SHINLEAF AND PIPSISSEWA

Members of the genera Pyrola (shinleaf) and Chimaphila (pipsissewa, prince’s pine) are small, evergreen plants that are found in Deering’s woodlands. They belong to a small group of genera, some of which lack chlorophyll. These genera, which additionally include locally common Indian pipe (Monotropa) along with sweet-pinesap (Monotropopsis) and pine-drops (Pterospora), have historically been classified in their own family, the Pyrolaceae, but are now considered to belong to the blueberry/heath family, the Ericaceae, subfamily Monotropoideae.

Members of the Monotropoideae are mycoheterotrophs. That is, they fully or partially obtain organic carbon from mycorrhizal fungi. Their seeds, ‘dust seeds,’ are exceptionally small and have undifferentiated embryos. Dust seeds occur in diverse families of flowering plants, perhaps most notably in orchids. The dust seeds in Monotropoideae require the presence of fungi, either direct contact with a fungus or the presence of a diffusible substance therefrom, to germinate (symbiotic germination). After germination ‘seedlings’ remain subterranean for several years, fully dependent on fungi for supply of carbon. Some mycohetrotrophs, including species of Pyrola and Chimaphila, develop the ability to photosynthesize as they develop and apparently no longer depend upon fungi to provide organic carbon. Others, such as the pure white Indian pipe (Monotropa uniflora), never develop the ability to phytosynthesize, and actually parasitize mycorrhizal fungi that associate with tree roots, thereby obtaining carbon indirectly from the phytosynthesis of the tree. Interestingly, in initial stages of growth the range of fungi associated with the developing seedlings is relatively large, the fully mycoheterophic species such as Indian pipe narrowing to more specific fungal associates as their seedlings develop. However among those early fungal associates, only those present at plant maturity stimulate germination.

Monotropa uniflora, Indian pipe, lacks chlorophyll.

Shinleaf (Pyrola)

The name ‘shinleaf’ refers to the use of their leaves in reducing pain resulting from bruises and wounds. The relief possibly provided by the salicylic acid (asprin) contained in the leaves.

The leaves of Pyrola species tend to be dark green and persist through the winter. The plants are never more than a six or eight inches high. Flowers are produced along a stalk, called a raceme and are white or pink. Five species of Pyrola are found in New England and all are natives. I have found two species in Deering: P. americana and P. elliptica.

Pyrola americana (American shinleaf, American wintergreen) and P elliptica (elliptic leaved shinleaf) both have white flowers and flower from June to August. These species are difficult to separate. Leaf blades of P. americana are ideally rounded, but can be elliptical as in P. elliptica. The chief differences are in the sizes of the calyx and the number and location of stipules.

Pyrola americana is also known as P. rotundifolia. It is found in woods, thickets and bogs in eastern North America and adjacent Canada, south to North Carolina and Kentucky, and Wisconsin. In Deering, I have found it at Hunter’s Pond and along Smith Brook trail in the Audubon Sanctuary.

Pyrola americana is sometimes called ‘American wintergreen,’ but it is not related to wintergreen (Gaultheria procumbens), also a member of the heath family.

The calyx teeth of P. americana are short relative to the petals, and the stipule clasps the base of the peduncle that supports each flower.

Pyrola elliptica is more common than P. americana, and has a wider distribution in North America, extending across the northern tier of states and provinces to Idaho and British Columbia. I have found it once in Deering, on Hedgehog Mountain Road.

The teeth of the calyx are short relative to the length of the petals, and one, unclasped stipule is found at the flower base.

Pipsissewa, prince’s pine (Chimaphila)

The Chimaphila plants you see arise from underground stems (rhizomes). The erect branches bear leaves all winter. The genus name is from the Greek cheima (“winter”) and philein (“to love”). I have heard two sources from Native American languages for the name ‘pipsissewa’: ‘forest flower,’ and ‘to break into small pieces’, referring to stones in the urinary tract. Two species of Chimaphila occur in New England and both are found in Deering.

Chimaphila umbellata is circumboreal in North America and northern Europe. It is found in well-drained woods in almost all of continental North America, including Alaska, except for Texas and several states in the far south, and Canadian Northwest Territories and Nunavut. In Deering have found Pipsissewa on Hedgehog Mountain road and Smith Brook Trail in the Audubon Sanctuary.

Pipsissewa is used in homeopathic medicine, and leaves are reported to flavor rootbeer, make a tea and flavor candy. Native North Americans used Pipsissewa root for a wide variety of ailments. Over harvesting the roots has endangered populations in some areas.

The plant spreads by seed and by extension of the root system and is said to be a good ground cover.

Pipsissewa, spotted wintergreen, striped wintergreen (Chimaphila maculata) is characterized by its variegated leaves that have a pale green stripe in the middle. The characteristic leaves make this plant easy to identify even when there are no flowers. Chimaphila maculata is native to native to eastern North America and occurs in all eastern states, west to Illinois, and in Quebec and Ontario. It favors partial sun to medium shade, dry-mesic conditions, and an acidic soil containing some rocky material or sand. It seems to be far less common than C. umbellata. Chimaphila maculata is considered to be endangered in Maine and Illinois. It has not been reported to occur in Hillsborough county before now. I have found it once on Hedgehog Mountain road.

Stripped wintergreen flowers from late spring into early summer.

Leaves of C. maculata are toxic to sheep and are avoided by deer. There is a long list of medicinal applications for stripped wintergreen, also known as ‘rheumatism root.’ However, there might be a reason to be cautious when considering collecting this plant for its medicinal value for one of its names is ‘wild arsenic,’ and handing the plant is reported to cause skin irritation and an allergic reaction in some.

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