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The Forest Service National Center for Reforestation, Nurseries, and Genetic Resources (RNGR) is a leading source of technical information for nurseries and land managers regarding production and planting of trees and other native plants for reforestation, restoration, and conservation.

 
NPN Protocol Details Image

Machaeranthera (grindelioides)

Hannah Demler
Innovative Restoration Technician
258 Main St Suite 200
Lander, Wyoming 82520
hannah.demler@tnc.org

Family Scientific Name: Asteraceae
Family Common Name: Aster Family
Scientific Name: Machaeranthera grindelioides
Common Name: rayless tansyaster
Species Code: MAGR2
Ecotype: Fremont County, Wyoming
General Distribution: M. grindelioides is found throughout the Mountain West of the United States and extending North into Alberta and Saskatchewan.
Propagation Goal: Plants
Propagation Method: Seed
Propagule Collection: Fruit is an achene with a pappus. M. grindelioides seed is cream to tan in color. Seed is collected by removing mature seed from seed heads. Seeds mature uniformly on individual plants throughout late summer. Seed was stored in paper or cloth bags at room temperature until cleaned and then vacuum sealed and placed in a freezer for long term storage.

Seeds/lb for this ecotype was ~453,600
Propagule Processing: Seeds exhibit physiological dormancy (PD)
Pre-Planting Treatments: Seeds require cold moist stratification for optimum germination. In a germination trial, seeds that underwent no cold stratification had an average percent germination of only 33 % after a 28-day incubation under a diurnal temperature regime of 9/25 ° C (corresponding to the average temperatures in Fremont county, WY in June). Four different cold stratification durations were tested, where seeds were incubated in sealed petri dishes on 0.7 % (w/v) agar at 3 ±2° C for 1, 2, 3, and 4 months prior to the germination trial. Average seed germination was > 75% for seeds that had undergone 2, 3, or 4 months of cold stratification, with the highest germination under the 3-month duration (86 % germination following 3 months cold stratification and 28 days at 9/25 ° C). We also included a gibberellic acid (GA3) treatment on un-stratified seeds to test chemically-induced dormancy relief compared to cold stratification. 1mM GA3 was added into the 0.7% (w/v) agar and average germination after 28 days at 9/25 ° C was 46 %. The overall low germination of the GA3 treated seeds indicates that under these conditions and at the concentration tested, it is not an effective means of dormancy relief for M. grindelioides.

Citation:

2023. Propagation protocol for production of Machaeranthera grindelioides Plants Lander, Wyoming. In: Native Plant Network. URL: https://NativePlantNetwork.org (accessed 2024/07/02). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.