Tom Schweich  

Introduction

There are many sources of information about plant names, their descriptions, and how to identify them. There are numerous published floras for the whole state of Colorado, Colorado east slope and west slope, and the Intermountain Region, not to mention the less-scholarly wildflower books. The various data bases will permit preparation of plant lists for a location, or a range of geographic coordinates, will also giving link to further web sites such as Flora of North America (FNANM) an Encyclopedia of Life. These are all excellent resources. I used them all myself in the preparation of this flora. Data base lists selected by geographic coordinates, and those selected by named localities, were used to provide an initial list of collections. The published floras of larger regions were used to check on names, descriptions, and distribution.

However, the editing process of reviewing collections, and reviewing the absence of collections, provides the benefits that come from preparing a local flora:

1. Apply local knowledge of geography to collections, their name determinations, and georeferencing. Living in a location can give a better understanding of local geography, and the location of historic reference points. This makes it easier to compare georeferencing to described collecting location.

2. Identify questionable collections or determinations. Some examples might be:
   1. A collection dated 1822 from Golden, although Golden was not named until 1859. This turned out to be an E. L. Greene collection from 1872.
   2. A collection to which two different names have been applied. For example, E. H. Brunquist's PM-123 is determined as Cirsium undulatum (Nutt.) Spreng at KHD, and C. ochrocentrum A. Gray at CS. The thing to do is to look at both vouchers and determine which name should be applied, or whether the collection was really a mixed collection.
   3. A little more subtle case occurs when there are many single collections a related taxa. For example, among Oenothera and Gaura (which is sometimes placed in Oenothera), there are nine taxa for which there is only one collection in Golden and vicinity, and the remaining four taxa collected here have only two collections each. It seems unusual that there would be so many single collections of a taxon, and perhaps some of them are misidentified.

3. Identify gaps in collections. Why hasn't an expected common species found in a certain area?

   For example, I found what I thought was Brickellia californica on North Table Mountain. Yet my data base searches yielded no records of collections. Searching again for all collections of B. californica in Jefferson and surrounding counties showed a single collection of the taxon by Loraine Yeatts on South Table Mountain. However, the collection had been georeferenced incorrectly and would not have appeared in a simple data base query. I have added that collection (and taxon name) to the local flora, and sent a comment to the herbarium about the incorrect coordinates.

4. Fill in gaps in collections, collect in under-collected areas, or of under-collected plants.

   For example, mapping the locations of collections that can be georeferenced showed that there are few collections from the lower slopes of Lookout Mountain and no collections from the small northern portion of Dinosaur Ridge near the Rooney Road Sports Complex. These areas may now be targeted for collecting.

5. Identify plants that may have been extirpated, or may be new arrivals.

   An example might be my collection 1109 of Balsamorhiza sagittata on Tin Cup Ridge. Usually this plant is described as being on the west slope only. How did it get here to the east slope? Generally, it is suggested that it was planted. But, was it intentionally planted in an out of the way place? Or planted by a bird? Or other animal?

6. Understand the history of botanic or floristic work in a local area. Who collected? Why?

In the case of unpublished volumes of FNANM, I generally reviewed multiple sources, starting with Ackerfield (2015), the Plant List (http://www.theplantlist.org/), USDA Plants, the Jepson Manual, Weber and Wittmann (2012), and Harrington (1954), and then picked a modern name in common usage.

However, over time, I began to follow Plants of the World (POWO, 2022) as it seemed to the most broad and up-to-date coverage. Plants of the World also connects to the historical literature through IPNI - International Plant Names Index and the Biodiversity Heritage Library.

Once a name is selected, different names given in Ackerfield (2015, 2022 2nd ed.), Weber and Wittmann (2012), or Harrington (1954), are listed as synonyms.

Geography

Golden City Limits

Within the City of Golden, there are a few parcels that are city-owned, and large enough to be collected. The Fossil Trace Golf Course occupies 216 ac. (87 ha.). It is not really a hotbed of biodiversity, but the elk like to hang out there in the winter. City-owned open space on the west and south slopes of North Table Mountain comprises 135 ac. (54 ha.). Eagle Ridge is the third largest parcel at 79 ac. (32 ha.) and the Grampsas Sport Complex contains 58 ac. (24 ha.). There is a small hilly parcel near the top of Washington Avenue of 4 ac. (1.6 ha.). This last parcel is perhaps the most interesting as it contains a relatively intact small (1.5 ac.) remnant mixed-grass prairie on the top of the hill.

Golden sensu latu (s.l.)

North Table Mountain

There are two commonly used social trails leading to North Table Mountain One is off Dunraven Circle in Table Rock. The other is at Easley Road and Colorado Highway 58.

The Dunraven Circle social trail is quite handy. Short, only 160 meters in length, it gives easy access to the North Table Loop, and then there is only another 245 meters to the Mesa Top Trail. It is, of course, signed “No Trespassing.” In theory, there is an access point to the Tablerock Trail from Tablerock Subdivision about 430 m. to the northeast. This access point can accessed from either Dunraven Circle or Devil's Head Circle by way of a concrete multiuse trail. Unfortunately, that trail is also signed “No Trespassing.”

The author led Colorado Native Plant Society field trips to North Table Mountain in 2016, 2017, and 2019. The plant lists from those field trips are kept constantly up to date by this web site. See Plant Check List for North Table Mountain, Jefferson County, United States.

South Table Mountain

Castle Rock from Lubahn Trail trailhead

• Lubahn Trail, Belvedere at 18th, Belvedere at 19th.
• Fossil Trail, on Golden Hills Road.
• Camp George West Park.

• West Denver West Parkway.
• Old Quarry Road.

• Lookout View Drive.
• Rimrock Drive.
• Quaker Street.

Lookout Mountain

Only the eastern-facing slopes of Lookout Mountain are covered by this checklist flora.

Land ownership (1,221 ac.) is primarily Jefferson County Open Space for Windy Saddle Park, Apex Open Space Park, Lookout Mountain Nature Center, and small portion of Matthews/Winters Park. Denver Parks owns a large parcel (69 ac.) on top of Lookout Mountain. Martin Marietta is the largest private landowner for their quarry, followed by the Missionary Sisters of the Sacred Heart (Mother Cabrini Shrine).

Colorado School of Mines Survey Field

The next largest single parcel is the Colorado School of Mines Survey Field. It consists of 2 parcels totaling about 226 acres. At the upper, west side, it abuts Lookout Mountain.

Though owned by a public agency, the Survey Field is not really open to the public, in the sense of a public park or open space. The school needs to know who in on their property, and to cover themselves for liability issues.

The Survey Field has been disturbed by roads, mining, and utilities. It is also quite weedy in places. Regardless, it is a unique piece of open space in Golden, given its size, and its place between Golden and Lookout Mountain.

Kinney Run / Deadman Gulch

The City of Golden-owned parcels in the vicinity of Eagle Ridge (a small hogback), Deadman Gulch, Kinney Run, and Heritage Dells comprise about 90 acres. There are also some city-owned watercourses near the south-west end of those shown on this map.

Of the four names applied to this area, only two: Deadman Gulch and Heritage Dells, are recognized by the U.S. Board on Geographic Names (BGN, n.d.). The source for “Kinney Run” is unknown, but is probably a euphemism used by developers for Deadman Gulch. The original source may be “Kenneys Creek” found on the 1938 Morrison quadrangle applied to a creek flowing north along present-day Johnson Avenue, then northwest along South Golden Road. Similarly, the source for “Eagle Ridge” is also unknown, but was probably chosen by real estate developers in the area.

City of Golden-owned Parcels in the vicinity of Kinney Run

South and west of Eagle Ridge is the heart of Deadman Gulch/Kinney Run. A little over 31 acres, this parcel is oriented north-south, and fairly narrow from east to west.

Kinney Run in early Spring.	View of Kinney Run in early Spring.

The vegetation of Kinney Run is a mosaic of Foothills Shrubland and Riparian, with some remnant Mixed-Grass Prairie. Despite the extensive disturbance and planting of non-natives, many native grasses and forbs (non-woody perennials) can still be found in Kinney Run. Roundtip Twinpod (Physaria vitulifera) and Front Range Beardtongue (Penstemon virens) bloom in the spring on the rock outcrops of the Lyons Sandstone along with Mountain Mahogany (Cercocarpus montanus). Green Needlegrass (Nassella viridula) and Needle and Thread (Hesperostipa comata) are found around the edges of the Chokecherry (Prunus virginiana) thickets below the cliffs. The wetter areas near the creek support both Golden Currant (Ribes aureum) and Wax Currant (R. cereum), along with Wild Bergamot (Monarda fistulosa) and the Cloaked Bulrush (Scirpus pallidus). The drier slopes opposite Eagle Ridge support many examples of remnant Prairie vegetation, such as Prairie Groundsel (Packera plattensis), Cowboy Delight (Sphaeralcea coccinea), and Blanketflower (Gaillardia aristata).

Tin Cup Ridge

Tin Cup Ridge is the northward extension of Dinosaur Ridge into Golden. Interstate 70 cuts through Dinosaur Ridge and separates the two parts of the ridge.

The easiest way to access Tin Cup Ridge is from the Rooney Road Sports Complex.

At the south end, Tin Cup Ridge can also be accessed from the T-Rex Park and Ride Lot. And, for the truly intrepid, it is possible to access Tin Cup Ridge from the north, through the Wrigley's Chicago Bar & Grill parking lot from the intersection of Colfax Avenue and Zeta Street. It was necessary to use this entrance when the Rooney Road Sports Complex was closed because of the COVID-19 pandemic.

Matthews/Winters Park

There is a small portion of Matthews/Winters Park that is north of Interstate 70, and just south of the Golden city limits. This area is not open to the public.

Apex Park

Apex Park is about 700 acres. Of those, about 500 acres are within the City of Golden. The larger southern portion of the park is heavily used and a popular destination for hiking and mountain biking. There is a smaller northern portion of the park that is closed for resource protection.

There is one trailhead and two other access points to Apex Park. The trailhead is on Heritage Road near Colfax Avenue. The access points are on Lookout Mountain Road and Poco Calle Road. They have minimal parking and no facilities.

Some clever map-reading will disclose other ways to enter Apex Park. However, doing so is difficult without crossing private property or inadvertently entering the restricted area.

Tony Grampsas Memorial Sports Complex

CSM Paraglider Landing Area

Dakota Ridge and Cressman Gulch

The south end of Dakota Ridge and the adjacent Cressman Gulch is in the very northern part of Golden. I have applied the name Dakota Ridge to this hogback because that is the only name I have seen applied to it. The name was applied by Van Horn (1957) in Bedrock Geology of the Golden Quadrangle. “Dakota Ridge” is also sometimes applied to the corresponding hogback south of Golden. However the GNIS (BGN, 2019) applies the name “Dinosaur Ridge.”

Regardless of the naming question, Cressman Gulch and the Dakota Ridge hogback above it measure to be 39 acres. The eastern portion, about 13 acres by my estimate and therefore quite unofficial, is likely to be used for the relocation of Colorado Highway 93 sometime in the future. The remaining 26 acres is primarily contributed by the south end of the hogback. There are open mines on the hogback, which are fenced, and not open to access by the public.

There is no historic botanic data for Dakota Ridge. The author made about 54 collections in 2020, and combined with additional observations, there are 86 plant species known from the ridge and adjacent gulch.

One collection is of particular interest. It is Linaria canadensis (L.) Dum.-Cours. Var. texana (Scheele) Pennell, with a common name of “Blue Toadflax.” A commonly used synonym for this plant is Nuttallanthus texanus (Scheele) D. A. Sutton. This name was proposed by Sutton (1988) to separate the new world Linaria from the old world Linaria. However, recent phylogenetic work (Fernandez-Mazuecos, et al., 2013) shows that the new world plants need to be retained in the old world genus Linaria. There is historic collection made along the railroad tracks in Golden from more than a century ago. More recently, it was collected at Rocky Flats and White Ranch.

Coll. No. 2077, Linaria canadensis var. texana

Tucker Gulch

Tucker Gulch and the lower part of Cressman Gulch, i.e., south and east of Colorado Highway 93, form a kind of linear open space, if the term “open space” can be applied to a long narrow shape. While much of the lower part of Tucker Gulch is still railroad right of way, the portion owned by the City of Golden is 34 acres. Tucker Gulch between the highway and Clear Creek is about 3.2 km. in length, and Cressman Gulch from the highway to the mouth at Tucker Gulch is about 1.5 km. in length. When combined with the railroad land, the width varies from a minimum of 17 m. to a maximum of 109 m., although generally the width is about 30 to 50 m.

The vegetation in Tucker Gulch is quite weedy. There are only a few collections made in Tucker Gulch and of them only one is native: Heterotheca villosa “Hairy False Goldenaster.” Among the non-native plants, one, Alopecurus arundinaceus “Creeping Meadow Foxtail” is an uncommon grass in Jefferson County, and therefore at least mildly interesting.

Schweich Hill

The little piece of City of Golden open space at the north end of Washington Avenue, near Cannonball Creek Brewery, measures 4 acres. Tracts A & B of the parcel was accepted by the City of Golden by Resolution No. 516, adopted December 23, 1993. Both tracts are dedicated as open space, although Tract B was also dedicated for W470 expansion.

North Washington Open Space as seen from North Table Mountain	View of North Washington Open Space from Mount Galbraith

Feld trips sponsored by Colorado Native Plant Society visited the open space parcel in 2018 and again in 2022.

There are 136 taxa (species of plants) in 42 plant families, mostly grasses and forbs (non-woody perennials). None of the plants collected or observed are Colorado-ranked rare plants (Colorado Natural Heritage Program, 1997+). There are 13 species of Colorado-listed Noxious Weeds (Colorado Department of Agriculture, 2014-2019). There is one species on List A, Euphorbia myrsinites L. “Myrtle Spurge,” and seven List B species. At least one species of noxious weed, Dipsacus laciniata, has not been seen for several years due to repeated weeding.

A small portion covering the top of the hill, about 1.5 acres in size, could be identified as Western Great Plains Foothill and Piedmont Grassland with mixed tall and short grass species. Significantly sized other portions, would be identified as Smooth Brome (Bromus inermis Leyss) Ruderal Vegetation.

There is substantial disturbance around the edges of the parcel. Disturbance includes grading, water lines or other utilities, construction, landscaping or revegetation, yard debris disposal and mowing by neighbors, and social trails and amenities. It is unclear when the water line was placed across the parcel, but the current vault appears in 7/4/2005 imagery. The center of the open space is less-disturbed, where the primary disturbances are social trails and amenities.

There are four easily identifiable social trails crossing all or part of the parcels. The primary social trail crosses the parcels east to west across the top of the hill. This trail bisects the area of remnant native vegetation on the top of the hill and is frequently used by hikers, dog walkers, and by a few mountain bikes. The opportunities for rerouting this trail away from the native vegetation, while still permitting access to the top of the hill, seem quite limited. The trail is eroding on the stepest slope at the eastern slope of the hill. There is one social amenity, i.e., a bench near the top of the hill. The bench and associated access trail first appear in 10/7/2012 imagery. The access trail to this bench passes perilously close to several individual plants of Missouri Foxtail Cactus.

The top of the hill is occasionally used for picnics or similar activities as evidenced from a rather large trampled area. I have even encountered a wedding photography party on top to the hill. Unfortunately, the trampled area is at the center of the best native vegetation. This causes damage to the small area of native prairie and indicates why the trail needs to be signed with a plea for users to remain on the trail.

I keep a separate report about this open space, which can be found on my home page with a title of “Botanical Resources of Schweich Hill, Golden, Colorado.”

Nearby Areas Excluded

There are a few lists available for Green Mountain. The most recent is Yeatts & Yeatts (2009).

Geology

Golden sits roughly in the center of the Rocky Mountain Front. This long, straight, persistent structural boundary originated between 1.4 and 1.1 billion years ago in the Mesoproterozoic Era. It was intruded by the Pikes Peak granite (1.09 billion years) in central Colorado. The Rocky Mountain Front began as a boundary between thick cratonic lithosphere to the east (modern coordinates) and an orogenic plateau to the west and remains so today. The structural boundary was reactivated during the breakup of the supercontinent Rodinia (1.1 to 0.6 billion years ago) and again during deformation associated with formation of both the Ancestral (≈300 Ma) and Laramide (80-40 Ma) Rocky Mountains. The landscape we now see was enhanced during the late Miocene to Holocene (ca. 6–0 Ma) by tectonic uplift. Increased monsoonal precipitation caused differential erosion along the mountain front, exhuming an imposing 0.5– 1.2 km escarpment that is bordered by hogbacks of Mesozoic strata and incised by major river canyons. The hogbacks do not occur in central Golden as they are cut off by the Golden fault. However, there are hogbacks in both north and south Golden s.l., i.e, Dakota Ridge in the north, and Tin Cup Ridge in the south.

Soils

Soils in the Golden area were enumerated in Price and Amen (2001, 2008 rev.). Seventy-nine different soil types are recognized in Golden sensu latu

Vegetation of Golden

There are three basic types of vegetation in Golden s.l.:

• Mixed-grass prairie.
• Foothill shrubland.
• Riparian or wetland vegetation.

I haven’t used formal names, such as those found in the National Vegetation Classification System (USNVC, 2019), because none of the areas in Golden s.l. have received the formal attention and documentation required for a more formal definition.

View similar to the historic view of Golden.	View of north Golden 1870-1880. Countesy of Denver Public Library.

• Heterotheca villosa (Hairy False Goldenaster),
• Oxytropis lambertii (Purple Locoweed),
• Penstemon secundiflorus (Sidebells Beardtongue), and
• Viola nuttallii (Nuttall’s Violet).

Shrubs are represented on the prairie by Ribes cereum (Wax Currant) and Prunus virginiana (Chokecherry).

In the watercourses, such as Tucker Gulch and Arapahoe Gulch, is a riparian vegetation consisting of willows and cottonwoods (Salix spp.), with sedges (Carex sp.) and rushes (Juncus sp.), and sometimes cat tails (Typha sp.).

Away from the valley bottoms, on the slopes of North and South Table Mountains and Mount Galbraith is a foothill shrubland. These can be very dry and exposed favoring Cercocarpus montanus (Alder-Leaf Mountain Mahogany). A little more mesic habitat favors shrubs such as Rhus trilobata (Squawbush) and Prunus americana (American Plum). The small watercourses may support Acer glabrum (Rocky Mountain Maple) and Physocarpus monogynus (Mountain Ninebark).

Of course, the boundaries between these vegetation types are rarely sharp, and representatives of one vegetation type will often be found growing with representatives of another type.

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