Buffalo-Bur (Solanum rostratum) is in the nightshade family family (Solanaceae). Across the U.S., iNaturalist users have logged 1,091 research-grade flowering observations of it in our sample, peaking in August.
Nationally it blooms mainly from May to October, but timing varies a lot by state and elevation — see the table below.
When to photograph Buffalo-Bur: observations by month (U.S.)
About Buffalo-Bur
Solanum rostratum is a species of nightshade (genus Solanum) that is native to the United States and northern and central Mexico. Common names include buffalobur nightshade, buffalo-bur, spiny nightshade, Colorado bur, Kansas thistle, Mexican thistle, and Texas thistle.From Wikipedia via iNaturalist — article, CC BY-SA.
Buffalo-Bur by state
| State | Observations | Peak month | Main season |
|---|---|---|---|
| Texas | 658 | September | May–Oct |
| Colorado | 79 | August | Jun–Sep |
| Minnesota | 39 | August | Jul–Sep |
| Kansas | 37 | July | Jun–Sep |
| Arizona | 34 | July | Jul–Sep |
| New Mexico | 33 | July | Jun–Oct |
| Oklahoma | 26 | August | Jun–Sep |
| South Dakota | 26 | August | Jul–Aug |
| Nebraska | 25 | August | Jun–Sep |
| Iowa | 22 | August | Aug–Aug |
| Nevada | 14 | July | Jul–Aug |
| New York | 12 | August | Jul–Aug |
| Utah | 11 | August | Jul–Aug |
| Washington | 9 | August | Aug–Sep |
| Virginia | 7 | June | Jun–Jun |
| California | 6 | October | Oct–Oct |
| North Dakota | 6 | June | Jun–Jun |
| Oregon | 5 | August | Aug–Aug |
| Pennsylvania | 5 | July | Jul–Aug |
Main season = months with at least 30% of the state's peak-month count.
Related wildflowers (nightshade family)
Carolina horsenettle
Sacred Datura
Bittersweet Nightshade
Silverleaf Nightshade
Purple Groundcherry
Tree Tobacco
Thickleaf Groundcherry
Desert Tobacco
Photography tips
- Photograph flowers on calm, overcast mornings to avoid wind blur and harsh shadows.
- Get low: a shallow depth of field (f/2.8–f/5.6) isolates a bloom against soft color.
- Stay on trails — trampling meadows kills plants and ruins next year's display.
- Try a kaleidoscope abstract of a single bloom with our online kaleidoscope tool.
FAQ
When is the best time to photograph Buffalo-Bur?
Nationally, August has the most observations, with the main season from May to October.
Where is Buffalo-Bur most often seen?
The most observations come from Texas, Colorado, Minnesota.