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Asclepias humistrata; photograph (c) Tom Field, some rights reserved (CC BY) CC BY(c) Tom Field, some rights reserved (CC BY) · observed growing wild · 2026-07-13

Asclepias humistrata Walter

Sandhill milkweed; Pinewoods milkweed; Pink-veined milkplant

Apocynaceae · Alabama, Florida +5

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Asclepias humistrata, photograph author not stated, no rights reservedAsclepias humistrata, photograph (c) Athena Philips, some rights reserved (CC BY)Asclepias humistrata, photograph (c) Tom Field, some rights reserved (CC BY)Asclepias humistrata, photograph (c) Laura Gaudette, some rights reserved (CC BY)Asclepias humistrata, photograph (c) Stan Shebs, some rights reserved (CC BY-SA)Asclepias humistrata, photograph (c) Scott Allen Davis, some rights reserved (CC BY) 79 photographs ›
Habitat figures
Cold floor (1 night in 100)
-2.1°C
Record low -10.4 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
32°C
Jul at the habitat CHELSA
Rain a year (median across the range)
1,352mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
18–41DLI
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 summers: the rain comes January to March and June to September, read as a summer growing season. rain rule, CHELSA
Northern hemisphere unless you set your site. The chart is in the habitat's months.

Summary

Asclepias humistrata, or the sandhill milkweed, is a species of milkweed plant. It is also known as pinewoods milkweed and pink-veined milkplant. It belongs in the subfamily Asclepiadoideae. It is native to the southeastern United States. More on Wikipedia ›

Quoted from Wikipedia, "Asclepias humistrata", CC BY-SA 4.0.

About the genus · Asclepias

Asclepias is a genus of herbaceous, perennial, flowering plants known as milkweeds, named for their latex, a milky substance containing cardiac glycosides termed cardenolides, exuded where cells are damaged. Most species are toxic to humans and many other species, primarily due to the presence of cardenolides. However, as with many such plants, some species feed upon milkweed leaves or the nectar from their flowers. More on Wikipedia ›

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

Cultivation

Seasons

The rain rule reads a summer growing season: 70% of the median year's rain (996 mm of 1,374 mm) falls in January to March and June to September, warmer than the year (wet-season mean 21.1 °C against a yearly mean of 20.3 °C). Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: December to March and July to September.

Rain

1,374 mm in the median year at the habitat, 996 mm of it January to March and June to September. Wettest month August at 186 mm, driest month November at 63 mm. Across the grid cells of the range the year's total runs 1,253 mm to 1,622 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,352 mm, is the year's rain at the top of the page; the 1,374 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: 18 to 41 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 16, 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 -2.1 °C, the absolute minimum -10.4 °C, 351 frost nights in 44 years, 8.0 a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 36.6 °C. Monthly means: the coldest month's mean nightly low 8.4 °C in January (across the grid cells of the range 3.9 °C to 11.2 °C), the warmest month's mean daily high 31.8 °C in July (median year across the grid cells of the range, CHELSA). Cold floor: -2.1 °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: 57 to 64% 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 +16 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 Asclepias humistrata through the yearWarmest month July, mean daily high 32 °C; coldest month January, mean nightly low 8.4 °C; 1,374 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°frost36.6° 99th-percentile day, NASA POWER-10.4° lowest night in 44 years, NASA POWER°C · day and nightcold quarter050100150200250mm rainDLI 18–41RH 57–64%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 540 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 °C18 / 13–2119 / 15–2222 / 18–2426 / 23–2730 / 27–3031 / 29–3232 / 30–3231 / 30–3230 / 28–3026 / 23–2822 / 19–2519 / 14–22
Night °C8 / 4–1110 / 5–1212 / 9–1415 / 12–1719 / 17–2022 / 21–2424 / 23–2524 / 23–2522 / 20–2318 / 14–2014 / 10–1610 / 5–13
Rain mm90 / 66–12289 / 70–137110 / 97–15374 / 62–11182 / 64–100181 / 127–204185 / 141–210186 / 140–209155 / 104–17885 / 69–11163 / 49–11274 / 63–122
DLI20 / 18–2225 / 22–2632 / 30–3339 / 37–4041 / 40–4239 / 37–4038 / 37–3934 / 34–3530 / 29–3227 / 25–2822 / 19–2318 / 16–20
RH %58 / 57–5958 / 56–5958 / 55–5957 / 54–5858 / 56–6062 / 59–6363 / 61–6464 / 62–6562 / 60–6460 / 57–6158 / 57–5959 / 57–59
How this section is made
Each figure is the median across the 540 grid cells on land that hold in-range records (1156 records in those cells; 12 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 1206:1954 (29.675, -82.275). Over 44 years there: absolute minimum -10.4 °C, 1st-percentile night -2.1 °C, 99th-percentile day 36.6 °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 540 distinct grid cells holding 1156 of the 1206 in-range records (12 further cells with records at sea, by the elevation layer, left out); extremes and elevation at the typical cell 1206:1954 (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 29.50_-82.500, lapse-corrected +16 m at 6.5 °C/km. Elevation: ETOPO 2022, 41 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.
NativeAlabama, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina · 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 marker28.864, -82.136 · in the densest population, 775 records (49% of those in range)
Kew's description“perennial” · “subtropical” · 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 1156 of them in the land cells it reads, of 1206 placed to within 10 km; the map shows only the 412 openly licensed ones, which alone would put the marker 15 km away. 2 records outside the WCVP native range not used. 385 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

Asclepias humistrata, photograph 1did not loadAsclepias humistrata, photograph 2did not loadAsclepias humistrata, photograph 3did not loadAsclepias humistrata, photograph 4did not loadAsclepias humistrata, photograph 5did not loadAsclepias humistrata, photograph 6did not load

Photographs: author not stated, no rights reserved · CC0; (c) Athena Philips, some rights reserved (CC BY); (c) Tom Field, some rights reserved (CC BY); (c) Laura Gaudette, some rights reserved (CC BY); (c) Stan Shebs, some rights reserved (CC BY-SA); (c) Scott Allen Davis, some rights reserved (CC BY).

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

Liatris tenuifolia Liatris tenuifolia Shortleaf blazing star Photo: CC BY, carterDalea pinnata Dalea pinnata Summer farewell Photo: CC0, author not statedPinguicula caerulea Pinguicula caerulea Blueflower butterwort Photo: CC BY, Ashwin Srinivasan Paepalanthus minor Eriocaulaceae Quercus pumila Quercus pumila Runner oak Photo: CC BY, carterEleocharis vivipara Eleocharis vivipara Viviparous spikerush Photo: CC BY, geosesarma

Other Asclepias 48 in the reference

Asclepias albicans Asclepias albicans White-Stem milkweed Photo: CC BY, Matt BergerAsclepias amplexicaulis Asclepias amplexicaulis Blunt-leaf milkweed Photo: CC0, author not statedAsclepias angustifolia Asclepias angustifolia Arizona milkweed Photo: CC BY, Cheng-Te HsuAsclepias asperula Asclepias asperula Antelope horns Photo: CC BY, Parker James LloydAsclepias brachystephana Asclepias brachystephana Shortcrown milkweed Photo: CC BY, Cody HinchliffAsclepias californica Asclepias californica California milkweed Photo: CC BY, klickloAsclepias cordifolia Asclepias cordifolia Purple milkweed Photo: CC BY-SA, Brian FinzelAsclepias cryptoceras Asclepias cryptoceras Humboldt Mountains milkweed Photo: CC BY, Parker James LloydAsclepias curassavica Asclepias curassavica Bloodflower Photo: CC BY, Ricard Busquets ReverteAsclepias engelmanniana Asclepias engelmanniana Engelmann's milkweed Photo: CC BY, Rajan RaoAsclepias eriocarpa Asclepias eriocarpa Indian milkweed Photo: CC BY, klickloAsclepias erosa Asclepias erosa Desert milkweed Photo: CC BY, CK2AZ all 49 ›

Names & registers

Under another author Asclepias amplexicaulis Michx. is an older name of this species, not Asclepias amplexicaulis, a species of the reference. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Apocynaceae
Described by
Walter
Native to
Alabama, Florida, Georgia +4
Wild records
1591 in range · 412 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 2026-10-21
GBIF species record gbif.species answeredasked 2026-10-21
GBIF synonyms gbif.synonyms answeredasked 2026-10-21
GBIF common names gbif.vernacular answeredasked 2026-10-21names fetched 2026-10-21
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; 26 records within 1 km of a botanic garden, herbarium or zoo left out (25 at a botanic garden or arboretum, 1 at a zoo; Wikidata's list)
Habitat climate climate answeredasked 2026-10-21
Daily extremes (NASA POWER) climate.extremes answeredasked 2026-10-21NASA POWER (MERRA-2) daily 1981–2024, cell 29.50_-82.500, lapse-corrected +16 m at 6.5 °C/km
Wikidata wikidata answeredasked 2026-10-21
Wikipedia wikipedia answeredasked 2026-10-21
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 2026-10-21
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 42 datasets via GBIF.org; each carries its own licence.

Cultifolio

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