Monday, December 15, 2014

Cranefly Orchid

The evergreen leaf of the Cranefly Orchid often has purplish bumps.

     Believe it or not, winter is one of the best times to find some of our native orchids. One of these is the Cranefly Orchid, which is also our most common. Perhaps this is because it may not be as picky of which mycorrhizal fungi it needs to survive as other North American orchids. Some other native orchids, such as the Ladyslippers, are very specific of which fungi they form a symbiotic relationship with. This is why they are not only rare, but normally cannot be moved, for if the fungi dies, so does the orchid. Cranefly orchids seem less specific of the fungi they need, but are certainly not considered common. They are considered endangered in some states.
     The reason that the Cranefly Orchid stands out during winter is that it is evergreen. More so, if you flip the leaf over, it is a bright purple underneath. This makes it easy to identify and also is the reason for the second part of its scientific name: Tipularia discolor. "Tipula" is Latin for "cranefly." It is the sole member of its genus in North America.

The underside of a Cranefly Orchid leaf showing its distinctive purple color.
     Each plant has a single leaf that emerges in September or so, but they can form small colonies with the tuberous roots close together and thus look multi-leaved. The lone leaf disappears in late spring when the plant flowers, so mark the location now if you wish to see one in bloom. This winter leafing out is termed a hibernal leaf.

Cranefly orchids flowering at night, awaiting their moth pollinators. They are somewhat fragrant at night also, helping to attract Noctuid moths.

     The flowers bloom in late summer after the leaves have disappeared, often in August. They are not that showy to us, being small, but are very attractive to Noctuid moths which are the main pollinators. Almost all of the pollination happens at night. Despite their common name, they are not pollinated by craneflies. I have however seen the pollen bags (pollininara) attached to moths, often to their eyes.

Cranefly orchid flowers up close. Some say they look like craneflies aloft and that being the reason for the name. Others think it was a misunderstanding about their main pollinators.

    The small flowers are said by some to look like craneflies, leaning to one side or the other and are asymmetrical. This is said by some to have resulted in its common names of Cranefly Orchid or Crippled Cranefly Orchids. The unusual flower shape and small size has also led to another common name: Elfin Spurs.

Cranefly orchid seed pods.

     The tuberous roots (corms in botanical terms) are said to be edible and potato-like, but I've never tried them. I think they are much too uncommon to harvest. Best to leave them for the moths, especially since they are, like most orchids, a favorite of deer and so are becoming rarer every day with the rising over populations of deer. I hope to spot them on winter woodland walks for a long time to come.

Sunday, December 7, 2014

Oak Galls

One of the Oak Apple Galls (Amphibolips spp), a type of Cynapid wasp

     Galls are growths caused by an organism (usually an insect or mite) in an another organism (normally plants). There are over 2,000 different types in North America. Each type is very uniform in shape, host plant specific, and generally only occur on specific parts of their hosts. How the gall maker induces the plant to grow in such a uniform manner is not completely understood. The gall inducer lives inside the gall, which provides protection, nourishment, and water. It is for all practical purposes, its edible home.

Oak Bullet Gall (perhaps Disholcospis globulus?), caused by a Cynapid wasp.

     I am unaware of any plant that hosts more gall species than the oaks (Quercus spp.). Over 800 kinds of galls need oaks in order to survive. The vast majority of these galls are produced by the larvae of tiny wasps in the Cynapid family. There is not much known about the life cycle itself of most gall producers, and oak gall makers are no different. Here a few that I've encountered.

Lobed Oak Gall (Cynips strobiliana) on Swamp White Oak. This Cynapid wasp is usually restricted to Bur and Swamp White Oaks.

Gouty Oak Galls (Callirhytis quercuspunctata?) caused by Cynapid wasps.

Wooly Oak Leaf Galls (Callirhytis lanata) formed by Cynapid wasps.

Oak Wool Gall, another type of Cynapid wasp.

Horned Oak Gall (perhaps Callirhytis spp?), formed by another Cynapid wasp.

     If you were to look inside any active gall, you would find the gall maker inside feeding. If you see holes on the outside of the gall itself however, there is a good chance that gall maker(s) has already exited through the opening. Galls may contain one or multiple occupants within the overall structure depending on the species. Below you can see the larvae that was living inside a pin oak gall (click to enlarge as always).

Larvae inside of an oak gall

     Although the majority of oak galls are produced by Cynapid wasps, a few are caused by some others organisms, especially various midges. A few of these are presented below.

Oak Pill Gall (Cincticornia spp?) caused by one of the gall midges.

Oak Leaf Galls (Polystephe pilulae?) caused by midges.

Vein Pocket Galls (Macrodiplosis qoruca?) caused by midges.

     This is just a small sample of the many kinds of oak galls, and I have done my best to identify them, but please realize that there is so much still left to discover about galls and disagreement about others. It is amazing what little we know of even some of the organisms that live right outside many of our homes. It just goes to show the vastness of the natural world, even that found near the nation's capitol.