This table lists all species profiled on PIER with the genus beginning with the letter H. An alphabetical index to all PIER species is also available. Also, the complete alphabetical of all PIER species is available, but it is a large list and may take a while to load on systems with slower internet connections. It includes those of environmental concern (including those that are probably of threat only to islands with high elevations) as well as agricultural and ruderal weeds. Each species is linked by its scientific name to an individual write-up containing relevant information.
Species are listed in alphabetic order. You can browse this list or use the "find" function on your web browser to search by scientific name.
Can't find it here? Check the list of synonyms for other names (the more common synonyms are included below) or search other lists and databases available on the Internet.
Stumped by botanical terms? Here are links to a brief glossary and a search engine for botanical terms.
| Scientific name (+Family) | Often-used other Latin names | Habit |
Present on
Pacific Islands? |
Primarily a threat
at high elevations? |
| Haematoxylum campechianum (Fabaceae) | tree | Yes | No | |
| Hakea salicifolia (Proteaceae) | Embothrium salicifolium Vent.; Hakea saligna (Andrews) Knight | shrub/tree | No | No |
| Hamelia patens (Rubiaceae) | Hamelia erecta Jacq.; Hamelia nodosa M. Martens & Galeotti | shrub | Yes | No |
| Harungana madagascariensis (Clusiaceae) | tree | No | No | |
| Hedera algeriensis (Araliaceae) | vine | No | No | |
| Hedera canariensis (Araliaceae) | Hedera helix subsp. canariensis (Willd.) Cout. | vine | No | No |
| Hedera helix (Araliaceae) | vine | Yes | No | |
| Hedychium coronarium (Zingiberaceae) | herb | Yes | No | |
| Hedychium flavescens (Zingiberaceae) | herb | Yes | No | |
| Hedychium gardnerianum (Zingiberaceae) | herb | Yes | No | |
| Helianthus annuus (Asteraceae) | Helianthus lenticularis Douglas | herb | Yes | No |
| Helianthus argophyllus (Asteraceae) | herb | Yes | No | |
| Helichrysum foetidum (Asteraceae) | Gnaphalium foetidum L. | herb | Yes | Yes |
| Heliconia spp. (Heliconiaceae) | herb | Yes | No | |
| Heliocarpus popayanensis (Malvaceae) | Heliocarpus americanus L. | tree | Yes | No |
| Heliotropium indicum (Boraginaceae) | herb | Yes | No | |
| Heliotropium ovalifolium (Boraginaceae) | herb | No | No | |
| Heliotropium procumbens (Boraginaceae) | herb | Yes | No | |
| Hemarthria altissima (Poaceae) | Manisuris altissima (Poir.) Hitchc.; Rottboellia altissima Poir. | grass | Yes | No |
| Hemigraphis alternata (Acanthaceae) | Hemigraphis colorata (Blume) Hallier fil.; Ruellia alternata Burm. f. | herb | Yes | No |
| Hemigraphis reptans (Acanthaceae) | herb | Yes | No | |
| Heteranthera reniformis (Pontederiaceae) | aquatic herb | No | No | |
| Heterocentron subtriplinervium (Melastomataceae) | herb | Yes | No | |
| Heteromeles arbutifolia (Rosaceae) | Heteromeles salicifolia (C. Presl) Abrams; Photinia arbutifolia Lindl.; Photinia salicifolia C. Presl | shrub/tree | Yes | No |
| Heterospathe elata (Arecaceae) | Heterospathe palauensis Becc. | tree | Yes | No |
| Heterotheca grandiflora (Asteraceae) | herb | Yes | No | |
| Hevea brasiliensis (Euphorbiaceae) | tree | Yes | No | |
| Hibiscus diversifolius (Malvaceae) | herb | Yes | No | |
| Hibiscus sabdariffa (Malvaceae) | shrub | Yes | No | |
| Hibiscus syriacus (Malvaceae) | shrub | Yes | No | |
| Hippeastrum puniceum (Amaryllidaceae) | herb | Yes | No | |
| Hippeastrum striatum (Amaryllidaceae) | Amaryllis striata Lam.; Hippeastrum puniceum, misapplied in Hawai‘i and likely elsewhere. | herb | Yes | No |
| Hippobroma longiflora (Campanulaceae) | Isotoma longiflora (L.) C. Presl; Laurentia longiflora (L.) Endl. | herb | Yes | No |
| Hiptage benghalensis (Malpighiaceae) | Hiptage madablota Gaertn.; Triopteris jamaicensis L. | shrub | Yes | No |
| Hirschfeldia incana (Brassicaceae) | herb | Yes | No | |
| Holcus lanatus (Poaceae) | grass | Yes | Yes | |
| Homalanthus populifolius (Euphorbiaceae) | Omalanthus populifolius Graham | tree | Yes | No |
| Hordeum chilense (Poaceae) | Critesion chilense (Roem. & Schult.) Á. Löve | grass | Yes | Yes |
| Hordeum murinum (Poaceae) | grass | Yes | No | |
| Hordeum secalinum (Poaceae) | Critesion secalinum (Schreb.) Á. Löve; Hordeum pratense Huds. | grass | Yes | Yes |
| Houttuynia cordata (Saururaceae) | herb | Yes | No | |
| Hovenia dulcis (Rhamnaceae) | tree | No | No | |
| Howea forsteriana (Arecaceae) | Denea forsteriana (F. Muell. ex H. Wendl.) O. F. Cook; Kentia forsteriana F. Muell. ex H. Wendl. | tree | Yes | No |
| Hoya australis (Apocynaceae) | Hoya dalrympliana F. Muell. | vine | Yes | No |
| Hura crepitans (Euphorbiaceae) | tree | No | No | |
| Hybanthus attenuatus (Violaceae) | herb | No | No | |
| Hydrangea macrophylla (Hydrangeaceae) | Hortensia opuloides Lam.; Hydrangea chungii Rehder; Hydrangea kwangsiensis Hu; Hydrangea opuloides (Lam.) K. Koch; Hydrangea serrata (Thunb.) Ser.; Hydrangea stylosa Hook. f. & Thomson; Hydrangea thunbergii Siebold; Viburnum macrophyllum Thunb. | herb | Yes | No |
| Hydrilla verticillata (Hydrocharitaceae) | aquatic herb | Yes | No | |
| Hydrocotyle bonariensis (Araliaceae) | herb | No | No | |
| Hydrocotyle ranunculoides (Araliaceae) | herb | No | No | |
| Hydrolea zeylanica (Hydroleaceae) | Nama zeylanica L. | aquatic herb | No | No |
| Hygrophila costata (Acanthaceae) | Hygrophila brasiliensis (Spreng.) Lindau; Hygrophila guianensis Nees.; Ruellia brasiliensis Spreng. | aquatic herb | No | No |
| Hygrophila polysperma (Acanthaceae) | aquatic herb | No | No | |
| Hylocereus costaricensis (Cactaceae) | cactus | Yes | No | |
| Hylocereus polyrhizus (Cactaceae) | cactus | Yes | No | |
| Hylocereus undatus (Cactaceae) | succulent | Yes | No | |
| Hymenachne amplexicaulis (Poaceae) | grass | No | No | |
| Hyparrhenia rufa (Poaceae) | grass | Yes | No | |
| Hypericum androsaemum (Hypericaceae) | shrub | No | No | |
| Hypericum calycinum (Hypericaceae) | shrub | Yes | Yes | |
| Hypericum canariense (Hypericaceae) | shrub | Yes | No | |
| Hypericum perforatum (Hypericaceae) | herb | Yes | No | |
| Hypochoeris glabra (Asteraceae) | herb | Yes | No | |
| Hypochoeris radicata (Asteraceae) | herb | Yes | No | |
| Hypoestes phyllostachya (Acanthaceae) | Hypoestes sanguinolenta hort. | herb | Yes | No |
| Hyptis brevipes (Lamiaceae) | herb | No | No | |
| Hyptis capitata (Lamiaceae) | herb | Yes | No | |
| Hyptis mutabilis (Lamiaceae) | herb | Yes | No | |
| Hyptis pectinata (Lamiaceae) | herb | Yes | No | |
| Hyptis rhomboidea (Lamiaceae) | Hyptis capitata var. mexicana Briq.; Hyptis capitata var. pilosa Briq.; Hyptis decurrens (Blanco) Epling | herb | Yes | No |
| Hyptis sidifolia (Lamiaceae) | herb | Yes | No | |
| Hyptis suaveolens (Lamiaceae) | herb | Yes | No |