When does flatbud prickly poppy bloom in California?

Most often in July. Across 396 dated, research-grade observations of Argemone munita in California, the flowering season runs roughly April to October.

Peak July In flower 396 Examined 462 State California

Flowering 396 in flower of 462 examined

29%

25%

69%

85%

98%

96%

99%

93%

89%

86%

17%

Proportion of examined Argemone munita in California in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	2	7	29%	8% to 64%
Feb	4	16	25%	10% to 50%
Mar	24	35	69%	52% to 81%
Apr	57	67	85%	75% to 92%
May	79	81	98%	91% to 99%
Jun	79	82	96%	90% to 99%
Jul	66	67	99%	92% to 100%
Aug	40	43	93%	81% to 98%
Sep	32	36	89%	75% to 96%
Oct	12	14	86%	60% to 96%
Nov	0	8	0%	0% to 32%
Dec	1	6	17%	3% to 56%

Peak flowering in Jul. Each bar is the share of Argemone munita in California 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. 396 of 462 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 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 California found Argemone munita in flower, not a forecast. It is computed only from observations made in California, 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

Argemone munita

flatbud prickly poppy

Sourcesevery claim on this page

GBIF (iNaturalist Research-grade Observations). Dated flowering annotations in California. 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.