Don Rideout and I decided to botanize Henderson Canyon on Saturday, 1/7/23,
to see if there were any plants of Phacelia rotundifolia present.  We didn't find any in Clark Valley on the previous trip, but thought there might be a better chance to see them in Henderson Canyon, since we knew it had received more rain.

We were right about Henderson Canyon getting more rain, from the large number of annual species we saw there, but the rock exposures where Phacelia rotundifolia was found were essentially barren.  The rainfall wasn't enough to germinate annuals that grow in south-facing rock faces.

Although we expected to see more plants in bloom in Henderson Canyon, we were very surprised by how much was in bloom in Henderson Canyon, including along the now-closed-to-driving one mile access road.  There were the expected carpets of sand verbena at the start, at the junction of Borrego Springs Road and Henderson Canyon Road.  But within moments we were seeing blooms of desert dandelion, Phacelia distans, Camissoniopsis pallida, Cryptantha micrantha (Eremocarya micrantha), Filago depressa (=Logfia depressa), Chaenactis fremontii, and even an Opuntia basilaris with blooms!

Altogether, we saw 51 species in bloom.  The list is given at the end of this report.
You can see 42 of the blooming species in Don's and my iNat posts:,tchester&term_id=12&term_value_id=13

This is all the more remarkable since we saw only 11 species in bloom just six miles east in Clark Valley on the previous trip.

Including non-blooming species, Don and I posted 94 obs of 71 species:,tchester


On my drive in from Fallbrook, wild cucumber, Marah macrocarpa, had popped along the part of SR76 above Pauma Valley.  There were even a few plants of Castilleja foliolosa in bloom.  The Ribes indecorum just below the Red Gate Road pullout was still in full bloom.

I finally was able to stop at the glorious Arctostaphylos glauca on SR76 near the San Luis Rey picnic area.  Alas, it was no longer glorious, since many of the blooms had fallen off.  But those fallen blooms made a carpet of white at the foot of the plant.

My post:

Unfortunately, Sahara mustard essentially lines the Montezuma Road from the western park entrance down to close to the Crawford Overlook, and it is already mostly in fruit.  In the area of the Overlook, Acmispon glaber has popped.  There is not much else in bloom until near the bottom of the Grade, which still has Perityle in bloom.

About 15 cheery blooms of desert dandelion greeted us in the first part of the Henderson Canyon access road.  Don took a pix of one flower when we started hiking, and again on our return near sunset, when it had closed up:

We were quite surprised to see a single beavertail cactus in bloom, and Don also photographed it at noon and at sunset.  Its blooms had not closed much:

It is always a pleasure to see our showy Diplacus bigelovii in bloom, and especially fun when it is flowering alongside the stems in fruit from last year.  Don's posts:

I noticed that one anthill had a ton of Datura discolor seeds discarded on the waste pile, and immediately realized that those seeds must have had eliaosomes attached to them to attract the ants. The eliaosomes are the small white parts attached to the seeds, which are a bribe to ants to carry off the seed plus eliaosome to their nest.  At their nest, they consume the eliaosome, and then discard the seed, spreading the Datura seeds farther than they could go on their own.  Don examined a nearby plant, and by golly, it still had seeds with eliaosomes attached.  Interestingly, another nearby plant had no eliaosomes attached to its seeds.

My post:

We also saw some peculiar scratch marks in at least four places along the road, clearly made by a mammal of some sort, but with no clue as to why it made those scratches.  Our best guess is that a bobcat urinated in these spots and made those scratches.  Comments welcome!  My post:

We were a bit bummed to arrive at the location of the Phacelia rotundifolia, to find not even Perityle growing on the rock outcrop.  But that meant we wouldn't be delayed in our plant to hike to mile 2.8 from the car, and explore a side canyon that had no observations posted from it at iNat.

We got to the side canyon just before 2 p.m., giving us an hour to explore it.

Don's pix of the entrance to the side canyon:

A half hour later Don took this pix of me surveying the area for something new:

I had put on a sweatshirt since we lost the sun in this side canyon due to the canyon walls.

We, mostly Don, posted 44 observations from this side canyon!,tchester

Our hour was up all too soon, and we turned around shortly after having a snack at 3 p.m.  Don's pix of the upper part of the side canyon and the beautiful clouds:

We made it back to the car just before needing flashlights or heavy winter coats.

List of species in bloom:

#Pls in bloom   Name

99    Abronia villosa var. villosa
99    Allionia incarnata var. incarnata
99    Chamaesyce polycarpa
99    Chamaesyce setiloba
99    Chylismia claviformis ssp. peirsonii
99    Cryptantha angustifolia
99    Hyptis emoryi
99    Parietaria hespera var. hespera
99    Perityle emoryi

50    Cryptantha micrantha var. micrantha
50    Phacelia distans

40    Ditaxis lanceolata
40    Mimulus bigelovii var. bigelovii

30    Physalis crassifolia

20    Brassica tournefortii
20    Chamaesyce arizonica
20    Eschscholzia minutiflora ssp. minutiflora
20    Justicia californica

15    Malacothrix glabrata

10    Aristida adscensionis
10    Camissoniopsis pallida ssp. pallida

5    Bebbia juncea var. aspera
5    Cryptantha maritima
5    Datura discolor
5    Fagonia laevis
5    Logfia depressa
5    Mirabilis laevis var. retrorsa

3    Erodium cicutarium

2    Adenophyllum porophylloides
2    Ambrosia salsola var. salsola
2    Chaenactis fremontii
2    Eriogonum wrightii var. nodosum
2    Eulobus californicus
2    Pectis papposa var. papposa
2    Pectocarya recurvata
2    Stephanomeria pauciflora
2    Trichoptilium incisum
2    Trixis californica var. californica

1    Amaranthus fimbriatus
1    Bahiopsis parishii
1    Boerhavia triquetra var. intermedia
1    Cryptantha barbigera var. barbigera
1    Emmenanthe penduliflora var. penduliflora
1    Encelia farinosa
1    Eriogonum fasciculatum var. polifolium
1    Eriogonum inflatum
1    Eschscholzia parishii
1    Euphorbia eriantha
1    Hibiscus denudatus
1    Opuntia basilaris var. basilaris
1    Sisymbrium irio

tom chester