Oct. IS, 1914 Fungous Disease of Hemp 83 



the cultural work. The fungus developed in the same sequence as in 

 nature, the Dendrophoma stage appearing first, regardless as to whether 

 the cultures were made from microconidia, macroconidia, or ascospores. 

 Sections of the pycnidia made at a later date demonstrated that the 

 development of the macroconidia followed the microconidia in the same 

 pycnidium. In sections made at a still later date asci were found develop- 

 ing in the same locule with the mature macroconidia. The three spore 

 forms of the fungus as developed in culture agreed perfectly in character 

 with those found in nature. The variations observed in size and shape 

 of macroconidia and shape of the asci were also exhibited by the fungus 

 in nature. The one notable difference, however, was in the stronger 

 development of stroma in the cultures. Since the Dendrophoma spores 

 and the Macrophoma spores developed in the same pycnidia, the macro- 

 conidia and ascospores in the same perithecia, and all three forms in the 

 same stroma, it is definitely proved that these three forms represent the 

 different stages in the life history of one fungus (fig. 1, A). 



From the critical microscopical study of the Dendrophoma stage of this 

 fungus in nature and in culture it is shown to be morphologically identical 

 with a specimen of Dendrophoma marconii described by Cavara in Italy 

 in 1887.' No stroma is produced as the fungus occurs on the host, 

 although a well-developed stroma is produced in culture. This stromatic 

 development is suggestive of the genus Dothiorella, but it is not a constant 

 character, and as the fungus agrees so closely with Cavara's description 

 of Dendrophoma on hemp,^ the authors consider these two forms to be 

 identical. 



During the course of the microscopic study of Dr. Cavara's material a 

 second type of spore was found which corresponded exactly with the 

 macrospores discussed in this paper. No mention of these was made in 

 Dr. Cavara's paper, however, and the writers were unable to determine 

 whether or not they had been observed by him. 



Among the few fungi described on hemp and related genera no species 

 were found possessing the characters of the perfect stage of the fungus 

 here discussed. In 1831 a fungus was observed by Schweinitz on hemp, 

 and was called by him Sphaeria cannabis Schw.^ This species is of histor- 

 ical interest only, for the description is too meager to be of any taxonomic 

 value. The characters of the ascosporic stage place the fungus in the 

 genus Botryosphacria as defined by Saccardo.* As the imperfect stage of 

 this fungus is considered identical with the first described form, Dendro- 

 phoma marcnnii Cav., the specific name is retained and the fungus is 

 designated Bolryosphaeriamarconii (Cav.) Charles and Jenkins. 



Botryosphaeria marconii (Cav.) Charles and Jenkins. 



Perithecia globose, perforate, diseased area pale olive buff to gray, 140 to 160 /< in 

 diameter; basidia bearing microconidia mostly dichotomously branched, septate, 

 hyaline; microconidia polymorphic, ovate, elliptical, or terete, continuous, hyaline, 

 4 to 5K by i}^ to 2/(; macroconidia fusiform or ellipsoid, continuous, hyaline to glau- 

 cous, 16 to 18 by 5 to 6 11; basidia of macroconidia slender, generally 12 to 15 /< in 

 length; asci clavate, 8-spored, 80 to 90 by 13 to 15 n; paraphyses filiform; spores 

 fusoid, hyaline to pale light grape green, 16 to 18 by 7' to 8 ft. Microconidia, macro- 

 conidia, and asci produced in the same perithecium. On Cannabis saliva. 



' Briosi, Giovanni, and Cavara, Fridiano. I Funghi Parassiti delle Piante Coltivate od Utili. no 20. 

 Pavia. 1887. ExitccaUF. 



2 Cavara, Fridiano. Appunti di patologia vegetale (alcuni (unghi parassiti di piante coltivate.) In Att i 

 1st. Bot. Univ. Pavia, Is. 2I. v. i. p. 426. iSSS. 



'Schweinitz. L. D. von. Synopsis (ungorum in America boreali media degentium secundum observa- 

 tlones. In Trans. Amer. Phil. Soc. n. s.. v. 4, p. 222. no. 1741. 1834. 



Saccardo, P. A. Sylloge Fungomm ... v. 2. p. 432. Patavii, 1883. 



* Saccardo, P. A. Sylloge Fungoruju . . . v. i, p. 456. Patavii, 1882. 



