Plant Species of San Jacinto Mountain:
Cordylanthus nevinii and C. rigidus, birdbeaks
Cordylanthus nevinii and C. rigidus, birdbeaks
| Cordylanthus nevinii, Nevin's bird's beak | C. rigidus ssp. setiger, bristly bird's beak
Fig. 1. The easiest way to discriminate Cordylanthus nevinii (left) from C. rigidus (right) is that the flowers of C. nevinii are usually single, or in loose clusters of two to three flowers, and the flowers of C. rigidus are usually in compact, head-like clusters of five or more flowers. See Plants of Orange County for some nice photographs showing the variation in the flower clusters.
| All parts of the plant of C. rigidus are usually quite bristly, as seen in this photo, whereas all parts of the plant of C. nevinii have softer-looking long hairs (see below). The color of the main body of the plant of C. nevinii is usually gray-green tinged red-purple, as shown here. C. rigidus comes in both a green form and the reddish form shown here. The photo of C. nevinii is from the Marion Mountain Trail on 14 September 2010. The photo of C. rigidus is from 5S10 (Red Hill Road) taken on 27 Septebmer 2023. All photos on this page were taken by the author. Click on the pictures for larger versions. | |||
Introduction
Cordylanthus species have exceedingly-cute flowers that really do look like bird's beaks when they are observed from above; see Fig.1. But the flowers are very different from normal flowers, since they never open to allow easy access to their sexual parts!
I hadn't ever wondered what was going on with this flower until 3 August 2015, when Michael Charters wanted to know what was inside the flower on a trip on the Blue Ridge Trail in the San Gabriel Mountains. Michael dissected a flower in the field to find its amazingly-hairy filaments with a pair of anthers fused at their pollen sacs, and the anther sacs / pistil hidden within the tip of the flower.
Michael was so fascinated by the part of this flower he then read aloud the Jepson Manual description of the Cordylanthus flower (Michael always carried the printed version of the Jepson Manual). After he read that, we thought it might be the longest and best flower description of any genus in the Jepson eFlora!
I was speculating that maybe the flower was self-pollinated when ever-observant Adrienne Ballway spotted a native bee zipping around the flowers, taking what seemed like milliseconds to land on the flower and stick its tongue into it to pollinate it and get the nectar or pollen reward. In contrast, she saw the European honeybee struggle to land on the flower and open it up, taking seconds to open it up, but succeeding.
Then we saw a smaller bee-fly-like insect zipping around the flowers, but seemingly having no idea whether a flower was mature or not, since it repeatedly circled around flowers that were either clearly finished, or in bud.
In general, in the field, plants generally waste no time in proving my speculations wrong. (:-)
At home, I found a wonderful photo by Aaron Schusteff, that captured a native bee opening up the flower! We didn't observe the bee going into the flower like in Aaron's shot, probably because it happened too quickly. Adrienne said the bee grasped the outside of the flower, and then just stuck its tongue / whatever inside the flower, in a very smooth quick operation.
Fig. 2 shows a "bee's-eye view" of a C. nevinii flower.
Fig. 2. A "bee's-eye view" of a C. nevinii flower. This flower is "inverted" compared to normal Cordylanthus flowers, with its "upper lip" on the bottom and its "lower lip" on the top! The "upper lip" forms a hood that encloses the anthers and style. Photo taken in Tahquitz Creek, section T9, on 7 September 2009.
At San Jacinto Mountain, we have two Cordylanthus species. C. rigidus is our most common one, found at elevations mostly around 5000 feet, but ranging up to 6400 feet on the west side, and up to 7500 feet on the Skyline Trail on the east side. This species has a number of common names, "bristly bird's beak", "rigid bird's beak", "stiffbranch bird's beak", "dark-tipped bird's beak", or just "bird's beak".
All of our plants are subspecies setiger, distinguished by details of their outer bracts. "Seti" means "bristle". The subspecies used to be called setigerus, but apparently that wasn't the correct Latin form of the subspecies name. Our plants used to be called C. filifolius before that species was made ssp. setiger of C. rigidus. When it was subsumed into C. rigidus, they forgot to update the corolla color in the species description. The corolla of C. filifolius is described as "white with two purple lines" in Munz 1974. User @idymark at iNat has a nice photograph showing two purple lines in the corolla.
The corolla of C. rigidus is given as "± yellow" in the Jepson eFlora, which presumably describes that genus before C. filifolius was made a part of it. Although most photographs of C. rigidus from San Jacinto Mountain show white corollas, the corolla shown in Fig. 3 below is greenish-yellow in its upper third.
C. nevinii is only found at higher elevations of 6000 to 8600 feet, but ranges down to 5740 feet on the Sawmill Road. This species has only one common name, "Nevin's bird's beak".
The easiest way to discriminate these two species is that the flowers of C. nevinii are usually single, or in loose clusters of two to three flowers, and the flowers of C. rigidus are usually in compact, head-like clusters of five or more flowers; see Fig. 1.
If you are in doubt about the determination of a plant, there are additional ways to discriminate them. The three-lobed outer bract of each flower is much shorter than the flower for C. nevinii, and has white tips. For C. rigidus, its three-lobed outer bract of each flower is almost the same length as the flower, and has dark tips; see Fig. 3. However, note that there is considerable variability in the length of the outer bracts for each species; 5 to 10 mm (a factor of 2) for C. nevinii, and 5 to 20 mm (a factor of 4!) for C. rigidus.
| Cordylanthus nevinii, Nevin's bird's beak | C. rigidus ssp. setiger, bristly bird's beak
Fig. 3. Photos showing the difference in the outer bracts for C. nevinii (left), and for C. rigidus (right). The tips of the bracts are circled in each pix. Photo of C. nevinii taken on the Marion Mountain Trail on 14 September 2010. Photo of C. rigidus taken on the Skyline Trail on 31 August 2012.
| Click on the pictures for larger versions. | |||
The hairs also differ between the species. C. rigidus, as you might expect from its name of "bristly bird's beak", has stiff white hairs on nearly all of its parts. Our ssp. setiger does not have any glandular hairs. In contrast, C. nevinii has abundant very short glandular hairs, accompanied by a smaller number of soft white longer hairs.
Fig. 4 shows the hairs at the mid-stem for each species.
| Cordylanthus nevinii, Nevin's bird's beak | C. rigidus ssp. setiger, bristly bird's beak
Fig. 4. Left: The stem of C. nevinii is covered with short-stalk glandular hairs, with a smaller number of longer soft white hairs. Right: The stem of C. rigidus has scattered very noticeable stiff white bristly hairs, along with some very short stiff white hairs. Both photos taken from the Deer Springs Trail, from different locations, on 7 July 2023.
| Click on the pictures for larger versions. | |||
All pictures shown on this page were taken by the author.