Tuesday, March 13 – Western Big Bend National Park

Andrea “Squeak” Jones

Michelle “Homegirl” Cawley

Third day in Big Bend NP with six major botanizing stops in the Western portion of the Park, including Santa Elena Canyon, Sotol Vista, Tuff Canyon, and Cattail Springs. Last night we did not have to endure a windstorm and Andy (SM) and Michelle looked on longingly at the hack circle while they chopped vegetables for veggie stir-fry. The ‘lipid obligates’ in the group opted for grilled cheese and tomato sandwiches instead of veggie stir-fry; the word around the hayfield (our campsite) was that the veggie stir-fry was tasty – mostly thanks to Andy. Tonight we have spaghetti with TVP – woo hoo bring it on!

Back to the botanizing. Continued to note abrupt boundaries in the distributions of Dyssodia pentachaeta, and Lupinus harvardii. We observed that L. havardii was continuous along the road, but patchy away from the road. Highlights of the day include several species not encountered elsewhere on the trip, including Aquilegia longissima, Adiantum capillus-veneris, Castilleja lanata, Salvia coccinea, Toxicodendron radicans var exzemium, and Typha angustifolia, which were all observed on the Cattail Springs hike (Stop 13-6).

Stop 13-1: Along Ross Maxwell Scenic Drive

Location: N 29°18.228 W 103°22.589

Ross Maxwell Scenic Drive is a 30-mile-long road that starts along the edge of the Burro Mesa, travels along the western edge of the Chisos Mountains, and descends the alluvial slopes and bajadas down to the Rio Grande River and Santa Elena Canyon. As we drove from east to west towards our first destination (Santa Elena Canyon), we observed distinct boundaries of Dyssodia pentachaeta and stopped to check it out. D. pentachaeta appeared to be dominant where present. The boundary of D. pentachaeta curves, and sadly casts doubt on the fence theory. Nerisyrenia camporum was present throughout the site, but appeared more dominant where D. pentachaeta was not present.

Species	Cover	Species	Cover
Agave lechugilla	2	Linum rigidum	1
Astragalus sp.	1	Nama hispidum	1
Bailyea multiradiata	3	Nerisyrenia camporum	3
Bouteloua sp.	2	Oenothera kunthiana	1
Dyssodia pentachaeta	4	Opuntia leptocaulis	1
Echinocactus texensis	1	Opuntia macrocentra	2
Fouquieria splendens	1	Phacelia integrifolia	1
Larrea tridentata	4	Prosopsis glandulosa	2

Drive to Santa Elena Canyon

Off in the distance – White whale identified Populus angustifolia (while driving – oh yeah they’re good!). Quick photo stops along the way noted the following species.

Species	Cover	Species	Cover
Argemone chisosensis		Lobelia cardinalis
Cassia durangensis		Mentzelia multiflora
Cryptanthum sp.		Populus angustifolia
Erigeron modestus		Robinia sp.

Stop 13-2: Santa Elena Canyon

Location: N 29°10.039’ W 103° 36.616’ [Map]

[Photo - trail through Santa Elena Canyon]

Santa Elena Canyon is one of the three major canyons of the Rio Grande in Big Bend National Park. The canyon is 18 miles long and reaches a depth of 1,500 feet. The South-facing cliff (the one on the right as you approach the canyon) is the eastern edge of the Mesa de Anguila, the large mesa in the western portion of Big Bend National Park. The North-facing cliff (the one on the left as you approach the canyon) is the Sierra Ponce, the northern boundary of Mexico. The mesa is formed of Lower Cretaceous limestone layers that were elevated along the Terlingua Fault.

Species	Cover	Species	Cover
Acacia greggii	3	Hechtia scariosa	1
Acalypha neomexicana		Jatropha dioca	2
Agave lechuguilla	2	Myosotis
Allionia incarnata	1	Nama hispidum
Aristilochia wrightii	1	Nicotiana glauca	3
Arundo donax	4	Nicotiana trigonophylla
Bouteloua sp.	3	Oenothera triloba
Chamaesaracha villosa	1	Opuntia rufida	2
Chilopsis linearis	3	Phragmites australis	3
Echinocactus sp.	1	Prosopsis glandulosa	2
Equisitum laevigatum	1	Psilostrophe tagentina	1
Eucnide bartonioides	1	Salix interior	3
Euphorbia eriantha	1	Stenosiphon linifolius
Eustoma granidflorum	2	Tamarix sp.	4
Fouquieria splendens	2	Xanthium strumarium
Fraxinus velutina

To get to the canyon we first crossed Terlingua Creek, at this time of the year just a trickle. The wide, sandy creek-bed (not to mention a floodmark near the roof of the outhouses at the trail-head) is suggestive of the variable nature of the water flow in this area. After crossing the creek-bed we entered a virtual jungle of invasive species. Salt Cedar (Tamarisk chinensis), Giant Reed (Arundo donax) and Tree Tobacco (Nicotiana glauca) were found on the riparian strip along the river. In stark contrast, several elusive native species were found as we hiked along the canyon walls, including: Texas False-Agave (Hechtia texensis) and Wright Dutchman's Pipe (Aristolochia wrightii). Hechtia texensis & Tillandsia are the only members of the Bromeliaceae in the area.

Stop 13-3: Tuff Canyon

Location: N 29°08.985’ W 103°29.186’  [Map]

[Photo - Excursion group adjacent to Tuff Canyon]

Drove by Cottonwood Campground. Numerous campsites were available and if we supported Downtown Becky Brown we would not have had to camp in the hayfield this evening. Lesson learned – have faith in Becky B.

Tuff canyon derives its name from the layers of volcanic ash, or tuff, that form the canyon walls. Blue Creek, one of the largest drainages of the Chisos Mountains, carved through the soft gray tuff to create the canyon. Farther into the canyon, harder lava flows appear, forming erosion resistant ledges.

We saw lots of Lupinus. havardii as we hiked down into the canyon. We noted Linum puberlarum mixed with L. rigidum and another species of Nama that we were unable to identify (but it was taller than N. hispidum). There was no water in Blue Creek on our visit, so the bottom of the canyon was a dry wash with ‘islands’ where Prosopsis glandulosa was common. We also noted (but failed to identify) several vines. Finally, we noted a diminutive creeping Rubiaceae with small white flowers.

Species	Cover	Species	Cover
Acacia constricta	3	Nama hispidum	2
Acacia greggii	3	Nama sp.	1
Bailyea multiradiata	2	Nerisyrenia camporum	2
Bouteloua spp.	2	Nicotania trigonophylla	1
Chamaesaracha villosa	1	Nicotiana glauca	1
Cosmos paviflori (?)	1	Oenothera triloba	1
Euphorbia eriantha	1	Opuntia leptocaulis	2
Fouqueria splendens	2	Opuntia macrocentra	2
Guterriza sp.	1	Plantago insularis	1
Jatropha dioca	2	Prosopsis glandulosa	3
Krameria erecta		Rubicaceae	1
Larrea tridentata	3	Salix sp.	2
Linum puberalum	2	Streptanthus carinatus
Linum rigidum	2	Thelesperma megapotamicum	1
Lupinus havartii	3	Yucca torreyi
Mentzelia multiflora	1	Unknown Legume with yellow perfect flower, five petals.	1

Stop 13-4: Mule Ears Peaks (Lookout & lunch stop)

Location: N 29°09.997’ W 103°26.092’ [Map]

Mule Ears Peaks is a part of the southern extension of the Chisos Mountains, the Sierra Quemada (“Burned Mountains”). The unique formation was created by differential erosion of lava beds. The “mule ears” are hard caps of lava that remained after the surrounding, softer lava, was eroded away. The soft gray soil in this area is also likely to be tuff.

Botanically this stop was exciting because we finally made the distinction between the two Dalea species: D. formosa (shrub) and D. wrightii (perennial herb). There were also several different species of cacti in bloom at this site.

Species	Cover	Species	Cover
Agave lechuguilla		Jatropha dioca
Bouteloua spp.		Linum puberalum
Chamaesachara villinosa		Nama hispidum
Chenopodium sp.		Opuntia engelmannii
Dalea formosa		Opuntia imbricata
Dalea wrightii		Opuntia macrocentra
Echinocereus chloranthus

Stop 13-5: Sotol Vista

Location: N 29° 12.877’ W 103° 22.596’ [Map]

[Photo - Dasylirion & Bouteloua grassland near Sotol Vista]

The Nature Conservancy classifies the community we found at this stop as: Dasylirion leiophyllum-Agave lechuguilla/Bouteloua hirsuta-Bouteloua gracilis-Bouteloua eriopoda Shrubland. This community is found on the more rolling and steeper slopes of the Chisos Mountains in shallow, rocky soils at elevations below 4,500 ft. The community has medium densities of cover dominated by grasses. Both D. leiophyllum and A. lechuguilla contribute greatly to the density of the cover. We observed that the aspect of the slope played an important part in determining the density and type of vegetation. North-facing slopes were darker green and there was a noticeably higher density of shrub cover. Gymnosperma glutinosum, Dasylirion leiophyllum, and Agave lechuguilla were all more dense on the North facing slope as was a shrublet Acacia, possibly A. angustissima. There was more bare ground and grass cover on the south-facing slopes. Notation in cover class column (i.e., N, S, R) refer to whether species was noted as being more common on north-facing slopes, south-facing slopes, or the ridge. Botanizing cut short by rain (read: fair-weather botanists).

Species	Cover	Species	Cover
Acacia angustissima	N	Dyssodia pentachaeta
Agave lechuguilla		Echinocactus horizonthal
Aristida glauca	S	Gymnosperma glutinosum	N
Bailyea multiradiata		Larrea tridentata	S
Bouteloua curdapendula		Nama hispidum	R
Bouteloua gracilis	S	Nerisyrenia camporum
Boutleloua eriopoda	S	Opuntia imbricata
Corypantha dasyacantha var varicolor		Opuntia macrocentra
Dalea formosa	N	Polygala alba	S
Dalea sp.	S	Symphoricarpos rotundifolia	R
Dasylirion leiophyllum

Stop 13-6: Hike to Cattail Falls

Location: N 29°16.983’ W 103°20.947’ [Map]

[Photo - Mesic Acer-Quercus woodland below Cattail Falls]

This hike was especially entertaining for several reasons: 1) it was the site of the lizard crushing; 2) there was a hack attack; and 3) we hiked through a variety of different vegetation types and recorded many new species. Bob’s response to hacking at the waterfall: “You can lead them to plants, but you can’t make them look at ‘em.” Names of those who hacked at the waterfall are confidential, but let the record show that Michelle (the chronic hacker) did not partake in hacking at the waterfall.

Our hike began in the scrubby shrubby desert landscape to which we were slowly becoming accustomed. We started up along a dry sandy wash, with cobbly/gravelly slopes on either side. Eventually, we reached a more mesic and protected area. At the sight of trees, several botanists went into a mad frenzy looking for “sex” in an attempt to identify familiar, yet unusual species. They were rewarded with several less common species restricted to the Chisos Mountains, like Quercus graciilformis and Prunus serotina subsp virens. If it weren’t for the ever-present Opuntia along the trail, the waterfall area with its wildflowers, trees and Adiantum capillus-veneris may have lulled us into believing that we were back home. The Chisos provides the only occurrences of Vauquelina corymbosa in the US, and we observed it growing happily near the falls.

The species list is broken down by those recorded on the hike and those recorded near the waterfall. We also identified three individuals to family, including Onagraceae, Labiatae, and Primulaceae.

Species recorded on the Hike in:

Species	Cover	Species	Cover
Agave havardiana		Mammilaria heyderi
Aristida sp.		Nama hispidum
Bailyea multiradiata		Nama sp.
Bouteloua spp.		Oenothera sp. (lizard crushing prevented positive id)
Castilleja lanata		Oenothera triloba
Dalea Formosa		Opuntia engelmannii
Dalea wrightii		Opuntia imbricata
Dasylirion leiophyllum		Prosopsis glandulosa
Dyssodia pentachaeta		Rhus virens
Echinocereus chloranthus		Ruellia nudiflora
Ephedra sp.		Streptanthus carinatus
Fouqueria splendens		Verbana bipnnatifida
Gymnosperma glutinosum		Verbena halei
Linaria texana		Yucca torreyii
Lithospermum incisum

Species recorded near the Waterfall:

Species	Cover	Species	Cover
Adiantum capillus-veneris		Prunus serotina subsp virens
Aquilegia longissima		Quercus gracilformis
Epipactis giantea		Quercus gravesii
Fraxinus veluntina		Quercus pungens
Juncus sp.		Salvia coccinea
Juniperus sp.		Toxicodendron radicans var exzemium
Opuntia chisonsensis		Typha angustifolia
Opuntia engelmannii		Ungnadia speciosa
Phordendron sp.		Vauquelina corymbosa