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Flower dande
https://www.inaturalist.org/people/dande CC0 About the plant What it is and where it grows — not part of any germination protocol.
Habit perennial Plants of the World Online
Habit Perennial, Forb/herb PLANTS Database
Flower Pink-purple, lavender, lavender-blue Wikipedia
Native range Colorado, Wyoming GBIF Backbone Taxonomy Toxicity is noted only where a source states it. No note here is not a finding of safety.
Sources: Plants of the World Online — Royal Botanic Gardens, Kew; PLANTS Database — USDA NRCS; Wikipedia — Wikipedia contributors; GBIF Backbone Taxonomy — Global Biodiversity Information Facility.
Worth knowing Its Greek name means cup-bearing, for the large cup-like bracts under its flowers. Rare and limited in range, it is vulnerable to human development; mule deer in an enclosure in Middle Park almost never ate it. Wikipedia: Penstemon cyathophorus This source reports 5 treatments. All are shown.
Protocol 1 N. C. Deno, 1998 Difficulty Low Rated by us, not by the source.
Start around March 8, 2027 for a May 3 last frost.
1 2 Sow and cover
Temperature: 70°F 21°C
No stated waiting before sowing. Then 28 days to germinate.
100% germination in 14–28 days.
Seed Germination Theory and Practice, 2nd Supplement — N. C. Deno, 1998 · 2nd Supplement, Penstemon p. 52Public domain Show the original text Penstemon (Scrophulariaceae). Some of the following data are updates on species reported in the 1st Suppl. As noted in the 2nd Ed. and 1st Suppl., 'there is a wide range of germination behaviors in this genus ranging from requirements for light, oscillating temperatures, low temperatures, and GA-3. P. cyathophorus germ. 70 GA-3(100% in 2-4 w), 40(1/9 8th w), OT(8/12 in March-April), and none in 70D or 70L. Seeds DS 2 y germ. 40-70(3/14 on 3rd d) and 70(none). Seed Germination Theory and Practice, 2nd Supplement, 2nd Supplement, Penstemon p. 52. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list. Protocol 2 N. C. Deno, 1998 Difficulty Moderate Rated by us, not by the source.
1 Sow outdoors and leave it
Up in March-April.
No stated waiting before sowing.
67% germination.
This source doesn't state how long step 1 lasts.
Seed Germination Theory and Practice, 2nd Supplement — N. C. Deno, 1998 · 2nd Supplement, Penstemon p. 52Public domain Show the original text Penstemon (Scrophulariaceae). Some of the following data are updates on species reported in the 1st Suppl. As noted in the 2nd Ed. and 1st Suppl., 'there is a wide range of germination behaviors in this genus ranging from requirements for light, oscillating temperatures, low temperatures, and GA-3. P. cyathophorus germ. 70 GA-3(100% in 2-4 w), 40(1/9 8th w), OT(8/12 in March-April), and none in 70D or 70L. Seeds DS 2 y germ. 40-70(3/14 on 3rd d) and 70(none). Seed Germination Theory and Practice, 2nd Supplement, 2nd Supplement, Penstemon p. 52. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list. Protocol 3 N. C. Deno, 1998 Difficulty High Rated by us, not by the source.
Start around January 3, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on January 2, 2025.
1 Dry storage
Duration: 730 days · Temperature: 70°F 21°C
2 Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
3 Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
about 2 years from start to step 3. Germination happens during step 3, in 3 days.
21% germination in 3 days.
Seed Germination Theory and Practice, 2nd Supplement — N. C. Deno, 1998 · 2nd Supplement, Penstemon p. 52Public domain Show the original text Penstemon (Scrophulariaceae). Some of the following data are updates on species reported in the 1st Suppl. As noted in the 2nd Ed. and 1st Suppl., 'there is a wide range of germination behaviors in this genus ranging from requirements for light, oscillating temperatures, low temperatures, and GA-3. P. cyathophorus germ. 70 GA-3(100% in 2-4 w), 40(1/9 8th w), OT(8/12 in March-April), and none in 70D or 70L. Seeds DS 2 y germ. 40-70(3/14 on 3rd d) and 70(none). Seed Germination Theory and Practice, 2nd Supplement, 2nd Supplement, Penstemon p. 52. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list. Protocol 4 N. C. Deno, 1998 Difficulty High Rated by us, not by the source.
Start around February 8, 2027 for a May 3 last frost.
1 Cold moist stratification
Temperature: 40°F 4°C
Germination happens during step 1, in 56 days.
11% germination in 56 days.
Seed Germination Theory and Practice, 2nd Supplement — N. C. Deno, 1998 · 2nd Supplement, Penstemon p. 52Public domain Show the original text Penstemon (Scrophulariaceae). Some of the following data are updates on species reported in the 1st Suppl. As noted in the 2nd Ed. and 1st Suppl., 'there is a wide range of germination behaviors in this genus ranging from requirements for light, oscillating temperatures, low temperatures, and GA-3. P. cyathophorus germ. 70 GA-3(100% in 2-4 w), 40(1/9 8th w), OT(8/12 in March-April), and none in 70D or 70L. Seeds DS 2 y germ. 40-70(3/14 on 3rd d) and 70(none). Seed Germination Theory and Practice, 2nd Supplement, 2nd Supplement, Penstemon p. 52. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list. Protocol 5 N. C. Deno, 1998 1 Sow and cover
Temperature: 70°F 21°C · Light: dark
No stated waiting before sowing.
0% germination.
Nothing germinated at 70.
Seed Germination Theory and Practice, 2nd Supplement — N. C. Deno, 1998 · 2nd Supplement, Penstemon p. 52Public domain Show the original text Penstemon (Scrophulariaceae). Some of the following data are updates on species reported in the 1st Suppl. As noted in the 2nd Ed. and 1st Suppl., 'there is a wide range of germination behaviors in this genus ranging from requirements for light, oscillating temperatures, low temperatures, and GA-3. P. cyathophorus germ. 70 GA-3(100% in 2-4 w), 40(1/9 8th w), OT(8/12 in March-April), and none in 70D or 70L. Seeds DS 2 y germ. 40-70(3/14 on 3rd d) and 70(none). Seed Germination Theory and Practice, 2nd Supplement, 2nd Supplement, Penstemon p. 52. Quoted exactly. Every value on this card comes from this record; the step names come from a fixed list. How each step is done , in Deno’s words, and what Verified and Derived mean.
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