89 



flowers are white when fully expanded, and are all similar 

 and hermaphrodite. It is expected to prove a valuable addition 

 to the number of hardy flowering shrubs of which so many 

 have been introduced by Messrs. Veitch during the last few 

 years. Herbert ia amatorum was described for the first time 

 last year {Kew Bulletin, 1907, p. 321), from material raised 

 from seed sent to Kew by Dr. C. B. Cantera, of Montevideo, 

 Uruguay. It differs from H. amoena, Griseb., and H. coerulea, 

 Herb., in having a white obcordate blotch on the claws of the 

 outer perianth-segments. It is the most handsome of the species 

 so tar introduced. Pseurfohtrix Fortunei has been in cultivation 

 for many years, seeds having first been sent to England by 

 fortune in 1853, but it is not common in gardens, and appears to 

 be rare m its native country, China. Fortune found it only in 

 the I rovince of Chekiang ; since his time it has been met with in 

 Kiangsi. The drawing was prepared f 

 at Kew in June, 1907. 



om 



t 



The Red Rust of Tea.-By H. H. Mann and C. M. Hutchinson. 

 {Memo/rs of the Department of Agriculture of India, Vol. I . 

 No. 6, 1907.) 



The disease of the tea plant, known as Red Rust, Cephaleuros 

 virescens, Kunze, is of special interest to botanists in that it is 



one of the few cases in which an alga is* parasitic upon a 

 flowering plant. 



First observed about ] 880, and determined by Cunningham in 

 1889 to be caused by an algal parasite, Red Rust has during recent 

 years assumed serious proportions. In the latest contribution to 

 the subject several new points are brought to light, a short account 

 therefore of the disease may not be without interest. 



Cephaleuros virescens, Kunze, the alga in question, is a member 

 of the Trentepohliaceac. That order, although one of the Chloro- 

 phyceae, is characterised by the possession of haematochromin, a 

 pigment which usually masks the chlorophyll giving the algae an 

 orange or brownish-red hue. Members of the Trentepohliaceae 

 are abundant in the tropics, many species occurring as epiphytes 

 on hard-leaved plants, where they frequently enter into com- 

 bination with fungi to form lichens. In our own country the 

 well-known Trentepohlia aurea is a representative of the group. 



After an introductory and historical chapter the authors turn to 

 the general effect of Cephaleuros virescens, and point out the two 

 distinct forms in which Red Rust is found, viz., the leaf form and 

 the stem form. 



On the leaf the alga is usually epiphytic, and the damage occa- 

 sioned is insignificant; on the stems and branches, on the other 

 hand, it is endophytic, and the effect is more serious. The shoots 

 gradually become unhealthy and die, and, in bad cases, entire 

 trees ultimately succumb. 



The details concerning the leaf-form need not be referred to 

 here, the blight in that position being only important as a source 



