Table 2.
Comparison between wood anatomical traits of climbing and erect species within major Apocynaceae groups. Tribes in grey are rauvolfioids, red represents Asclepiadoideae, and green is Periplocoideae. Numbers in parentheses behind clade names are the number of wood samples investigated (generally one sample per species with a few exceptions; see Appendices S1 and S2 for sampling specifics). +: present; –: absent; (): traits occasionally present but not found in all clade members. * (probably) includes intermediate growth forms, ** includes erect Diplorhynchus. Vessel dimensions exclude narrow vessels in case of vessel dimorphism.
| Range of average vessel diameter (µm) | Range of average vessel element length (µm) | Species with mainly solitary vessels | Species with mainly vessels in radial multiples | Species with mainly vessels in clusters | Vessel dimorphism | Range of average fiber length (µm) | Laticifers | Vascular variants | ||
|---|---|---|---|---|---|---|---|---|---|---|
| Alyxieae | Erect (2) | 60 | 480‐1370 | + | + | ‐ | ‐ | 1240‐2980 | ‐ | ‐ |
| Climbing (10) | 80‐220 | 430‐940 | + | ‐ | ‐ | ‐ | 730‐1740 | (+) | ‐ | |
| Melodineae** | Erect (3) | 40‐70 | 550‐710 | + | ‐ | ‐ | ‐ | 1420‐1630 | + | ‐ |
| Climbing (3) | 70‐130 | 470‐720 | + | ‐ | ‐ | ‐ | 1050‐1150 | ‐ | ‐ | |
| Willughbeeae | Erect (8) | 50‐120 | 430‐1020 | ‐ | + | ‐ | ‐ | 920‐1700 | ‐ | ‐ |
| Climbing (17) | 60‐230 | 410‐630 | + | ‐ | (+) | (+) | 580‐1690 | + | ‐ | |
| Periplocoideae | Erect (4*) | 40‐50 | 225‐320 | + | ‐ | ‐ | ‐ | 540‐600 | ‐ | ‐ |
| Climbing (4) | 100‐240 | 250‐450 | + | ‐ | + | (+) | 500‐850 | ‐ | + | |
| Asclepiadeae | Erect (16*) | 30‐90 | 160‐570 | + | + | + | (+) | 340‐1110 | (+) | ‐ |
| Climbing (16) | 60‐190 | 250‐500 | + | ‐ | + | + | 420‐740 | (+) | + |