Plant Guide to Waterfall Trail, Eaton Canyon, San Gabriel Mountains

Plant Guide to Waterfall Trail, Eaton Canyon, San Gabriel Mountains

This is a working list, about which we make no guarantees at all until we officially release it. Use at your own risk!

Introduction and Explanation of Plant Trail Guides
Introduction
Highlights of This Trail
Plant Communities and Floristics
Fieldwork Dates and Summary of List Changes With Time
The Plant Guide
Comments On Specific Species
Introduction

Directions to the trailhead:
From I-210 East: Take the Altadena Drive Exit, and go north on Altadena Drive.
From I-210 West: Take the San Gabriel Boulevard Exit (signed for Eaton Canyon Nature Center), continue past Sierra Madre to Altadena Drive, and turn right (north) on Altadena Drive.
Take Altadena Drive north about 2.5 miles to Crescent Drive and turn right. Turn right at the next block, Pinecrest Drive. The trailhead for the Mt. Wilson Toll Road is at the gate as Pinecrest Drive curves left. Take the Toll Road 0.16 miles to the end of the Bridge. Take the Eaton Canyon Park Main Road right to the streambed, then go right on the trail which will take you under the bridge.
Parking on Pinecrest Drive is limited to 2 hours on the weekdays and not at all on the weekends, thanks to the selfish neighbors there (see 26-1 Eaton Canyon Nature Center to Henninger Flats). So if you'll be there more than 2 hours, simply park one block away.
See also Eaton Canyon and Flora of Lower Eaton Canyon.
Highlights of This Trail

This trail is primarily riparian. You cross the stream many times, and never stray far from it.
Our list contains 70 taxa, of which 64 have so far been identified, in about 0.76 miles of trail. Of these 64 taxa, 15 (23%) are non-native. These numbers are all roughly average for trails at this elevation.
Compared to the rest of our trails, this trail is low in the number of native taxa. This quite likely could be due to the incompleteness of the guide. However, it could also be due to the high number of invasive non-native species here, especially eupatory, which has displaced many native species.
The botanical highlights of this trail are:

Plant Communities and Floristics

Number of Unique Taxa On This Trail

The following histogram gives the number of trails in our database that contain each taxon on this trail. We had 73 trails in our database when this histogram was made; 3 of those trails, including this one, are in Eaton Canyon. A number of "1" means the taxon has only been found on this trail among the trails in our database; numbers of "3" or smaller may indicate taxa found only in this area.
We have two additional trails about six miles to the west / northwest.

Number of Trails
Containing A Taxon Number Of Taxa
On This Trail % of Taxa
On This Trail
1 0 0%
2 3 5%
3 1 2%
4 3 5%
5 1 2%

1-5 8 13%
6-10 11 17%
11-15 11 17%
16-20 12 19%
21-25 6 9%
26-30 6 9%
31-35 5 8%
36-40 5 8%
Total Taxa 64 100%

We found 6 additional species not in the above table, since they have not been identified yet. The unidentified ones are marked with ? or sp in the id? column in the guide, and have no entries in the #all column.
The taxa that are unique, or almost unique, to this trail or area, out of our 73 trails on 29 January 2004, are:

#all Latin Name Common Name Distribution in Southern California / Distribution in Trail Guides
2 common beggar-ticks Bidens pilosa var. pilosa SW; also found on the Brown Mountain Fire Road ~six miles west.
2 golden currant Ribes aureum var. gracillimum SW; also found on the lower Arroyo Seco trail ~six miles west.
2 round-leaved boykinia Boykinia rotundifolia UNCOMMON; TR, PR; also found on the Sturtevant Trail ~six miles east.
3 Jerusalem oak Chenopodium botrys Most of CA; also found on the Mt. Wilson Toll Road Loop and a single plant on the Manzanita Trail.

This is the only trail on which we have seen Venus-hair fern, Adiantum capillus-veneris, but it is not reachable from the trail. One sees quite a lot of it at the waterfall, but it is out of reach. Free samples sometimes can be found floating in the water below the plants.
Fieldwork Dates and Summary of List Changes With Time

The following table gives the dates the trail was walked and taxa recorded. After each visit, the table gives the total number of taxa on the list and the breakdown of the taxa without positive identification. See Explanation of Plant Trail Guides to understand the symbols below.

Visit Date Visit # # taxa # "?" # "sp" # "~" # "ssp"
1/22/2004 1 70 3 3 6 1

The Plant Guide

Version for printing, without lines and other text on this page (4 pages)

Mile s # id? Common Name Latin Name #here #all
0.00 Begin guide in the bed of the wash, directly under the middle of the Toll Road Bridge, on the west (left) side of the stream, elevation 1200 feet.
0.00 l 1 mule fat Baccharis salicifolia 5 / 5 28
0.00 r 2 *smilo grass Piptatherum miliaceum 50 / 9 16
0.00 b 3 *common beggar-ticks Bidens pilosa var. pilosa 99 / 9 2
0.00 l 4 *redstem filaree Erodium cicutarium 10 / 2 32
0.00 r 5 *eupatory Ageratina adenophora 99 / 9 6
0.00 r 6 white alder Alnus rhombifolia 20 / 9 9
0.00 r 7 Hooker's evening-primrose Oenothera elata ssp. hirsutissima 20 / 5 4
0.00 r 8 mugwort Artemisia douglasiana 20 / 5 23
0.00 l 9 *greater periwinkle Vinca major 1 / 1 6
0.00 r 10 *shortpod mustard Hirschfeldia incana 20 / 9 38
0.00 r 11 *giant reed Arundo donax 20 / 3 7
0.00 r 12 arroyo willow Salix lasiolepis 4 / 2 26
0.00 b Check for a different willow.
0.00 l 13 narrowleaf bedstraw Galium angustifolium ssp. angustifolium 10 / 9 39
0.00 r 14 giant needlegrass Achnatherum coronatum 20 / 9 18
0.01 l 15 California-aster Lessingia filaginifolia var. filaginifolia 30 / 5 38
0.01 l 16 California buckwheat Eriogonum fasciculatum var. foliolosum 20 / 5 38
0.01 l 17 branching phacelia Phacelia ramosissima var. latifolia 30 / 9 23
0.01 l 18 long-stemmed buckwheat Eriogonum elongatum var. elongatum 5 / 2 17
0.01 l 19 California brickellbush Brickellia californica 10 / 5 23
0.01 l 20 ssp deerweed Lotus scoparius var. scoparius 10 / 9 19
0.01 l Old metal structure - support for a gatepost?
0.01 l (sweet alyssum, Lobularia maritima)
0.02 r 21 *tree tobacco Nicotiana glauca 10 / 9 15
0.02 l 22 coast live oak Quercus agrifolia var. agrifolia 10 / 9 31
0.03 l 23 *sow thistle Sonchus oleraceus 1 / 1 21
0.03 l Vandalized old building; cross stream to right side
0.04 r 24 canyon live oak Quercus chrysolepis 10 / 9 19
0.04 l (California blackberry, Rubus ursinus)
0.07 Trail turns left 90° and crosses stream to left side
0.09 l 25 short-leaved cliff-aster Malacothrix saxatilis var. tenuifolia 20 / 9 9
0.12 r 26 laurel sumac Malosma laurina 5 / 2 29
0.13 l 27 golden yarrow Eriophyllum confertiflorum var. confertiflorum 10 / 5 40
0.13 l 28 coffee fern Pellaea andromedifolia 5 / 2 17
0.13 l 29 common bedstraw Galium aparine 20 / 5 20
0.13 l (fountain grass, Pennisetum setaceum)
0.14 r (ladder brake, Pteris vittata)
0.14 (sugar bush, Rhus ovata)
0.15 l 30 California coffeeberry Rhamnus californica ssp. californica 2 / 2 12
0.15 l 31 chicory-leaved stephanomeria Stephanomeria cichoriacea 5 / 1 5
0.15 Cross stream to right side
0.16 r 32 California bay Umbellularia californica 2 / 1 9
0.17 r 33 bigleaf maple Acer macrophyllum 1 / 1 6
0.17 l (common fig, Ficus carica)
0.17 r 34 poison oak Toxicodendron diversilobum 10 / 3 29
0.17 l 35 *common chickweed Stellaria media 99 / 9 16
0.18 r 36 *horehound Marrubium vulgare 1 / 1 20
0.19 r 37 ? small-flowered melica? Melica imperfecta? 10 / 3
0.20 l 38 ? unk thistle ? 3 / 3
0.20 l 39 horseweed Conyza canadensis 5 / 1 24
0.21 Cross stream to left side
0.22 l 40 *Spanish broom Spartium junceum 1 / 1 7
0.24 l 41 ~ wild sweetpea Lathyrus vestitus var. vestitus 1 / 1 7
0.26 r 42 white nightshade Solanum douglasii 5 / 5 12
0.26 l Jct. high alternate path.
0.27 l 43 southern miner's lettuce Claytonia perfoliata ssp. mexicana 20 / 3 14
0.27 l 44 golden currant Ribes aureum var. gracillimum 1 / 1 2
0.28 l 45 white everlasting Gnaphalium canescens ssp. microcephalum 5 / 5 30
0.28 l 46 bush monkeyflower Mimulus aurantiacus 2 / 2 31
0.29 r Jct. short trail to right side of stream; continue straight.
0.29 l 47 black sage Salvia mellifera 1 / 1 29
0.31 l Jct. other end of high alternate path.
0.31 r 48 birch-leaf mountain-mahogany Cercocarpus betuloides var. betuloides 1 / 1 14
0.33 l 49 California blackberry Rubus ursinus 5 / 1 12
0.33 Cross stream to right side
0.37 r 50 ~ eucrypta Eucrypta chrysanthemifolia var. chrysanthemifolia 10 / 1 15
0.38 l Jct. path
0.39 r 51 lemonade berry Rhus integrifolia 1 / 1 11
0.39 r 52 California lace fern Aspidotis californica 3 / 1 4
0.40 r 53 hillside gooseberry Ribes californicum var. hesperium 1 / 1 4
0.41 l 54 *Jerusalem oak Chenopodium botrys 10 / 1 3
0.42 r Large entranched side canyon.
0.46 r 55 sp Canterbury bells? Phacelia minor? 10 / 1
0.46 r 56 California suncup Camissonia californica 10 / 1 13
0.46 r 57 *red brome Bromus madritensis ssp. rubens 10 / 1 35
0.46 r 58 chia Salvia columbariae 10 / 1 17
0.46 r 59 sp popcorn flower Cryptantha sp. 3 / 1
0.46 r Check for a different annual phacelia.
0.46 r 60 *windmill pink Silene gallica 10 / 1 21
0.47 r 61 collar lupine Lupinus truncatus 3 / 1 16
0.47 r 62 threadstem Pterostegia drymarioides 1 / 1 14
0.48 r 63 sp bittercress Cardamine sp. 3 / 1
0.51 Cross stream to left side
0.52 Y-jct; go left, up.
0.53 r 64 creek senecio Senecio flaccidus var. douglasii 1 / 1 9
0.53 l 65 ~ Vasey's prickly pear Opuntia Xvaseyi 1 / 1 15
0.54 b 66 chaparral yucca Yucca whipplei 3 / 1 20
0.55 l 67 ~ hollyleaf redberry Rhamnus ilicifolia 1 / 1 31
0.59 Y-jct; stay left (right branch crosses the stream)
0.60 Cross stream to right side
0.62 Cross stream to left side
0.67 r 68 ? smooth cat's ear? Hypochaeris glabra? 10 / 1
0.67 r 69 ~ arched elegant rock-cress Arabis sparsiflora var. arcuata 5 / 3 6
0.70 Cross stream to right side
0.73 Cross stream to left side
0.76 r 70 ~ round-leaved boykinia Boykinia rotundifolia 2 / 1 2
0.76 r (Venus-hair fern, Adiantum capillus-veneris)
0.76 End guide at waterfall, elevation ~1340 feet.

Comments On Specific Species

Hordeum murinum. These are perfect ssp. leporinum in Munz, with 4.7 spikelets per cm of rachis, male lateral spikelets, and an inflorescence that is partially sheathed. However, they key to ssp. glaucum in JM, with the central floret slightly < lateral florets and the anthers of lateral florets ~2x anthers of central floret! The central lemma awn is slightly longer than the lateral lemma awns, not shorter, per the JM description.
Hence we have chosen to not give a subspecies here, and will accumulate further data from other locations to see how common this situation is.
Lotus scoparius var. brevialatus. The subspecies was determined from plants later on the trail; thus it is possible that this specimen is var. scoparius, since both varieties are found in the vicinity.
Dichelostemma capitatum ssp. capitatum. Only leaves were seen at this location, hence the ~ in the id? column. This taxon was found later on the trail.
Cupressus sp., Pinus sp., Quercus lobata, Robinia pseudoacacia, and Casuarina equisetifolia. The Sierra Club hikers who use this trail, in a well-intentioned by uninformed action, planted these species along the south side of the trail to eventually provide shade for hikers and bikers along this very unshaded route.

Number of Trails Containing A Taxon	Number Of Taxa On This Trail	% of Taxa On This Trail
1	0	0%
2	3	5%
3	1	2%
4	3	5%
5	1	2%

1-5	8	13%
6-10	11	17%
11-15	11	17%
16-20	12	19%
21-25	6	9%
26-30	6	9%
31-35	5	8%
36-40	5	8%
Total Taxa	64	100%

#all	Latin Name	Common Name	Distribution in Southern California / Distribution in Trail Guides
2	common beggar-ticks	Bidens pilosa var. pilosa	SW; also found on the Brown Mountain Fire Road ~six miles west.
2	golden currant	Ribes aureum var. gracillimum	SW; also found on the lower Arroyo Seco trail ~six miles west.
2	round-leaved boykinia	Boykinia rotundifolia	UNCOMMON; TR, PR; also found on the Sturtevant Trail ~six miles east.
3	Jerusalem oak	Chenopodium botrys	Most of CA; also found on the Mt. Wilson Toll Road Loop and a single plant on the Manzanita Trail.

Visit Date	Visit #	# taxa	# "?"	# "sp"	# "~"	# "ssp"
1/22/2004	1	70	3	3	6	1

Mile	s	#	id?	Common Name	Latin Name	#here	#all
0.00				Begin guide in the bed of the wash, directly under the middle of the Toll Road Bridge, on the west (left) side of the stream, elevation 1200 feet.
0.00	l	1		mule fat	Baccharis salicifolia	5 / 5	28
0.00	r	2		*smilo grass	Piptatherum miliaceum	50 / 9	16
0.00	b	3		*common beggar-ticks	Bidens pilosa var. pilosa	99 / 9	2
0.00	l	4		*redstem filaree	Erodium cicutarium	10 / 2	32
0.00	r	5		*eupatory	Ageratina adenophora	99 / 9	6
0.00	r	6		white alder	Alnus rhombifolia	20 / 9	9
0.00	r	7		Hooker's evening-primrose	Oenothera elata ssp. hirsutissima	20 / 5	4
0.00	r	8		mugwort	Artemisia douglasiana	20 / 5	23
0.00	l	9		*greater periwinkle	Vinca major	1 / 1	6
0.00	r	10		*shortpod mustard	Hirschfeldia incana	20 / 9	38
0.00	r	11		*giant reed	Arundo donax	20 / 3	7
0.00	r	12		arroyo willow	Salix lasiolepis	4 / 2	26
0.00	b			Check for a different willow.
0.00	l	13		narrowleaf bedstraw	Galium angustifolium ssp. angustifolium	10 / 9	39
0.00	r	14		giant needlegrass	Achnatherum coronatum	20 / 9	18
0.01	l	15		California-aster	Lessingia filaginifolia var. filaginifolia	30 / 5	38
0.01	l	16		California buckwheat	Eriogonum fasciculatum var. foliolosum	20 / 5	38
0.01	l	17		branching phacelia	Phacelia ramosissima var. latifolia	30 / 9	23
0.01	l	18		long-stemmed buckwheat	Eriogonum elongatum var. elongatum	5 / 2	17
0.01	l	19		California brickellbush	Brickellia californica	10 / 5	23
0.01	l	20	ssp	deerweed	Lotus scoparius var. scoparius	10 / 9	19
0.01	l			Old metal structure - support for a gatepost?
0.01	l			(sweet alyssum, Lobularia maritima)
0.02	r	21		*tree tobacco	Nicotiana glauca	10 / 9	15
0.02	l	22		coast live oak	Quercus agrifolia var. agrifolia	10 / 9	31
0.03	l	23		*sow thistle	Sonchus oleraceus	1 / 1	21
0.03	l			Vandalized old building; cross stream to right side
0.04	r	24		canyon live oak	Quercus chrysolepis	10 / 9	19
0.04	l			(California blackberry, Rubus ursinus)
0.07				Trail turns left 90° and crosses stream to left side
0.09	l	25		short-leaved cliff-aster	Malacothrix saxatilis var. tenuifolia	20 / 9	9
0.12	r	26		laurel sumac	Malosma laurina	5 / 2	29
0.13	l	27		golden yarrow	Eriophyllum confertiflorum var. confertiflorum	10 / 5	40
0.13	l	28		coffee fern	Pellaea andromedifolia	5 / 2	17
0.13	l	29		common bedstraw	Galium aparine	20 / 5	20
0.13	l			(fountain grass, Pennisetum setaceum)
0.14	r			(ladder brake, Pteris vittata)
0.14				(sugar bush, Rhus ovata)
0.15	l	30		California coffeeberry	Rhamnus californica ssp. californica	2 / 2	12
0.15	l	31		chicory-leaved stephanomeria	Stephanomeria cichoriacea	5 / 1	5
0.15				Cross stream to right side
0.16	r	32		California bay	Umbellularia californica	2 / 1	9
0.17	r	33		bigleaf maple	Acer macrophyllum	1 / 1	6
0.17	l			(common fig, Ficus carica)
0.17	r	34		poison oak	Toxicodendron diversilobum	10 / 3	29
0.17	l	35		*common chickweed	Stellaria media	99 / 9	16
0.18	r	36		*horehound	Marrubium vulgare	1 / 1	20
0.19	r	37	?	small-flowered melica?	Melica imperfecta?	10 / 3
0.20	l	38	?	unk thistle	?	3 / 3
0.20	l	39		horseweed	Conyza canadensis	5 / 1	24
0.21				Cross stream to left side
0.22	l	40		*Spanish broom	Spartium junceum	1 / 1	7
0.24	l	41	~	wild sweetpea	Lathyrus vestitus var. vestitus	1 / 1	7
0.26	r	42		white nightshade	Solanum douglasii	5 / 5	12
0.26	l			Jct. high alternate path.
0.27	l	43		southern miner's lettuce	Claytonia perfoliata ssp. mexicana	20 / 3	14
0.27	l	44		golden currant	Ribes aureum var. gracillimum	1 / 1	2
0.28	l	45		white everlasting	Gnaphalium canescens ssp. microcephalum	5 / 5	30
0.28	l	46		bush monkeyflower	Mimulus aurantiacus	2 / 2	31
0.29	r			Jct. short trail to right side of stream; continue straight.
0.29	l	47		black sage	Salvia mellifera	1 / 1	29
0.31	l			Jct. other end of high alternate path.
0.31	r	48		birch-leaf mountain-mahogany	Cercocarpus betuloides var. betuloides	1 / 1	14
0.33	l	49		California blackberry	Rubus ursinus	5 / 1	12
0.33				Cross stream to right side
0.37	r	50	~	eucrypta	Eucrypta chrysanthemifolia var. chrysanthemifolia	10 / 1	15
0.38	l			Jct. path
0.39	r	51		lemonade berry	Rhus integrifolia	1 / 1	11
0.39	r	52		California lace fern	Aspidotis californica	3 / 1	4
0.40	r	53		hillside gooseberry	Ribes californicum var. hesperium	1 / 1	4
0.41	l	54		*Jerusalem oak	Chenopodium botrys	10 / 1	3
0.42	r			Large entranched side canyon.
0.46	r	55	sp	Canterbury bells?	Phacelia minor?	10 / 1
0.46	r	56		California suncup	Camissonia californica	10 / 1	13
0.46	r	57		*red brome	Bromus madritensis ssp. rubens	10 / 1	35
0.46	r	58		chia	Salvia columbariae	10 / 1	17
0.46	r	59	sp	popcorn flower	Cryptantha sp.	3 / 1
0.46	r			Check for a different annual phacelia.
0.46	r	60		*windmill pink	Silene gallica	10 / 1	21
0.47	r	61		collar lupine	Lupinus truncatus	3 / 1	16
0.47	r	62		threadstem	Pterostegia drymarioides	1 / 1	14
0.48	r	63	sp	bittercress	Cardamine sp.	3 / 1
0.51				Cross stream to left side
0.52				Y-jct; go left, up.
0.53	r	64		creek senecio	Senecio flaccidus var. douglasii	1 / 1	9
0.53	l	65	~	Vasey's prickly pear	Opuntia Xvaseyi	1 / 1	15
0.54	b	66		chaparral yucca	Yucca whipplei	3 / 1	20
0.55	l	67	~	hollyleaf redberry	Rhamnus ilicifolia	1 / 1	31
0.59				Y-jct; stay left (right branch crosses the stream)
0.60				Cross stream to right side
0.62				Cross stream to left side
0.67	r	68	?	smooth cat's ear?	Hypochaeris glabra?	10 / 1
0.67	r	69	~	arched elegant rock-cress	Arabis sparsiflora var. arcuata	5 / 3	6
0.70				Cross stream to right side
0.73				Cross stream to left side
0.76	r	70	~	round-leaved boykinia	Boykinia rotundifolia	2 / 1	2
0.76	r			(Venus-hair fern, Adiantum capillus-veneris)
0.76				End guide at waterfall, elevation ~1340 feet.

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Flora of Lower Eaton Canyon
Plants of Southern California: Trail Guides

Copyright © 2003-2004 by Jane Strong and Tom Chester.
Permission is freely granted to reproduce any or all of this page as long as credit is given to us at this source:
http://tchester.org/sgm/plants/guides/mw_toll_road_loop.html
Comments and feedback: Jane Strong | Tom Chester
Updated 11 May 2004.