516 JOURNAL OF THE ROYAL HORTTCULTTTRAIi SOCTF^rV. 



water. Formalin is safer to handle than bichloride of mercury and 

 just as effectual. — C. H. L. 



Primula obconica. Remedy for Chlorosis. By G. Arends i 

 {Le Jard., vol. xxiv,, No. 550, p. 27 ; Jan. 20, 1910). — The simultaneous 

 application of sulphate of iron and nitrate of soda has a miraculous effect | 

 upon this troublesome disease. The etiolated leaves resume their natural \ 

 colour, and the new leaves come up green. Dose, 50 gr. iron sulphate, 

 50 gr. sodium nitrate, to 100 litres water. Of this take 1 /1000th part 

 (1 gr. per litre). In a week the effect will be marked.- — F. A. W. 



Primula SOnchifolia. By G. Forrest {Gard. Chron. xlvii. (1910), 

 p. 58 ; Jan. 22 ; fig.). — This pretty little species with blue flowers, native 

 in N.W. Yunnan, is illustrated. It flowers before the leaves appear,- 

 but is difficult of cultivation in this country, sharing this characteristic 

 with many of the alpine species. — F. J. C. 



Ray-flowers of Composites, Variation in Number of. By Dr. 



Paul Vogler {Beih. Bot. Cent. xxv. 1. Abt. Heft iii. pp. 387-396; with 

 5 figs. ; 1910). — Further observations of Chrysanthemum Parthenium, 

 Boltonia latisquama, and Senecio alpinus are given. In the first- 

 mentioned he found that of 1750 flowers on manured soil 250 had 

 21 ray-florets, whilst of 370 from not manured soil 69 had 13 ray- 

 florets. 



The Boltonia showed a tendency to the Fibonnaci number, 55 (56, 

 55, 56 in one garden, 1907, 1908, 1909; 55, 54, 53 in another garden; 

 and 56 in "Park," 1909). In one year, 1907 (Park), the greatest 

 frequency was 61. 



Of the Senecio 3100 heads were examined, with the following 

 results: the Eigi (500 examined), 1600 metres alt., 1906, 22 ray- 

 florets in 89 heads; the Eigi (500 examined), 1300 metres alt., 1906, 

 19 ray-florets in 94 heads; the Eigi (250 examined), 1500 metres alt., 

 1906, 19 ray-florets in 48 heads; St. Gall (400 examined), 700 metres 

 alt., 1907, 21 ray-florets in 80 heads; St. Gall (700 examined), 700 

 metres alt., 1907, 20 ray-florets in 128 heads; Eigi (500 examined), 

 1300 metres alt., 1908, 19 ray-florets in 70 heads; Eigi (250 examined). 

 1300 metres alt., 1908, 19 ray-florets in 40 heads.— G. F. S.-E. 



Rhododendron Benthamianum, Hemsl. By W. B. Hemsley 

 (Gard. Chron. xlvii. (1910), p. 4; Jan. 1). — This new species is similar 

 in growth to R. Harrovianum (q.v.), but has shorter leaves, green 

 pedicels, and flowers purple throughout. It was raised by Messrs. 

 Veitch from seed collected by Mr. E. H. Wilson in W. China. — F. J. C. 



Rhododendron Harrovianum, Hemsl. By W. B. Hemsley 

 {Gard. Chron. xlvii. (1910), p. 4; Jan. 1). — This is a new species raised 

 by Messrs. Veitch from seed collected by Mr. E. H. Wilson in 

 W. China. It is a dwarf, small-leaved evergreen plant, bearing small 

 flowers of the colour of R. poiUicum. — F. J. C. 



