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Packera dubia; photograph author not stated, no rights reserved CC0author not stated, no rights reserved · observed growing wild · 2026-03-10

Packera dubia (Spreng.) Trock & Mabb.

Asteraceae · Oklahoma, New Jersey +12

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Packera dubia, photograph author not stated, no rights reservedPackera dubia, photograph author not stated, no rights reservedPackera dubia, photograph (c) Alex Stach, some rights reserved (CC BY)Packera dubia, photograph (c) Bob Schwartz, some rights reserved (CC BY)Packera dubia, photograph (c) Tom Field, some rights reserved (CC BY)Packera dubia, photograph (c) Tom Field, some rights reserved (CC BY) 66 photographs ›
Habitat figures
Cold floor (1 night in 100)
-5.1°C
Record low -16.2 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
32°C
Jul and Aug at the habitat CHELSA
Rain a year (median across the range)
1,287mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
15–40DLI
Lowest to highest month (DLI) CHELSA
The year in your months, northern hemisphere
  1. Jan
  2. Feb
  3. Mar
  4. Apr
  5. May
  6. Jun
  7. Jul
  8. Aug
  9. Sep
  10. Oct
  11. Nov
  12. Dec
Rain spread: 70% of the median year's rain takes 9 months, so no short rainy season. rain rule, CHELSA
Northern hemisphere unless you set your site. The chart is in the habitat's months.

Summary

Packera dubia (synonym Packera tomentosa), often known by the name woolly ragwort, is a perennial species of flowering plant in the Asteraceae family. It is native to the southeastern United States, primarily to the coastal plain but extending into some areas inland and is common throughout its range, where it typically inhabits open, sandy areas and granitic outcrops. This species produces a head of yellow flowers in late spring. Its seeds have been shown to vary in mass within a single flower head as an adaptation to improve dispersal in disturbed habitats.

Quoted from Wikipedia, "Packera dubia", CC BY-SA 4.0.

About the genus · Packera

Packera is a genus of about 75 species of plants in the daisy family, Asteraceae. Most species are commonly called ragworts or grounsels. Its members were previously included in the genus Senecio but were moved to genus Packera based on chromosome numbers, a variety of morphological characters, and molecular phylogenetic evidence.

Quoted from Wikipedia, "Packera", CC BY-SA 4.0.

Cultivation

Seasons

The rain rule reads no short rainy season: 70% of the median year's rain (961 mm of 1,243 mm) takes 9 months, March to September and November to December. Mean temperature moves 22.0 °C between the warmest and coldest month. Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: September to March and May to June.

Rain

1,243 mm in the median year at the habitat, 961 mm of it March to September and November to December. Wettest months (2 at 113 mm), driest month January at 92 mm. Across the grid cells of the range the year's total runs 1,155 mm to 1,437 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,287 mm, is the year's rain at the top of the page; the 1,243 mm here is the median year's, the twelve monthly medians added, which the rain rule reads. Habitat calendar, northern hemisphere; median year across the grid cells of the range, CHELSA.

Light

Open sky over the habitat: 15 to 40 mol/m²/day across the year (daily light integral, median year across the grid cells of the range, CHELSA; the lowest 10th-percentile month across the cells is 13, the highest 90th-percentile month 42).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is -5.1 °C, the absolute minimum -16.2 °C, 1,408 frost nights in 44 years, 32.0 a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 33.9 °C. Monthly means: the coldest month's mean nightly low 1.5 °C in January (across the grid cells of the range -0.5 °C to 5.4 °C), the warmest month's mean daily high 32.2 °C in July (median year across the grid cells of the range, CHELSA). Cold floor: -5.1 °C, which is the 1st-percentile night over 44 years at a typical spot in the range (NASA POWER).

Humidity

Relative humidity at the habitat: 56 to 60% across the year (monthly means, median year across the grid cells of the range, CHELSA). A figure about the air, saying nothing about how the plant takes water.

How this section is made

Each card states this species' habitat figures with their sources, and what two fixed rules read from them; nothing here says what the plant does, wants or tolerates. The rules · the terms.

Seasons. Read from the median year of CHELSA monthly rainfall and mean temperature across the grid cells of the range: the rain rule takes the smallest set of months carrying 70% of the rain and calls it winter when its mean is more than half a degree below the year's, summer when more than that above, and neither in between; the temperature rule, used only under 120 mm, names the cooler six months when they are at least a degree cooler than the other six. Months are shifted for the other hemisphere only where the temperature curve moves 4 °C or more and the habitat lies 10° or more from the equator. A reading of the curves, not an observation of the plant.

Rain. CHELSA monthly precipitation, median year across the grid cells of the range. The rain that falls where the species is recorded; nothing about how the plant takes water.

Light. CHELSA shortwave radiation at each envelope cell, a daily-mean flux taken to a daily total and converted at 2.07 mol of PAR per MJ. The sky over the habitat, measured; what reaches a plant under a rock, a shrub or a shade cloth is not.

Temperature. NASA POWER daily minima and maxima over 44 years at a typical spot in the range, lapse-corrected -5 m to its elevation; CHELSA monthly means, median year across the grid cells of the range. The cold floor is the 1st-percentile night named in its sentence. Not a measured survival limit for any plant in a pot.

Humidity. CHELSA relative humidity, median year across the grid cells of the range.

Climate across the habitat

Habitat months, northern hemisphere

Habitat climate of Packera dubia through the yearWarmest months July and August, mean daily high 32 °C; coldest month January, mean nightly low 1.5 °C; 1,243 mm of rain in the median year (the twelve monthly medians added). Medians across the range, from CHELSA; the extremes at the edge from NASA POWER. Habitat months, northern hemisphere.-20°-10°0°10°20°30°40°frost33.9° 99th-percentile day, NASA POWER-16.2° lowest night in 44 years, NASA POWER°C · day and nightcold quarter050100150200mm rainDLI 15–40RH 56–60%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 587 habitat cells, CHELSA cold quarter: the three months around the coldest month's mean nightly low extremes over 44 years at a typical spot in the range, from NASA POWER, marked at the edge, in no month DLI, mol/m²/dayRH %each on its own scale
Figures by month
JanFebMarAprMayJunJulAugSepOctNovDec
Day °C10 / 7–1513 / 8–1718 / 12–2122 / 18–2527 / 23–2930 / 27–3232 / 29–3332 / 28–3428 / 25–3023 / 20–2517 / 14–2011 / 9–16
Night °C2 / -1–53 / 1–77 / 4–1011 / 9–1416 / 14–1821 / 19–2223 / 22–2423 / 21–2419 / 18–2113 / 12–168 / 7–113 / 1–7
Rain mm92 / 83–12093 / 79–127113 / 98–13599 / 80–129105 / 84–151111 / 94–140113 / 91–149110 / 72–155103 / 85–13297 / 83–138105 / 78–133102 / 86–139
DLI17 / 15–1821 / 21–2328 / 28–3035 / 35–3839 / 37–4140 / 39–4240 / 38–4237 / 34–3831 / 28–3224 / 23–2618 / 17–2015 / 13–17
RH %58 / 56–5957 / 55–5856 / 55–5856 / 54–5758 / 56–6059 / 58–6159 / 58–6260 / 57–6359 / 56–6157 / 56–5857 / 56–5958 / 56–59
How this section is made
Each figure is the median across the 587 grid cells on land that hold in-range records (1045 records in those cells; 1 more cell holds records but no land by the elevation layer, so those records sit at sea and the cell is left out), with the 10th–90th percentile span across those cells after the slash where it differs. A dash is a month one or more of those cells has no figure for in the grid (a variable CHELSA does not carry there), so no median is taken rather than one over fewer cells. Extremes and elevation were read at a typical spot in the range, cell 1059:2073 (37.025, -76.325). Over 44 years there: absolute minimum -16.2 °C, 1st-percentile night -5.1 °C, 99th-percentile day 33.9 °C. Normals: CHELSA V2.1 1981–2010 climatology, 0.05° cells (each the mean of ~36 1 km pixels). Across the range: median and 10th–90th percentile of each month across the 587 distinct grid cells holding 1045 of the 1047 in-range records (1 further cell with records at sea, by the elevation layer, left out); extremes and elevation at the typical cell 1059:2073 (its coldest month's mean nightly low nearest the median across cells); its position is the cell centre. Extremes: NASA POWER (MERRA-2) daily 1981–2024, cell 37.00_-76.250, lapse-corrected -5 m at 6.5 °C/km. Elevation: ETOPO 2022, 2 m (cell mean).

Natural habitat

Native range as published by WCVP; the marker is where the records are densest and decides nothing: the climate was read across the cells of the in-range records placed well enough to read one, not at the marker.
Openly licensed records inside the range, framed on where they fall.
NativeOklahoma, New Jersey, Texas, Alabama, Arkansas, Delaware, Florida, Georgia, Louisiana, Maryland, Mississippi, North Carolina, South Carolina, Virginia · regions are the level-3 units of the World Geographical Scheme for Recording Plant Distributions, as Kew's World Checklist records ranges, some under historical names such as Yugoslavia or Czechoslovakia (how).
Map marker34.645, -92.959 · in the densest population, 758 records (56% of those in range)
Kew's description“temperate” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 1351 georeferenced records inside the native range; the climate across the range on the 1045 of them in the land cells it reads, of 1047 placed to within 10 km; the map shows only the 396 openly licensed ones, which alone would put the marker 29 km away. 9 records outside the WCVP native range not used. 304 in-range records are placed to worse than 10 km, or with no stated accuracy (admitted only as a person's observation to three decimals), and stay on the map but off the climate.
How this section is made
The map marker: the openly licensed record nearest the middle of the densest 1° population inside the densest 4° block of the 1351 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Packera dubia, photograph 1did not loadPackera dubia, photograph 2did not loadPackera dubia, photograph 3did not loadPackera dubia, photograph 4did not loadPackera dubia, photograph 5did not loadPackera dubia, photograph 6did not load

Photographs: author not stated, no rights reserved · CC0 (2); (c) Alex Stach, some rights reserved (CC BY); (c) Bob Schwartz, some rights reserved (CC BY); (c) Tom Field, some rights reserved (CC BY) (2).

Similar habitat climate The 6 nearest by mean daily high, mean nightly low and rain, month by month. How.

Anatherum ternarium Poaceae Quercus pagoda Quercus pagoda Cherry-bark oak Photo: CC BY, Anne ParkerPassiflora incarnata Passiflora incarnata Purple passionflower Photo: CC0, author not statedUlmus alata Ulmus alata Winged elm Photo: CC BY, C FishtahlerHoustonia pusilla Houstonia pusilla Tiny bluet Photo: CC BY-SA, Turner BrockmanLycopus rubellus Lycopus rubellus Stalked water-horehound Photo: CC BY, Kristály Cravens-Liszak

Other Packera 12 in the reference

Packera anonyma Packera anonyma Small's ragwort Photo: CC BY, Daniel J. LaytonPackera aurea Packera aurea Golden ragwort Photo: CC BY, Matt FelperinPackera cana Packera cana Woolly groundsel Photo: CC BY, Daughter DadPackera glabella Packera glabella Butterweed Photo: CC0, author not statedPackera multilobata Packera multilobata Lobe-leaf groundsel Photo: CC BY, Andrew DudleyPackera obovata Packera obovata Round-leaf ragwort Photo: CC0, author not statedPackera paupercula Packera paupercula Balsam groundsel Photo: CC BY, Patrick JacksonPackera plattensis Packera plattensis Prairie groundsel Photo: CC BY, Jeff HansenPackera pseudaurea Packera pseudaurea False-gold groundsel Photo: CC0, author not statedPackera schweinitziana Packera schweinitziana Schweinitz's ragwort Photo: CC BY, Tom ScavoPackera tampicana Packera tampicana Great Plains ragwort Photo: CC0, author not statedPackera werneriifolia Packera werneriifolia Hoary groundsel Photo: CC BY, Anders Hastings

Names & registers

Also known as Cineraria diversifolia; Cineraria dubia; Cineraria heterophylla; Cineraria integrifolia; Cineraria integrifolia var. minor and 7 more. (GBIF Backbone)

GBIFPOWOIPNIWikidataWikipediaiNaturalist

The record

Family
Asteraceae
Described by
(Spreng.) Trock & Mabb.
Native to
Oklahoma, New Jersey, Texas +11
Wild records
1351 in range · 396 open

Every figure here is derived from public data by a stated rule and names its source; nothing about this species is written for its page by a person or by AI, apart from the marked, credited quotations. How →

Where this page came from built 2026-10-22
GBIF species record gbif.species answeredasked 2026-10-22
GBIF synonyms gbif.synonyms answeredasked 2026-10-22
GBIF common names gbif.vernacular answeredasked 2026-10-22names fetched 2026-10-22
WCVP native range wcvp.distribution answeredas of 2026-06-04
GBIF occurrence records gbif.occurrences answeredas of 2026-10-21GBIF occurrence download https://doi.org/10.15468/dl.hbdw64, of 2026-10-21; 11 records within 1 km of a botanic garden, herbarium or zoo left out (11 at a botanic garden or arboretum; Wikidata's list)
Habitat climate climate answeredasked 2026-10-22
Daily extremes (NASA POWER) climate.extremes answeredasked 2026-10-22NASA POWER (MERRA-2) daily 1981–2024, cell 37.00_-76.250, lapse-corrected -5 m at 6.5 °C/km
Wikidata wikidata answeredasked 2026-10-22
Wikipedia wikipedia answeredasked 2026-10-22
iNaturalist photographs, wild inat.photos.wild answeredasked 2026-10-22from iNaturalist's open data of 2026-09-27: research-grade observations with an open-licence photograph, the 24 whose photographs iNaturalist received last (the open data holds no votes); filled 2026-10-22
iNaturalist photographs, cultivated inat.photos.cultivated not asked
GBIF media gbif.media answeredasked 2026-10-22
OpenAlex papers openalex not askednot yet asked for this reference; a later fill takes the papers from OpenAlex's snapshot

Every source is recorded as having answered, reported nothing, refused, failed, not been asked, or answered twice where one answer is taken (“not taken: two items answered”), and, for a source asked when this page was built, when: the figures are as the source held them that day; a source read from a file (Kew's World Checklist, a GBIF download) says "as of" the file's day instead; a row carried from an earlier build of the page names that build instead. Only “nothing to report” is ever shown as an absence. Records came from 60 datasets via GBIF.org; each carries its own licence.

Cultifolio

Opening your plants…