Athyrium (americanum)

Tara Luna USDI NPS - Glacier National Park West Glacier, Montana 59936 (406) 888-7835 http://plant-materials.nrcs.usda.gov/azpmc

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Family Scientific Name:	Dryopteridaceae
Family Common Name:	Wood Fern family
Scientific Name:	Athyrium americanum (Butters) Maxon
Common Synonym:	Athyrium alpestre (Hoppe) Milde americanum
Common Name:	American Alpine Ladyfern
Species Code:	ATHAME
Ecotype:	Cedar/Devil's Club habitat, understory species,. Glacier National Park, Flathead Co., MT.
General Distribution:	A. americanum is a circumboreal species, occurring at mid to high montane elevations, often near timberline, in rocky slopes and stream borders.
Propagation Goal:	plants
Propagation Method:	seed
ProductType:	Container (plug)
Stock Type:	800 ml container
Time To Grow:	1 Years
Target Specifications:	Stock Type: Container sporophyte<br> Height: 30 cm, 7 mature fronds<br> Caliper: n/a<br> Root System: Fully developed rhizomatous root mass in containers.
Propagule Collection:	Spore Processing: No indusium is present. Collect fronds when spores are tan in color. Spore bearing fronds are collected in late August. Fronds are placed in bags and taken to drying room immediately after collection.
Propagule Processing:	Fronds are placed in a room with no air movement, spore surface down on butcher paper. Spores will appear as a fine dust on the paper after several days of drying.
Pre-Planting Treatments:	Collect spores from the surface of paper and surface sow in sterilized flats filled with sterile, finely milled sphagnum peat moss. Water spores with distilled water and seal flats with clear plastic wrap to seal in moisture and prevent fungal contamination. Place flats under 60 watt soft incandescent lights set at 12 hour per day illumination. Germination of spores will occur after 15 days. The thread like germ filaments can be seen with the aid of a microscope and will appear asa fine green threads on the surface of the medium. A constant temperature of 20 C to 25 C should be maintained throughout the growth of the prothalli. Container Type and Volume: Sporophytes are transplanted into 4.5" pots and 1 gallon containers. Growing Medium: Promix #1 Medium.
Growing Area Preparation/ Annual Practices for Perennial Crops:	Sealed flats are grown under grow lights, for 2 to 3 months. Continued growth under greenhouse conditions at 20 to 25C for 2 to 3 months, followed by growth in the outdoor shadehouse for 6 months.
Establishment Phase:	Spores germinate 10 to 15 days after sowing. The heart shaped prothalli continue to grow for 6 to 8 weeks. Examination of the prothalli under a microscope will reveal the presence of the reproductive structures; the antheridia (male) and archegonia (female), located along the margins and notch of the prothalli. At this stage, it is critical to maintain a thin film of distilled water over the surface of the prothalli for fertilization to occur. It is critical to maintain sterile conditions during germination and establishment. Trays must be inspected for fungal contamination on a regular basis. If fungal contamination occurs, remove infected portions of the medium and treat trays with a highly diluted (1/4 recommended rate)fungicide drench. Treat with dilute fungicide only if prothalli are well developed. Reseal flats immediately and water only with distilled water. Once sporophytes appear, clear plastic is removed from the trays and asceptic conditions are no longer necessary.
Length of Establishment Phase:	2 to 3 months
Active Growth Phase:	Appearance of sporophytes occurred 3 months after spore germination. Individual plants are transplanted from flats to pots when they are 2 inches tall. After establishment in the greenhouse, they are moved to the outdoor shadehouse in late spring. Plants are fertilized with 13-13-13 Osmocote fertilizer and Micromax micronutrients mixed into medium.
Length of Active Growth Phase:	7 months
Hardening Phase:	Plants are fertilized with 10-20-20 liquid NPK at 200 ppm during August and September. Plants were given one final irrigation prior to winterization.
Length of Hardening Phase:	2 months
Harvesting, Storage and Shipping:	Total Time to Harvest: 1 year production time from spores. Harvest Date: September Storage Conditions: Overwinter in outdoor shadehouse under insulating foam and snow.
Length of Storage:	5 months
Other Comments:	Plants have been held successfully for two years in 800 ml (4.5" )and 3L (1 gallon ) containers in the nursery. Root mass is extensive and rhizomatous. Nursery grown plants produced spore bearing fronds 2 years after germination. Vegetative Propagation Method: Rhizome Divisions Type of Cutting: Rhizome sectioning/ wounding Cutting Treatments: Rhizomes are split down the center axis with knife, cut into 20 cm lengths.Time to Transplant: 1 year
References:	Flora of the Pacific Northwest, Hitchcock and Cronquist, Univ. of Washington Press, 7th printing, 1990. Ferns to Know and Grow, Foster, F.G., Timber Press, 1984. Glacier Park Native Plant Nursery Propagation Records, unpublished. Flora of North America, Volume 2 Pteridophytes and Gymnosperms, FNA Editorial Committee, Oxford University Press, 1993.

Citation:

Luna, Tara; Evans, Jeff; Wick, Dale. 2008. Propagation protocol for production of Container (plug) Athyrium americanum (Butters) Maxon plants 800 ml container; USDI NPS - Glacier National Park West Glacier, Montana. In: Native Plant Network. URL: https://NativePlantNetwork.org (accessed 2024/05/18). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.