The Bruce Watts Census of
Funastrum crispum, wavyleaf twinevine
Funastrum crispum, wavyleaf twinevine
Bruce Watts, Lance Woolley, and Tom Chester
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| Fig. 1. Top: Color variation in the flowers. Bottom: The beautiful richly-colored large leaves that are wavy ("crisped") at the edges, that gave this species its name.
Photos by Bruce Watts, all from the Pinyon Flat area. Top left taken on 15 June 2015. Top right taken on 23 July 2016. Bottom taken 19 October 2022. Click on the pix for larger versions. | |
Introduction
Funastrum crispum (= Sarcostemma crispum) was unknown from California until 9 June 2009, when Jordan Zylstra discovered that the plants at Pinyon Flat matched that Arizona species perfectly. See Plant Species of the San Jacinto Mountains: Funastrum crispum, wavyleaf twinevine .
For a number of years, the known population size was only about one hundred plants, primarily from a Forest Service survey done in 2006 for a firebreak around the populated area of the community of Pinyon Flat. Even though Duncan Bell spent 23 days surveying in the Martinez Mountain watershed from 2014 to 2017, which contains a similar area called Little Pinyon Flat, he found only a single other location of this species, containing just four large plants in a drainage on the east side of Horsethief Creek.
In August 2016, Bruce Watts spent a few days surveying for F. crispum, but it was not a good time to do a survey, since half the plants were dead, and it was the middle of the summer heat.
Summer 2022 had wonderful monsoon rain, with repeated thunderstorms over the Pinyon Flat area. After seeing big healthy plants of F. crispum on the Cactus Spring Trail, and finding GPS locations at Calflora taken by Keir Morse, Bruce decided to census the plants in the Pinyon Flat area.
In eight days of surveys, from 15 October to 7 December 2022, with Lance Woolley assisting on two days, and Norm Johnson on one, Bruce found a total of over 700 plants! Detailed results are presented below, along with his field observations.
Field Notes from the 2022 F. crispum census
The vines are mostly found near desert washes. The plants are found in much larger quantities near these drainages, with plants growing on the banks but not directly in the washes.
About 70% of the plants grow on the south-facing side of the plants they climb. Isolated plants growing out in the open in full sun have F. crispum plants growing on all sides.
Small oaks are abundant near these washes so the vines are common on the oaks, however, they will grow on any plant in the right environment. We found plants growing on oaks, Purshia tridentata, Pinus quadrifolia, Bernardia incana, Yucca schidigera, Senegalia greggii, and even one vine growing on a grass.
The monsoonal rains of 2022 revived the larger plants and caused new plants to germinate. Those young plants were recorded separately. The newly-germinated plants are not yet large enough to climb up other plants; see Fig. 2. It will be interesting to see how many young plants reach maturity.
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| Fig. 2. Young plants that presumably germinated from the good monsoonal rainfall of Summer 2022.
Photos by Bruce Watts on 19 October 2022 from the Pinyon Flat area. Click on the pix for larger versions. |
I saw no plants in flower in October but there were about 60 unopened fruit. I counted fruit at the beginning but gave up when I had to count over 300 plants in one day by myself.
The seeds are large and heavy; see Fig. 3. Apparently most stay in the vicinity of the large plants, since most of seedlings are under the big plants.
Fig. 3. Seeds in a half-open fruit pod. Photo by Bruce Watts on 13 January 2018 from the Pinyon Flat area. Click on the pix to see more of the fruit pod and plant.
F. crispum Census Results
Information from each survey day is presented in Table 1, and a map showing the results is given in Fig. 4.
A total of 745 plants were counted by Bruce Watts and helpers, including dead-appearing plants and young plants, and Scott White reported two additional plants that were incidentally seen by him in an area near homes not surveyed by Bruce, for a total of 747 plants. 152 plants, 20% of the total number, were young plants that were not yet large enough to climb up other plants. Those young plants probably germinated from the summer rains this year.
Table 1. Information from each survey day
| Date | Participants | # Plants | # Young Plants# |
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| 10/15/22 | Bruce Watts | 31 | 26 |
| 10/20/22 | Bruce Watts | 73 | 27 |
| 10/21/22 | Scott White, Bob Packard* | 2 | -- |
| 10/24/22 | Bruce Watts, Lance Woolley | 212 | 35 |
| 10/25/22 | Bruce Watts | 328 | 50 |
| 11/05/22 | Bruce Watts, Norm Johnson | 34 | 2 |
| 11/07/22 | Bruce Watts, Lance Woolley | zero | |
| 11/11/22 | Bruce Watts | 26 | 13 |
| 12/07/22 | Bruce Watts | 41 | |
| All | 747 | 152 | |
*This wasn't a census; the plants were incidentally seen, and this area, near homes, was not surveyed by Bruce.
#Young plants are ones that were not yet large enough to climb up other plants, and their numbers were included in the column with header # Plants. Those young plants probably germinated from the summer rains this year.
Notes for some surveys:
11/05/22. 6 dead plants. No plants were found in the recent burn area.
12/07/22. All the plants looked frostbitten, and about a third of them were dried up and dead.
Fig. 4. Geographic map showing the number of plants counted. The smallest circles had 1 to 9 plants at each location. The medium-size circles had 10 to 28 plants at each location. The three largest-size circles had 38 to 42 plants at each location. Click on the pix to see a slightly-larger area. See also map with survey routes shown.
Additional Photos
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| Fig. 5. Additional photos of Funastrum crispum, by Bruce Watts.
Click on the pix for larger versions, except for the last pix which is already screen-sized. | |
Bruce thanks Norm Johnson, Stephen Sutton, and Jill C. Wild for transportation from Idyllwild to Pinyon Flat.