Table 1 Summary of external and histological features of Macrocystis pyrifera, Lessonia spicata and the hybrid between them found at Mar Brava, Chiloe. SD = Standard deviation.
Holdfast | M. pyrifera* | L. spicata* | Hybrid* |
|---|---|---|---|
Hapteria organization | Branched - unfused | Fused | Branched - unfused |
Hapteron diameter (cm) | 0.34 (0.07) | — | 1.13 (0.21) |
Holdfast diameter (cm) | 12.75 (2.92) | 13.98 (2.70) | 16.37 |
Stipe | |||
Main stipe sturdiness | Flexible | Semi-rigid | Semi-rigid |
Stipe shape | Cylindrical | Cylindrical/flat | Cylindrical/flat |
Main stipe diameter (cm) | 0.97 (0.23) | 1.76 (0.36) | 2.08 |
Fronds | |||
Frond shape | Linear to lanceolate | Linear to lanceolate | Linear to lanceolate |
Frond margins | Serrate | Entire to slightly denticulate | Entire/Serrate |
Frond surface | Corrugated | Smooth | Smooth/Corrugated |
Pneumatocysts | Present | Absent | Absent |
Sporophylls | Present | Absent | Present |
Internal structure | |||
Meristoderm thickness (cell layers) | 2–3** | 2–3** | 2–3 |
Cortex thickness (cell layers) | 10–15** | 10–15** | 8–10 |
Medulla thickness (µm) | 100** | 100** | 50–70 |
Sieve tubes | Present | Absent | Absent |
Mucilage ducts | Present | Absent | Present |
