A tubularintercellularductsurroundedby epithelialcells thatsecrete resins.

Left: Soft pine withlongitudinal resin canal.

Right: Spruce with resincanal in fusiform ray

RESIN CANAL(also called Resin Duct)

SEM: SUNY EW:NCSU

Normal resin canals only in somemembers of the Pine family (Pinaceae)

Resin canals normal in U.S. woods of• Pines (Pinus spp.)• Spruce (Picea spp.)• Larch (Larix spp.)• Douglas Fir (Pseudotsuga spp.)

These 4 genera have both longitudinal and radial resincanals that interconnect at some point, presumably to form a3-D . network.

Longitudinal resin canals not all that long, up to 3 ft. inLoblolly Pine. Note: They do NOT conduct water.

RESIN CANALS

RESIN CANALS

“Large” and usually numerous in the Pines“Small” and usually fewer in Spruce, Larch, and Douglas Fir.

Usually more common in the latewood, but not restricted to latewood

Sugar Pine Ponderosa Pine Larch

Hard Pine Resin Canals

Slightly magnified end view of LoblollyPine (A Cross Section).

Longitudinal resin canals appearas small yellow dots in thelatewood.

The “large” yellow stripes goingthrough the latewood are fusiformrays (with radial resin ducts)-- theyshow up better in the latewood.Arrow parallel to one fusiform rayextending through a number ofrings.

FUSIFORM RAYSFusiform rays have resin canalsin them.

The canal is surrounded byspecialized cells -- epithelialcells that secrete resin.

Most of the rays in the woodswith fusiform rays are still only 1cell wide.

Resin flow out of the tree in aradial direction if tree injured.

Normal Resin Canals Traumatic Resin Canals

After injury (frost, fire, animal or mechanical damage), somesoftwood trees respond by forming extra resin canals.

Would traumatic resincanals be good for thetree?

Would traumatic resincanals increase the value ofthe wood?

How would the presence oftraumatic resin canalsaffect drying and finishingof wood?