Hesperocallis undulata, desert lily, Fact Sheet Expanded

This page elaborates on some of the information given in the Desert Lily Fact Sheet.

Population survey on 28 February 2024 near the junction of S2 and Indian Gorge Road. Tom Chester and Walt Fidler spent one hour on 28 February 2024 mapping desert lily plants, and making a histogram of the number of leaves per plant, both for flowering plants and non-flowering plants.

Results of the geographic location survey are shown in Fig. 1.

Fig. 1. Map of Tom's survey route (green line) on 28 February 2024, showing where desert lilies were found by Tom and Walt (blue diamonds). Walt was usually walking a parallel track to Tom's, so some of his GPS points are near and parallel the green line. The length of the black arrow is 0.25 miles. Our survey route was 1.0 miles total. See also a Google Earth Map of the area. Click on the map to get a larger scale map.

No desert lilies were found in the wash (see the Google Earth Map), which was a small part of the survey area. Outside the wash, although the area where desert lilies were found looked very similar to areas where they were not found, there were differences, which may or may not have been important. The area to the south and west of the wash is derived from the alluvial fan from Indian Gorge (note the drainage patterns in it in the Google Earth image), whereas the area to the north and east of the wash is mostly influenced by the Carrizo River. The area without desert lilies had more undisturbed cryptobiotic crust, and appeared slightly whiter in color. There may have been other differences, such as the depth of the soil, that were important.

We counted plants with and without an inflorescence for a small area with the largest number of GPS points. 54 plants, 77%, had an inflorescence out of a total of 70 plants counted. Fig. 2 gives a histogram of the number of leaves for some of those plants that produced an inflorescence, and some of those plants that did not.

Fig. 2. Histogram of the number of basal rosette leaves per plant, separately for plants producing an inflorescence and ones not producing an inflorescence.

The plants surveyed here that are sending up an inflorescence had three to six rosette leaves. No plants with fewer leaves produced an inflorescence. However, some plants with three to six rosette leaves had not produced an inflorescence at the time of our survey, although some might still send one up in the near future.

Photographs of some of these plants are posted at iNat. Those observations include:

Walt also recorded desert lilies on two of his more general surveys, finding one desert lily on 3 November 2022, and 21 desert lilies on 7 February 2023 on the other side of S2. See a map that shows those nearby lilies.

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Copyright © 2020-2024 by Don Rideout and Tom Chester.
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Updated 3 March 2024.