C-1 



Germination Requirements and Seedling 

 Biology of Spalding's Catchfly (Silene spaldinqii ) 



In order to properly manage for the continued existence of a 

 rare plant, it is essential to understand the entire life history 

 of the species. The objectives of this study were to determine 

 the germination requirements and seedling life history of 

 Spalding's catchfly ( Silene spaldinqii ) . 



Methods 



I collected seed from populations of Spalding's catchfly at 

 Wild Horse Island in Lake County and the Tobacco Valley in 

 Lincoln County, Montana. Seed was taken from ripe fruits, dried 

 in paper envelopes and stored at room temperature. I sterilized 

 seeds in a solution of 20% laundry bleach for 15 minutes, rinsed 

 them thoroughly in distilled water and placed them on saturated 

 filter paper in petri dishes. Each petri dish contained 50-100 

 seeds. Two dishes were placed in the dark in a refrigerator at 

 ca. 3 C, and two dishes were kept at room temperature with a 10- 

 hour light regime. After 30 days I took the dishes from the 

 refrigerator and kept them at room temperature for five days. At 

 the end of this time I counted the germinated seeds and estimated 

 percent germination in all the dishes. 



I placed germinated seeds in small pots of garden soil and 

 raised the seedlings in the University of Montana, Botany 

 greenhouse. Potted plants were placed in the greenhouse in late 

 January, watered at regular intervals and observed through 

 September of the same year. 



Results and Discussion 



Less than 5% of the Silene seed in the room temperature 

 treatment had germinated at the end of the 35-day period, while 

 60-70% germination was achieved with the 30-day cold 

 stratification treatment. These results suggest that Spalding's 

 catchfly requires cold stratification for germination, and under 

 normal circumstances would germinate in early spring. 



Seedlings began growth immediately, and within 30 days most 

 rosettes had 4-6 leaves. At 60 days most rosettes had 6-14 

 leaves. After this two-month period, the rosettes ceased to 

 grow. The leaves remained green for another 60 days, and then 

 the rosettes senesced. After approximately 45 days many of the 

 senesced individuals put out new leaves. This occurred in late 

 September after the weather had cooled. Results of this study 

 suggest that, under field conditions, seedlings of Spalding's 

 catchfly germinate in the spring and grow while the soil is moist 

 and the weather is relatively cool. Plants are senescent during 

 the warm, dry, summer months and then revive with the onset of 



