A |
B |
C |
D |
E |
F |
G |
H |
I |
J |
K |
L |
M |
N |
O |
P |
Q |
R |
S |
T |
U |
V |
W |
X |
Y |
Z |
| - Udotea |
| Udotea petiolata |
| - Ulex |
| Ulex europaeus |
| Ulex gallii |
| - Ulex (Synonym) |
| - Ulex minor ssp. gallii |
| - Ulmus |
| Ulmus glabra |
| Ulmus laevis |
| Ulmus minor |
| - Ulva |
| Ulva intestinalis |
| Ulva lactuca |
| Ulva rigida |
| - Umbilicus |
| Umbilicus gaditanus |
| Umbilicus horizontalis |
| Umbilicus rupestris |
| - Urginea (Synonyme) |
| - Urginea hesperia |
| - Urginea maritima |
| - Urginea undulata |
| - Urospermum |
| Urospermum dalechampii |
| Urospermum picroides |
| - Urtica |
| Urtica dioica |
| - Usnea |
| Usnea sp. |