When does Lindheimer's Senna bloom in Texas?

Most often in September. Across 267 dated, research-grade observations of Senna lindheimeriana in Texas, the flowering season runs roughly June to September.

Peak September In flower 267 Examined 399 State Texas

Flowering 267 in flower of 399 examined

18%

35%

83%

82%

81%

95%

70%

68%

29%

Proportion of examined Senna lindheimeriana in Texas in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	0	11	0%	0% to 26%
Feb	0	3	too few examined
Mar	0	5	0%	0% to 43%
Apr	5	28	18%	8% to 36%
May	8	23	35%	19% to 55%
Jun	5	6	83%	44% to 97%
Jul	9	11	82%	52% to 95%
Aug	26	32	81%	65% to 91%
Sep	111	117	95%	89% to 98%
Oct	50	71	70%	59% to 80%
Nov	46	68	68%	56% to 78%
Dec	7	24	29%	15% to 49%

Peak flowering in Sep. Each bar is the share of Senna lindheimeriana in Texas 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. 267 of 399 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. One month has fewer than 5 examined observations, so no proportion is drawn for it. 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 Texas found Senna lindheimeriana in flower, not a forecast. It is computed only from observations made in Texas, 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

Senna lindheimeriana

Lindheimer's Senna

Sourcesevery claim on this page

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