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| Fig. 1. Left: Picture showing twining stem, opposite spear-shaped leaves, and the chocolate-brown flower. Right: Closeup of flower. Pictures taken by Tom Chester on 3 December 2010 from the "Salazaria Plateau" west of Yaqui Peak. Click on the pictures for larger versions. | ||
Table of Contents
Introduction
Vouchers
Geographic Distribution
Abundance
Elevation Analysis
List of Locations
Discovery Dates
Leaderboard for discoverers of Matelea Locations
Photographs
Taxonomic History
Introduction
Matelea parvifolia, spearleaf, is one of the rarest plant species in the Borrego Desert. In five years of surveys, from 2005 to 2010, we found a grand total of eight plants in six locations! The numbers started climbing when we began botanizing its home in the Borrego Desert, in the Plum Canyon area and Smuggler Canyon area. But even after over 400 surveys, the total number of plants found is just 142, from a total of 43 separate locations. Those 43 locations are quite clustered, making up only 11 areas after application of the clustering algorithm used by the Consortium of California Herbaria.
Although this species is rare in the Borrego Desert, it is a widespread species. It primarily lives in the southwestern quarter of Arizona, extending to our area on the west, northern Baja on the southwest, and just barely into mainland Mexico, New Mexico and Texas.
The major difficulty in spotting this species is that it is nearly invisible, even at full bloom, primarily because it is normally a short twining vine growing inconspicuously on a bigger plant. Fig. 2 shows some typical appearances of Matelea plants on different support plants. Two of the four Matelea plants in Fig. 2 are in full bloom!
Photograph by Tom Chester, Pictograph Trail, 27 December 2013 | 
Photograph by Tom Chester, the "Salazaria Plateau" west of Yaqui Peak, 3 December 2010 |
Photograph by Tom Chester, Hill south of parking area at entrance to Plum Canyon, 12 December 2012 | 
Photograph by Tom Chester, PCT north of Scissors Crossing, 6 January 2012 |
More photographs of these plants, including close-ups, are given below.
Matelea doesn't seem to care for the most part what plant it gets established under, and then uses as support. The most common in our experience is a small jojoba plant, typically 2-3 feet high. The tallest Matelea plant we've ever seen was seven feet tall twining around an ocotillo stem. The happiest plant we ever saw was growing around a barrel cactus. Other support plants include Ambrosia dumosa, Ephedra aspera, and dead plants that could no longer be securely identified. One voucher said it was growing on a cholla. A support plant is not a necessity; we've seen Matelea growing out of cracks in boulders, and from the ground at the base of boulders.
A special skill is needed to be able to find Matelea plants, which is why this page gives a Leaderboard for discoverers of Matelea Locations.
However, despite the difficulty in finding this species, it seems to be truly rare in our area. There was one voucher of it from Glorietta Canyon from 1996 that we were never able to relocate, despite 12 days of field surveys there, including two in which the only goal of the survey was to look for Matelea, by people who were familiar with Matelea and good detectors of it. That voucher was of a plant growing at the base of a cholla, which would have been easily found at the time of year we did our surveys.
Although we never found it in our surveys, Mary Jo Churchwell came across a specimen there growing in a Hyptis emoryi while collecting in that area for the San Diego County Plant Atlas. We immediately went to see it. Her location was not covered by any of our 12 days of surveys, although we surveyed within 300 feet of that location previously! We can confidently say that Matelea is exceedingly rare in the Glorietta Canyon area. (There were a number of chollas at that location, so it is possible this is the location of the 1996 vouchers, and the plant extant on the cholla was no longer alive.)
Vouchers
The analysis on this page discusses only the 43 observations from our surveys as of 17 January 2014. The table may have been updated with later observations.
Voucher information has not been added to this page yet. We'll add information throughout this page from vouchers in the future, but here is a quick summary of the voucher information.
One of our locations was in our surveys only because Mary Jo Churchwell told us about coming across and vouchering this species from Glorietta Canyon, and giving us a precise GPS location.
There are a total of seven different vouchered locations, including the one from Mary Jo Churchwell. Two other of those seven voucher locations are also the same as our locations:
- One from Wayne Armstrong is almost surely of the same population we independently discovered at the mouth of Plum Canyon. But Wayne discovered it 30 years earlier!
- One from Susan Bazell is probably from one of the two populations we independently found six days earlier than her voucher date on the California Riding and Hiking Trail above Hellhole Canyon.
The other voucher locations are from:
- Yaqui Well
- Blair Valley
- Saddle separating Little Blair Valley and Big Blair Valley
- Sentenac Canyon, approx. 2 miles east of Scissors Crossing (the "6 miles" in the locality is an error).
Geographic Distribution
The geographic distribution of Matelea parvifolia from all of our ABDSP surveys as of 1/17/14 is shown in Fig. 1. See also the clustering version of these points.
The plot in Fig. 1 is complete for all our (~400?) surveys from 2003 - 2014. Although we have only completed digitizing about one-fourth of all of our surveys, we targeted this species to digitize its points from the surveys not-yet digitized. (See also the map of all digitized locations as of 1/10/14).
Note that Matelea is confined to a fairly narrow longitude range. Most of our locations are from just two places: the Plum Canyon area (10 locations), and the Smuggler Canyon area (8 locations).
Table 1 gives some record locations, such as the highest and lowest elevation locations.
Table 1. Record locations for Matelea
| Record | Location |
|---|---|
| Lowest Elevation | 1435 feet, Glorietta Canyon |
| Highest Elevation | 4670 feet, On the Schad Whale Peak Trail where it crosses Smuggler Canyon |
| Northernmost San Diego County | 33.39606° latitude, Box Canyon off Coyote Creek |
| Southernmost San Diego County | 32.93113° latitude, Upper Moonlight Canyon, Agua Caliente County Park |
See the SEINet distribution map for the distribution of this species in the southwestern U.S. and northern Mexico.
Abundance
Perhaps the most interesting and unusual characteristic of the distribution of this species is that we have never found more than 14 plants at a single location, and the median number of plants per location is ONE! Fig. 2 shows the number of plants per location as a function of elevation.
This is very unusual for species in the Borrego Desert, which nearly all have at least one location where there are 50 or 99 plants.
Elevation Analysis
Fig. 3 gives a histogram of the number of locations versus elevation.
There are approximately a constant number of plants per elevation bin from 1400 to 3800 feet, with only two plants found at higher elevations.
There is no mystery about why the plants suddenly appear above 1400 feet. They like to grow in dry, rocky areas, not in the flat desert floor, and the desert floor extends to about 1000 feet elevation on the west of Borrego Springs. It takes another roughly 400 feet of elevation before its habitat appears in any abundance.
Above about 4000 feet the plant community changes from desert transition to montane, and a lot of desert plants drop out at that elevation.
The full interpretation of this plot can not be done until we make similar plots for all our survey points for comparison. In particular:
- we have surveyed less area above 3000 feet, since we've been concentrating on the flora of the Borrego Desert below 3000 feet; and
- the amount of area available to survey varies with elevation.
In particular, the number of plants at elevations of 3000 to 3800 feet jumped in December 2013 and January 2014 simply because we did a number of surveys at that elevation in Smuggler Canyon, where it seems to live in greatest abundance (see Table 1).
Since we have surveyed a lot of area below 1400 feet without finding Matelea, this species clearly doesn't live below that elevation here. Our highest-elevation location, on the Whale Peak Trail, at 4647 feet, is the highest elevation Matelea known in California. The Jepson Manual Second Edition elevation range of 700-1000 m (2300-3300 feet) is clearly too small, which often happens with species that have few vouchers. Munz 1974 gave it as rare, 2000-3000 ft.
The Vascular Plants of Arizona treatment gives an elevation range of 1500-4500 feet, that essentially exactly matches the range we have observed.
Fig. 4 plots the latitude vs. elevation for all the locations from our surveys.
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Fig. 4. Left: a crop of the geographic map on Fig. 1. Right: Latitude vs. elevation for Matelea locations from our surveys. The latitude scale approximately matches that of the map on the left, so that the geographic location of the points can be seen.
The Smuggler Canyon / Whale Peak area is responsible for all the points above 3000 feet.
List of Locations
The complete list of our locations for Matelea is given in Table 2, with a histogram of discovery dates in Fig. 5. The recent large number of discoveries is primarily due to us botanizing where Matelea is most abundant.
Table 2. Complete list of survey locations for Matelea
| # | Date | Survey Area | Elevation (feet) | # Plants | Discoverer |
|---|---|---|---|---|---|
| 1 | 12/23/05 | California Riding and Hiking Trail - VC up to saddle | 1520 | 1 | James Dillane |
| 2 | 12/23/05 | California Riding and Hiking Trail - VC up to saddle | 1990 | 2 | James Dillane |
| 3 | 01/03/07 | Agua Caliente – Moonlight Canyon Loop | 1540 | 1 | James Dillane |
| 4 | 12/29/08 | Henderson Canyon south side | 1480 | 2 | James Dillane |
| 5 | 11/25/09 | Box Canyon off Coyote Creek | 2600 | 1 | James Dillane |
| 6 | 12/03/10 | Salazaria Plateau | 2920 | 1 | James Dillane |
| 7 | 05/20/11 | Pholisma branch of Mine Canyon | 2540 | 2 | James Dillane |
| 8 | 01/06/12 | PCT north of Scissors Crossing | 2875 | 5 | Tom Chester or Mike Crouse |
| 9 | 02/17/12 | Vallecito Hills | 1660 | 1 | Mike Crouse |
| 10 | 02/22/12 | Agua Caliente to Vallecito | 1650 | 1 | James Dillane and Mike Crouse |
| 11 | 03/16/12 | Agua Caliente Upper Moonlight Canyon | 2050 | 14 | James Dillane |
| 12 | 04/23/12 | Whale Peak Trail | 4670 | 5 | Mike Crouse |
| 13 | 12/12/12 | Plum Canyon | 1700 | 6 | James Dillane |
| 14 | 12/28/12 | Canyon to east of Plum Canyon | 2480 | 1 | Tom Chester / Keir Morse |
| 15 | 12/28/12 | Canyon to east of Plum Canyon | 2475 | 10 | Tom Chester / Keir Morse |
| 16 | 12/28/12 | Canyon to east of Plum Canyon | 2565 | 1 | Tom Chester / Keir Morse |
| 17 | 01/02/13 | Plum Canyon | 2965 | 8 | Tom Chester |
| 18 | 01/02/13 | Plum Canyon | 3000 | 2 | Tom Chester |
| 19 | 02/15/13 | Yaqui Pass nw area | 1615 | 1 | Tom Chester and Adrienne Ballwey |
| 20 | 02/28/13 | Glorietta Wash and its Canyon | 1435 | 4 | Mary Jo Churchwell |
| 21 | 03/22/13 | Plum Canyon | 2125 | 1 | Adrienne Ballwey |
| 22 | 03/22/13 | Plum Canyon | 2120 | 1 | Adrienne Ballwey |
| 23 | 03/31/13 | Plum Canyon – Kate survey as part of tour | 2030 | 1 | Kate Harper |
| 24 | 10/13/13 | Canyon east of Plum Canyon – Keir Morse trip | 2365 | 1 | Keir Morse |
| 25 | 12/15/13 | Pictograph Trail / Smuggler Canyon Loop | 3060 | 3 | Angelique Herman |
| 26 | 12/15/13 | Pictograph Trail / Smuggler Canyon Loop | 3310 | 3 | Keir Morse |
| 27 | 12/27/13 | Pictograph Trail / Smuggler Canyon | 3360 | 2 | Kate Harper |
| 28 | 12/27/13 | Pictograph Trail / Smuggler Canyon | 3425 | 1 | Tom Chester |
| 29 | 01/07/14 | Pictograph Trail / Smuggler Canyon – keir morse survey | 3300 | 1 | Keir Morse |
| 30 | 01/07/14 | Pictograph Trail / Smuggler Canyon – keir morse survey | 3660 | 1 | Keir Morse |
| 31 | 01/07/14 | Pictograph Trail / Smuggler Canyon – keir morse survey | 4120 | 6 | Keir Morse |
| 32 | 01/11/14 | Smuggler Canyon Thymophylla survey | 3120 | 1 | Tom Chester |
| 33 | 01/11/14 | Smuggler Canyon Thymophylla survey | 3315 | 11 | Adrienne Ballwey |
| 34 | 01/11/14 | Smuggler Canyon Thymophylla survey | 3520 | 9 | Keir Morse |
| 35 | 01/15/14 | Smuggler Canyon Thymophylla survey | 3220 | 9 | Tom Chester |
| 36 | 01/15/14 | Smuggler Canyon Thymophylla survey | 3485 | 1 | Tom Chester |
| 37 | 01/15/14 | Smuggler Canyon Thymophylla survey | 3515 | 1 | James Dillane |
| 38 | 01/15/14 | Smuggler Canyon Thymophylla survey | 3560 | 8 | Tom Chester |
| 39 | 01/15/14 | Smuggler Canyon Thymophylla survey | 3220 | 1 | Kate Harper |
| 40 | 01/15/14 | Smuggler Canyon Thymophylla survey | 3275 | 2 | Kate Harper |
| 41 | 01/15/14 | Smuggler Canyon Thymophylla survey | 3295 | 4 | Kate Harper |
| 42 | 01/15/14 | Smuggler Canyon Thymophylla survey | 3400 | 1 | Kate Harper |
| 43 | 01/15/14 | Smuggler Canyon Thymophylla survey | 3560 | 4 | Kate Harper |
| 44 | 01/23/14 | Whale Peak Trail | 4235 | 1 | Kate Harper |
Discovery Dates
Fig. 5. Histogram of the discovery dates for Matelea locations. The recent large number of discoveries is primarily due to us botanizing where Matelea is most abundant.
The discoverer is called out separately in Table 2, because sometimes this species is extremely hard to see. Table 3 gives the leaderboard for those with the sharpest Matelea detectors. When two people jointly discovered a given location, each was given one half the credit.
Leaderboard for discoverers of Matelea Locations
Table 3. Leaderboard for discoverers of Matelea Locations
| # Locations discovered | Discoverer |
|---|---|
| 10.5 | James Dillane |
| 9.5 | Tom Chester |
| 8.0 | Kate Harper |
| 7.5 | Keir Morse |
| 3.5 | Adrienne Ballwey |
| 3.0 | Mike Crouse |
| 1.0 | Mary Jo Churchwell |
| 1.0 | Angelique Herman |
Photographs
From Plum Canyon, 12 December 2012, of a plant twining around stems of a Simmondsia chinensis, jojoba and a dead or dormant branch of Ambrosia dumosa, burroweed, that is sticking out of the jojoba. It is growing near the top of an exposed sparsely-vegetated very small hill/ridge just south of SR78 with sand andexposed rocks on the surface.
- Habitat photograph
- Plants providing support for spearleaf vines from a distance
- Spearleaf plant twining densely around stem of burroweed and sparsely around stems of jojoba: top view
- Plant twining densely around stem of burroweed and sparsely around stems of jojoba: side view
- closer side view
- closeup of spearleaf vines and leaves
- closeup of spearleaf vines and leaves
- Seedpod and seeds with fluffy tufts of hair
- Young plants growing up from ground at base of boulder
- isolated young stem at lower left and bases of others stems at upper right
From the PCT north of Scissors Crossing, 6 January 2012, of a plant growing around a Ferocactus cylindraceus, barrel cactus, on a south-facing dry slope amidst broken rock.
- Habitat photograph
- Closer view of habitat
- Closeup of plant on barrel cactus
- Closeup of stems tangled in the barrel cactus
- Closeup of stems growing away from the barrel cactus
- Closeup of stem and leaves
- Closeup of stem and leaves with scale
- Flower and beginning fruit
From Mine Canyon, 20 May 2011, of a plant growing out in the open, from a crack at the base of a boulder in a shaded canyon bottom.
- Habitat photograph
- Closer view of entire plant
- Young fruit
- Closeup of fruit tip, with remnant corolla
From the "Salazaria Plateau" west of Yaqui Peak, 3 December 2010, of a plant growing in an Ephedra in an open area with clay soil amidst scattered small rocks.
- Habitat photograph and support plant
- Closer view of plant with flower
- Closeup of leaves and stem
- Closeup of leaves and stem with scale
- Bud
- Flower and bud with scale
- Flower with scale
- Closeup of flower with scale
- Closeup of flower with scale
Taxonomic History
This section contains only some tidbits of info so far, and has not yet been written up in a coherent way.
Gonolobus parvifolius Torr. Rept. Bot. Mex. Bound. Survy. 166, 1859.
Gonolobus hastulatus A. Gray, Proc. Amer. Acad. 12:78, 1877.
Vincetoxicum hastulatum (A. Gray) Heller, Muhlenbergia 1:2. 1900
Gonolobus californicus Jepson, Man. 771. 1925.
Listed as "Gonolobus(?) parvifolius (n. sp.), from Sides of hills, canon of the Rio Grande, below Mt. Carmel, October; Parry. Mountain near the Limpia, western Texas; Wright. Corolla dull yellow, (brown when dry).
The type specimen of Gonolobus californicus is from a collection by T.S. Brandegee. He collected it twice, in "c. 1895" and on apr 6, 1901, with the locality given as "Ironwood Well" which is now known as Yaqui Well. there is no other information on the label.
One of these vouchers is the type specimen for Jepson's name. Jepson described it as a new species in his 1925 manual, as Gonolobus californicus. Jepson states:
Greek gonia, angle, and lobos, pod, one of the early species with angled fruits.
In 1941, Woodson published a monograph on the North American Asclepiadaceae, and give this species the name Matelea parvifolia.
The name Matelea for the genus was given in 1775, in Aubl. Fl. Guian. 1:277. t.109.
Other things to add to this page:
jaeger says vincetoxicum means "poison conqueror" because of its supposed antidotal powers. take a look at the cartoon face on the sticky note at top on this voucher image: http://ucjeps.berkeley.edu/cgi-bin/display_smasch_img.pl?smasch_accno=JEPS24526
Confusion of name with Matelea parviflora.
We thank Jane Strong for comments on this manuscript.