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Flower Andrey Zharkikh from Salt Lake City, USA CC BY 2.0 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, Subshrub PLANTS Database
Flower Lavender, blue, violet Wikipedia
Native range Utah, 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 Acaulis means stemless. NatureServe rated it imperiled in 2022: it grows in about 20 places where Wyoming and Utah meet, with between 100,000 and 1,000,000 plants, but with a short-term downward trend. Wikipedia: Penstemon acaulis This source reports three treatments. All are shown.
Protocol 1 N. C. Deno, 1993 Difficulty High Rated by us, not by the source.
Start around March 15, 2027 for a May 3 last frost.
1 Cold moist stratification
Temperature: 40°F 4°C
Germination happens during step 1; time not stated, 21 days assumed.
10% germination.
Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Penstemon p. 187Public domain Show the original text Penstemon (Scrophulariaceae). Four types of germination were observed. Most Rocky Mountain species of a perennial nature germ. largely at 40 and often sowing at 70 was fatal or near fatal. A second group are short lived species that can flower the first year from seed typified by P. acaulis germ 70(1/10) and none at 40. Seed Germination Theory and Practice, 2nd ed., Ch. 20, Penstemon p. 187. 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, 1993 Difficulty High Rated by us, not by the source.
Start around March 15, 2027 for a May 3 last frost.
1 Sow and cover
Temperature: 70°F 21°C
No stated waiting before sowing. Germination time not stated; 21 days assumed.
10% germination.
Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Penstemon p. 187Public domain Show the original text Penstemon (Scrophulariaceae). Four types of germination were observed. Most Rocky Mountain species of a perennial nature germ. largely at 40 and often sowing at 70 was fatal or near fatal. A second group are short lived species that can flower the first year from seed typified by P. acaulis germ 70(1/10) and none at 40. Seed Germination Theory and Practice, 2nd ed., Ch. 20, Penstemon p. 187. 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, 1993 1 Cold moist stratification
Temperature: 40°F 4°C
Germination happens during step 1.
0% germination.
Nothing germinated at 40.
This source doesn't state how long step 1 lasts.
Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Penstemon p. 187Public domain Show the original text Penstemon (Scrophulariaceae). Four types of germination were observed. Most Rocky Mountain species of a perennial nature germ. largely at 40 and often sowing at 70 was fatal or near fatal. A second group are short lived species that can flower the first year from seed typified by P. acaulis germ 70(1/10) and none at 40. Seed Germination Theory and Practice, 2nd ed., Ch. 20, Penstemon p. 187. 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.
Germination trials Readers’ own records of sowing this species, published after review. Share your trial · All trials
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