Article Figures & Data
Tables
App name Cost of use (USD) * Suggestions consistently offered Community identifications Size of plant species database from website claim Developer PictureThis $29.99/year − − 10,000 + Glority, LLC iNaturalist N/A + + Not stated iNaturalist, LLC Plant Identification++ $1.49/week, $3.99/month, $29.99/year + − Not stated Touchberry, Inc. PlantNet (Pl@ntNet) N/A + + 26,722 world flora 8,490 USA flora plantnet- project.org LeafSnap N/A + − All 185 tree species in the NE Forest Appixi PlantSnap $2.99/month, $19.99/year + + 650,000 PlantSnap, Inc. ↵*Cost of use values are based on the cost at the time of the study in summer 2020.
- Table 2.
A listing of species used in the evaluation of phone apps for plant identification. Percentages of correct responses across 6 apps are shown for bark and leaf images for both identification and suggestion at genus and species levels.
Genus identification Species identification Genus suggestions Species suggestions Family Genus Species Bark Leaf Bark Leaf Bark Leaf Bark Leaf Altingiaceae Liquidambar styraciflua 20% 100% 20% 100% 65% 100% 65% 100% Anacardiaceae Rhus typhina 25% 95% 20% 65% 45% 100% 35% 95% Betulaceae Betula allegheniensis 85% 25% 35% 15% 100% 70% 45% 65% Betulaceae Betula lenta 75% 45% 50% 45% 95% 90% 55% 50% Betulaceae Betula nigra 90% 85% 65% 50% 95% 95% 100% 95% Betulaceae Betula populifolia 95% 100% 35% 40% 95% 100% 70% 100% Betulaceae Carpinus caroliniana 80% 80% 50% 30% 95% 100% 65% 85% Cornaceae Cornus florida 50% 95% 50% 60% 75% 100% 75% 100% Cupressaceae Juniperus virginiana 20% 100% 20% 80% 80% 100% 80% 90% Cupressaceae Taxodium distichum 50% 95% 50% 90% 95% 100% 95% 100% Fabaceae Cercis canadensis 5% 95% 5% 90% 5% 100% 5% 100% Fabaceae Gleditsia triacanthos 45% 85% 45% 85% 80% 100% 80% 100% Fabaceae Robinia pseudoacacia 50% 100% 50% 100% 70% 100% 70% 100% Fagaceae Castanea dentata 25% 100% 25% 90% 50% 100% 50% 100% Fagaceae Fagus grandifolia 90% 100% 70% 95% 100% 100% 90% 100% Fagaceae Quercus alba 70% 100% 55% 70% 95% 100% 85% 100% Fagaceae Quercus bicolor 10% 100% 0% 70% 55% 100% 20% 95% Fagaceae Quercus coccinea 45% 100% 0% 0% 90% 100% 25% 70% Fagaceae Quercus montana 75% 70% 50% 40% 90% 100% 50% 55% Fagaceae Quercus palustris 60% 100% 20% 85% 85% 100% 60% 90% Fagaceae Quercus rubra 55% 100% 50% 90% 95% 100% 80% 95% Ginkgoaceae Ginkgo biloba 5% 100% 5% 100% 35% 100% 35% 100% Juglandaceae Carya cordiformis 60% 100% 0% 10% 70% 100% 15% 45% Juglandaceae Carya ovata 40% 100% 40% 10% 75% 100% 50% 50% Juglandaceae Juglans nigra 40% 100% 40% 100% 90% 100% 75% 100% Lauraceae Sassafras albidum 15% 100% 15% 100% 40% 100% 40% 100% Magnoliaceae Liriodendron tulipifera 30% 100% 30% 100% 75% 100% 75% 100% Magnoliaceae Magnolia soulangeana 0% 50% 0% 13% 25% 75% 10% 28% Magnoliaceae Magnolia stellata 10% 25% 0% 10% 30% 55% 0% 25% Malvaceae Tilia cordata 25% 100% 10% 90% 65% 100% 55% 100% Malvaceae Tilia tomentosa 10% 100% 0% 10% 60% 100% 5% 40% Moraceae Maclura pomifera 15% 55% 15% 55% 35% 90% 35% 90% Nyssaceae Nyssa sylvatica 5% 60% 5% 60% 35% 85% 35% 85% Oleaceae Fraxinus americana 80% 90% 75% 40% 85% 100% 80% 80% Oleaceae Fraxinus pennsylvanica 45% 90% 15% 30% 75% 100% 25% 70% Pinaceae Picea abies 60% 90% 60% 75% 90% 95% 70% 75% Pinaceae Picea pungens 60% 100% 0% 100% 90% 100% 35% 100% Pinaceae Pinus rigida 85% 90% 15% 10% 90% 90% 75% 70% Pinaceae Pinus strobus 50% 100% 45% 95% 75% 100% 75% 100% Pinaceae Pinus sylvestris 100% 90% 0% 15% 100% 90% 60% 60% Pinaceae Pseudotsuga menziesii 0% 60% 0% 60% 20% 90% 20% 90% Pinaceae Tsuga canadensis 20% 100% 20% 50% 50% 100% 50% 100% Platanaceae Platanus occidentalis 75% 100% 55% 100% 85% 100% 70% 100% Platanaceae Platanus × hispanica 95% 100% 38% 30% 100% 100% 50% 40% Rosaceae Prunus serotina 80% 90% 55% 90% 90% 100% 75% 100% Rosaceae Pyrus calleryana 5% 100% 0% 50% 25% 100% 10% 95% Salicaceae Salix babylonica 55% 100% 35% 90% 65% 100% 55% 100% Sapindaceae Acer platanoides 40% 100% 35% 100% 75% 100% 70% 100% Sapindaceae Acer rubrum 35% 100% 20% 100% 75% 100% 50% 100% Sapindaceae Acer saccharinum 40% 100% 35% 100% 70% 100% 60% 100% Sapindaceae Acer saccharum 35% 100% 35% 55% 80% 100% 50% 100% Sapindaceae Aesculus hippocastanum 15% 100% 15% 100% 40% 100% 40% 100% Simaroubaceae Ailanthus altissima 20% 100% 20% 100% 20% 100% 20% 100% Ulmaceae Ulmus americana 10% 90% 10% 75% 60% 95% 60% 95% Ulmaceae Zelkova serrata 45% 80% 45% 80% 50% 95% 50% 95% Average 44.09% 89.64% 28.23% 65.32% 69.09% 96.64% 52.36% 85.77% - Table 3.
A listing of the percentages of correct responses for 6 plant identification apps across 55 commonly observed tree species in New Jersey forests and landscapes. Percentages are means of 4 images for each species for bark and leaf. Combined percentage values are means of 8 observations for bark and leaf combined. PictureThis* and Plant Identification* percentages have been adjusted from their respective percentages by lowering the photo count by the number of photos for which the apps failed to make any identification (1 and 47 photos, respectively).
Genus identification Species identification App Combined Bark Leaf Combined Bark Leaf PictureThis 81.36% 65.45% 97.27% 67.84% 51.82% 83.86% iNaturalist 70.23% 48.18% 92.27% 50.68% 31.82% 69.55% Plant Identification 63.86% 40.00% 87.73% 44.09% 25.00% 63.18% PlantNet 60.00% 34.55% 85.45% 36.36% 17.27% 55.45% LeafSnap 59.09% 32.27% 85.91% 35.11% 14.77% 55.45% PlantSnap 36.59% 1.36% 71.82% 20.45% 0.00% 40.91% PictureThis* 81.55% 65.75% 97.27% 67.54% 52.05% 82.95% Plant Identification* 71.50% 49.16% 90.19% 49.36% 30.73% 64.95% Genus suggestions Species suggestions App Combined Bark Leaf Combined Bark Leaf PictureThis 81.36% 65.45% 97.27% 67.84% 52.27% 84.32% iNaturalist 89.55% 79.55% 99.55% 83.41% 70.91% 95.91% Plant Identification 66.59% 41.36% 91.82% 50.23% 27.27% 73.18% PlantNet 88.41% 79.55% 97.27% 70.68% 54.55% 86.82% LeafSnap 88.86% 79.55% 98.18% 72.73% 56.82% 88.64% PlantSnap 46.36% 2.27% 90.45% 39.55% 0.45% 78.64% PictureThis* 81.55% 65.75% 97.27% 68.00% 52.51% 83.41% Plant Identification* 74.55% 50.84% 94.39% 56.23% 33.52% 75.23% - Table 4.
A listing of the percentages of correct responses across 6 plant identification apps as organized by classification level for 55 tree species in New Jersey forests and landscapes. Only orders and families with 2 or more genera represented in the data were included in this table. Similarly, only genera with 2 or more tested species were included.
Taxonomic orders Order (tested species count) Genus identification Species identification Combined Bark Leaf Combined Bark Leaf Fabales (3) 63.33% 33.33% 93.33% 62.50% 33.33% 91.67% Fagales (16) 75.00% 62.19% 87.81% 44.53% 36.56% 52.50% Magnoliales (3) 35.83% 13.33% 58.33% 25.42% 10.00% 40.83% Pinales (9) 70.56% 49.44% 91.67% 43.61% 23.33% 63.89% Rosales (4) 62.50% 35.00% 90.00% 50.63% 27.50% 73.75% Taxonomic families Family (number of species tested within family) Genus identification Species identification Combined Bark Leaf Combined Bark Leaf Betulaceae (5) 76.00% 85.00% 67.00% 41.50% 47.00% 36.00% Cupressaceae (2) 66.25% 35.00% 97.50% 60.00% 35.00% 85.00% Fabaceae (3) 63.33% 33.33% 93.33% 62.50% 33.33% 91.67% Fagaceae (8) 75.00% 53.75% 96.25% 50.63% 33.75% 67.50% Juglandaceae (3) 73.33% 46.67% 100.00% 33.33% 26.67% 40.00% Magnoliaceae (3) 35.83% 13.33% 58.33% 25.42% 10.00% 40.83% Pinaceae (7) 71.79% 53.57% 90.00% 38.93% 20.00% 57.86% Rosaceae (2) 68.75% 42.50% 95.00% 48.75% 27.50% 70.00% Sapindaceae (5) 66.50% 33.00% 100.00% 59.50% 28.00% 91.00% Genera Genus (number of species represented within genus) Genus identification Species identification Combined Bark Leaf Combined Bark Leaf Acer (4) 68.75% 37.50% 100.00% 60.00% 31.25% 88.75% Betula (4) 75.00% 86.25% 63.75% 41.88% 46.25% 37.50% Carya (2) 75.00% 50.00% 100.00% 15.00% 20.00% 10.00% Fraxinus (2) 76.25% 62.50% 90.00% 40.00% 45.00% 35.00% Magnolia (2) 21.25% 5.00% 37.50% 5.63% 0.00% 11.25% Picea (2) 77.50% 60.00% 95.00% 58.75% 30.00% 87.50% Pinus (3) 85.83% 78.33% 93.33% 30.00% 20.00% 40.00% Platanus (2) 92.50% 85.00% 100.00% 55.63% 46.25% 65.00% Quercus (6) 73.75% 52.50% 95.00% 44.17% 29.17% 59.17% Tilia (2) 58.75% 17.50% 100.00% 27.50% 5.00% 50.00%