Plant Guide to Colby Trail, Glendora, San Gabriel Mountains

Plant Guide to Colby Trail, Glendora, 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 SR57 North: Take the Auto Centre Drive exit, just before SR57 turns into the I-210. Then left to Lone Hill Avenue, left on US66 (Alosta Avenue) to Loraine Avenue, then right on Loraine to its northern end.
From I-210 East: Take the Grand Avenue exit. Turn left and head north to Sierra Madre Avenue, then right to Loraine Avenue. Turn left on Loraine to its northern end.
There is parking for ~five cars on the cul-de-sac at the end of Loraine, but the street is signed no parking below the cul-de-sac at its end.
Thomas Brothers L.A. County map 569, G3.
Highlights of This Trail

This trail is riparian in its lower stretch, with specimens of some species much larger than normal. It contains a vernally moist area, possibly with a vernal pool in wet years, as well as a flattish area with native grasslands that includes the ENDANGERED Brodiaea filifolia. The Jepson Manual says that this species is extirpated from Los Angeles County, but this area is proof that at least a small pocket of these plants survives here.
The upper portion of the trail is fairly typical low elevation San Gabriel Mountains chaparral, but there are patches of volcanic rock, very unusual in the foothills of the San Gabriel Mountains. These Glendora Volcanics are of middle Miocene age (~13 million years ago), roughly the time when the San Andreas Fault first became active. The volcanic rocks are composed of andesitic flows, flow-breccias, tuff-breccias and tuffs (mapped by Shelton, 1955, Geol. Soc. American Bull. 66: 45-90). It probably isn't an accident that these volcanic rocks were deposited along the fault at the foot of the San Gabriel Mountains here, since that was the ancestral San Andreas Fault before it jumped to the northern base of the mountains. (Source: Geology and Mineral Wealth of the California Transverse Ranges, South Coast Geological Society, 1982.)
It is interesting that the only two locations we have found Brodiaea filifolia on our 74 trail lists so far both have similar volcanic rock of roughly the same age. (The other location is the Vernal Pool Trail on the basalt of the Santa Rosa Plateau Ecological Reserve.)
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 74 trails in our database when this histogram was made. This is the only trail in Glendora, but we have a number of trails along the south edge of the San Gabriel Mountains. A number of "1" means the taxon has only been found on this trail among the trails in our database.

Number of Trails
Containing A Taxon Number Of Taxa
On This Trail % of Taxa
On This Trail
1 1 1%
2 6 6%
3 5 5%
4 4 4%
5 2 2%

1-5 18 18%
6-10 16 16%
11-15 21 21%
16-20 8 8%
21-25 12 12%
26-30 6 6%
31-35 10 10%
36-40 8 8%
41-45 2 2%
Total Taxa 101 100%

We found one additional species not in the above table, since it has not been identified yet, the Cuscuta sp. below, marked with sp in the id? column in the guide, and without an entry in the #all column.
The taxa that are unique, or almost unique, to this trail or area, out of our 74 trails on 11 May 2004, are:

TBS

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"
4/22/2004 1 102 0 3 4 2

We thank Bob Muns, and two other people for their help with the fieldwork on 4/22/04. We thank one of those people with pointing out the interesting volcanics on this trail!
In addition, Michael Charters found the Phacelia minor and Brassica rapa on 2/23/05.
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 trail at the northern end of Loraine Avenue in Glendora.
0.00 c 1 *white goosefoot Chenopodium album / 13
0.00 b 2 *foxtail barley Hordeum murinum ssp. glaucum / 7
0.00 l 3 *ripgut brome Bromus diandrus / 37
0.00 l 4 common bedstraw Galium aparine / 23
0.00 r 5 *horehound Marrubium vulgare / 21
0.00 r 6 *prickly lettuce Lactuca serriola / 23
0.00 r 7 ~ *knotweed Polygonum arenastrum / 9
0.00 r 8 *Bermuda grass Cynodon dactylon / 18
0.00 l (chaparral yucca, Yucca whipplei)
0.00 l 9 ~ Engelmann leather oak hybrid Quercus engelmannii X Q. durata var. gabrielensis / 3
0.00 l 10 Vasey's prickly-pear Opuntia vaseyi / 17
0.00 l 11 *Russian thistle Salsola tragus / 23
0.00 l 12 coast live oak Quercus agrifolia var. agrifolia / 32
0.00 l 13 *cheeseweed Malva parviflora / 13
0.00 c 14 *redstem filaree Erodium cicutarium / 39
0.00 r 15 *wild oats Avena fatua / 15
0.00 r 16 *sow thistle Sonchus oleraceus / 24
0.01 l Kiosk and shaded benches
0.01 r 17 *Bermuda buttercup Oxalis pes-caprae / 6
r 18 *smilo grass Piptatherum miliaceum / 17
r 19 laurel sumac Malosma laurina / 30
l Signpost: "Poison oak [territory?]"
l 20 branching phacelia Phacelia ramosissima var. latifolia / 26
l 21 white nightshade Solanum douglasii / 14
l 22 poison oak Toxicodendron diversilobum / 32
l 23 blue elderberry Sambucus mexicana / 36
l 24 south coast morning-glory Calystegia macrostegia ssp. intermedia / 14
r 25 sacred datura Datura wrightii / 14
l 26 wild-cucumber Marah macrocarpus var. macrocarpus / 36
r 27 western sycamore Platanus racemosa / 18
r 28 *petty spurge Euphorbia peplus / 8
0.04 r 29 Southern California black walnut Juglans californica var. californica / 4
l 30 small-flowered melica Melica imperfecta / 30
l 31 heartleaf penstemon Keckiella cordifolia / 20
l 32 toyon Heteromeles arbutifolia / 36
r 33 ~ *Mexican Fan Palm Washingtonia robusta⁺ / 2
r (passion flower, Passiflora caerulea)
l 34 virgin's bower Clematis ligusticifolia⁺ / 6
0.08 l 35 *hedge mustard Sisymbrium officinale / 13
l 36 California brickellbush Brickellia californica / 24
r 37 *Italian thistle Carduus pycnocephalus / 11
l 38 *California burclover Medicago polymorpha / 27
l 39 *bur chervil Anthriscus caucalis / 7
r 40 *passion flower Passiflora caerulea / 1
r 41 pellitory Parietaria hespera var. hespera / 4
r 42 hillside gooseberry Ribes californicum var. hesperium / 5
l 43 sp 3 needle pine Pinus sp. /
l 44 southern honeysuckle Lonicera subspicata var. denudata / 31
l 45 basketbush Rhus trilobata / 15
r 46 California everlasting Gnaphalium californicum / 27
l 47 *tocalote Centaurea melitensis / 33
l 48 *scarlet pimpernel Anagallis arvensis / 17
l 49 *shortpod mustard Hirschfeldia incana / 39
l Troop 486 Eagle Scout Project for erosion control.
l 50 *milk thistle Silybum marianum / 9
l 51 white sage Salvia apiana⁺ / 29
l 52 California fuchsia Epilobium canum ssp. canum⁺ / 12
l 53 ssp California buckwheat Eriogonum fasciculatum var. foliolosum⁺ / 39
l 54 *slender wild oats Avena barbata / 24
l (small-seeded spurge, Chamaesyce polycarpa)
l 55 California sagebrush Artemisia californica / 33
l 56 white everlasting Gnaphalium canescens ssp. microcephalum / 31
l 57 long-stemmed buckwheat Eriogonum elongatum var. elongatum / 18
l (short-leaved cliff-aster, Malacothrix saxatilis var. tenuifolia)
l 58 California four o'clock Mirabilis californica / 15
l 59 chaparral yucca Yucca whipplei / 22
0.14 l 60 *purple false-brome Brachypodium distachyon / 4
l 61 bush monkeyflower Mimulus aurantiacus / 32
l 62 sp dodder Cuscuta sp. / 2
l 63 narrowleaf bedstraw Galium angustifolium ssp. angustifolium / 41
r 64 hollyleaf redberry Rhamnus ilicifolia / 32
0.16 l 65 deerweed Lotus scoparius var. scoparius⁺ / 21
l 66 golden yarrow Eriophyllum confertiflorum var. confertiflorum / 43
l 67 long-leaf bush lupine Lupinus longifolius / 3
r 68 wild sweetpea Lathyrus vestitus var. vestitus / 8
r 69 San Gabriel Mtns. leather oak Quercus durata var. gabrielensis / 4
0.18 l 70 short-leaved cliff-aster Malacothrix saxatilis var. tenuifolia / 10
0.20 r Jct. road; sign: "[left] To gate 1.0 mile; [right] To berm 0.4 mile"; continue straight
0.22 l Jct. path; go left on it.
0.23 r 71 annual sunflower Helianthus annuus / 9
0.23 r 72 sp *wand mullein Verbascum virgatum / 3
0.23 r 73 *curly dock Rumex crispus / 14
0.23 r 74 purple needlegrass Nassella pulchra / 10
0.24 Trail is immediately to left of gate with fence only to the right of the gate.
0.24 l 75 thread-leaved brodiaea Brodiaea filifolia / 2
0.24 l 76 *prickly sow thistle Sonchus asper ssp. asper / 15
0.24 r 77 *field bindweed Convolvulus arvensis / 2
0.26 l 78 *white-stemmed filaree Erodium moschatum / 12
0.26 r (fountain grass, Pennisetum setaceum)
0.27 79 *red brome Bromus madritensis ssp. rubens / 39
0.27 Turn-around, but then head to the east off-trail for more Brodiaea and the lemonade berry.
0.31 80 lemonade berry Rhus integrifolia⁺ / 12
0.34 Back on the main road; go right, back down trail.
0.36 Back at the jct. with the road to the berm; go left and take it.
0.39 l 81 *purple wild radish Raphanus sativus / 10
0.40 r (California buckeye, Aesculus californica)
0.41 82 California black oak Quercus kelloggii / 11
0.44 Road goes up short steep hill.
0.47 b 83 *castor bean Ricinus communis / 13
0.47 l (wall bedstraw, Galium parisiense)
0.48 Road ends at the top of the hill and the berm; return to the road junction.
0.60 Back at the road jct; go right, uphill.
0.62 l 84 *goldentop Lamarckia aurea / 12
0.66 Trail curves right 90°
0.67 l 85 *tree tobacco Nicotiana glauca / 17
0.69 r 86 *Peruvian pepper tree Schinus molle / 5
0.71 87 caterpillar phacelia Phacelia cicutaria var. hispida / 9
0.75 88 California buckwheat Eriogonum fasciculatum var. polifolium / 12
0.76 l 89 nodding needlegrass Nassella cernua / 8
l (giant wild-rye, Leymus condensatus)
0.81 r 90 *common beggar-ticks Bidens pilosa var. pilosa / 3
0.82 l lemonade berry Rhus integrifolia⁺ /
0.82 r 91 mugwort Artemisia douglasiana / 24
0.83 r 92 telegraph weed Heterotheca grandiflora / 23
0.86 l (chamise, Adenostoma fasciculatum)
0.87 l A yellow bush monkeyflower, Mimulus aurantiacus, immediately next to a red bush monkeyflower. Maybe this is why the Jepson Manual combined the two formerly-separate species into one!
0.89 r Jct. path (with more Brodiaea?); Trail turns left 90° and steepens.
0.90 r 93 black sage Salvia mellifera / 32
0.90 l 94 ssp *rattail fescue Vulpia myuros / 6
0.96 Trail curves right 90°
0.96 r 95 gray sage Salvia apiana X S. mellifera / 3
0.97 r (coffee fern, Pellaea andromedifolia)
0.97 r 96 blue dicks Dichelostemma capitatum ssp. capitatum / 31
0.98 r (California peony, Paeonia californica)
0.99 l 97 purple clarkia Clarkia purpurea ssp. quadrivulnera / 13
0.99 r (creek senecio, Senecio flaccidus var. douglasii)
1.00 r (lanceleaf dudleya, Dudleya lanceolata)
1.02 r (bicolored everlasting, Gnaphalium bicolor)
1.03 r 98 rattlesnake weed Chamaesyce albomarginata / 2
1.04 b 99 *winter vetch Vicia villosa ssp. varia / 11
1.04 b 100 *smooth cat's ear Hypochaeris glabra / 22
1.05 l 101 ~ bristly goldenaster Heterotheca sessiliflora ssp. echioides / 6
1.06 l 102 *alfalfa Medicago sativa / 2
1.08 Jct. Glendora Mountain Road; end guide.

Comments On Specific Species

Washingtonia robusta. Location not precise.
Clematis ligusticifolia. The identification was from blooming plants located just off-trail a short distance farther along the trail.
Salvia apiana, Epilobium canum ssp. canum, Eriogonum fasciculatum var. foliolosum. The first three specimens on the trail were planted by the Boy Scouts, but each species is found naturally a short distance up the trail.
Lotus scoparius var. scoparius. The identification of the subspecies was from plants blooming near the Brodiaea filifolia.
Rhus integrifolia. The first noted specimen is off-trail near the other plants of Brodiaea filifolia; the first specimen along the trail is also noted, but not numbered.

Number of Trails Containing A Taxon	Number Of Taxa On This Trail	% of Taxa On This Trail
1	1	1%
2	6	6%
3	5	5%
4	4	4%
5	2	2%

1-5	18	18%
6-10	16	16%
11-15	21	21%
16-20	8	8%
21-25	12	12%
26-30	6	6%
31-35	10	10%
36-40	8	8%
41-45	2	2%
Total Taxa	101	100%

Visit Date	Visit #	# taxa	# "?"	# "sp"	# "~"	# "ssp"
4/22/2004	1	102	0	3	4	2

Mile	s	#	id?	Common Name	Latin Name	#here	#all
0.00				Begin trail at the northern end of Loraine Avenue in Glendora.
0.00	c	1		*white goosefoot	Chenopodium album	/	13
0.00	b	2		*foxtail barley	Hordeum murinum ssp. glaucum	/	7
0.00	l	3		*ripgut brome	Bromus diandrus	/	37
0.00	l	4		common bedstraw	Galium aparine	/	23
0.00	r	5		*horehound	Marrubium vulgare	/	21
0.00	r	6		*prickly lettuce	Lactuca serriola	/	23
0.00	r	7	~	*knotweed	Polygonum arenastrum	/	9
0.00	r	8		*Bermuda grass	Cynodon dactylon	/	18
0.00	l			(chaparral yucca, Yucca whipplei)
0.00	l	9	~	Engelmann leather oak hybrid	Quercus engelmannii X Q. durata var. gabrielensis	/	3
0.00	l	10		Vasey's prickly-pear	Opuntia vaseyi	/	17
0.00	l	11		*Russian thistle	Salsola tragus	/	23
0.00	l	12		coast live oak	Quercus agrifolia var. agrifolia	/	32
0.00	l	13		*cheeseweed	Malva parviflora	/	13
0.00	c	14		*redstem filaree	Erodium cicutarium	/	39
0.00	r	15		*wild oats	Avena fatua	/	15
0.00	r	16		*sow thistle	Sonchus oleraceus	/	24
0.01	l			Kiosk and shaded benches
0.01	r	17		*Bermuda buttercup	Oxalis pes-caprae	/	6
	r	18		*smilo grass	Piptatherum miliaceum	/	17
	r	19		laurel sumac	Malosma laurina	/	30
	l			Signpost: "Poison oak [territory?]"
	l	20		branching phacelia	Phacelia ramosissima var. latifolia	/	26
	l	21		white nightshade	Solanum douglasii	/	14
	l	22		poison oak	Toxicodendron diversilobum	/	32
	l	23		blue elderberry	Sambucus mexicana	/	36
	l	24		south coast morning-glory	Calystegia macrostegia ssp. intermedia	/	14
	r	25		sacred datura	Datura wrightii	/	14
	l	26		wild-cucumber	Marah macrocarpus var. macrocarpus	/	36
	r	27		western sycamore	Platanus racemosa	/	18
	r	28		*petty spurge	Euphorbia peplus	/	8
0.04	r	29		Southern California black walnut	Juglans californica var. californica	/	4
	l	30		small-flowered melica	Melica imperfecta	/	30
	l	31		heartleaf penstemon	Keckiella cordifolia	/	20
	l	32		toyon	Heteromeles arbutifolia	/	36
	r	33	~	*Mexican Fan Palm	Washingtonia robusta⁺	/	2
	r			(passion flower, Passiflora caerulea)
	l	34		virgin's bower	Clematis ligusticifolia⁺	/	6
0.08	l	35		*hedge mustard	Sisymbrium officinale	/	13
	l	36		California brickellbush	Brickellia californica	/	24
	r	37		*Italian thistle	Carduus pycnocephalus	/	11
	l	38		*California burclover	Medicago polymorpha	/	27
	l	39		*bur chervil	Anthriscus caucalis	/	7
	r	40		*passion flower	Passiflora caerulea	/	1
	r	41		pellitory	Parietaria hespera var. hespera	/	4
	r	42		hillside gooseberry	Ribes californicum var. hesperium	/	5
	l	43	sp	3 needle pine	Pinus sp.	/
	l	44		southern honeysuckle	Lonicera subspicata var. denudata	/	31
	l	45		basketbush	Rhus trilobata	/	15
	r	46		California everlasting	Gnaphalium californicum	/	27
	l	47		*tocalote	Centaurea melitensis	/	33
	l	48		*scarlet pimpernel	Anagallis arvensis	/	17
	l	49		*shortpod mustard	Hirschfeldia incana	/	39
	l			Troop 486 Eagle Scout Project for erosion control.
	l	50		*milk thistle	Silybum marianum	/	9
	l	51		white sage	Salvia apiana⁺	/	29
	l	52		California fuchsia	Epilobium canum ssp. canum⁺	/	12
	l	53	ssp	California buckwheat	Eriogonum fasciculatum var. foliolosum⁺	/	39
	l	54		*slender wild oats	Avena barbata	/	24
	l			(small-seeded spurge, Chamaesyce polycarpa)
	l	55		California sagebrush	Artemisia californica	/	33
	l	56		white everlasting	Gnaphalium canescens ssp. microcephalum	/	31
	l	57		long-stemmed buckwheat	Eriogonum elongatum var. elongatum	/	18
	l			(short-leaved cliff-aster, Malacothrix saxatilis var. tenuifolia)
	l	58		California four o'clock	Mirabilis californica	/	15
	l	59		chaparral yucca	Yucca whipplei	/	22
0.14	l	60		*purple false-brome	Brachypodium distachyon	/	4
	l	61		bush monkeyflower	Mimulus aurantiacus	/	32
	l	62	sp	dodder	Cuscuta sp.	/	2
	l	63		narrowleaf bedstraw	Galium angustifolium ssp. angustifolium	/	41
	r	64		hollyleaf redberry	Rhamnus ilicifolia	/	32
0.16	l	65		deerweed	Lotus scoparius var. scoparius⁺	/	21
	l	66		golden yarrow	Eriophyllum confertiflorum var. confertiflorum	/	43
	l	67		long-leaf bush lupine	Lupinus longifolius	/	3
	r	68		wild sweetpea	Lathyrus vestitus var. vestitus	/	8
	r	69		San Gabriel Mtns. leather oak	Quercus durata var. gabrielensis	/	4
0.18	l	70		short-leaved cliff-aster	Malacothrix saxatilis var. tenuifolia	/	10
0.20	r			Jct. road; sign: "[left] To gate 1.0 mile; [right] To berm 0.4 mile"; continue straight
0.22	l			Jct. path; go left on it.
0.23	r	71		annual sunflower	Helianthus annuus	/	9
0.23	r	72	sp	*wand mullein	Verbascum virgatum	/	3
0.23	r	73		*curly dock	Rumex crispus	/	14
0.23	r	74		purple needlegrass	Nassella pulchra	/	10
0.24				Trail is immediately to left of gate with fence only to the right of the gate.
0.24	l	75		thread-leaved brodiaea	Brodiaea filifolia	/	2
0.24	l	76		*prickly sow thistle	Sonchus asper ssp. asper	/	15
0.24	r	77		*field bindweed	Convolvulus arvensis	/	2
0.26	l	78		*white-stemmed filaree	Erodium moschatum	/	12
0.26	r			(fountain grass, Pennisetum setaceum)
0.27		79		*red brome	Bromus madritensis ssp. rubens	/	39
0.27				Turn-around, but then head to the east off-trail for more Brodiaea and the lemonade berry.
0.31		80		lemonade berry	Rhus integrifolia⁺	/	12
0.34				Back on the main road; go right, back down trail.
0.36				Back at the jct. with the road to the berm; go left and take it.
0.39	l	81		*purple wild radish	Raphanus sativus	/	10
0.40	r			(California buckeye, Aesculus californica)
0.41		82		California black oak	Quercus kelloggii	/	11
0.44				Road goes up short steep hill.
0.47	b	83		*castor bean	Ricinus communis	/	13
0.47	l			(wall bedstraw, Galium parisiense)
0.48				Road ends at the top of the hill and the berm; return to the road junction.
0.60				Back at the road jct; go right, uphill.
0.62	l	84		*goldentop	Lamarckia aurea	/	12
0.66				Trail curves right 90°
0.67	l	85		*tree tobacco	Nicotiana glauca	/	17
0.69	r	86		*Peruvian pepper tree	Schinus molle	/	5
0.71		87		caterpillar phacelia	Phacelia cicutaria var. hispida	/	9
0.75		88		California buckwheat	Eriogonum fasciculatum var. polifolium	/	12
0.76	l	89		nodding needlegrass	Nassella cernua	/	8
	l			(giant wild-rye, Leymus condensatus)
0.81	r	90		*common beggar-ticks	Bidens pilosa var. pilosa	/	3
0.82	l			lemonade berry	Rhus integrifolia⁺	/
0.82	r	91		mugwort	Artemisia douglasiana	/	24
0.83	r	92		telegraph weed	Heterotheca grandiflora	/	23
0.86	l			(chamise, Adenostoma fasciculatum)
0.87	l			A yellow bush monkeyflower, Mimulus aurantiacus, immediately next to a red bush monkeyflower. Maybe this is why the Jepson Manual combined the two formerly-separate species into one!
0.89	r			Jct. path (with more Brodiaea?); Trail turns left 90° and steepens.
0.90	r	93		black sage	Salvia mellifera	/	32
0.90	l	94	ssp	*rattail fescue	Vulpia myuros	/	6
0.96				Trail curves right 90°
0.96	r	95		gray sage	Salvia apiana X S. mellifera	/	3
0.97	r			(coffee fern, Pellaea andromedifolia)
0.97	r	96		blue dicks	Dichelostemma capitatum ssp. capitatum	/	31
0.98	r			(California peony, Paeonia californica)
0.99	l	97		purple clarkia	Clarkia purpurea ssp. quadrivulnera	/	13
0.99	r			(creek senecio, Senecio flaccidus var. douglasii)
1.00	r			(lanceleaf dudleya, Dudleya lanceolata)
1.02	r			(bicolored everlasting, Gnaphalium bicolor)
1.03	r	98		rattlesnake weed	Chamaesyce albomarginata	/	2
1.04	b	99		*winter vetch	Vicia villosa ssp. varia	/	11
1.04	b	100		*smooth cat's ear	Hypochaeris glabra	/	22
1.05	l	101	~	bristly goldenaster	Heterotheca sessiliflora ssp. echioides	/	6
1.06	l	102		*alfalfa	Medicago sativa	/	2
1.08				Jct. Glendora Mountain Road; end guide.

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Plants of Southern California: Trail Guides

Copyright © 2004 by Jane Strong and Tom Chester.
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Comments and feedback: Jane Strong | Tom Chester
Updated 24 February 2005.