TAXUS 
601 
Tambourissa Sonner. Monimiaceae. 14 sp. Java, Mascarenes. 
Tamonea Aubl. Melastomaceae (1). 550 sp. trop. Am. 
Tamus Linn. Dioscoreaceae. 2 sp. Eur., Medit. T. communis L. 
(black bryony) in Brit. Climbing plants, hibernating by tubers 
formed by a lateral outgrowth of the first two internodes of the stem, 
Tanacetum Toum. ex Linn. Compositae (vn). 50 sp. N. Hemisph. 
T. vulgare L. (tansy) is often cultivated as a popular remedy in colds 
&c. Included in Chrysanthemum in Nat. Pfi. 
Taonabo Aubl. = Ternstroemia Mutis. 
Taraxacum Linn. Compositae (xm). 25 sp. temp. T. officinale 
Weber (dandelion) is almost cosmop. The thick primary root is 
perennial and is crowned by a very short sympodial stem ; each year 
a new bud is formed on the leafy axis, to come into active growth in 
the following year. The roots as they grow to maturity contract and 
thus drag the stem downwards so that it never rises much above the 
soil. If the root be cut through, a callus forms over the wound, and 
from this adventitious shoots develope. The floral mechanism &c. 
are of the usual type of the order, and show the final autogamy very 
clearly. 
Tarchonanthus Linn. Compositae (iv). 3 sp. S. Afr. 
Taxaceae. An order of Coniferae (q.v.). 
Taxodium Rich. (excl. Glyptostrobus Endl.). Coniferae (Arauc. 1 c; 
see C. for genus characters). 2 sp. N. Am. (swamp-cypresses), T. 
distichum Rich, and T . mexicanum Carr. In the former, and especially 
in swampy ground, curious ‘ knees ’ are formed, which are hollow 
spherical branches projecting upwards from the roots ; they are sup- 
posed to be aerating organs (cf. Sonneratia). 
Taxus (Tourn.) Linn. Coniferae (Taxaceae, 4 ; see C. for genus 
characters). About 8 sp. N. temp., of which T. baccata L., the yew, 
is best known. There are no short shoots, but the leaves of the 
spreading branches arrange themselves more or less closely in two 
rows with their upper surfaces nearly in one plane, giving a dorsi- 
ventral structure to the shoot. The firs, are dioecious, solitary in the 
axils of the leaves of the preceding year. The c? has a few scale-leaves 
below and about 8 or 10 sta., each of which is shield-shaped with a 
number of pollen-sacs on the axial side of the shield arranged round 
its stalk like the sporangia in Equisetum. The ? has a rather com- 
plex structure. The primary axis bears scale-leaves only. In the 
axil of one of the uppermost of these arises a shoot, continuing the 
line of the first axis and bearing 3 pairs of scales and a terminal 
ovule. This is orthotropous with one integument, and developes into 
a seed surrounded by a cup-shaped red and fleshy aril. 
The wood of the yew is valuable ; in the middle ages it was the 
chief material used in making bows. The leaves are very poisonous, 
but the aril is harmless. Birds swallow it, and thus distribute the 
seeds. 
