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Penstemon mensarum

Grand Mesa Beardtongue · Tiger Beardtongue

Family PlantaginaceaeGenus Penstemon

Upright spikes of blue-violet tubular flowers over gray-green leaves, on plants standing in black nursery pots topped with grit.
The whole plantpeganum from Henfield, EnglandCC BY-SA 2.0

About the plant

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

Habit
perennialPlants of the World Online
Habit
Perennial, Forb/herbPLANTS Database
Flower
Blue, purple-blue, violetWikipedia
Native range
ColoradoGBIF 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

  • Mensarum means "of the table" in Botanical Latin, a reference to Grand Mesa in Colorado, where it is found. NatureServe rated it vulnerable in 2023 because of its limited range. Wikipedia: Penstemon mensarum

This source reports 7 treatments. All are shown.

Protocol 1

DerivedN. C. Deno, 1998

Difficulty Low Rated by us, not by the source.

Start around March 22, 2027 for a May 3 last frost.

  1. Gibberellic acid soak

  2. Sow and cover

    Temperature: 70°F 21°C

No stated waiting before sowing. Then 14 days to germinate.

100% germination in 14 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. mensarum germ. 70 GA-3(100% in 2nd w), 40(2/14 in 9th w), OT(100% in March), 70L-40-70L(1/15) and 70D-40-70D-40(1/16 in 5th w). Seeds DS 1 y germ. 40(4/9 in 6th w). Seeds DS 2 y germ 40(4/9 in 6th w)-70D(1/9 on 5th d).
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

DerivedN. C. Deno, 1998

Difficulty Low Rated by us, not by the source.

  1. Sow outdoors and leave it

    Up in March.

No stated waiting before sowing.

100% 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. mensarum germ. 70 GA-3(100% in 2nd w), 40(2/14 in 9th w), OT(100% in March), 70L-40-70L(1/15) and 70D-40-70D-40(1/16 in 5th w). Seeds DS 1 y germ. 40(4/9 in 6th w). Seeds DS 2 y germ 40(4/9 in 6th w)-70D(1/9 on 5th d).
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

DerivedN. C. Deno, 1998

Difficulty Moderate Rated by us, not by the source.

Start around February 23, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on February 22, 2026.

  1. Dry storage

    Duration: 365 daysTemperature: 70°F 21°C

  2. Cold moist stratification

    Temperature: 40°F 4°C

about 12 months from start to step 2. Germination happens during step 2, in 42 days.

44% germination in 42 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. mensarum germ. 70 GA-3(100% in 2nd w), 40(2/14 in 9th w), OT(100% in March), 70L-40-70L(1/15) and 70D-40-70D-40(1/16 in 5th w). Seeds DS 1 y germ. 40(4/9 in 6th w). Seeds DS 2 y germ 40(4/9 in 6th w)-70D(1/9 on 5th d).
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

DerivedN. C. Deno, 1998

Difficulty Moderate Rated by us, not by the source.

Start around February 23, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on February 22, 2025.

  1. Dry storage

    Duration: 730 daysTemperature: 70°F 21°C

  2. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  3. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C Light: dark

    1/9 germinated in this phase.

Steps after step 2 run on after germination.

about 2 years from start to step 2. Germination happens during step 2, in 42 days.

44% germination in 42 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. mensarum germ. 70 GA-3(100% in 2nd w), 40(2/14 in 9th w), OT(100% in March), 70L-40-70L(1/15) and 70D-40-70D-40(1/16 in 5th w). Seeds DS 1 y germ. 40(4/9 in 6th w). Seeds DS 2 y germ 40(4/9 in 6th w)-70D(1/9 on 5th d).
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

DerivedN. C. Deno, 1998

Difficulty High Rated by us, not by the source.

Start around February 1, 2027 for a May 3 last frost.

  1. Cold moist stratification

    Temperature: 40°F 4°C

Germination happens during step 1, in 63 days.

14% germination in 63 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. mensarum germ. 70 GA-3(100% in 2nd w), 40(2/14 in 9th w), OT(100% in March), 70L-40-70L(1/15) and 70D-40-70D-40(1/16 in 5th w). Seeds DS 1 y germ. 40(4/9 in 6th w). Seeds DS 2 y germ 40(4/9 in 6th w)-70D(1/9 on 5th d).
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 6

DerivedN. C. Deno, 1998

Difficulty Very high Rated by us, not by the source.

Start around September 17, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on September 16, 2026.

  1. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C Light: light

  2. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  3. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C Light: light

about 6 months from start to step 3. Germination happens during step 3; time not stated, 21 days assumed.

7% germination.

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. mensarum germ. 70 GA-3(100% in 2nd w), 40(2/14 in 9th w), OT(100% in March), 70L-40-70L(1/15) and 70D-40-70D-40(1/16 in 5th w). Seeds DS 1 y germ. 40(4/9 in 6th w). Seeds DS 2 y germ 40(4/9 in 6th w)-70D(1/9 on 5th d).
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 7

DerivedN. C. Deno, 1998

Difficulty Very high Rated by us, not by the source.

Start around June 5, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on June 4, 2026.

  1. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C Light: dark

  2. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  3. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C Light: dark

  4. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

about 9 months from start to step 4. Germination happens during step 4, in 35 days.

6% germination in 35 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. mensarum germ. 70 GA-3(100% in 2nd w), 40(2/14 in 9th w), OT(100% in March), 70L-40-70L(1/15) and 70D-40-70D-40(1/16 in 5th w). Seeds DS 1 y germ. 40(4/9 in 6th w). Seeds DS 2 y germ 40(4/9 in 6th w)-70D(1/9 on 5th d).
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.

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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