Table 1. Characters separating Argocoffeopsis, Calycosiphonia and the new genus Kupeantha.
Characters diagnostic for Kupeantha shown in bold. Number of ovules per locule based on Sonké et al. (2007) and Robbrecht (1981).
| Argocoffeopsis | Calycosiphonia | Kupeantha | |
|---|---|---|---|
| Habit | Climbing shrubs | Treelets | Small shrubs to treelets |
| Evergreen or deciduous | Deciduous or Evergreen | Evergreen | Evergreen |
| Inflorescences | Terminal or axillary & opposite brachyblasts with a series of 2–4 pairs of reduced leaves (homologous with cupular calyculi with foliar lobes) 2.5 cm long | Appearing axillary, fasciculate, terminal on contracted brachyblasts, with leaf pairs reduced to 2–3 pairs cupular calyculi, some of foliar lobes foliose 3.5mm long | Appearing axillary, fasciculate. Terminal on contracted brachyblasts, with leaf pairs reduced to 2–4 cupular calyculi, the foliar lobes minute, c. 0.2 mm long |
| Lateral buds | Axillary, concealed in stipule sheaths | Axillary, concealed in stipule sheaths | Supra-axillary, emerging from stem 1–4 mm above stipule sheaths, spike-like |
| Epidermis of leafy branches (dried specimens) | Pale brown or grey, hairy or (3/8 spp.) glabrous | Black only for a few mm of the most distal internode, otherwise white or pale brown, slightly spongy. | Black (distal (1–)2(–4) internodes, proximal internodes white, spongy |
| Leaf-blade venation | Tertiary nerves conspicuous. Quaternary nerves usually conspicuous, finely reticulate. | Tertiary nerves conspicuous. Quaternary nerves obscure ± scalariform | Tertiary & quaternary nerves obscure & inconspicuous (except K. pentamera where both conspicuous & finely reticulate). Not scalariform. |
| Calyx | Tube distinct, c. ¼ length of ovary, with minute lobes | Tube well-developed, about half as long as ovary, lobes absent | Tube reduced to a minute rim, (shorter than disc), lobes absent |
| Anthers | Non-locellate | Locellate | Non-locellate |
| Terminal connective appendage | Absent or present | Absent | Present |
| Staminal filament length | (1–)2–3 mm | 2–3 mm | 0.2–0.5 (–2.2 mm in K. fosimondi) |
| Anther attachment | ± basifixed | Medifixed | ± basifixed |
| Pollen | (3–)4–5-colporate | 3-colporate | 3-colporate (observed only in K. kupensis) |
| Ovules per locule | 1 | 2 (rarely 1) | 1 |
| Leaf blade domatia | Present | Absent or present | Absent |