Alcohol flux (aka slime flux, bacterial wetwood) - found on stressed mimosa and willow trees.
White froth, acidic & nearly colorless; often has pleasant fermentative odor.
 

Botrytis on tomato stem (found in hydroponic greenhouse)
Manage with fungicide labeled for tomatoes.

Comandra blister rust on Pinus Elderica
Do not plant Elderica pine in Ponderosa areas (Prescott, Sedona).

Dwarf mistletoe parasite on Pondersoa - Arceuthobium vaginatum
Affects Ponderosa pine, Pinyon pine, Douglas fir, true fir; prune infected branches or remove infected trees.

View the publication in the UA Campus Repository

Rust: (Ravenelia versitalis) on catclaw
No management recommended.

Cedar-apple rust (Gymnosporangium) on Hawthorn
No management recommended.

Sycamore anthracnose - Fungus
Management 
Photo: Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org

Bacterial leaf scorch, Xylella fastidios
https://aces.nmsu.edu/ces/plantclinic/documents/xylella-fastidiosa-facts...(link is external)
Photos: N. Goldberg NMSU-PDC

Seiridium Canker on Leyland Cypress

View the publication in the UA Campus Repository
 

Dodder, Cuscuta genus
Annual seed-bearing parasitic vine, thin, thread-like, yellow or orange stems grow rapidly, wrapping around the host plant

Mexican hat Ratibida columnifera with fasciation, which is an abnormal fusion and flattening of plant organs, usually stems, resulting in ribbon-like, coiled and contorted tissue. Cause can be related to hormonal, genetic, bacterial, fungal, viral or environmental conditions. Remove odd growth. Photo by Mary Barnes.

No treatment at this advanced stage. This disease shows up in aspen as they get older.
Photo from Cindy Pitcher. Diagnosis by Bob Gessner.