CONVOLVULACEZ. 47 
The name Box Thorn is really a mistranslation of the German word 
‘‘Bocksdorn’’ or of the Dutch ‘‘ Boksdorn’’ used at the Cape. The 
plant has no affinities with the true Box (Bzxws), and the name should be 
etymologically Bucksthorn, but as there is already a Ruck Thorn (Rhamnus) 
it is advisable to retain that of Box Thorn for Zyczum. The case is com. 
parable with the corruption of the French ‘‘ ecrevisse’’ into the English 
“* cray-fish.”’ 
For the reasons for placing this plant under the Thistle Act, see page 
26. 
= Among the native Australian genera of Solanacee two appear to 
be wholly poisonous, namely, Anthocercis and Duboisia or Pitury, but both 
appear to be unpalatable to stock and to be untouched by them except under 
very special circumstances. Anthocercis albicans, Cunn., is a Victorian 
species. | Duboisin sulphate is used by oculists to dilate the pupil of the 
eye in those cases in which atropin iritates the eye unduly. It is sup- 
posed to be much more poisonous and Dr. Barrett informs me it is only 
sparingly used. It is quite possible that dust and fluff from these plants 
when dry might injure the eves of animals browsing among them, and cases 
of blindness in stock are not uncommonly referred bv stockmen to the 
agency of plants. So far, I have keen unable to trace any such case to a 
definite plant. 
CoNVOLVULACEZ (CONVOLVULUS FAMILY). 
The flowers are four or five partite, often showy, the ovary superior, 
the capsule small and containing two to six seeds. 
A small order of climbing, twining, or parasitic usually perennial herbs, 
which: includes a few decorative plants but several troublesome or danger- 
ous weeds. ' 
Cuscuta. The Dodder. This annual parasite is easily recognised by 
its slender, twining, yellowish-green, practically leafless stems attached by 
minute suckers to thé host plant, and bearing clusters of whitish or pinkish 
flowers. It is as great a pest to agriculture as the Mistletoe is to forestry. 
Two native species (C. tasmanica, Engelm., and C. australis, R. Br.), are 
known and have played some part in keeping down native and introduced 
weeds (St. John’s Wort, &c.). The most injurious dodders appear to be 
the introduced ones (Cuscenta epithymum, L., C. europea, L., C. Trifolit, 
_ Bab., &c.), which are continually imported into Australia and New Zea- 
land with impure agricultural seed. These parasites will destroy any 
leguminous crop if unchecked. Where a whole field is infested, the 
entire crop should be ploughed under, and if this is done before much seed 
has been formed, after a year’s fallowing (bare or green) followed by 
wheat, oats, maize or a similar crop, it will be safe to use the land for 
clover, lucerne or leguminous crops. If allowed to seed freely, the seed 
in the soil may not be exhausted for five or six years. 
When small infested patches are found, a trench should be dug round 
the patch. over which straw or long chaff sprinkled with kerosene has been 
spread. After firing and burning off, the soil can be thrown over the 
auarantined area, covering and burning anv parts which have escaped 
destruction. It is wise not to remove the infested plants for burning, as 
pieces left on the field or dropped in fresh places re-establish themselves 
and spread the evil. To attempt to tear out the dodder with a rake is 
even more foolish. Spraving with copper sulphate or iron sulphate solu- 
tions has been recommended, but a badly infested crop cannot be saved 
in this or anv other way. It is better to lose completely a small area of 
the crop by burning than to risk a much more serious infestation next year. 
