Botany Blog Plants of the Northeastern U.S.

While most plants are autotrophic (capturing energy directly from sunlight through photosynthesis), a few obtain energy by parasitizing fungi or other plants. Some are both autotrophic and parasitic and these are called hemiparasites. The following species are holoparasites that are completely dependent on their hosts. Those that parasitize fungi are called mycoheterotrophs.

The traditional circumscription of the family Orobanchaceae included only holoparasites. It now includes hemiparasites formerly treated as part of the Scrophulariaceae. The following three species are the former.

Squawroot (Conophilis americana) is a parasite of oaks.

Beechdrops (Epifagus virginiana) is a parasite of American Beech (Fagus grandifolia)

One-flowered Broomrape (Orobanche uniflora) is an annual that can parasitize a number of different herbaceous plant species

One genus in the family Orchidaceae is parasitic in Central NY. There are three species of Corallorhiza found here and the most common is Early Coralroot (Corallorhiza trifida)

The genus Monotropa in the family Ericaceae includes two mycoheterotrophic species that occur in CNY. Pinesap (M. hypopithys) is found in acid woodlands under pines.

Indian Pipe (Monotropa uniflora) is more common and occurs in a variety of forested habitats. It differs from Pinesap in producing one flower per flowering stalk.

One species in the family Santalaceae is found in CNY. Eastern Dwarf Mistletoe (Arceuthobium pusillum) differs from the other species covered here in that the seeds germinate directly on the host. It is found almost exclusively on Black Spruce (Picea marina) in acid swamps and bogs.

The last group of plants are vines in the Morning Glory Family (Convolvulaceae). Dodders are annual vines that begin life underground but soon lose contact with the soil. The thin twining stems wrap around the stems of other plants, appearing like tangles of orange threads. There are a few species, the most common being Cuscuta gronovii

Flowers are produced beginning in July

In researching the flora of New York State I came across some interesting information regarding the early establishment of Chestnut Blight (Cryphonectria parasitica). In the report of the state botanist of 1908, it was reported that the blight had not yet become established in the Catskill Mountain region. The northernmost extent of its range in NY at that time was thought to be Dutchess County, although it was not clearly established there.

The thing that really caught my eye was the thinking at the time regarding the threat this fungal disease posed to our native Chestnut. According to Peck, “It is more likely that the pessimistic views concerning its rapid spread and destructive consequences, entertained by some writers, will scarcely be realized. Unusually destructive outbreaks of parasitic fungi are apt to be dependent on unusual climatic conditions and therefore to be of short duration”. Clearly this was not the case, and it is hard to find a chestnut tree today of any appreciable size if one can find one at all. The species is essentially now ecologically extinct.

Cardinal flowers are now blooming along the Tioughnioga River. I normally find this plant growing among other plants and as a result the inflorescence  tends to bend toward the light. Today I got lucky and found a large colony growing by itself and they had racemes that were straight upright.

Lesser purple fringed orchids (Platanthera psychodes) are just beginning to bloom here in central NY. These were found today in a swamp under some poison sumac. Green fringed orchid (Platanthera lacera) was also blooming in the same area. There were many little club-spur orchids (Platanthera clavellata) in bud that should be opening in a few weeks.

It was overcast so a flash was needed to get a closeup of the flowers, which is why the background is so dark.