emilydblack 的最愛

I took a specimen home and examined it under my dissecting microscope. The scape below the involucre is glabrous, and most of the basal leaves have a similar shape to the involucre, which is on the lower part of the scape. A third characteristic are the long hairs on the underside of the sepals.

This set of images of some herps is derived from a wildlife survey on a private ranch in western Palo Pinto County, downstream of Possum Kingdom Lake. The marked location is approximate. Scanned from 35mm Ektachrome slide. Date is estimated from date stamp on slides of “July 79”.

Documenting locations of Engelmann's Thistle around Ennis

Here, on hwy287 access road near Rudd Rd.

I just learned to distinguish it from Texas thistle using the key in Flora of North Central Texas:
Stem leaves (except uppermost) deeply pinnatifid, divided 1/4 to - 3/4 to midrib.

"Pinnatifid" is hard to describe, so google it or look at these pictures. I include one of the leaf for that reason.

I found I can spot those leaves up to about 30ft away.

Per key at :

https://www.inaturalist.org/journal/nathantaylor7583/12462-croton-list-of-central-and-north-central-texas

C. lindheimeri:

• Sepals longer than fruit, the tips curving inward enclosing the fruit
• Leaves cordate at the base;

• Single main stem, robust, not branching at the base.
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  @alusk, you might be interested. Near the Arboretum fence at the Great Lawn