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Yes, stiffleaf cheesewood is rated fire resistant, though its laboratory results call for a cautious reading.
Fire and Emergency New Zealand places this tree in the low/moderate class, which falls on the recommended side of its seven-level scale. Placement, spacing, irrigation, and removal of dead material remain necessary under Fire Safe Marin's guidance, which lists stiffleaf cheesewood as fire resistant. University of California Forest Products Laboratory compilers also found three earlier references recommending dwarf karo for high-fire-risk areas. The Diablo Firesafe Council reports favorable fire performance in three or more references. The University of California Forest Products Laboratory flags two problems with the earlier lists: undefined rating terms and a frequent lack of scientific basis.
Laboratory findings add some friction to that agreement. A 2016 shoot-flammability study placed stiffleaf cheesewood in its moderate category after the samples were air-dried for 24 hours. A separate FLAMITS measurement records an ignition frequency of 100% for predried branches tested on a grill. That number reports the frequency observed in that experiment; the database does not convert it into a recommendation or impose one threshold across different tests, devices, and plant parts.
The fairest conclusion is that several fire-safety sources favor stiffleaf cheesewood, while limited primary testing assigns its shoots moderate flammability.
Form
tree
Rated in
California; Global; Marin County, California; New Zealand
On this lot
1. Fire evidence and conditions
Fire evidence
Fire-resistant — location does not change the cited classification.
The guide presents itself as fire performance ratings for common landscape plants in a fire-prone California setting. FireApproved publishes 104 exact owners as republished California context. It is not an independent rating, a current endorsement, or parcel suitability.
Marin County (CA footprint); partial normalized coverage · 2019-01-01
The publication is explicitly limited to plants common to Marin County. FireApproved publishes 104 exact owners as Marin regional context while retaining its placement, spacing, irrigation, and maintenance boundary. It is not statewide California guidance or parcel suitability.
The UC Forest Products Laboratory says the guide covers properties of common California landscaping plants and was prepared for California fire agencies. FireApproved publishes 130 exact owners at historical California publication scope. The report is a 1997 compilation, not a current endorsement, site rating, or independent test of every row.
2. Why this plant is relevant here
State distribution
Documented in CA.
Native range
Introduced / established
2 sourced range or established records. This is not an invasive warning.
USDA hardiness
3. Legal, ecological, and broader status
Legal-list status
Seed-list status
Reported invasive here
Broader regional context
Federal context
How to read this page
The status above is computed from the cited rows below: independent recommendations can support a fire-resistant result, an avoid row can produce keep-away, and disagreement stays visible as conflict. Placement notes preserve each source’s own scheme rather than translating unlike rules into one scale. This is evidence about a plant, not permission to plant it in every part of the defensible space; Zone 0 remains noncombustible.
Native and introduced range evidence
These are exact U.S. botanical-area records from the cited range source. Native and
introduced describe biogeographic relationship, not fire performance or planting approval.
Doubtful and extinct rows stay visible but do not count as current presence.
The lossless worldwide derivative is retained once in the research corpus; object pages repeat only exact U.S. areas needed by the local lens. The JSON twin carries the same page assertions.
Conditions in the fire evidence
These describe tested or rated plant material. They are not horticultural maintenance instructions.
Placement rules below use each source's own distances or named zones, tied to its rating.
They are not interchangeable with the directory's current Zone 0 guidance.
Defensible Space Landscaping in the Urban/Wildland Interf…: Chapter 4, Landscape Vegetation Database [ucfpl-1997] (with its recommendation)
Fire Performance of Common Plants: Table 1 (favorable in 3 or more references) [diablo-guide-to-plants-three-reference-vote] (with its recommendation)
The evidence
Grouped by what each source concluded. Primary evidence rated the plant itself
(a lab, field program, or original curation); corroboration compiled or
republished another source's rating and resolves to its root lineage.
Recommends (4)
Low Flammability Plants directory — Fire and Emergency New Zealand (plant flammability testing at Lincoln University) · 2026 · original sourcePrimary evidenceLab-testedlineage: lincoln-nz-tree
Fire Performance of Common Plants (Guide to Plants) — Diablo Firesafe Council · live page captured 2026-08-29 · original sourceCorroborationMirrorlineage: ucfpl-berkeley resolves to Defensible Space Landscaping in the Urban/Wildland Interface: A Compilation of Fire Performance Ratings of Residential Landscape Plants
“Table 1: favorable fire performance rating in 3 or more references (refs 25,40,41)”
The Diablo Firesafe Council Guide to Plants lists Pittosporum crassifolium (Dwarf karo) as shrub, evergreen, in Table 1: plants with a favorable fire performance rating in 3 or more references. The guide cites 3 of its 57 numbered references for this row (25,40,41). The guide states the ranking terms in its underlying references were mostly undefined and makes no attempt to rank within the list, and that fire performance is compromised without maintenance.
8 cited rows from this source; its identity, lineage and tier are stated once.
Primary study Cui2020a: Cui, X., Paterson, A. M., Wyse, S. V., Alam, M. A., Maurin, K. J. L., Pieper, R., ... Curran, T. J. (2020a). Shoot flammability of vascular plants is phylogenetically conserved and related to habitat fire-proneness and growth form. Nature Plants, 6, 355-359.
Shared row context: plant part branches; fuel all; predrying yes; device grill; site Cui2020a-1; sampling ND.
“ignition frequency (%): 100”
FLAMITS record 1466; Ignitability measurement.
“maximum sample temperature (°C): 391”
FLAMITS record 1660; Combustibility measurement.
“burning duration (s): 7.6”
FLAMITS record 1854; Sustainability measurement.
“estimated burnt biomass (%): 6.9”
FLAMITS record 2048; Consumability measurement.
Primary study Wyse2016: Wyse, S. V., Perry, G. L. W., O'Connell, D. M., Holland, P. S., Wright, M. J., Hosted, C. L., ... Curran, T. J. (2016). A quantitative assessment of shoot flammability for 60 tree and shrub species supports rankings based on expert opinion. International Journal of Wildland Fire, 25, 466-477.
Shared row context: plant part branches; fuel all; predrying yes; device grill; site Wyse2016-3; sampling ND.
