When does tropical threefold bloom in Texas?

Most often in March. Across 218 dated, research-grade observations of Trixis inula in Texas, the flowering season runs roughly January to November.

Peak March In flower 218 Examined 229 State Texas

Flowering 218 in flower of 229 examined

Proportion of examined Trixis inula in Texas in flower, by month
Month In flower Examined Share 95% interval
Jan 25 26 96% 81% to 99%
Feb 22 23 96% 79% to 99%
Mar 8 8 100% 68% to 100%
Apr 33 34 97% 85% to 99%
May 10 11 91% 62% to 98%
Jun 6 6 100% 61% to 100%
Jul 6 6 100% 61% to 100%
Aug 2 2 too few examined
Sep 0 0 too few examined
Oct 39 39 100% 91% to 100%
Nov 53 56 95% 85% to 98%
Dec 14 18 78% 55% to 91%

Peak flowering in Mar. Each bar is the share of Trixis inula 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. 218 of 229 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 2 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 Texas found Trixis inula 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

Sourcesevery claim on this page

  1. 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.
  2. World Flora Online Plant List. The accepted name. CC0. Retrieved 2026-07-12.