When does Douglas' grasswidow bloom in Oregon?

Most often in January. Across 402 dated, research-grade observations of Olsynium douglasii in Oregon, the flowering season runs roughly January to May.

Peak January In flower 402 Examined 427 State Oregon

Flowering 402 in flower of 427 examined

100%

98%

86%

92%

Proportion of examined Olsynium douglasii in Oregon in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	5	5	100%	57% to 100%
Feb	41	41	100%	91% to 100%
Mar	217	221	98%	95% to 99%
Apr	114	132	86%	79% to 91%
May	24	26	92%	76% to 98%
Jun	1	1	too few examined
Jul	0	0	too few examined
Aug	0	0	too few examined
Sep	0	0	too few examined
Oct	0	0	too few examined
Nov	0	1	too few examined
Dec	0	0	too few examined

Peak flowering in Jan. Each bar is the share of Olsynium douglasii in Oregon 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. 402 of 427 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 7 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.wt38fd.

What this is, and what it is not

This is a record of when people in Oregon found Olsynium douglasii in flower, not a forecast. It is computed only from observations made in Oregon, so it is not the species’ global average dragged onto a map: the same plant flowers on different dates in different places, and that is the entire point of the page.

It will not tell you what your particular plant will do this year. Bloom time moves with the season, with altitude, and with the weather, and a warm February pulls everything forward. We publish the distribution and the sample size, and we refuse to draw a month that too few people examined.

The plant

Olsynium douglasii

Douglas' grasswidow

Sourcesevery claim on this page

GBIF (iNaturalist Research-grade Observations). Dated flowering annotations in Oregon. Every record achieved iNaturalist quality grade Research, which is applied upstream at export. 10.15468/dl.wt38fd. Retrieved 2026-07-14.
World Flora Online Plant List. The accepted name. CC0. Retrieved 2026-07-12.