Appendix.
Microscopic analysis, incidence of nectar, nectary type and location, number of modified stomata per examined flower part, stoma size (mm2) and spur wall thickness (cell layers) in the examined species of Disa and Brownleea.
| Taxon | Analysis | Nectar | Nectary type and location | Number of stomata | Stoma size (mm2) | Spur wall thickness (cell layers) |
|---|---|---|---|---|---|---|
| Brownleea | ||||||
| B. galpinii subsp. major | SEM | 1 | S | 0 (2) | – | – |
| B. macroceras | SEM | 1 | S | 0 (2) | – | – |
| B. parviflora | SEM | 1 | S | 0 (2) | – | – |
| Disa | ||||||
| D. caulescens | SEM | 0 | 0 | 0 (6) | – | 6 ± 0·2 (17, 2) |
| D. filicornis | SEM | 0 | 0 | 10·5 ± 1·5 (2)* | 0·83 ± 0·045 (9, 1) | 6 ± 0·5 (2, 1) |
| D. racemosa | SEM | 0 | 0 | 90 ± 52 (2)* | 1·49 ± 0·055 (25, 1) | 10 ± 0·5 (2, 1) |
| D. tripetaloides | SEM | 0 | 0 | 0 (2) | – | 8 ± 0·4 (10, 2) |
| D. uniflora | SM, SEM | 1 | 2, S | 3·9 ± 2·4 (11) | 2·78 ± 0·404 (7, 3) | 13 ± 0·6 (17, 3) |
| Atromaculiferae | ||||||
| D. glandulosa | SM, SEM | 1 | 2, S | 0 (3) | – | – |
| D. vaginata | SM, SEM | 1 | 2, S | 0 (2) | – | 6 ± 0·3 (11, 2) |
| Phlebidia | ||||||
| D. longicornu | SM, SEM | 1 | 2, P, (S) | 0·3 ± 0·2 (7) | 1·69 ± 0·495 (2, 2) | 8 ± 0·4 (12, 2) |
| Pardoglossa | ||||||
| D. rosea | SEM | 0 | 0 | 0 (2) | – | 5 ± 0 (2, 1) |
| Schizodium | ||||||
| D. flexuosa | SEM | 0 | 0 | 0 (2) | – | 6 ± 0·2 (5, 1) |
| D. obliqua subsp. obliqua | SEM | 0 | 0 | 0 (4) | – | 5 ± 0·2 (20, 3) |
| Vaginaria | ||||||
| D. fasciata | SEM | 0 | 0 | 0 (1) | – | 6 ± 0·3 (3, 1) |
| Coryphaea | ||||||
| D. sagittalis | SEM | 0 | 0 | 0·7 ± 0 (4) | 0·64 (1, 4) | 5 ± 0·3 (11, 4) |
| D. rungweensis | SEM | 1 | 2, 0 | 0 (3) | – | 6 ± 0·2 (14, 3) |
| Disella | ||||||
| D. bodkinii | SEM | 0 | 0 | 233·5 ± 4·5 (2)* | 1·61 ± 0·107 (7, 2) | – |
| D. elegans | SM, SEM | 1 | 2, P, L | 0 (3) | – | – |
| D. obtusa subsp. hottentotica | SEM | 0 | 0 | 0 (4) | – | 5 ± 0·2 (6, 2) |
| D. uncinata | SEM | 0 | 0 | 0 (2) | – | 5 ± 0·6 (3, 1) |
| Monadenia | ||||||
| D. bolusiana | SEM | 0 | 0 | 44·5 ± 0·5 (2) | 1·24 ± 0·078 (6, 1) | 6 ± 0·3 (7, 1) |
| D. bracteata | SEM | 1 | 1, S | 31 ± 6·1 (6) | 1·17 ± 0·065 (7, 3) | 4 ± 0·2 (10, 2) |
| D. brevicornis | SM, SEM | 1 | 1, S | 77 (1) | 1·14 ± 0·069 (5, 1) | 6 ± 0·2 (7, 1) |
| D. comosa | SEM | 0 | 0 | 30·5 ± 0·5 (2) | 1·7 ± 0·154 (9, 1) | 7 ± 0·4 (6, 1) |
| D. cylindrica | SM, SEM | 1 | 1, S | 39·3 ± 11·9 (3) | 1·31 ± 0·164 (5, 2) | 5 ± 0·2 (13, 2) |
| D. ophrydea | SEM | 1 | 1, S | 11·5 ± 3·5 (2) | 0·94 ± 0·064 (4, 1) | 5 ± 0·4 (14, 2) |
| D. rufescens | SEM | 1 | 1, S | 26 ± 1 (2) | 1·92 ± 0·142 (7, 2) | 7 ± 0·7 (7, 1) |
| D. sabulosa | SEM | 1 | 1, S | 30 ± 2 (2) | 1·73 ± 0·148 (5, 2) | 6 ± 0·2 (9, 2) |
| Reticulibractea | ||||||
| D. harveiana subsp. longicalcarata | SEM | 0 | 0 | 8 ± 2·5 (3) | 1·73 ± 0·126 (7, 1) | 9 ± 0·4 (15, 2) |
| D. karooica | SEM | 0 | 0 | 2·5 ± 0·5 (2) | 2 ± 0·327 (3, 2) | 8 ± 0·3 (9, 1) |
| Repandra | ||||||
| D. cornuta | SEM | 0 | 0 | 59 (1) | 1·1 ± 0·102 (7, 1) | – |
| D. tysonii | SEM | 0 | 0 | 69·7 ± 29 (3) | 0·97 ± 0·059 (36, 2) | 8 ± 0·3 (15, 3) |
| Trichochila | ||||||
| D. graminifolia | SEM | 0 | 0 | 0 (1) | – | 7 ± 0·7 (5, 1) |
| D. hians | SEM | 0 | 0 | 0 (2) | – | 6 ± 0·3 (7, 1) |
| D. salteri | SEM | 1 | 2, S | 0 (3) | – | 5 ± 0·3 (16, 3) |
| D. tenuis | SEM | 1 | 2, S | 0 (1) | – | 6 ± 0·4 (5, 1) |
| Stenocarpa | ||||||
| D. cephalotes subsp. cephalotes | SEM | 0 | 0 | 0 (1) | – | 5 ± 0·2 (5, 1) |
| D. gladioliflora subsp. gladioliflora | SEM | 0 | 0 | 0 (2) | – | 6 ± 0·3 (11, 2) |
| D. nivea | SEM | 0 | 0 | 0 (1) | – | 7 ± 0·6 (5, 1) |
| D. saxicola | SEM | 0 | 0 | 0 (2) | – | 6 ± 0·3 (8, 1) |
| D. stricta | SEM | 0 | 0 | 0 (2) | – | 4 ± 0·2 (7, 1) |
| D. vigilans | SEM | 0 | 0 | 0 (1) | – | 7 ± 0·5 (4, 1) |
| Emarginatae | ||||||
| D. nervosa | SEM | 0 | 0 | 0 (1) | – | 7 ± 0·3 (3, 1) |
| D. patula var. transvaalensis | SEM | 0 | 0 | 2 (1) | 0·9 ± 0·161 (5, 1) | 7 ± 0·4 (7, 1) |
| D. stachyoides | SEM | 0 | 0 | 0 (1) | – | 6 ± 0·3 (4, 1) |
| Spirales | ||||||
| D. tenella subsp. tenella | SEM | 0 | 0 | 0 (2) | – | 7 ± 0·3 (9, 2) |
| Aconitoideae | ||||||
| D. aconitoides subsp. aconitoides | SEM | 0 | 0 | 3 ± 3 (2) | 1·11 ± 0·183 (3, 2) | 4 (1, 1) |
| Micranthae | ||||||
| D. chrysostachya | SM, SEM | 1 | 1, S | 718·6 ± 62·3 (11) | 1·38 ± 0·042 (45, 5) | – |
| D. cooperi | SM, SEM | 1 | 1, S | 300·5 ± 19·5 (2) | 2·14 ± 0·185 (13, 2) | 9 ± 0·4 (13, 2) |
| D. crassicornis | SM, SEM | 1 | 1, S | 107 (1) | 2·21 ± 0·114 (15, 3) | 10 ± 0·4 (9, 1) |
| D. erubescens subsp. erubescens | SEM | 1 | 1, S | 7 (1) | 0·64 ± 0·134 (3, 1) | 9 ± 0·9 (8, 1) |
| D. fragrans subsp. fragrans | SEM | 1 | 1, S | 41 ± 1·2 (3) | 1·55 ± 0·072 (19, 2) | 6 ± 0·2 (7, 3) |
| D. galpinii | SEM | 1 | 1, S | 96 (1) | 1·21 ± 0·063 (7, 1) | 8 ± 0·5 (10, 1) |
| D. hircicornis | SEM | 1 | 1, S | 32 ± 7 (2) | 1·74 ± 0·134 (9, 1) | 8 ± 0·6 (4, 1) |
| D. polygonoides | SM | 1 | 1, S | + (5) | – | – |
| D. rhodantha | SM | 1 | 1, S | + (3) | – | – |
| D. sankeyi | SEM | 1 | 1, S | 31·5 ± 5·5 (2) | 0·94 ± 0·05 (15, 3) | 9 ± 0·6 (17, 3) |
| D. scullyi | SM, SEM | 1 | 1, S | 354 (1) | 1·1 ± 0·066 (20, 1) | 9 ± 0·5 (7, 1) |
| D. thodei | SM | 1 | 1, S | + (2) | – | – |
| D. versicolor | SM, SEM | 1 | 1, S | 11 ± 2·7 (4) | 1·01 ± 0·167 (4, 1) | 8 ± 0·5 (11, 2) |
| D. woodii | SEM | 1 | 1, S | 14·3 ± 1·2 (3) | 0·65 ± 0·047 (8, 2) | 5 ± 0·2 (9, 3) |
| D. zuluensis | SM | 1 | 1, S | + (2) | – | – |
Nectar column: 1, nectar-producing; 0, nectarless. Nectary type: 0, no nectary; 1, modified stomata; 2, secretory epidermis. Nectary location: S, spur; P, petals, L, lip. Values are means ± standard error. Sample sizes for number of stomata are given as (nspecimens), those for stomata size and spur-wall thickness as (nmeasurement, nspecimens).
* Spur absent; + stomata present, no count available; SM, stereomicroscopy.