A free, open-source progressive web app (PWA) field guide to 1,485 plants, mosses, and lichens of Los Angeles County. Wildflowers, trees, shrubs, ferns, grasses, cacti, aquatic plants, vines, mosses, and lichens — with photos, field marks, bloom times, ecological notes, and iNaturalist observation maps.
Live at la-flora.org
- 1,485 species across 10 taxa groups — 1,052 native, 367 introduced, 66 invasive
- iNaturalist life list tracking — enter your iNat username to see which species you've observed
- Satellite observation maps — iNat occurrence maps for every species
- Photo caching — photos fetched from iNat API and cached in IndexedDB for fast loading
- Offline-capable — service worker caches all files for offline use
- 100% ecological association notes — every species has a unique species-specific ecological note with named wildlife species, fire ecology, indigenous ethnobotany, and sourced extraordinary claims
- 10 endangered species verified against CNPS Rare Plant Inventory and federal listings
- 160 look-alike differentiation notes — Jepson eFlora diagnostic keys for confusable species pairs, including all safety-critical toxic species
- Cross-linked ecosystem — 199 deep links connecting plants to companion guides for bugs, birds, and mammals, with target taxa group routing
- Elevation filter — toggle Coast / Lowland / Foothill / Mid-elevation / Mountain
- Establishment filter — toggle Native / Introduced / Invasive species
- Endemic filter — show only California endemic species
- Rarity filter — All / Common / Uncommon / Rare / Endangered
- Family chips — filter by plant family with taxonomic or alphabetical sorting
- Responsive — designed for mobile field use
- No tracking, no ads, no login required
Every species card includes ecological associations verified against published sources. Coverage across 1,476 species:
| Ecological dimension | Species | Coverage | Sources |
|---|---|---|---|
| Specific pollinator families | 731 | 49% | Xerces Society, Las Pilitas, UC Riverside |
| Named bird species | 873 | 59% | LA Audubon, eBird, CWHR |
| Butterfly/moth species | 217 | 15% | Las Pilitas, Art Shapiro (UC Davis) |
| Fire ecology | 210 | 14% | Keeley & Fotheringham, CA Chaparral Institute |
| Mammal/herp associations | 261 | 18% | CWHR, USDA browse database |
| Indigenous ethnobotany | 136 | 9% | Timbrook (2007), Bean & Saubel (1972), McCawley (1996) |
| Look-alike (vs) notes | 160 | 11% | Jepson eFlora diagnostic keys |
| Mycorrhizal associations | 57 | 4% | UC Berkeley mycology |
| Conservation status | 45 | 3% | CNPS, USFWS, CDFW |
- 29/29 butterfly species documented in LA County — each named on its host/nectar plants
- 11 moth species including California Oak Moth, Polyphemus Moth, Elegant Sheep Moth
- 86 bird species linkable to All About Birds (Cornell Lab / Merlin)
- ~42 mammal/herp species linkable to la-fauna.org
- 6 specialist bee genera (Andrena, Diadasia, Colletes, Osmia, Habropoda, Peponapis)
- 4 endangered bee species (Bombus crotchii, B. occidentalis, Osmia ribifloris, Habropoda depressa)
Ecological associations contain clickable links to companion field guides. GROUP_LINKS include target taxa group hashes so users land on the correct tab (e.g., ?search=mining+bee#nativeBees).
| Destination | Link map | Entries | Description |
|---|---|---|---|
| labugs.org | BUG_LINKS | 42 | Butterfly/moth species → species deep-link |
| labugs.org | GROUP_LINKS | 29 | Pollinator groups → filtered search with target tab |
| allaboutbirds.org | BIRD_LINKS | 86 | Bird species → Cornell Lab / Merlin |
| la-fauna.org | FAUNA_LINKS | 42 | Mammal/herp species → vertebrate guide |
- 160 look-alike (vs) notes using Jepson eFlora diagnostic characters
- All 12+ oak species distinguishable via leaf shape, bark, acorn, and habitat
- All 15 pine species distinguishable via needle count, cone size, bark scent
- All safety-critical toxic species (Poison Hemlock, Sacred Datura, Oleander, Castor Bean, Star Lily) have vs notes
- Sage trio, buckwheat pair, manzanita pair, sumac trio, Ceanothus complex, monkeyflower trio, penstemon trio, paintbrush trio all keyed
v3 two-file PWA architecture:
index.html — 92 KB (CSS + JS + config, no framework)
species-data.json — 1,070 KB (species data, loaded async)
sw.js — 1 KB (service worker, network-first + cache-fallback)
manifest.json — PWA manifest
icons/ — App icons (128, 192, 512, 1024px + apple-touch)
Hosted on Netlify via drag-and-drop zip deployment.
- Zip all files:
index.html,species-data.json,sw.js,manifest.json,_headers,_redirects,icons/ - Drag zip to app.netlify.com/drop
- Configure custom domain:
la-flora.org
This guide architecture is designed to be adapted to any geographic region. The species data is entirely separate from the application code, so creating a guide for a different county, state, or bioregion requires only replacing the species data.
-
species-data.json— Replace with species data for your region. Each species entry follows this schema:{ "sn": "Quercus agrifolia", "cn": "Coast Live Oak", "fam": "Fagaceae", "est": "native", "st": "common", "elev": "low,foot", "desc": "Evergreen tree to 80 ft with dense rounded crown...", "bloom": "Mar-May", "hp": "Supports 300+ insect species (UC Berkeley)...", "fm": { "Leaves": "Evergreen, convex, spiny margin...", "Bark": "Gray, furrowed...", "vs": "Distinguished from scrub oak by tree form..." } } -
index.html— Update the following sections:- Site title and domain references
- Cross-link maps (
BUG_LINKS,BIRD_LINKS,FAUNA_LINKS,GROUP_LINKS) — update to your region's companion guides or remove - iNaturalist
place_idin the API call (LA County = 962; find yours at inaturalist.org/places) - Footer links to companion guides
- Elevation band labels if your region's bands differ
-
manifest.json— Update app name and short_name -
sw.js— Update cache name
The recommended workflow for building a regional species list:
- Start with iNaturalist: Query research-grade observations for your place_id to get a baseline species list
- Cross-reference with regional floras: Verify against published floras, Jepson eFlora (California), or equivalent regional references
- Add ecological associations: Use local Audubon data, Xerces Society pollinator lists, state wildlife habitat databases (CWHR in California), and published ethnobotany sources for your region's indigenous peoples
- Verify fire ecology: If applicable, use regional fire ecology databases (Keeley & Fotheringham for California chaparral)
- Add look-alike notes: Use regional flora keys for confusable species pairs, prioritizing safety-critical toxic species
A comprehensive continuation prompt is included in this repository at continuation-prompt.md. It contains the complete build history, architectural decisions, data quality standards, and ecological source references needed to continue development in a new AI session. Feed this prompt to Claude or another AI assistant to resume work on the guide.
Species data verified against iNaturalist research-grade observations (LA County, place_id=962, >=2 RG observations). Full gap audit run 2026-03-25.
- Jepson eFlora (ucjeps.berkeley.edu/eflora) — primary source for diagnostic keys and vs notes
- Calflora, CNPS Calscape, Cal-IPC Inventory
- Muns & Chester, Flora of the Santa Monica Mountains (1999/2002)
- Cooper, Flora of Griffith Park (2015)
- Xerces Society, California Pollinator Plant List
- Las Pilitas Nursery, butterfly-plant database (laspilitas.com)
- LA Audubon Society, native plant bird study (2022)
- California Chaparral Institute (californiachaparral.org)
- Keeley & Fotheringham, chaparral fire ecology research
- CWHR — California Wildlife Habitat Relationships System (CDFW)
- Art Shapiro's Butterfly Site (UC Davis) — butterfly.ucdavis.edu
- Timbrook, Jan. Chumash Ethnobotany (2007)
- Bean, Lowell & Saubel, Katherine. Temalpakh: Cahuilla Indian Knowledge and Usage of Plants (1972)
- McCawley, William. The First Angelinos: The Gabrielino Indians of Los Angeles (1996)
- Tucker & Ryan, Revised Catalog of California Lichens
- Malcolm, Shevock & Norris, California Mosses
Part of the LA County Field Guide Suite:
- labugs.org — Invertebrate Field Guide (3,438 species)
- lafungi.org — Fungi Field Guide (724 species)
- la-fauna.org — Vertebrate Field Guide (planned)
GPL v3. See LICENSE for details.
For informational purposes only — not a substitute for expert identification. Do not eat wild plants based on this guide.
Rhys Marsh · Los Angeles, CA