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Capnoides sempervirens

Harlequin Flower · Pale Corydalis · Pink Corydalis

Family PapaveraceaeGenus Capnoides

Two pink tubular flowers tipped with yellow, hanging from a wiry arching stem with small blue-green leaves
FlowerAaron CarlsonCC BY-SA 2.0

About the plant

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

The plant

Habit
Perennial, WildflowerExtension Gardener Plant Toolbox
Habit
annual or biennialPlants of the World Online
Height
1-4 ft0.3-1.2 mExtension Gardener Plant Toolbox
Spread
1-2 ft30-60 cmExtension Gardener Plant Toolbox
Flower
Gold/Yellow, Pink, Purple/LavenderExtension Gardener Plant Toolbox
Blooms
Fall, Spring, SummerExtension Gardener Plant Toolbox
Native range
Alaska, Alberta, British Columbia, Connecticut, Georgia, Illinois and elsewhereGBIF Backbone Taxonomy
Hardiness zones
2-6Extension Gardener Plant Toolbox

Growing conditions

Sun
Full sun; Partial ShadeExtension Gardener Plant Toolbox
Soil
Shallow RockyExtension Gardener Plant Toolbox
Soil pH
Acid (<6.0), Neutral (6.0-8.0)Extension Gardener Plant Toolbox
Moisture
Good Drainage, Occasionally DryExtension Gardener Plant Toolbox

Toxicity is noted only where a source states it. No note here is not a finding of safety.

Sources: Extension Gardener Plant Toolbox — NC State Extension; Plants of the World Online — Royal Botanic Gardens, Kew; GBIF Backbone Taxonomy — Global Biodiversity Information Facility.

Worth knowing

  • Rock harlequin is the only species in its genus. It grows in rocky woods and on burned or disturbed ground across northern North America. Wikipedia: Capnoides

This source reports 4 treatments. All are shown.

Protocol 1

DerivedN. C. Deno, 1998

Difficulty High Rated by us, not by the source.

Start around August 27, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on August 26, 2026.

  1. Dry storage

    Duration: 180 daysTemperature: 70°F 21°C

  2. Sow and cover

    Temperature: 70°F 21°C Light: dark

about 6 months from start to sowing. Then 42 days to germinate.

20% germination in 21–42 days.

Seed Germination Theory and Practice, 2nd Supplement — N. C. Deno, 1998 · 2nd Supplement, Corydalis p. 26Public domain
Show the original text
Corydalis (Fumariaceae). C. sempervirens germ. 70L(1/9 in 2nd w), 70D(0/8), and 40-70D(2/10 in 2-8 d). Seeds DS 6 m germ. 70D(20% in 3-6 w). Seeds DS 1 y were dead.
Seed Germination Theory and Practice, 2nd Supplement, 2nd Supplement, Corydalis p. 26. 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 High Rated by us, not by the source.

Start around December 28, 2026 for a May 3 last frost.

  1. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  2. Warm moist stratification

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

about 3 months from start to step 2. Germination happens during step 2, in 8 days.

20% germination in 2–8 days.

Seed Germination Theory and Practice, 2nd Supplement — N. C. Deno, 1998 · 2nd Supplement, Corydalis p. 26Public domain
Show the original text
Corydalis (Fumariaceae). C. sempervirens germ. 70L(1/9 in 2nd w), 70D(0/8), and 40-70D(2/10 in 2-8 d). Seeds DS 6 m germ. 70D(20% in 3-6 w). Seeds DS 1 y were dead.
Seed Germination Theory and Practice, 2nd Supplement, 2nd Supplement, Corydalis p. 26. 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 High Rated by us, not by the source.

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

  1. Sow and cover

    Temperature: 70°F 21°C Light: light

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

11% germination in 14 days.

Seed Germination Theory and Practice, 2nd Supplement — N. C. Deno, 1998 · 2nd Supplement, Corydalis p. 26Public domain
Show the original text
Corydalis (Fumariaceae). C. sempervirens germ. 70L(1/9 in 2nd w), 70D(0/8), and 40-70D(2/10 in 2-8 d). Seeds DS 6 m germ. 70D(20% in 3-6 w). Seeds DS 1 y were dead.
Seed Germination Theory and Practice, 2nd Supplement, 2nd Supplement, Corydalis p. 26. 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 Very high Rated by us, not by the source.

  1. Sow and cover

    Temperature: 70°F 21°C Light: dark

No stated waiting before sowing.

0% germination.

Seed Germination Theory and Practice, 2nd Supplement — N. C. Deno, 1998 · 2nd Supplement, Corydalis p. 26Public domain
Show the original text
Corydalis (Fumariaceae). C. sempervirens germ. 70L(1/9 in 2nd w), 70D(0/8), and 40-70D(2/10 in 2-8 d). Seeds DS 6 m germ. 70D(20% in 3-6 w). Seeds DS 1 y were dead.
Seed Germination Theory and Practice, 2nd Supplement, 2nd Supplement, Corydalis p. 26. 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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