Table 1.
Species where within-population optimal outcrossing has been assessed after experimental single-donor hand pollination
| Species | Life form | Seed dispersal | Scale assessed | Fitness assessed | Within-population OOD | Pollinators | References |
|---|---|---|---|---|---|---|---|
| Delphinium nelsonii | Herb SC | Within 1 m | Self,1, 3, 10, 30, 100, 1000 m | Seed set per flower Seedling survival, growth rate | 3–10 m: Highest seed set, highest survival and faster production of flowers | Hummingbirds Bumblebees | Price and Waser, 1979; Waser and Price, 1994 |
| Castilleja miniata | Herb SI | Unreported | Self, 0.5, 2, 10, 30 m (1979) and self, 0.5, 1, 5, 10, 30 m (1980) | Seeds per pod | 2 m (1979 and combined): Seeds per pod (no OOD detected in 1980) | Hummingbirds | Lertzman, 1981 |
| Blandfordia nobilis | Herb SI | Unreported | 0–5, 10, 50, 200 m | Seed set per unparasitized carpel | Not detected: No difference between treatments | Honeyeaters | Zimmerman and Pyke, 1988 |
| Espeletia schultzii | Shrub SI | Within 2 m | 1, 3, 6, 10, 15, 20, 50, 150, 500 m, 10 km, 78 km (variation between sites and years) | Proportion of filled achenes, proportion of aborted seeds, seedling survivorship | Not detected: Lower success after near-neighbour crosses | Hummingbirds Bumblebees (Berry and Calvo, 1989) | Sobrevila, 1988 |
| Ipomopsis aggregata | Herb SI | Within 1 m | 0, 1, 10, 100 m | Seed set, seedling survival, flowering time, | 10 m: Higher seed set, higher seedling survival, greater chance of flowering/earlier flowering | Hummingbirds | Waser and Price, 1989 |
| Impatiens capensis | Herb SC | Ballistically; within 20 cm | 2, 10, 50 m | Seed mass, seed maturation, emergence, seedling height | 29 m (estimate): Height of offspring at 1 month | Hummingbirds Bumblebees (Travers et al., 2003) | McCall et al., 1991 |
| Anchusa crispa | Herb SC | Ants; within 75 cm (Quilichini and Debussche, 2000) | Self, 5–10, 10–20, 20–30 m | Achenes per fruit, germination, survival, cymes per plant, flowers per cyme | Not detected: Selfed-pollinated plants have lower number of achenes per fruit and germination but higher survival, cymes per plant and flowers per cyme | Hummingbirds Insects | Quilichini et al., 2001 |
| Grevillea mucronulata | Shrub SI | Gravity | Self, 1–4 m, 30–50 m, 5 km | Initiation, seed set, seed size, seed mass, germination time, seedling height, leaf area, number of leaves | 30–50 m: Highest seed set, seed size, germination, leaf area, number of leaves | Honeyeaters | Forrest et al., 2011 |
| Picea glauca | Tree | <200 m | 0–3200 m (including self and nearest neighbour) | Seed set, germination, seedling growth, | Not detected: Lower viability and seedling height after self-pollination | Wind-pollinated | Coles and Fowler, 1979 |
| Scleranthus annuus | Herb SC | Gravity | Self, 6, 12, 25, 50, 100 m | Seedling stamen arrangements and fertility | 6–12 m: Highest number of stamens, more staminodes developing into fertile stamens | Self (occasionally ants) | Svensson, 1988 |
| Polemonium viscosum | Herb SI | Unreported | Randomly paired up to 60 m | Number of seeds, seed mass | Not detected: Distance has no impact | Bumblebees | Newport, 1989 |
| Costus allenii | Herb SC | Unreported | Mean interparental distances of 60, 200, 264 and 318 m; included multiple pollen donors | Seed production, seed weight, percentage germination, vegetative growth | Average 264 m: Highest seed production and percent germination | Euglossine bees (Schemske, 1981) | Schemske and Pautler, 1984 |
| Phlox drummondii | Herb SI | Explosive force of fruit | Self, random up to 35 m | Seed abortion | Not detected: Self-pollination increases seed abortion | Lepidopterans | Levin, 1984 |
| Amianthium muscaetoxicum | Herb near SI | Unreported | 5, 15, 60 m | Fruit production, seeds per fruit, seeds per plant, seed mass | Not detected: Lower fruit production and seeds per fruit after near-neighbour crosses in two of three populations | Beetles (Travis, 1984) | Redmond et al., 1989 |
| Gentiana pneumonanthe | Herb SC | Wind; within a few metres | Self, 1–50 cm, 50–100 cm, 1–2 m, 2–5 m, 5–10 m, 10–20 m, >20 m and 800 m | Seed set and seed mass, germination, seedling mass, adult mass, total relative fitness | Not detected: Lower fitness after self-pollination | Bumblebees | Oostermeijer et al., 1995 |
| Agave schottii | Shrub SC | Within a few metres | 1, 10, 100, 2500 m | Fruit set, seed set, seed mass, germination, combined relative fitness | 10 m: Seed set combined relative fitness | Bumblebees and sphinx moths (Schaffer and Schaffer, 1977) | Trame et al., 1995 |
| Gentianella germanica | Herb SC | Wind; <130 cm (Verkaar et al., 1983) | Self, 1 m, 10 m, 25 km | Seeds per fruit, seed mass, germination rate, number of leaves, rosette diameter, cumulative leaf length, survival of seedlings (over 175 d period) | 10 m: Faster germination, larger number of leaves, rosette size | Diptera and small bees | Fischer and Matthies, 1997 |
| Trillium erectum | Herb SC | Ant dispersal; 0.02–10 m | 1, 10, 100, 1500 m | Fruit and seed production, seed: ovule ratio | Not detected: Lower seed production after self-pollination | Insect | Irwin, 2001 |
| Trillium grandiflorum | Herb SC | Ant dispersal; 0.02–10m | 1, 10, 100, 1500 m | Fruit and seed production, seed:ovule ratio | Not detected: Lower seed production after self-pollination | Insect | Irwin, 2001 |
| Alstroemeria aurea | Herb SC | Within a few metres | 1, 10, 100 m | Germinated pollen grains, number of pollen tubes, | Not detected: Pollen tube number increases with distance | Bumblebees | Souto et al., 2002 |
| Digitalis purpurea | Herb SC | Ballistically; within a few metres | Self, 1, 6, 30 m | Seed set, seed mass, germination, seedling survival, seedling growth, time to flowering, flower number | 6 m: Highest cumulative fitness (seed germination, juvenile survival, flower number) | Bumblebees | Grindeland, 2008 |
| Grevillea sphacelata | Shrub SI | Unreported | <5 m, 200 m, 3–4 km away | Fruit development, fruit set, seeds per fruit, seed mass, germination success, seedling survival, seeding growth, seedling photosynthesis | Not detected: Distance had negligible impact | Insects (primarily Apis mellifera) | Ayre and O’Brien, 2013 |
| Phlox hirsuta | Herb SI | Gravity; within 1 m | 1, 10, 100 m, 6740 m | Seed set, seed abortion, seed mass, emergence, radical length, cotyledon emergence, number of leaves, number of flowers | Not detected: No impact within population, shorter radicles and less cotyledon emergence after between-population crosses | Insects | Ruane et al., 2015 |
SI, self-incompatible; SC, self-compatible.