April, 1921. The Canadian Field-Naturalist. 75 



parent transitions to Angiosperms. ' It During the w;iole trip only one species 



bears cones like gymnosperms but in tlie of our great rose family was seen, only 



axil of each scale is a flower of Angio- three crucifers and only three members 



spemiic structure. Its distribution is no of the buttercup family (all Clematis). 



less remarkable than its morphology. In On the other hand, families poorly repre- 



this locality it is found in an^ area of only sented here but relatively abundant there 



a few square miles. This and another are the Asclepiadaceae, Tiliaceae (chiefly 



similar locality further nort^ are the only shrubby Grewias), Gerauiaceae, Aizoaceae, 



places in the world where it is found. Zygophyllaeeae and Anacardiaceae, Fam- 



Tumboa's neighbors have adopted var- ilies with many representatives in both 

 ied methods of contending with the places are Liliaceae, Leguminosae and Corn- 

 drought. The Naras, Acanthosicyos hoi'- positae. 



rida (Cucurbitaceae), has completely dis- The old river beds constitute an inter- 

 carded its leaves and consists simply of a esting variation from the desert waste, 

 mass of green, hard, extremely sjiarp Their periodic flooding from the interior 

 pointed thorns sprawling over the sand, enables a richer though still sparse vegeta- 

 ns roots go down to subterranean water tion to survive. An occasional gardener 

 and may be fifteen meters long. The Ge- takes advantage of this moisture to raise 

 raniaceous Sarcocaulon has completely wa- a few vegetables which are sold at fabulous 

 terproof ed itself in a coat of hard wax prices to the town dwellers. A number of 

 which may be ten millimeters thick. The large wells as big as a house are dug in 

 coat remains as a hollow shell long after the dry river bottom. Into these a little 

 the plant has died and rotted away. The water soaks during the night and is pump- 

 wax burns readily and the pkmt is there- ed out next day on to the small garden, 

 fore called Hottentot candle. Several spe- After a time t^ie wells go completely, dry 

 eies jiave imitated the succulent cactus and the gardener moves a half-mile along 

 though belonging to veiy different fam- the river and digs a new set. Sometimes 

 ilies. Several members of the milkweed several moves are made between floodings. 

 family have become switch plants. Strang- In these river bottoms the vegetation 

 est of all perhaps in this climate is the consists chiefly of scattered shrubs and 

 ice-plant (Mesembryanthemum) with its trees. There are the date palm, a fig, 

 large soft leaves completely covered by several thorny acacias, the tamarisk and 

 droplets of cool liquM. To expose its wa- an ebony. One of the most successful 

 ter in this way when the supply is so plants in this habitat is a tobacco (Nico- 

 extremely scanty seems to be about the tiana glauca) whic^ reaches the size of a 

 worst thing the plant could do. small tree. It was introduced by the early 



A fact whie^i soon strikes the botanist missionaries, 

 is that in spite of strong resemblances in Farther inland the increased moisture 

 external features to the plants of Amer- supports a somewhat richer vegetation. In 

 ican deserts these belong to very different places the vegetation is of a type which 

 families. For example, cue sees many cac- rapidly bursts into flower after a rain and 

 tus-like plants but no cacti. A large pro- then dries up until the next rain. In few 

 portion of the flora consists of members places is the ground completely covered, 

 of the milkweed family which are there the plants being in scattered clumps and 

 switch-plants. Families which the North consisting chiefly of grasses. The German 

 American botanist has never seen there Government had encouraged in every pos- 

 simulate our own xerophytes to a remark- sible way the agricultural development of 

 able degree. So strong is t/ie resemblance t^he colony, but even the best parts of the 

 in many cases that one can scarcely believe country are unsuited to anything but ran- 

 that the flowers, showing the true botani- ching. The few ranchers wiho had been 

 cal relationship, really belong to the plants induced to settle in the eastern portion 

 on which they are found. We have here were making a precarious livelihood at the 

 a good illustration of entirely unrelated beginning of the war. A few municipal- 

 plants acquiring the same characteristics ities in Canada are worth more agi'icultur- 

 nnder similar conditions. ally than the whole territory. 



