Caulanthus species, jewel-flowers
Table of Contents
Introduction
Origin and Meaning of Name
Distinguishing Characteristics and Similar Species
Pictures of Young Plants, Mature Plants, and Dead Plants
Habitat, Distribution and Abundance
References
Introduction
We have four Caulanthus species in the Borrego Desert:
- Caulanthus cooperi, Cooper's jewel-flower
- Caulanthus hallii, Hall's caulanthus
- Caulanthus lasiophyllus, California mustard (aka Guillenia lasiophylla)
- Caulanthus simulans, Payson's wild cabbage
In the table below giving the photographs, the two most distinctive species, C. cooperi and C. lasiophyllus, are placed on the outside columns so that the two more similar species, C. hallii and C. simulans, are side by side.
These species are distinctive enough that nearly all the time plants can be identified simply by matching the pictures below.
All of these species are enormously variable in height, so no conclusions should be drawn from differences in size.
See Distinguishing Characteristics and Similar Species for a list of some of the key characteristics for each species.
Caulanthus cooperiCaulanthus halliiCaulanthus simulansCaulanthus lasiophyllus
Fig. 1. Pictures of the Caulanthus species found in the Borrego Desert. Click on the pictures for larger versions.
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All pictures by Tom Chester except for the last picture of Caulanthus simulans by James Dillane. Locations and dates for each pictures are in the file name, given in the URL when you click on the pictures. They aren't given in the usual place below the pictures in order to not interrupt the picture comparsions.
Origin and Meaning of Name
Distinguishing Characteristics and Similar Species
Some of the distinguishing characteristics are given in Table 1. Note that the species are not present in alphabetical order in the columns. They are presented in the same order as in the Figure above, to keep the two most similar species, C. hallii and C. simulans, side by side.
Table 1.
| Characteristic | Caulanthus cooperi | Caulanthus hallii | Caulanthus simulans | Caulanthus lasiophyllus |
|---|---|---|---|---|
| Stem | weak, wavy, not stiff | erect, slender to robust | erect | generally erect, infrequently wavy |
| Plant hairs | none or minute | stiff hairy | stiff hairy | stiff hairy |
| Cauline leaf base | sessile, lobed to clasping | base not lobed, not clasping | sessile, lobed to clasping | petioled |
| Pedicel hairs | none | minute | densely bristly | none |
| Calyx shape | slender, slightly wider at base | urn-shaped (short and fat) | urn-shaped (short and fat) | uniform in width |
| Sepal color | whitish to yellowish to yellow-green (purplish) | white to yellow | yellow | greenish |
| Petal color | yellow | yellow | yellow | white |
| Fruit orientation | spreading to descending to reflexed | ascending to spreading | spreading to reflexed | generally reflexed |
| Fruit shape | generally curved | straight to curved | straight to curved | curved, especially near tip |