Characters | P. arabicus | P. asirensis | P. barbatus | P. cylindraceus | P. hijazensis | P. pseudomarrubioides | P. tenuiflorus |
Seed morphology | |||||||
1. Seed shape (mm) | Sub spherical | Ovoid | Ovoid | Sub spherical | Ovoid | Sub spherical | Sub spherical |
2. Seed size | 0.7 - 0.8 × 0.6 - 0.7 | 1.3 - 1.5 × 1.1 - 1.2 | 1.2 - 1.5 × 0.8 - 1 | 0.7 - 0.8 × 0.6 - 0.7 | 1.1 - 1.5 × 0.7-1 | 0.6 - 0.7 × 0.5 - 0.6 | 0.8 - 1 × 0.7 - 0.9 |
3. Seed color | Reddish-brown | Reddish- brown | Black | Yellow- brown | Reddish- brown | Yellow-brown | Reddish-brown |
Pollen morphology | |||||||
4. Polar axis (P μm) | (20 - 26) 23 | (22 - 30) 26 | (26 - 36) 31 | (20 - 26) 23 | (21 - 25) 23 | (16 - 24) 20 | (37 - 44) 41 |
5. Equatorial diameter (E μm) | (15 - 21) 18 | (20 - 25) 22 | (20 - 28) 24 | (15 - 21) 18 | (13 - 16) 15 | (14 - 18) 16 | (26 - 32) 29 |
6. P/E | 1.28 | 1.18 | 1.29 | 1.28 | 1.5 | 1.25 | 1.41 |
7. Pollen shape | Subprolate | Subprolate | Subprolate | Subprolate | Prolate | Subprolate | Prolate |
8. pollen type | Hexa- Zonocolpate | Hexa- Zonocolpate | Hexa- Zonocolpate | Hexa- Zonocolpate | Hexa- Zonocolpate | Hexa- Zonocolpate | Hexa- Zonocolpate |
9. Exine sculpture | Bi-reticulate | Bi-reticulate | Primary lumina is reticulate and secondary is granulate- perforate | Bi-reticulate | Primary lumina is reticulate and secondary is microreticulate | Primary lumina is reticulate and secondary is microreticulate | Primary lumina is reticulate and secondary is microreticulate |
Trichomes morphology | |||||||
10. Unbranched multicellularhairs | + | + | + | + | + | + | + |
11. Bi-cellular hairs | + | - | - | + | - | - | - |
12. Branched multicellular hairs | + | - | - | - | - | - | - |
13. Multicellular glandular hairs | + | - | - | - | - | - | - |
14. Long-stalked capitate hairs | - | - | - | - | + | - | - |
15. Peltate hairs | - | - | - | + |
| + | - |