Taphrina pruni: Pocket Plum galls

The photo here is from Hainault Forest's website which shows many other examples of galls caused by various agents including fungi, insects etc.

Genus: Taphrina
Family: Taphrinaceae
Order: Taphrinales

Taphrina pruni transforms the ovaries of plums into hollow galls without a stone - hence the name 'Pocket Plum'.

Taphrina deformans: Peach Leaf Curl

[photos from The Fifth Kingdom Chapter 4b and Backyard Nature]

Genus: Taphrina
Family: Taphrinaceae
Order: Taphrinales

In Peach Leaf Curl the leaves become thickened, distorted and turn yellow or reddish in colour, later causing the leaves to turn brown, dusty with ascospores and to fall. Taphrina deformans also affects the flowers and peach fruits, causing them either to drop early or become crooked at the stem or develop reddish to purple, wart-like deformities on the fruit surface.

Peach Leaf Curl (Kearnseyville Tree Fruit Research and Education Centre, West Virginia University)

"the lifecycle begins with an ascospore. The ascospore itself produces smaller spores by budding. On the leaf surface these spores produce more spores by budding, and when conditions are just right the spores sprout mycelium -- maybe after two spores fuse together. The full story isn't yet known."

"The mycelium enters the leaf and works its way among the leaf's cells. At this time, while a lot of complex genetic stuff is going on inside the mycelium cells, something causes the leaf's cells to elongate, causing twisting and blistering of the leaf. Eventually certain cells of the mycelium begin enlarging, growing to such an extent that they cause the leaf's cuticle, or "skin," to burst. Now these special, enlarged mycelium cells work themselves onto the leaf's surface and form a very thin surface called the hymenium consisting of stacked-together, clublike asci. The asci rupture, releasing ascospores, and now the life cycle starts over."
[from Backyard Nature]

Taphrina betulina - Witches Broom

[photo by James Lindsey@Wikimedia Commons]

Genus: Taphrina
Family: Taphrinaceae
Order: Taphrinales

Birch Witches' Brooms are masses of densely branched small twigs that resemble a witch's broom stuck in the tree's canopy. Witches' Brooms can be induced by various parasites including Taphrina betulina Rostrup. (Current thinking believes gall inducing phytoplasma may be responsible for some witches' brooms.)

Witches' Broom on Wikipedia

Birch Leaf Curl is induced by a Taphrina betulae (Fckl.) Johans. infection.

It has been found that Taphrina betulina infections in White Birch (Betula pubescens) trees cause reduced growth (by an average of 25%) and vigour, and 'Witches' Broom' growths (pictured here), the number and sizes of which correlate to the DBH (diameter at breast height), but not to the reductions in height and vigour [1].

1. (from Abstract) The effects of Taphrina betulina infection on growth of Betula pubescens, Y. A. Simmons and S. Woodward, European Journal of Forest Pathology, 2007 - Vol 24, Issue 5, p.277-286

Ascomycetes: Taphrina

[from Wikipedia - highlighting is not]

Genus: Taphrina
Family: Taphrinaceae
Order: Taphrinales
Class: Taphrinomycetes
Subphylum: Taphromycotina
Phylum: Ascomycota

Taphrina is fungal genus within the Ascomycota that causes leaf and catkin curl diseases and witch's brooms of certain flowering plants. One of the more commonly observed species causes peach leaf curl.

Taphrina typically grow as yeasts during one phase of their life-cycles, then infect plant tissues in which typical hyphae are formed, and ultimately they form a naked layer of asci on the deformed, often brightly pigmented surfaces of their hosts.

No discrete fruitbody is formed outside of the gall-like or blister-like tissues of the hosts. The asci form a layer lacking paraphyses, and they lack croziers. The acospores frequently bud into multiple yeast cells within the asci.

Phylogenetically, Taphrina is a member of a basal group within the Ascomycota, and type genus for the subphylum Taphrinomycotina, the class Taphrinomycetes, and order Taphrinales.

Some common Taphrina species:

• Taphrina betulina Rostrup - Birch Witches' Broom
• Taphrina pruni Tul. - Pocket Plums (gall affecting fruit on Blackthorn)
• Taphrina carpini - on Hornbeam
• Taphrina deformans - Peach Leaf Curl
• Taphrina caerulescens - Oak Leaf Blister
• Taphrina sacchari - Maple leaf blister
• Taphrina populina - Poplar