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Penstemon caespitosus

Mat Beardtongue · Mat Penstemon

Family PlantaginaceaeGenus Penstemon

A tight mat of small gray-green leaves smothered in violet-blue tubular flowers, wedged between sandstone boulders and grit.
The whole plantCecelia Alexander https://www.inaturalist.org/people/aspidoscelisCC0

About the plant

What it is and where it grows — not part of any germination protocol.

Habit
subshrubPlants of the World Online
Habit
Perennial, Forb/herb, SubshrubPLANTS Database
Flower
Blue, purplish lavenderWikipedia
Native range
Arizona, Colorado, Utah, WyomingGBIF 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

  • Mat penstemon hugs the ground and is widely grown in rock gardens in Europe and America; the RHS recommends it for crevice gardens. The US Fish and Wildlife Service considers it important for supporting the pollinators of the rare Penstemon debilis. Wikipedia: Penstemon caespitosus

Protocol

DerivedN. C. Deno, 1993

Difficulty Moderate Rated by us, not by the source.

  1. Gibberellic acid soak

  2. Sow and cover

    Temperature: 70°F 21°C Light: dark

No stated waiting before sowing. Then 42 days to germinate.

30% germination in 42 days.

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. caespitosus desertipictus germ. 70D GA-3(30% in 6th w) and 70D-40(none).
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.

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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