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Pedicularis racemosa; photograph (c) Kalvin Chan, some rights reserved (CC BY) CC BY(c) Kalvin Chan, some rights reserved (CC BY) · observed growing wild · 2026-09-24

Pedicularis racemosa Douglas ex Benth.

Leafy lousewort; Sickletop betony; Parrot's-beak; Sickletop lousewort

Orobanchaceae · Alberta, British Columbia +10

Cited as Kew's World Checklist cites it, Pedicularis racemosa Douglas ex Benth.: GBIF's backbone key for this page carries the name with another author, Douglas ex Hook.

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Pedicularis racemosa, photograph (c) Jason Alexander, some rights reserved (CC BY)Pedicularis racemosa, photograph (c) Jason Alexander, some rights reserved (CC BY)Pedicularis racemosa, photograph (c) Max Miley, some rights reserved (CC BY)Pedicularis racemosa, photograph (c) Max Miley, some rights reserved (CC BY)Pedicularis racemosa, photograph (c) Alexis Tinker-Tsavalas, some rights reserved (CC BY)Pedicularis racemosa, photograph author not stated, no rights reserved 73 photographs ›
Habitat figures
Cold floor (1 night in 100)
-24.2°C
Record low -36.8 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
21°C
Jul and Aug at the habitat CHELSA
Rain a year (median across the range)
1,229mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
9–47DLI
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 October to March and May, with nights below freezing; no growing season read. rain rule, CHELSA
Northern hemisphere unless you set your site. The chart is in the habitat's months.

Summary

Pedicularis racemosa is a species of flowering plant in the family Orobanchaceae known by the common names sickletop lousewort and leafy lousewort. It is native to western North America, where it grows in coniferous forests. This is a perennial herb producing several stems up to 80 centimetres (31 in) tall, greenish to dark red in color. The leaves are up to 10 centimetres (4 in) long, linear in shape and lined with teeth. More on Wikipedia ›

Quoted from Wikipedia, "Pedicularis racemosa", CC BY-SA 4.0.

Cultivation

Seasons

The rain rule reads a rainy season and no growing season: 70% of the median year's rain (828 mm of 1,182 mm) falls in October to March and May, the cooler part of the year, but the mean nightly low is below freezing in February, March, April, June, November, December and January, so the rule reads no growing season from it. Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: April to September and November.

Rain

1,182 mm in the median year at the habitat, 828 mm of it October to March and May. Wettest month December at 147 mm, driest months (2 at 53 mm). Across the grid cells of the range the year's total runs 720 mm to 2,702 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,229 mm, is the year's rain at the top of the page; the 1,182 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: 9 to 47 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 5, the highest 90th-percentile month 51).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is -24.2 °C, the absolute minimum -36.8 °C, 10,183 frost nights in 44 years, 231.4 a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 25.6 °C. Monthly means: the coldest month's mean nightly low -10.6 °C in December (across the grid cells of the range -17.8 °C to -4.1 °C), the warmest month's mean daily high 21.2 °C in July (median year across the grid cells of the range, CHELSA). Cold floor: -24.2 °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: 50 to 62% 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 +37 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 Pedicularis racemosa through the yearWarmest months July and August, mean daily high 21 °C; coldest month December, mean nightly low -10.6 °C; 1,182 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.-40°-20°0°20°40°frost25.6° 99th-percentile day, NASA POWER-36.8° lowest night in 44 years, NASA POWER°C · day and nightcold quarter0100200300400500mm rainDLI 9–47RH 50–62%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 1143 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 °C-2 / -7–3-1 / -5–52 / -2–86 / 2–1111 / 7–1617 / 13–2121 / 17–2621 / 17–2616 / 13–229 / 5–151 / -3–6-3 / -7–2
Night °C-10 / -17–-4-9 / -16–-4-6 / -12–-2-4 / -9–0-1 / -5–44 / 0–87 / 4–117 / 4–114 / 0–8-1 / -6–3-7 / -14–-1-11 / -18–-4
Rain mm133 / 45–395104 / 44–301107 / 57–28296 / 55–19297 / 59–14979 / 38–13553 / 19–10953 / 19–11573 / 32–12597 / 54–268143 / 52–427147 / 52–429
DLI11 / 7–1917 / 13–2626 / 21–3535 / 30–4342 / 36–4945 / 38–5147 / 41–5141 / 36–4533 / 26–3721 / 15–2812 / 7–219 / 5–17
RH %62 / 56–6761 / 57–6460 / 55–6457 / 53–6356 / 50–6254 / 46–6150 / 45–5851 / 45–5852 / 47–5855 / 51–6262 / 54–6862 / 56–67
How this section is made
Each figure is the median across the 1143 grid cells holding the 2139 in-range records, 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 818:1182 (49.075, -120.875). Over 44 years there: absolute minimum -36.8 °C, 1st-percentile night -24.2 °C, 99th-percentile day 25.6 °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 1143 distinct grid cells holding 2139 of the 2139 in-range records; extremes and elevation at the typical cell 818:1182 (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 49.00_-120.625, lapse-corrected +37 m at 6.5 °C/km. Elevation: ETOPO 2022, 1621 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.
NativeAlberta, British Columbia, Colorado, Idaho, Montana, Oregon, Washington, Wyoming, Arizona, California, Utah, New Mexico · 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 marker46.786, -121.738 · in the densest population, 1445 records (58% of those in range)
Kew's description“hemiparasitic perennial” · “subalpine or subarctic” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 2513 georeferenced records inside the native range; the climate across the range on the 2139 of them placed to within 10 km; the map shows only the 881 openly licensed ones, which alone would put the marker 67 km away. 3 records outside the WCVP native range not used. 374 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.
Other GBIF keysRecords also from GBIF's key 3171673 (Pedicularis racemosa Douglas ex Benth.): Kew's file holds it as Pedicularis racemosa Douglas ex Benth. (accepted); 822 records, from GBIF's search API on the day of the build.
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 2513 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Pedicularis racemosa, photograph 1did not loadPedicularis racemosa, photograph 2did not loadPedicularis racemosa, photograph 3did not loadPedicularis racemosa, photograph 4did not loadPedicularis racemosa, photograph 5did not loadPedicularis racemosa, photograph 6did not load

Photographs: (c) Jason Alexander, some rights reserved (CC BY) (2); (c) Max Miley, some rights reserved (CC BY) (2); (c) Alexis Tinker-Tsavalas, some rights reserved (CC BY); author not stated, no rights reserved · CC0.

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

Anticlea occidentalis Anticlea occidentalis Western feather-bells Photo: CC BY, Rowan FehrArnica latifolia Arnica latifolia Broad-leaved arnica Photo: CC BY, Brooke SmithPotentilla drummondii Potentilla drummondii Drummond's cinquefoil Photo: CC0, author not statedErythranthe lewisii Erythranthe lewisii Lewis' monkeyflower Photo: CC0, Ben KeenBistorta bistortoides Bistorta bistortoides Western bistort Photo: CC BY, Daughter DadGentiana calycosa Gentiana calycosa Mountain bog gentian Photo: CC0, author not stated

Other Pedicularis 16 in the reference

Pedicularis bracteosa Pedicularis bracteosa Bracted lousewort Photo: CC0, author not statedPedicularis canadensis Pedicularis canadensis Early lousewort Photo: CC0, author not statedPedicularis condensata Pedicularis condensata Orobanchaceae Photo: CC BY, Екатерина КравцоваPedicularis densiflora Pedicularis densiflora Red-flower pedicularis Photo: CC0, author not statedPedicularis foliosa Pedicularis foliosa Orobanchaceae Photo: CC BY, Flavien SaboureauPedicularis groenlandica Pedicularis groenlandica Elephant's-head Photo: CC BY, Daughter DadPedicularis lanceolata Pedicularis lanceolata Swamp lousewort Photo: CC BY, Daniel J. LaytonPedicularis oederi Pedicularis oederi Crimson-tipped Lousewort Photo: CC0, author not statedPedicularis palustris Pedicularis palustris Marsh lousewort Photo: CC BY, James CunninghamPedicularis rex Pedicularis rex Orobanchaceae Photo: CC BY, Wang.QGPedicularis sceptrum-carolinum Pedicularis sceptrum-carolinum Moor king lousewort Photo: CC0, author not statedPedicularis sibthorpii Pedicularis sibthorpii Orobanchaceae Photo: CC BY, Наталья Пикалова all 17 ›

Names & registers

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Orobanchaceae
Described by
Douglas ex Benth.
Native to
Alberta, British Columbia, Colorado +9
Wild records
2513 in range · 881 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 2026-10-22GBIF's key 7400180 is Pedicularis racemosa Douglas ex Hook.; the page links Kew's Pedicularis racemosa Douglas ex Benth., and the name is cited as Kew cites it
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 answeredasked 2026-10-22GBIF occurrence download https://doi.org/10.15468/dl.hbdw64, of 2026-10-21; 822 records of GBIF's key 3171673, Pedicularis racemosa Douglas ex Benth. (Kew's file holds it as Pedicularis racemosa Douglas ex Benth. (accepted)): GBIF occurrence search API
Habitat climate climate answeredasked 2026-10-22
Daily extremes (NASA POWER) climate.extremes answeredasked 2026-10-22NASA POWER (MERRA-2) daily 1981–2024, cell 49.00_-120.625, lapse-corrected +37 m at 6.5 °C/km
Wikidata wikidata answeredasked 2026-10-22found by its label; its IPNI identifier 30019480-2 is Kew's for Pedicularis racemosa Douglas ex Benth.
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 2026-10-22read from the page's key and its other keys: 1 from GBIF's key 3171673
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 90 datasets via GBIF.org; each carries its own licence.

Cultifolio

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