the air temperature inside the pit will rise. This air will become saturated with water vapor. The inside of the sheath will become warm whereas the outside will be relatively cold = in air-temperature. The result – as in our car in a cold winter day – water condenses on the inner surface of the plastic and the growing water drops glide towards the lowest place – into the mug. If these instructions result in the survival of one human being we shall be able to say that this chapter rescued a whole world.