FAMILY MARMORACEAE 



1199 



mentally, also CHENOPODIACEAE— 

 Beta vulgaris L., sugar beet ; Chenopo- 

 dium albvm L., lamb's quarters; C. 

 murale L., sowbane. CONVOLVULA- 

 CEAE — Citsciita campesiris Yuncker; C. 

 subinclusa Dur. and Hilg. CRUCI- 

 FERAE — Brassica incana (L.) F. W. 

 Schultz, mustard (tolerant). CUCUR- 

 BIT ACE AE — Cucumis melo L., canta- 

 loupe. P HYTOLACC ACE AE— Phyto- 

 lacca americana L., pokeweed. PLAN- 

 T AGIN ACE AE—Plantago major L., 

 plantain. POL YGON ACEAE—Fago- 

 pyru7n escidentmn Moench, buckwheat ; 

 Polygonum pennsylvanicinn L., knot- 

 weed. PRIM ULACEAE—Samolus 

 florihundus HBK., water pimpernel. 

 SOLA NA CEAE — Lycopersicon esculen- 

 tum Mill., tomato ; Nicotiana glauca Gra- 

 ham (tolerant); N. palmeri Gray; A''. 

 rustica L. (tolerant); A'', tabacum L. 

 (tolerant); Solanum tuberosum L., po- 

 tato. UMBELLIFERAE—Apium 

 graveolens L., celery. 



Insusceptible species : COMPOS I TAE 

 — Helianthus annuus L., sunflower; Lac- 

 tuca sativa L., lettuce. CR UC I FERAE 

 — Brassica oleracea L. , cabbage . POL Y- 

 GONACEAE — Eriogonum, fasciculatum 

 Benth., California buckwheat. SCRO- 

 PH ULARIACEAE—Verbascum thap- 

 sus L., mullein. SOLAN ACE AE— 

 Atropa belladonna L., belladonna. 



Geographical distribution : United 

 States (California). 



Induced disease : In dodder, no symp- 

 toms. In sugar beet, experimentally, 

 temporary systemic chlorotic spotting; 

 occasional faded areas in leaves in subse- 

 quent chronic stage of disease. In canta- 

 loupe, experimentally, chlorotic spotting, 

 reduction in leaf size, death of some 

 leaves, stunting of plant; melons small 

 and of poor . quality. In celery, experi- 

 mentally, systemic chlorosis followed by 

 dwarfing and mottling with subsequent 

 apparent recovery. 



Transmission : By dodder, Cuscuta cali- 

 fornica, C. campestris, and C. subinclusa. 

 By inoculation of extracted juice to some, 

 but not to other, host plants ; Phytolacca 

 americana is readily infected by rubbing 



methods in the presence of a small amount 

 of abrasive, and develops numerous 

 necrotic primary lesions that serve for 

 quantitative estimation of concentration 

 of virus in inoculum. Through seeds 

 from infected plants of dodder, Cuscuta 

 campestris; not through seeds from dis- 

 eased cantaloupe, buckwheat, or poke- 

 weed plants. No insect vector is known. 



Thermal inactivation : At 56 to 60° C 

 in 10 minutes. 



Filterability : Passes celite and Berke- 

 feld N and W filters. 



Other properties : Infective in dilu- 

 tions to 1 : 3000. Inactivated by drying 

 and by storage in expressed pokeweed 

 juice, within 48 hours. 



61. Marmor pelargonii spec. nov. 

 From New Latin Pelargonium, generic 

 name of common geranium. 



Common names : Pelargonium leaf -curl 

 virus ; virus of dropsy or Krauselkrank- 

 heit of geranium. 



Host : GERAN I ACE AE— Pelargon- 

 ium hortorum Bailey, geranium. 



Induced disease : In geranium, circular 

 or irregular chlorotic spots, sometimes 

 stellate or dendritic, | to 5 mm in di- 

 ameter, centers becoming brown with 

 chlorotic border ; severely affected leaves 

 become yellow and drop; spotted leaves 

 ruffled, crinkled, malformed, small, some- 

 times puckered and splitting. Petioles 

 and stems show corky, raised, necrotic 

 streaks; tops may die. Disease most 

 severe in spring, inconspicuous in sum- 

 mer. 



Transmission : By grafting. Not by 

 inoculation of expressed juice nor by use 

 of knife to prepare cuttings for propaga- 

 tion. Not through seed. No insect vec- 

 tor is known. 



Literature : Berkeley, Canad. Hort. and 

 Home Mag., 1938, 1938, 1-4; Blattn^, 

 Ochrana Rostlin, 13, 1933, 145 (Rev. 

 Appl. Mycol., 13, 1934, 378-379) ; Bremer, 

 Blumen-u. Pflanzenbau, J^8, 1933, 32-33 

 (Rev. Appl. Mycol., 12, 1933, 514); 

 Halstead, New Jersey Agr. Exp. Sta., 

 Rept. 14, 1893, 432-433; Jones, Washing- 

 ton Agr. Exp. Sta., Bull. 390, 1940; 



