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Ruellia humilis

Fringe-leaf Ruellia · Fringeleaf Wild Petunia · Wild Petunia

Family AcanthaceaeGenus Ruellia

A low clump of paired green leaves with pale lavender trumpet flowers, growing in a gravel bed beside a small black plant label.
The whole plantHardyplants at English WikipediaCC BY 3.0

About the plant

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

The plant

Habit
perennialPlants of the World Online
Habit
Perennial, Forb/herbPLANTS Database
Height
2.6 ft80 cmPLANTS Database
Flower
PurplePLANTS Database
Blooms
SummerPLANTS Database
Native range
Native to the lower 48 statesPLANTS Database

Growing conditions

Sun
Shade tolerance: LowPLANTS Database
Soil
Adapted to coarse, medium, fine textured soilsPLANTS Database
Soil pH
4.5-7.5PLANTS Database
Moisture
Moisture use: LowPLANTS Database
Watering
Drought tolerance: MediumPLANTS Database

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.

Worth knowing

This source reports two treatments. Both are shown.

Protocol 1

DerivedN. C. Deno, 1993

Difficulty 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

    4 germinated in this phase.

  2. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  3. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

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

17% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Ruellia p. 208Public domain
Show the original text
Ruellia (Acanthaceae). A. humilis requires either a period at 40 or GA-3 to effect germination at 70. Using the 40-70 procedure, the maximum 100% germination is achieved only if the time at 40 is 14 w. Shorter and longer times at 40 give reduced germination. For times at 40 of 0, 4, 6, 8, 10,12, 14, 18, and 22 weeks the respective percent germinations on shifting to 70 were 0, 2%, 6%, 27%, 29%, 47%,100%, 75%, and 88%. Germination is complete in 2-5 d after the shift to 70. Fresh seed and seed DS 6 m at 70 gave similar results. With GA-3 germination is 71% in 5-9 d at 70. Without the GA-3 treatment, sowing the seed at 70 is detrimental as shown by 70(4%)- 40-70(17%) for fresh seed and 70-40-70(2%) for seed DS 6 m at 70 or 40.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Ruellia p. 208. 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, 1993

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

Start around March 21, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on March 20, 2026.

  1. Dry storage

    Duration: 180 days

  2. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

  3. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  4. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

about 12 months from start to step 4. Germination happens during step 4; time not stated, 21 days assumed.

2% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Ruellia p. 208Public domain
Show the original text
Ruellia (Acanthaceae). A. humilis requires either a period at 40 or GA-3 to effect germination at 70. Using the 40-70 procedure, the maximum 100% germination is achieved only if the time at 40 is 14 w. Shorter and longer times at 40 give reduced germination. For times at 40 of 0, 4, 6, 8, 10,12, 14, 18, and 22 weeks the respective percent germinations on shifting to 70 were 0, 2%, 6%, 27%, 29%, 47%,100%, 75%, and 88%. Germination is complete in 2-5 d after the shift to 70. Fresh seed and seed DS 6 m at 70 gave similar results. With GA-3 germination is 71% in 5-9 d at 70. Without the GA-3 treatment, sowing the seed at 70 is detrimental as shown by 70(4%)- 40-70(17%) for fresh seed and 70-40-70(2%) for seed DS 6 m at 70 or 40.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Ruellia p. 208. 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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