Hawaii Plant Materials State Exam 2026 | Verified Questions
& Detailed Explanations | Landscape Architect Licensure
|instant pdf download
1. Which variety of ʻōhiʻa lehua (Metrosideros polymorpha) is characterized by dense silvery-gray hairs on the
undersides of its leaves and is typically found in high-elevation wet forests?
A) var. glaberrima
B) var. incana
C) var. polymorpha
D) var. macrophylla
Answer B: var. incana
Rationale: Metrosideros polymorpha var. incana is distinguished by its gray, hairy (tomentose) leaf undersides, an
adaptation to cool, misty montane conditions.
2. Which endemic loulu palm from the Waiʻanae Mountains has fan-shaped leaves with a dense white tomentum
on the lower surface?
A) Pritchardia martii
B) Pritchardia kaalae
C) Pritchardia remota
D) Pritchardia arecina
Answer B: Pritchardia kaalae
Rationale: Pritchardia kaalae, known as loulu hiwa, is endemic to the Waiʻanae range; its leaf undersides bear a
thick layer of white hairs.
3. A landscape architect wishes to distinguish the invasive naio (Myoporum laetum) from the native naio
(Myoporum sandwicense). Which leaf characteristic is the most reliable field differentiator?
A) Leaf margin serration and presence of conspicuous translucent oil glands
B) Leaf length and width
C) Petiole length
D) Presence of domatia
Answer A: Leaf margin serration and presence of conspicuous translucent oil glands
Rationale: Myoporum laetum has distinctly serrated leaf margins and prominent translucent oil glands visible
when held to light; Myoporum sandwicense has entire margins with far less obvious glandular dots.
,4. The more aggressive form of Rapid ʻŌhiʻa Death (ROD) that causes rapid wilt and canopy browning is caused by
which fungal pathogen?
A) Ceratocystis huliohia
B) Ceratocystis fimbriata
C) Ceratocystis lukuohia
D) Fusarium oxysporum
Answer C: Ceratocystis lukuohia
Rationale: Ceratocystis lukuohia causes the acute, fast-acting wilt form of ROD, while C. huliohia causes a slower
decline.
5. Which dryland endemic tree, closely related to koa, has stiff, narrow, sickle-shaped phyllodes and is commonly
used for reforestation of leeward, drought-prone sites?
A) Acacia koa
B) Acacia koaia
C) Acacia mangium
D) Acacia confusa
Answer B: Acacia koaia
Rationale: Acacia koaia (koaiʻa) is adapted to xeric conditions, with dense, narrow phyllodes and a shrubby to
small-tree form.
6. The lightweight, easily carved wood of which indigenous coastal tree was traditionally favored for crafting
ʻumeke (calabashes)?
A) Thespesia populnea
B) Cordia subcordata
C) Aleurites moluccana
D) Metrosideros polymorpha
Answer B: Cordia subcordata
Rationale: Kou (Cordia subcordata) wood is soft, lightweight, and easily worked, making it ideal for food vessels,
although it is now less common due to the kou leaf worm.
7. The endangered yellow-flowered hibiscus with a prominent maroon center that serves as the official state
flower of Hawaiʻi is:
A) Hibiscus arnottianus
B) Hibiscus kokio
C) Hibiscus brackenridgei
D) Hibiscus waimeae
, Answer C: Hibiscus brackenridgei
Rationale: Hibiscus brackenridgei (maʻo hau hele) is a Federally endangered species with sunny yellow petals and a
deep maroon eye.
8. This endemic wetland sedge, highly valued for its pliable culms used in the finest Niʻihau mats, has a
characteristic triangular stem. It is:
A) Cyperus javanicus
B) Cyperus laevigatus
C) Machaerina angustifolia
D) Fimbristylis cymosa
Answer B: Cyperus laevigatus
Rationale: Makaloa (Cyperus laevigatus) grows in coastal marshlands and its soft, triangular stems produce the
supple material for premium “makaloa” mats.
9. For a xeric, full-sun coastal site with alkaline sand, which native groundcover is best adapted, forming fleshy
mats that tolerate salt spray and burial by sand?
A) Vitex rotundifolia (pōhinahina)
B) Sesuvium portulacastrum (akulikuli)
C) Ipomoea pes-caprae (pōhuehue)
D) Sphagneticola trilobata (wedelia)
Answer B: Sesuvium portulacastrum (akulikuli)
Rationale: Akulikuli is a succulent, salt-tolerant coastal creeper that thrives in alkaline, well-drained sand and can
be periodically inundated by seawater.
10. An endangered Pritchardia species from South Kona is notable for its immense, entire leaf blades over 1 m
wide in juveniles. It is:
A) Pritchardia beccariana
B) Pritchardia schattaueri
C) Pritchardia lanigera
D) Pritchardia glabrata
Answer B: Pritchardia schattaueri
Rationale: Pritchardia schattaueri, a rare loulu, produces some of the largest undivided leaves of any Hawaiian
palm, especially in its juvenile stage.
11. The root bark of which indigenous tree yields a yellow-orange dye traditionally used for kapa, while its fruit is
famous for its strong, fetid aroma?
A) Gardenia brighamii
, B) Morinda citrifolia
C) Santalum paniculatum
D) Pittosporum confertiflorum
Answer B: Morinda citrifolia
Rationale: Noni (Morinda citrifolia) root produces a yellow pigment, and the fruit is notorious for its pungent,
cheese-like odor.
12. In Dodonaea viscosa (ʻaʻaliʻi), the leaf form most often associated with exposed, arid habitats, which reduces
transpirational surface area, is:
A) Broadly ovate leaves
B) Narrow, linear to lanceolate leaves
C) Deeply lobed leaves
D) Succulent, cylindrical leaves
Answer B: Narrow, linear to lanceolate leaves
Rationale: Arid-site ecotypes of ʻaʻaliʻi typically have reduced, narrow leaves (sometimes labeled var. angustifolia)
to minimize water loss.
13. Which extremely rare endemic mint from the Waiʻanae Mountains, with fragrant foliage and whorls of small
white flowers, is a high-priority species for conservation plantings?
A) Stenogyne kanehoana
B) Phyllostegia kaalaensis
C) Plectranthus parviflorus
D) Ocimum gratissimum
Answer B: Phyllostegia kaalaensis
Rationale: Phyllostegia kaalaensis is a critically endangered lamioid mint endemic to mesic Oʻahu forests, difficult
to cultivate but essential for restoration.
14. The astringent leaf buds of which Polynesian-introduced tree are traditionally chewed to treat oral thrush and
diarrhea, and its bark yields a brown dye?
A) Syzygium malaccense (mountain apple)
B) Artocarpus altilis (breadfruit)
C) Hibiscus tiliaceus (hau)
D) Piper methysticum (ʻawa)
Answer A: Syzygium malaccense (mountain apple)
Rationale: ʻŌhiʻa ʻai (Syzygium malaccense) leaf buds are rich in tannins and were used medicinally for mucous
membrane ailments.
& Detailed Explanations | Landscape Architect Licensure
|instant pdf download
1. Which variety of ʻōhiʻa lehua (Metrosideros polymorpha) is characterized by dense silvery-gray hairs on the
undersides of its leaves and is typically found in high-elevation wet forests?
A) var. glaberrima
B) var. incana
C) var. polymorpha
D) var. macrophylla
Answer B: var. incana
Rationale: Metrosideros polymorpha var. incana is distinguished by its gray, hairy (tomentose) leaf undersides, an
adaptation to cool, misty montane conditions.
2. Which endemic loulu palm from the Waiʻanae Mountains has fan-shaped leaves with a dense white tomentum
on the lower surface?
A) Pritchardia martii
B) Pritchardia kaalae
C) Pritchardia remota
D) Pritchardia arecina
Answer B: Pritchardia kaalae
Rationale: Pritchardia kaalae, known as loulu hiwa, is endemic to the Waiʻanae range; its leaf undersides bear a
thick layer of white hairs.
3. A landscape architect wishes to distinguish the invasive naio (Myoporum laetum) from the native naio
(Myoporum sandwicense). Which leaf characteristic is the most reliable field differentiator?
A) Leaf margin serration and presence of conspicuous translucent oil glands
B) Leaf length and width
C) Petiole length
D) Presence of domatia
Answer A: Leaf margin serration and presence of conspicuous translucent oil glands
Rationale: Myoporum laetum has distinctly serrated leaf margins and prominent translucent oil glands visible
when held to light; Myoporum sandwicense has entire margins with far less obvious glandular dots.
,4. The more aggressive form of Rapid ʻŌhiʻa Death (ROD) that causes rapid wilt and canopy browning is caused by
which fungal pathogen?
A) Ceratocystis huliohia
B) Ceratocystis fimbriata
C) Ceratocystis lukuohia
D) Fusarium oxysporum
Answer C: Ceratocystis lukuohia
Rationale: Ceratocystis lukuohia causes the acute, fast-acting wilt form of ROD, while C. huliohia causes a slower
decline.
5. Which dryland endemic tree, closely related to koa, has stiff, narrow, sickle-shaped phyllodes and is commonly
used for reforestation of leeward, drought-prone sites?
A) Acacia koa
B) Acacia koaia
C) Acacia mangium
D) Acacia confusa
Answer B: Acacia koaia
Rationale: Acacia koaia (koaiʻa) is adapted to xeric conditions, with dense, narrow phyllodes and a shrubby to
small-tree form.
6. The lightweight, easily carved wood of which indigenous coastal tree was traditionally favored for crafting
ʻumeke (calabashes)?
A) Thespesia populnea
B) Cordia subcordata
C) Aleurites moluccana
D) Metrosideros polymorpha
Answer B: Cordia subcordata
Rationale: Kou (Cordia subcordata) wood is soft, lightweight, and easily worked, making it ideal for food vessels,
although it is now less common due to the kou leaf worm.
7. The endangered yellow-flowered hibiscus with a prominent maroon center that serves as the official state
flower of Hawaiʻi is:
A) Hibiscus arnottianus
B) Hibiscus kokio
C) Hibiscus brackenridgei
D) Hibiscus waimeae
, Answer C: Hibiscus brackenridgei
Rationale: Hibiscus brackenridgei (maʻo hau hele) is a Federally endangered species with sunny yellow petals and a
deep maroon eye.
8. This endemic wetland sedge, highly valued for its pliable culms used in the finest Niʻihau mats, has a
characteristic triangular stem. It is:
A) Cyperus javanicus
B) Cyperus laevigatus
C) Machaerina angustifolia
D) Fimbristylis cymosa
Answer B: Cyperus laevigatus
Rationale: Makaloa (Cyperus laevigatus) grows in coastal marshlands and its soft, triangular stems produce the
supple material for premium “makaloa” mats.
9. For a xeric, full-sun coastal site with alkaline sand, which native groundcover is best adapted, forming fleshy
mats that tolerate salt spray and burial by sand?
A) Vitex rotundifolia (pōhinahina)
B) Sesuvium portulacastrum (akulikuli)
C) Ipomoea pes-caprae (pōhuehue)
D) Sphagneticola trilobata (wedelia)
Answer B: Sesuvium portulacastrum (akulikuli)
Rationale: Akulikuli is a succulent, salt-tolerant coastal creeper that thrives in alkaline, well-drained sand and can
be periodically inundated by seawater.
10. An endangered Pritchardia species from South Kona is notable for its immense, entire leaf blades over 1 m
wide in juveniles. It is:
A) Pritchardia beccariana
B) Pritchardia schattaueri
C) Pritchardia lanigera
D) Pritchardia glabrata
Answer B: Pritchardia schattaueri
Rationale: Pritchardia schattaueri, a rare loulu, produces some of the largest undivided leaves of any Hawaiian
palm, especially in its juvenile stage.
11. The root bark of which indigenous tree yields a yellow-orange dye traditionally used for kapa, while its fruit is
famous for its strong, fetid aroma?
A) Gardenia brighamii
, B) Morinda citrifolia
C) Santalum paniculatum
D) Pittosporum confertiflorum
Answer B: Morinda citrifolia
Rationale: Noni (Morinda citrifolia) root produces a yellow pigment, and the fruit is notorious for its pungent,
cheese-like odor.
12. In Dodonaea viscosa (ʻaʻaliʻi), the leaf form most often associated with exposed, arid habitats, which reduces
transpirational surface area, is:
A) Broadly ovate leaves
B) Narrow, linear to lanceolate leaves
C) Deeply lobed leaves
D) Succulent, cylindrical leaves
Answer B: Narrow, linear to lanceolate leaves
Rationale: Arid-site ecotypes of ʻaʻaliʻi typically have reduced, narrow leaves (sometimes labeled var. angustifolia)
to minimize water loss.
13. Which extremely rare endemic mint from the Waiʻanae Mountains, with fragrant foliage and whorls of small
white flowers, is a high-priority species for conservation plantings?
A) Stenogyne kanehoana
B) Phyllostegia kaalaensis
C) Plectranthus parviflorus
D) Ocimum gratissimum
Answer B: Phyllostegia kaalaensis
Rationale: Phyllostegia kaalaensis is a critically endangered lamioid mint endemic to mesic Oʻahu forests, difficult
to cultivate but essential for restoration.
14. The astringent leaf buds of which Polynesian-introduced tree are traditionally chewed to treat oral thrush and
diarrhea, and its bark yields a brown dye?
A) Syzygium malaccense (mountain apple)
B) Artocarpus altilis (breadfruit)
C) Hibiscus tiliaceus (hau)
D) Piper methysticum (ʻawa)
Answer A: Syzygium malaccense (mountain apple)
Rationale: ʻŌhiʻa ʻai (Syzygium malaccense) leaf buds are rich in tannins and were used medicinally for mucous
membrane ailments.
