Hymenocallis occidentalis (northern spiderlily)

Plate 1 figs. a–h · 8 separate observations

Hymenocallis occidentalis, photographed by Michelle W. （鍾偉瑋） — fig. a Michelle W. （鍾偉瑋）, CC BY 4.0 / 2022-04-27 / obs. 191234320

Hymenocallis occidentalis, photographed by Ryan Sorrells — fig. b Ryan Sorrells, CC BY 4.0 / obs. 191023906

Hymenocallis occidentalis, photographed by John Michael — fig. d John Michael, CC BY 4.0 / obs. 184432484

Hymenocallis occidentalis, photographed by Brian Finzel — fig. e Brian Finzel, CC BY-SA 4.0 / obs. 174458698

Hymenocallis occidentalis, photographed by Philip Vanbergen — fig. g Philip Vanbergen, CC0 1.0 / obs. 76479611

Hymenocallis occidentalis, photographed by John Kees — fig. h John Kees, CC0 1.0 / obs. 63435768

Every figure is a research-grade observation under CC0, CC BY or CC BY-SA, rehosted with the photographer’s name, the licence and the observation it came from. Photographs under a NonCommercial licence are excluded from this site and are never stored, which costs us a great many pictures and is not negotiable.

Native range 15 botanical countries

Native distribution of Hymenocallis occidentalis, after Kew’s World Checklist of Vascular Plants. Introduced, extinct and doubtful records are excluded, so this is where the plant is from, not everywhere it now grows.

Region	TDWG code	Continent
Alabama	ALA	NORTHERN AMERICA
Arkansas	ARK
Florida	FLA
Georgia	GEO
Illinois	ILL
Indiana	INI
Kentucky	KTY
Louisiana	LOU
Mississippi	MSI
Missouri	MSO
North Carolina	NCA
Oklahoma	OKL
South Carolina	SCA
Tennessee	TEN
Texas	TEX

Region boundaries approximated from Natural Earth (public domain) and mapped to TDWG World Geographical Scheme for Recording Plant Distributions (WGSRPD) level-3 botanical countries (Brummitt 2001). Indicative, not the official WGSRPD geometry.

Flowering 103 in flower of 144 examined

25%

29%

90%

91%

50%

Proportion of examined Hymenocallis occidentalis in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	0	0	too few examined
Feb	0	1	too few examined
Mar	0	6	0%	0% to 39%
Apr	3	12	25%	9% to 53%
May	0	7	0%	0% to 35%
Jun	2	7	29%	8% to 64%
Jul	45	50	90%	79% to 96%
Aug	49	54	91%	80% to 96%
Sep	3	6	50%	19% to 81%
Oct	0	0	too few examined
Nov	0	0	too few examined
Dec	1	1	too few examined

Peak flowering in Aug. Each bar is the share of Hymenocallis occidentalis observations in which someone actually recorded the reproductive state and found the plant in flower, not the raw number of flowering records. That distinction matters: people observe plants far more in spring than in winter, so a bare count of flowering records partly measures when people go outside. Dividing by the number examined removes that. 103 of 144 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 5 months have fewer than 5 examined observations, so no proportion is drawn for them. This is still a global aggregate and not a forecast for your garden: the same species flowers on different dates in different hemispheres. Where a species has fewer than 30 flowering records we do not draw this chart at all. Computed from 10.15468/dl.cgje2x.

Also published as 5 synonyms

A synonym is not an error. It is a record of botanists disagreeing, in print, about where this plant belongs. Each of these was somebody’s considered answer.

Hymenocallis bidentata Small
Hymenocallis eulae Shinners
Hymenocallis moldenkeana Traub
Hymenocallis moldenkiana Traub
Pancratium occidentale Leconte

Sourcesevery claim on this page

World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.
Wikidata. common name (P1843), joined on the World Flora Online identifier (P7715). CC0. Retrieved 2026-07-13.
Kew, World Checklist of Vascular Plants (WCVP v16). native distribution by TDWG level-3 botanical country, and life form. CC BY 3.0. Retrieved 2026-06-04.

We publish what we can source and we say so when we cannot. This page has no care advice and no toxicity claim, because we do not yet have those from a source we can cite.