28 MASS. EXPERIMENT STATION BULLETIN 382 



Passiflora racemosa, passion-flower. Softwood cuttings taken here in July 

 rooted 90 percent in sand in 8 weeks after treatment with indolebutyric 

 acid (50 mg./l., 24 hr.), 40 percent if untreated. Sandy soil may also be 

 used as a rooting medium (80). 



Periploca. Softwood cuttings of silk-vine and P. sepium taken here in early 

 August rooted 100 percent in sand-peat in 4 weeks with or without treat- 

 ment. Late August cuttings of silk-vine, in sand, failed to root in 4 weeks 

 without treatment but rooted 70 percent after powder-dip treatment with 

 indolebutyric acid, 1:500 (104). 



Philadelphus, mock-orange. Softwood. July, cuttings of many species root 

 well without treatment (44, 66, 116, 125) ; better sometimes in sand-peat that 

 in sand (14, 66). The only response of P. grandiUorus to treatment was more 

 roots on each cutting (125). Rooting of cuttings of P. cymosus (125) and 

 P. coronarius (83) was hastened by treatment with indolebutyric acid, the 

 former responding to 30 to 80 mg./l. , 4 hr., and the latter to 50 mg./l., 

 20 hr. 



Photinia. The species can be propagated by fall or late summer cuttings, 

 short side-shoots, with a heel (105). Fall cuttmgs of P. glabra rooted 100 

 percent in 62 days after treatment with indolebutyric acid (50 mg./l., 18 hr.), 

 5 percent without it (20). Summer cuttings of P. scrrulata rooted 20 percent 

 without treatment, 80 percent after treatment with indolebutyric acid 

 (20 mg./l., 6 hr.) (119). 



Physocarpus opulif alius, ninebark, is easily propagated by softwood, summer 

 cuttings. They rooted better in sand-peat than in sand, better at 60° F. 

 than at 70° F. (116). Cuttings of harder wood are also successfully 

 used. Taken in November, they rooted 80 percent in 53 days without 

 treatment and only a little better after treatment with indolebutyric acid 

 (50 mg./l., 40 hr.) (16). 



Picea Abies, Norway spruce. Cuttings rooted better if taken in November 

 than if taken in late winter (38), better if taken in December than if taken 

 in spring, summer, fall, or later in the winter (24). Best results have followed 

 the taking of cuttings, laterals rather than terminals (109), from the lower 

 in preference to the upper part of trees (35). Cuttings root with less diffi- 

 culty than do those of most spruces (106) ; and cuttings of the varieties nigra, 

 Maxwellii, Clanbrasiliana, and Ohlendorfii which were taken here in December 

 rooted at least 70 percent without treatment, no better and not always so 

 well with it. Treatments for 24 hours with solutions of indoleacetic (41) 

 or indolebutyric acid (24) failed to improve rooting significantly and 

 similar treatment with water alone was apparently somewhat injurious 

 (24). Powder-dip treatment with indolebutyric acid (4 mg./gm. talc) 

 caused some injury in many cases (24), but rooting was somewhat im- 

 proved by indoleacetic acid in talc (41). November cuttings, made with 

 the basal cut somewhat above the base of the current year's growth and 

 planted immediately in a mixture of equal parts of sand and peat humus in 

 shaded outdoor frames, rooted about 50 percent without treatment, 82 

 percent in 10 months after treatment with indoleacetic acid ( 5mg./gm. 

 talc) (39). Treated cuttings in that experiment rooted less well in sand, 

 but untreated cuttings from trees 40 years old, made with the basal cut 

 not far above the base of the current year's wood, rooted 80 percent in 

 sand; better, with less rotting, in open benches in a warm greenhouse 

 than in a closed sweat bench (24). 



