Índice: Species (currently accepted name)
- Hedera helix L. (1)
- Helianthemum canum (L.) Hornem. (3)
- Helianthemum caput-felis Boiss. (7)
- Helichrysum arenarium (L.) Moench (5)
- Helichrysum panormitanum subsp. melitense (Pignatti) Iamonico & Pignatti (1)
- Helichrysum zivojinii Černjavski & Soška (1)
- Helosciadium repens (Jacq.) W.D.J.Koch (27)
- Hemipilia cucullata (L.) Y.Tang, H.Peng & T.Yukawa (4)
- Heracleum sphondylium L. (1)
- Heracleum sphondylium subsp. alpinum (L.) Bonnier & Layens (5)
- Herminium monorchis (L.) R.Br. (2)
- Herniaria berlengiana (Chaudhri) Franco (1)
- Herniaria hemistemon J.Gay (1)
- Hieracium australe Fr. subsp. australe (1)
- Hierochloe odorata (L.) P. Beauv. (1)
- Himantoglossum calcaratum (Beck) Schltr. subsp. rumelicum (H.Baumann & R.Lorenz) Niketic & Djordjevic (1)
- Himantoglossum hircinum (L.) Spreng. (2)
- Hirtellina lobelii (DC.) Dittrich (1)
- Hladnikia pastinacifolia Rchb. (1)
- Hormathophylla saxigena (Jord. & Fourr.) D.A.German & Govaerts (1)
- Hornungia pauciflora (W.D.J.Koch) Soldano, F.Conti, Banfi & Galasso (3)
- Horstrissea dolinicola Greuter, Gerstb. & Egli (2)
- Hyacinthoides mauritanica (Schousb.) Speta (1)
- Hypericum aciferum (Greuter) N.Robson (1)
- Hypericum elodes L. (1)
- Hypericum nanum Poir. (1)
- Hypericum scruglii Bacch., Brullo & Salmeri (1)
- Hypericum tetrapterum Fr. (1)
- Hypochaeris maculata L. (3)