Example ⟳ +
An example collection, so you can see what this page does. Nothing added here is kept: leaving deletes it.
Eriastrum densifolium; photograph (c) Henrik Kibak, some rights reserved (CC BY) CC BY(c) Henrik Kibak, some rights reserved (CC BY) · observed growing wild · 2026-07-04

Eriastrum densifolium (Benth.) H.Mason

Giant woollystar

Polemoniaceae · California, Mexico Northwest

Add one to my plants
Sow seed
Eriastrum densifolium, photograph (c) Henrik Kibak, some rights reserved (CC BY)Eriastrum densifolium, photograph (c) Henrik Kibak, some rights reserved (CC BY)Eriastrum densifolium, photograph (c) Henrik Kibak, some rights reserved (CC BY)Eriastrum densifolium, photograph (c) Jess Mullins, some rights reserved (CC BY)Eriastrum densifolium, photograph (c) Jess Mullins, some rights reserved (CC BY)Eriastrum densifolium, photograph (c) Jess Mullins, some rights reserved (CC BY) 142 photographs ›
Habitat figures
Cold floor (1 night in 100)
-6.1°C
Record low -10.7 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
30°C
Jul and Aug at the habitat CHELSA
Rain a year (median across the range)
426mm
6 months of 25 mm or more in the median year CHELSA
Open-sky light
19–54DLI
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
Wet winters: the rain comes December to March, read as a winter growing season. rain rule, CHELSA
Northern hemisphere unless you set your site. The chart is in the habitat's months.

Summary

Eriastrum densifolium is a species of flowering plant in the phlox family known by the common name giant woollystar. This wildflower is native to California and Baja California where it grows in open areas such as sand dunes and dry washes. It grows on an erect stem with slightly hairy to densely woolly foliage, often giving the plant a dark gray-green color. The leaves are narrow and spike-shaped with pointed lobes. More on Wikipedia ›

Quoted from Wikipedia, "Eriastrum densifolium", CC BY-SA 4.0.

Cultivation

Seasons

The rain rule reads a winter growing season: 70% of the median year's rain (302 mm of 423 mm) falls in December to March, cooler than the year (wet-season mean 7.4 °C against a yearly mean of 13.8 °C). Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: June to September.

Rain

423 mm in the median year at the habitat, 302 mm of it December to March. Wettest month February at 90 mm, driest month June at 3 mm; 1 month under 5 mm. Across the grid cells of the range the year's total runs 225 mm to 598 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 426 mm, is the year's rain at the top of the page; the 423 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: 19 to 54 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 17, the highest 90th-percentile month 55).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is -6.1 °C, the absolute minimum -10.7 °C, 3,208 frost nights in 44 years, 72.9 a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 37.4 °C. Monthly means: the coldest month's mean nightly low 1.5 °C in January and December (across the grid cells of the range -3.6 °C to 6.3 °C), the warmest month's mean daily high 30.2 °C in July (median year across the grid cells of the range, CHELSA). Cold floor: -6.1 °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: 43 to 52% 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 +551 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 Eriastrum densifolium through the yearWarmest months July and August, mean daily high 30 °C; coldest months January and December, mean nightly low 1.5 °C; 423 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°frost37.4° 99th-percentile day, NASA POWER-10.7° lowest night in 44 years, NASA POWER°C · day and nightcold quarter0255075100125150mm rainDLI 19–54RH 43–52%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 463 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 °C13 / 7–1613 / 7–1716 / 10–2019 / 14–2323 / 18–2727 / 22–3130 / 25–3430 / 24–3427 / 22–3122 / 18–2616 / 12–2012 / 7–16
Night °C2 / -4–62 / -3–73 / -2–85 / 1–109 / 5–1213 / 9–1616 / 12–1916 / 12–1914 / 10–179 / 5–135 / 0–92 / -4–6
Rain mm82 / 41–12190 / 42–12967 / 31–9229 / 11–469 / 4–153 / 2–65 / 1–176 / 1–229 / 4–1621 / 10–2939 / 20–5863 / 33–96
DLI21 / 19–2326 / 24–2936 / 34–3945 / 43–4851 / 50–5354 / 53–5552 / 51–5348 / 46–4941 / 39–4232 / 30–3423 / 21–2619 / 17–22
RH %50 / 46–5652 / 48–5852 / 47–5850 / 44–5648 / 42–5644 / 38–5443 / 39–5444 / 40–5445 / 41–5446 / 42–5348 / 43–5450 / 45–56
How this section is made
Each figure is the median across the 463 grid cells on land that hold in-range records (1077 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 1114:1238 (34.275, -118.075). Over 44 years there: absolute minimum -10.7 °C, 1st-percentile night -6.1 °C, 99th-percentile day 37.4 °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 463 distinct grid cells holding 1077 of the 1078 in-range records (1 further cell with records at sea, by the elevation layer, left out); extremes and elevation at the typical cell 1114:1238 (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 34.50_-118.125, lapse-corrected +551 m at 6.5 °C/km. Elevation: ETOPO 2022, 1337 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.
NativeCalifornia, Mexico Northwest · introduced: Germany · 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 marker34.316, -117.5 · in the densest population, 940 records (59% of those in range)
Kew's description“subshrub” · “temperate” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 1591 georeferenced records inside the native range; the climate across the range on the 1077 of them in the land cells it reads, of 1078 placed to within 10 km; the map shows only the 317 openly licensed ones, which alone would put the marker 8 km away. 3 records outside the WCVP native range not used. 513 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 of the 1591 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Eriastrum densifolium, photograph 1did not loadEriastrum densifolium, photograph 2did not loadEriastrum densifolium, photograph 3did not loadEriastrum densifolium, photograph 4did not loadEriastrum densifolium, photograph 5did not loadEriastrum densifolium, photograph 6did not load

Photographs: (c) Henrik Kibak, some rights reserved (CC BY) (3); (c) Jess Mullins, some rights reserved (CC BY) (3).

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

Lupinus excubitus Lupinus excubitus Grape soda lupine Photo: CC0, author not stated Eriodictyon parryi Boraginaceae Mimetanthe pilosa Mimetanthe pilosa False monkeyflower Photo: CC0, author not statedGarrya flavescens Garrya flavescens Ashy silk-tassel Photo: CC BY, klickloKeckiella ternata Keckiella ternata Scarlet keckiella Photo: CC0, author not statedAsclepias californica Asclepias californica California milkweed Photo: CC BY, klicklo

Other Eriastrum 2 in the reference

Eriastrum eremicum Eriastrum eremicum Desert eriastrum Photo: CC0, author not statedEriastrum sapphirinum Eriastrum sapphirinum Sapphire woollystar Photo: CC0, author not stated

Names & registers

Also known as Gilia densiflora; Gilia densifolia; Hugelia densifolia; Navarretia densifolia subsp. eudensifolia. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Polemoniaceae
Described by
(Benth.) H.Mason
Native to
California, Mexico Northwest
Wild records
1591 in range · 317 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; 3 records within 1 km of a botanic garden, herbarium or zoo left out (2 at a botanic garden or arboretum, 1 at a herbarium; 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 34.50_-118.125, lapse-corrected +551 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 53 datasets via GBIF.org; each carries its own licence.

Cultifolio

Opening your plants…