Bunias orientalis

Holosteum umbellatum (jagged chickweed)
Holy See (Vatican City)
Honckenya peploides (seaside sandplant)
Honduras
Hong Kong
Hordelymus europaeus
Hordeum brachyantherum ssp. brachyantherum (meadow barley)
Hordeum distichum
Hordeum jubatum (foxtail barley)
Hordeum murinum
Hordeum murinum (mouse barley)
Hordeum pusillum (little barley)
Hornungia petraea
Hornungia procumbens (prostrate hutchinsia)
Houstonia caerulea (azure bluet)
Houstonia canadensis (Canadian summer bluet)
Houstonia longifolia (longleaf summer bluet)
Houstonia purpurea (Venus' pride)
Houstonia purpurea var. calycosa (Venus' pride)
Houstonia pusilla (tiny bluet)
Houstonia serpyllifolia (thymeleaf bluet)
Hoya carnosa
Humulus lupulus
Hungary
Huperzia porophila (rock clubmoss)
Hyacinthus orientalis
Hydrocharis morsus-ranae
Hydrocotyle americana (American marshpennywort)
Hydrocotyle prolifera (whorled marshpennywort)

Image of Bunias orientalis 1
Credit: Photo by Leo Michels. Usage: Public Domain