Plants of Southern California: Gilias of San Diego County
Gilias are delightful little flowers which are often frustrating to identify. The difficulty in identification comes from at least four factors:
- the common floras contain 60-77 taxa; to discriminate each of these taxa clearly often requires obscure or hard to discern characteristics.
- the similarity of some species. In fact, some species are so similar that some subspecies have been moved from one species to another! Many vouchers originally determined as one species have been redetermined as another; see examples here.
- the need for a microscope and careful observation to determine some plant characteristics needed for the separation.
- confusing or overlapping key couplets used by the floras to separate species, along with variability in some plant traits. In particular, many species with corollas that are normally not entirely white have white versions, which sometimes are then misdetermined as different species. Gilia species seem especially prone to losing one or more color components at times, which also makes normally-blue pollen turn white.
Many of the difficulties in the Munz or Jepson Manual key can be circumvented by making a key for a single geographic area.
The latest Checklist Of The Plants Of San Diego County, by Simpson and Rebman, third edition, 2001, contains just 14 gilia species (note added 16 April 2011: 13 after removal of G. micromeria). By restricting ourselves just to those 13 gilias, we can therefore already eliminate the vast majority of the 60 taxa found in Southern California and the 77 taxa found in all of California! Unfortunately for beginning botanists, the key used by Beauchamp was just the Munz key with non-San Diego County taxa removed, so it still contained the difficulties due to the presence of 46 other taxa in Southern California.
This page presents a much easier way to identify the gilias of San Diego County. However, this restriction to San Diego County means that this page cannot be used to identify gilias from other areas of California!!!.
This page is in two sections:
- The first section is for beginning botanists, and goes through step by step how to identify each species. This first section is currently incomplete, awaiting opportunities for us to complete the set of photographs to illustrate the species and their key identification characteristics. In several places, it also needs a more elementary description as well as adding in the common names. Finally, we also need to add G. angelensis in the section with flowers not in heads, since it sometimes comes that way.
- The second section is for advanced botanists who know how to use a key and are familiar with botanical terms.
See Other Gilia species possibly in San Diego County for some species that have come and gone, and others that might be here.
See also:
- Gilias of Lowermost Tahquitz Canyon, west of Palm Springs for more extensive photographs of G. angelensis, G. australis, and G. stellata.
- Gilia species of San Jacinto Mountain, for more extensive pictures of G. australis, G. diegensis, and G. ochroleuca ssp. exilis.
How To Identify The Gilias Of San Diego County For Beginning Botanists
Two Simple Discriminants To Separate The Gilias Into Three Groups
The 13 gilia species of San Diego County can be immediately and easily placed into three groups using two simple discriminants. The discriminants are given below, with pictures illustrating each one. The first is whether the flowers are in heads or not. The second is whether the leaf is pinnate with a narrow rachis or not (terms defined below).
Discriminant #1: Flowers In Heads Or Not
| Flowers In Heads | Flowers Not In Heads |
|---|---|
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Flowers in heads simply means that there are some inflorescence branches that have more than a single flower right next to another flower. (An inflorescence is the entire cluster of flowers and associated parts, down to, but not including, the leaves below the lowermost branch containing flowers. Sometimes some inflorescence branches may have a single flower per branch, so be sure to look at the inflorescence as a whole to see if most flowers are in heads.) In the first picture above on the left, there are five flowers per head on the left, and three flowers per head on the right. In the second picture above on the left, there are ~50 flowers per head.
Flowers not in heads means that every single flower has its own flower stem that is longer than typically a few cm or an inch. (Sometimes a few flower stems may be very short; the majority will not be.) You can clearly see that each flower is separate in the picture illustrating this above (on the right), although the flowers are still part of an inflorescence that has multiple flowers. Each ultimate branch of the inflorescence leads to a single flower, and never to a cluster of flowers which touch one another.
Discriminant #2: Leaves Pinnate With A Narrow Rachis Or Not
| Non-Pinnate Leaf | Pinnate Leaf With A Narrow Rachis (Leaf Stem) | Pinnate Leaf With A Broad Rachis |
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A pinnate leaf is a leaf divided into recognizably-separate leaflets (ones that could be torn off without tearing other leaflets) that are arranged in two rows on opposite sides of the central leaf stem like the divisions of a feather. The two rows may not have perfect symmetry, although they sometimes do. The leaflets themselves can be pinnate or not; it doesn't matter.
A non-pinnate leaf is not feather-like; it is all one structure, without leaflets. It is not possible to tear off a clearly-separate structure for a non-pinnate leaf.
The rachis is the central leaf stem, and is of interest here only for pinnate leaves. The leaflets of pinnate leaves attach to the rachis. For pinnate leaves, the rachis can be either narrow (not appreciably wider than thick), or it can be broad, wider than thick.
Using The Two Simple Discriminants To Separate The Gilias Into Three Groups
With these two simple discriminants, we can immediately divide the 13 gilia species into three groups:
- Group 1: Flowers in heads
Common Name Latin Name angel's gilia Gilia angelensis globe gilia Gilia capitata ssp. abrotanifolia purple-spot gilia Gilia clivorum - Group 2: Flowers not in heads; leaves non-pinnate or pinnate with a wide rachis
Common Name Latin Name miniature gilia Gilia capillaris coastal gilia Gilia diegensis yellow gilia Gilia filiformis shy gilia Gilia inconspicua broad-leaf gilia Gilia latifolia volcanic gilia Gilia ochroleuca ssp. exilis - Group 3: Flowers not in heads; Leaves pinnate with a narrow rachis
Common Name Latin Name southern gilia Gilia australis caraway-leaved gilia Gilia caruifolia star gilia Gilia stellata trans-montane gilia Gilia transmontana
Now let's take each group in term, and learn how to distinguish each species.
Group 1: Flowers in heads
It is easy to distinguish these three species simply from looking at the flower, although for two of them, you have to look at the flower from the side or measure the width of the flower across its front.
| Common Name | Latin Name | Picture |
|---|---|---|
| angel's gilia | Gilia angelensis | (image to be added) |
| globe gilia | Gilia capitata ssp. abrotanifolia |
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| purple-spot gilia | Gilia clivorum | (image to be added) |
Globe gilia, Gilia capitata ssp. abrotanifolia, is immediately distinguished because it has 25-100 flowers per heads.
(The rest of this section needs pictures and more elementary explanation; this is just a place-holder for now with the more technical discrimination.)
The other two species have 1-10 flowers per head and are distinguished by the shape and size of the flower:
3. corolla campanulate (bell-shaped), 5-12 mm wide; style exserted; heads with 1-10, typically 5, flowers G. angelensis
3'. corolla funnelform (funnel-shaped), 3-5 mm wide; style included; heads with 2-5 flowers G. clivorum
Pictures for these last two species will be added when we obtain them. The problem is that nearly all pictures show the flower from the front, not from the side.
Group 2: Flowers not in heads; leaves non-pinnate or pinnate with a wide rachis
Many of the species in this group can easily be recognized by distinctive features shown in the following pictures:
Group 3: Flowers not in heads; Leaves pinnate with a narrow rachis
This group requires the most skill to separate, but it contains only four of the 13 species.
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The first step is to observe the lower portion of the main stem, to look for cobwebby hairs on the stem, as in the picture to the right. You're looking for faint strands of hair that overlap, much like the wispy cobwebs in a basement where people haven't been for a while, and not like the obvious cobwebs in Halloween decorations. If you observe them, you've identified G. transmontana. | 
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If you observe no hairs at all, or hairs that do not appear cobwebby, then look at the flower from the side to determine whether the stamens and style are long-exserted or not, as in the picture to the right of G. caruifolia. (Long-exserted means those parts stick out well past the end of the flower lobes. Compare the stamens in the picture to the right with the short-exserted stamens and style in the pix of G. stellata immediately below.). If the stamens and style are long-exserted, you've identified G. caruifolia. | 
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The remaining two species are very close; to separate them you need a hand lens to look at the calyx and the hairs on the basal leaves.
| Species | Distinctive Features | Picture | |||
|---|---|---|---|---|---|
| G. stellata |
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Key To Gilias Of San Diego County For Advanced Botanists
1. flowers in heads
2. heads containing 25-100 flowers .... G. capitata ssp. abrotanifolia
2'. heads containing 1-10 flowers3. corolla campanulate, 5-12 mm wide; style exserted; heads with 1-10, typically 5, flowers .... G. angelensis
3'. corolla funnelform, 3-5 mm wide; style included; heads with 2-5 flowers ....G. clivorum
1'. flowers solitary (in groups of flowers subtended by a single leaf, each flower with its own peduncle of length gen > 1 cm)
4. basal lvs with a wide rachis or holly-like
5. lvs holly-like .... G. latifolia
5'. lvs not holly-like6. corolla throat gen yellow .... G. inconspicua
6'. corolla throat two-colored, purple and yellow7. corolla tube and throat combined 1.5-2 x calyx; corolla throat yellow in upper portion, blue-purple below .... G. diegensis
7'. corolla tube and throat combined 2-3 x calyx; corolla throat blue-purple in upper portion, yellow below .... G. ochroleuca ssp. exilis4'. basal lvs with a narrow rachis
8. Lvs well distributed on stem, linear
9. corolla entirely yellow .... G. filiformis
9'. corolla lobes never yellow .... G. capillaris8'. Lvs mostly in basal rosette; basal lf 1-3 pinnate
10. lower stems with cobwebby hairs; basal lvs 1-pinnate .... G. transmontana
10'. lower stems with no cobwebby hairs; basal lvs 1-3-pinnate11. stamens and style long-exserted; stamens inserted in middle of corolla-throat; pl 12-100 cm tall; found at elevations > 2100 feet .... G. caruifolia
11'. stamens and style not long-exserted; stamens inserted in upper corolla-throat, just below sinuses of corolla lobes; pl 10-45 cm tall; found at elevations < 6000 feet12. lower lvs with white, abruptly bent hairs .... G. stellata
12'. lower lvs with translucent, mostly straight hairs .... G. australis
Other Gilia species possibly in San Diego County
G. micromeria originally appeared as a species in San Diego County on this page, due to its presence in the 2001 San Diego County Checklist. But the voucher supporting its presence turned out to be a misdetermined G. diegensis.
Similarly, the G. latiflora in the 2006 San Diego County Checklist turned out to be a misdetermined G. stellata, which is a real chameleon of a species.
We strongly suspect the G. sinuata in the 2006 San Diego County Checklist is just the white form of G. diegensis, but we need to check the vouchers to be sure.
Finally, the 2006 San Diego County Checklist also gives G. scopulorum, which might be confused with the white form of G. stellata. We need to check the vouchers to be sure.
Text by Tom Chester; Pictures by Michael Charters and Tom Chester except the first pix on this page of G. angelensis is by Kay Madore.