239 
rendered to the cotton growers by way of direction and advice 
in all that concerned the industry. 
The Annual Reports of his Department bear testimony to his 
activities and the wide- te a character of his interests. 
Solenostemma Argel in the Sahara.—Amongst a number of 
drug plants collected in the French Sahara by Mr. Rodd, and 
recently received at Kew for identification from the Director 
of the Wellcome Chemical Research Laboratories, were specimens 
of Solenostemma Argel Hayne. This is a member of the family 
Asclepiadaceae and has hitherto been known from Egypt, Nubia, 
Kordofan and Arabia Petraea. Mr. Rodd collected his specimens 
in the Central Sahara in Northern Air (or Asben) and this record 
~ forms an interesting western extension of the area covered by the 
species so far as is known from the material and literature found 
at Kew 
Mr. Rodd also states that the plant is called ‘‘ Ghalis 
in Tamashegh and has similar curative properties to riba of 
the ‘‘ Agar”’ leaves from an unidentified tree also found in Air, 
but is more powerful, and its application (on camels only) is similar. 
The leaves of ‘‘ Agar” are powdered and applied dry to septic. 
sores, after these have been carefully washed, when the powder 
has curative and healing effects. “Ghalisum” may also be 
drunk or eaten by men as a blood cleanser. It has purgative 
properties and is said to make the patient drink plenty of water 
(? diuretic) or pee perhaps, that the patient should 
plenty of wate 
Muschler, es Fl. Egypt ii, 749 (1912) states that the local 
Arabian name for the plant is argel or hargel, and Hayne, 
Arzmeygew ix. t. 38 (1853), gives an excellent figure and states 
that the leaves of the plant are used like those of senna.—w.B.T. 
Citations of Generic Names in the Index Kewensis.—When 
the Index Kewensis was compiled, the year 1735 was generally 
accepted as the starting-point for the nomenclature of genera, | 
in accordance with the Laws of Botanical Nomenclature adopted 
by the International Botanical Congress at Paris in 1867. But 
in 1905, at the Vienna Congress, the year 1753 was fixed as the 
starting-point for both genera and species of Phanerogams 
(International Rules, Art. 19). Hence numerous references 
the publication of genera given in the Index Kewensis are no 
longer valid, being prior to 1753. In such cases Dalla Torre et 
Harms, Genera Siphonogamarum (1900-1907), may be consulted 
for the earliest valid citation. So many genera are concerned 
