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Dendromecon rigida

Californian Poppy Bush · Bush-poppy · Tree Poppy

Family PapaveraceaeGenus Dendromecon

A yellow four-petalled flower with a dense orange center, beside a round green bud on a gray-leaved shoot
FlowerNPSPublic domain

About the plant

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

Habit
shrubPlants of the World Online
Habit
Perennial, Shrub, TreePLANTS Database
Flower
YellowWikipedia
Native range
California, Mexico NorthwestGBIF 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.

This source reports three treatments. All are shown.

Protocol 1

DerivedN. C. Deno, 1996

Difficulty Moderate Rated by us, not by the source.

Start around November 24, 2026 for a May 3 last frost.

  1. Gibberellic acid soak

  2. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

    20 germinated in this phase.

  3. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

about 3 months from start to step 3. Germination happens during step 3, in 42 days.

40% germination in 21–42 days.

Seed Germination Theory and Practice, 1st Supplement — N. C. Deno, 1996 · 1st Supplement, Dendromecon p. 38Public domain
Show the original text
Dendromecon (Papaveraceae). D. rigida germ. 70 GA-3(20% in 4-7 w)- 40(40% in 3-6 w) and none in 70L, 70D, 40-70, or OT (after one y). The seeds expand and split first. The radicle does not appear until a week later followed by expansion of the cotyledons in two days. Seeds that had been DS at 40 for 3 y were dead.
Seed Germination Theory and Practice, 1st Supplement, 1st Supplement, Dendromecon p. 38. 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, 1996

  1. Sow and cover

    Temperature: 70°F 21°C Light: light

No stated waiting before sowing.

0% germination.

Nothing germinated at 70.

Seed Germination Theory and Practice, 1st Supplement — N. C. Deno, 1996 · 1st Supplement, Dendromecon p. 38Public domain
Show the original text
Dendromecon (Papaveraceae). D. rigida germ. 70 GA-3(20% in 4-7 w)- 40(40% in 3-6 w) and none in 70L, 70D, 40-70, or OT (after one y). The seeds expand and split first. The radicle does not appear until a week later followed by expansion of the cotyledons in two days. Seeds that had been DS at 40 for 3 y were dead.
Seed Germination Theory and Practice, 1st Supplement, 1st Supplement, Dendromecon p. 38. Quoted exactly. Every value on this card comes from this record; the step names come from a fixed list.

Protocol 3

DerivedN. C. Deno, 1996

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

  1. Sow outdoors and leave it

    Nothing germinated outdoors.

No stated waiting before sowing.

0% germination.

This source doesn't state how long step 1 lasts.

Seed Germination Theory and Practice, 1st Supplement — N. C. Deno, 1996 · 1st Supplement, Dendromecon p. 38Public domain
Show the original text
Dendromecon (Papaveraceae). D. rigida germ. 70 GA-3(20% in 4-7 w)- 40(40% in 3-6 w) and none in 70L, 70D, 40-70, or OT (after one y). The seeds expand and split first. The radicle does not appear until a week later followed by expansion of the cotyledons in two days. Seeds that had been DS at 40 for 3 y were dead.
Seed Germination Theory and Practice, 1st Supplement, 1st Supplement, Dendromecon p. 38. 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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