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Cuscuta californica; photograph (c) Gavin Skeen, some rights reserved (CC BY) CC BY(c) Gavin Skeen, some rights reserved (CC BY) · observed growing wild · 2026-09-21

Cuscuta californica Hook. & Arn.

California dodder

Convolvulaceae · Oregon, Washington +5

Cited as Kew's World Checklist cites it, Cuscuta californica Hook. & Arn.: GBIF's backbone key for this page carries the name with another author, Choisy.

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Cuscuta californica, photograph (c) Gavin Skeen, some rights reserved (CC BY)Cuscuta californica, photograph (c) Gavin Skeen, some rights reserved (CC BY)Cuscuta californica, photograph author not stated, no rights reservedCuscuta californica, photograph (c) lazarus, some rights reserved (CC BY)Cuscuta californica, photograph author not stated, no rights reservedCuscuta californica, photograph author not stated, no rights reserved 97 photographs ›
Habitat figures
Cold floor (1 night in 100)
-0.7°C
Record low -5.3 °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)
417mm
6 months of 25 mm or more in the median year CHELSA
Open-sky light
19–53DLI
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

Cuscuta californica is a species of dodder known by the common names chaparral dodder and California dodder. This is an annual parasitic plant that may resemble fine strands of spaghetti or twine strewn across other species in its habitat. A mature plant of this species may fulfill all of its food and water needs from the host plant, but they rarely kill their host. It is native to western United States and Baja California in Mexico.

Quoted from Wikipedia, "Cuscuta californica", CC BY-SA 4.0.

Cultivation

Seasons

The rain rule reads a winter growing season: 70% of the median year's rain (293 mm of 402 mm) falls in December to March, cooler than the year (wet-season mean 11.2 °C against a yearly mean of 16.1 °C). Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: June to September.

Rain

402 mm in the median year at the habitat, 293 mm of it December to March. Wettest month February at 89 mm, driest months (2 at 2 mm); 3 months under 5 mm. Across the grid cells of the range the year's total runs 227 mm to 885 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 417 mm, is the year's rain at the top of the page; the 402 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 53 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 14, 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 -0.7 °C, the absolute minimum -5.3 °C, 293 frost nights in 44 years, 6.7 a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 42.8 °C. Monthly means: the coldest month's mean nightly low 5.0 °C in January (across the grid cells of the range -1.0 °C to 9.4 °C), the warmest month's mean daily high 30.1 °C in August (median year across the grid cells of the range, CHELSA). Cold floor: -0.7 °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: 51 to 57% 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 -280 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 Cuscuta californica through the yearWarmest months July and August, mean daily high 30 °C; coldest month January, mean nightly low 5.0 °C; 402 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.-10°0°10°20°30°40°50°frost42.8° 99th-percentile day, NASA POWER-5.3° lowest night in 44 years, NASA POWER°C · day and nightcold quarter050100150200mm rainDLI 19–53RH 51–57%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 °C16 / 9–1817 / 10–1918 / 13–2120 / 15–2423 / 18–2827 / 21–3230 / 23–3530 / 24–3428 / 23–3224 / 18–2719 / 14–2216 / 9–18
Night °C5 / -1–96 / -1–107 / 1–119 / 3–1212 / 7–1415 / 10–1717 / 13–2118 / 14–2017 / 12–1913 / 7–168 / 2–125 / -1–10
Rain mm78 / 36–16989 / 39–16164 / 30–12729 / 11–618 / 3–302 / 1–92 / 1–113 / 1–167 / 5–1920 / 12–4938 / 17–11162 / 32–167
DLI21 / 15–2326 / 21–2935 / 30–3844 / 40–4749 / 47–5253 / 51–5551 / 50–5347 / 46–4840 / 39–4131 / 28–3323 / 18–2619 / 14–21
RH %54 / 48–5956 / 49–6057 / 48–6255 / 45–6155 / 44–6353 / 41–6451 / 40–6451 / 41–6451 / 42–6352 / 44–6152 / 45–5953 / 47–59
How this section is made
Each figure is the median across the 587 grid cells on land that hold in-range records (1302 records in those cells; 3 more cells hold records but no land by the elevation layer, so those records sit at sea and the cells are 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 1114:1233 (34.275, -118.325). Over 44 years there: absolute minimum -5.3 °C, 1st-percentile night -0.7 °C, 99th-percentile day 42.8 °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 1302 of the 1306 in-range records (3 further cells with records at sea, by the elevation layer, left out); extremes and elevation at the typical cell 1114:1233 (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 -280 m at 6.5 °C/km. Elevation: ETOPO 2022, 506 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.
NativeOregon, Washington, Arizona, California, Nevada, Utah, Mexico Northwest · 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 marker33.651, -117.599 · in the densest population, 1146 records (71% of those in range)
Kew's description“holoparasite” · “temperate” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 1617 georeferenced records inside the native range; the climate across the range on the 1302 of them in the land cells it reads, of 1306 placed to within 10 km; the map shows only the 246 openly licensed ones, which alone would put the marker 6 km away. 1 record outside the WCVP native range not used. 311 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 1617 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Cuscuta californica, photograph 1did not loadCuscuta californica, photograph 2did not loadCuscuta californica, photograph 3did not loadCuscuta californica, photograph 4did not loadCuscuta californica, photograph 5did not loadCuscuta californica, photograph 6did not load

Photographs: (c) Gavin Skeen, some rights reserved (CC BY) (2); author not stated, no rights reserved · CC0 (3); (c) lazarus, some rights reserved (CC BY).

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

Selaginella bigelovii Selaginella bigelovii Bushy spikemoss Photo: CC BY, Matt BergerDelphinium cardinale Delphinium cardinale Scarlet larkspur Photo: CC0, author not statedCalochortus splendens Calochortus splendens Splendid mariposa lily Photo: CC0, author not statedPhacelia cicutaria Phacelia cicutaria Caterpillar phacelia Photo: CC BY, Matt BergerLonicera subspicata Lonicera subspicata Southern honeysuckle Photo: CC0, author not statedGalium angustifolium Galium angustifolium Narrow-leaf bedstraw Photo: CC0, author not stated

Other Cuscuta 16 in the reference

Cuscuta australis Cuscuta australis Australian dodder Photo: CC BY, Augustin SoulardCuscuta campestris Cuscuta campestris Yellow dodder Photo: CC BY, 黃美滿Cuscuta chinensis Cuscuta chinensis Chinese dodder Photo: CC BY, Jo RobertsCuscuta epilinum Cuscuta epilinum Flax dodder Photo: Public domain, Steve Hurst @ USDA-NRCS PLANTS Database…Cuscuta epithymum Cuscuta epithymum Clover dodder Photo: CC BY, joy russellCuscuta europaea Cuscuta europaea Greater dodder Photo: CC BY, Евгений МаринкинCuscuta grandiflora Cuscuta grandiflora Convolvulaceae Photo: CC BY, Jhon A. Yuca-PalominoCuscuta gronovii Cuscuta gronovii Scaldweed Photo: CC BY-SA, Henry LabelCuscuta japonica Cuscuta japonica Japanese dodder Photo: CC BY, ITÔ, HirokiCuscuta lupuliformis Cuscuta lupuliformis Hop dodder Photo: CC BY, Анна МитрошенковаCuscuta odorata Cuscuta odorata Convolvulaceae Photo: CC BY, Pablo SilvaCuscuta pacifica Cuscuta pacifica Large saltmarsh dodder Photo: CC BY, dorian all 17 ›

Names & registers

Also known as Cuscuta acuminata; Cuscuta californica var. californica; Cuscuta californica var. graciliflora; Cuscuta californica var. longiloba; Grammica californica. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Convolvulaceae
Described by
Hook. & Arn.
Native to
Oregon, Washington, Arizona +4
Wild records
1617 in range · 246 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 8330270 is Cuscuta californica Choisy; the page links Kew's Cuscuta californica Hook. & Arn., 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 answeredas of 2026-10-21GBIF occurrence download https://doi.org/10.15468/dl.hbdw64, of 2026-10-21; 33 records within 1 km of a botanic garden, herbarium or zoo left out (16 at a botanic garden or arboretum, 5 at a herbarium, 12 at a zoo; 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 -280 m at 6.5 °C/km
Wikidata wikidata answeredasked 2026-10-22found by its label; its IPNI identifier 30025214-2 is Kew's for Cuscuta californica Choisy
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 56 datasets via GBIF.org; each carries its own licence.

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