Penstemon retrorsus
Adobe Hills Beardtongue
About the plant
What it is and where it grows — not part of any germination protocol.
- Habit
- subshrubPlants of the World Online
- Flower
- Blue-purpleWikipedia
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; Wikipedia — Wikipedia contributors.
Worth knowing
- Retrorsus means turned backwards, for the tiny backward-pointing hairs on its stems and leaves, visible only under magnification. The rare adobe penstemon grows only along parts of the Uncompahgre and Gunnison rivers, on barren shale slopes where few plants survive. Wikipedia: Penstemon retrorsus
This source reports two treatments. Both are shown.
Protocol 1
DerivedN. C. Deno, 1996Difficulty High
Start around February 22, 2027 for a May 3 last frost.
Cold moist stratification
Temperature: 40°F 4°C
Germination happens during step 1, in 42 days.
14% germination in 42 days.
Protocol 2
DerivedN. C. Deno, 1996Sow and cover
Temperature: 70°F 21°C Light: dark
No stated waiting before sowing.
0% germination.
Nothing germinated at 70.
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
No trials shared for this species yet.