. Studies on the vegetation of the Transcaspian lowlands. Botany. — 205 rule they do not exceed 30 centimetres. They have a white bark, and are usually branched, branch-thorns arising in the leaf-axils; the leaf-base is thick and persistent. The branch- thorns are generally short, about 1 centimetre long, and often bear only two leaves placed low down near the base. The branch-thorns may, however, become longer and bear several pairs of leaves. The flowers arise from the base of the branch-thorns either in the axils of the two low-set leaves, or next year they form part of the rosette-shoots w
. Studies on the vegetation of the Transcaspian lowlands. Botany. — 205 rule they do not exceed 30 centimetres. They have a white bark, and are usually branched, branch-thorns arising in the leaf-axils; the leaf-base is thick and persistent. The branch- thorns are generally short, about 1 centimetre long, and often bear only two leaves placed low down near the base. The branch-thorns may, however, become longer and bear several pairs of leaves. The flowers arise from the base of the branch-thorns either in the axils of the two low-set leaves, or next year they form part of the rosette-shoots which appear in the axils of these leaves. On long branch-thorns the flowers may also arise higher up. The year-shoots generally ter- minate in a thorn; their distal part always seems to die away. They flower during summer. The leaf is isolateral in struc- ture. There are stomata on both sides, generally flush with the sur- face but some of them are slightlj' raised and below them is a group of cells, 2—4 on each side, which are round and devoid of chloro- phyll; throughout the rest of the leaf these cells are wanting (flg. 45). The palisade tissue is 2 — 3 cells thick, and towards the interior it merges gradually into a large-celled aqueous tissue containing a slight amount of chlorophyll. The veins which lie a little nearer the upper side than the lower, have bundles of bast on both sides and here are found a few perfectly translucent Fig. 45. Lijcium ruthenicum. Part of leaf In transverse sec- tion. X 203. Nitraria Schoberi L. A shrub, barely one metre high which prefers the clay- desert. The bark is white, the leaves are thick and spath- ulate with short hairs, and are placed 2—4 together on a small cushion, with small scales between them. The leaves. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the origin
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1912
