Plant Skeletons Shrivel in the Sandy Hook Scrub

"Most plants die back to the ground ... but some leave behind a skeleton."

"Did you know that when the temperatures cool in the fall and the leaves are busy falling off the trees those beautiful field flowers are shriveling up and turning into plant skeletons? This is actually a term used by botanists. How about that? Even nature dresses up for Halloween. Meadows and open fields are crawling with skeletons in the fall” (page 20).

You can still have fun identifying plants after Labor Day during your nature walks at Sandy Hook. This is a guide to some of the more common plant skeletons you might notice.

The scientific plant names above the photos are linked to a great website for identifying plants in maritime habitats like Sandy Hook, “Cape May Plants – An Identification Guide” by CapeMayWildlife.

Since you are staring at the raw anatomy of a plant without its bloom to distract you, this post includes the names of the parts of the plants. Except where noted, all of the technical descriptions of the skeletons are taken almost verbatim from Carol Levine's 1995 book, “A Guide to Wildflowers in Winter”.

One-third to one-half of the plants at the Gateway National Recreation Area aren't native. If the plant skeleton is “invasive” there will be a link next to the scientific name to its page in the Invasive Plant Atlas of the United States. (Invasive plants are empty calories to the local, native food web, and many are introduced by what we plant in our yards . This is insightfully explained by Dr. Doug Tallamy of the University of Delaware during his testimony on October 2, 2018 to a subcommittee of the Pennsylvania Senate Agriculture and Rural Affairs Committee (1:09 – 27:30). His “Native Plant Finder” and Audubon's “Plants For Birds” webpages offer native alternatives, by zip code, to the junk ornamentals that are transforming our landscape.)

BAY/OCEAN

White Campion (Silene latifolia) Invasive.

My favorite because it looks like Peashooter in Plants vs. Zombies. The capsule is “shiny, smooth, oval, and one-chambered”. Peashooter's mouth is plain, while the capsule opening on the white campion is surrounded by “8-10 spreading teeth”.

Common Evening Primrose (Oenothera biennis)

Plant skeleton has flower racemes “at the terminal ends of branching stems”. Capsules are “4-chambered and cylindrical, splitting along the middle of the chambers”. Seed pod turns woody on larger plants in the winter.

Beach Wormwood (Artemisia campestris ssp. caudata)

The central stem terminates in a panicle of flower heads that are small beads of achenes. Sandy Hook has the largest known population of this state-listed plant in NJ (S2 - Imperiled), according to a 2012 report by the NJDEP. The second largest is also in Monmouth County, in the dunes west of the Keansburg boardwalk.

Common Milkweed (Asclepias syriaca)

Skeleton follicles are “warty, hairy, round at the bottom and pointy at the top, erect on deflexed stems”. Monarch butterfly populations have declined by 90% in the last 20 years, so the National Wildlife Federation has been promoting milkweed-planting throughout the monarch's migratory paths, that include Sandy Hook. Monarchs will only lay their oval, off-white eggs (scroll down) on the underside of the milkweed leaf.

Queen Annes Lace (Daucus carota) Invasive.

Many-rayed compound umbels at the end of the stems. Also known as the wild carrot – its root smells like one. (Bloom picture from USDA plant database.)

Knapweed (Centaurea sp.) Invasive.

Spotted knapweed bloom on left, tyrol knapweed skeleton on right. “Scraggly, much branched. Fruits are achenes widest at the apex, tapered at base. Pappus has two rows of bristles.”

Great mullein (Verbascum thapsus) Invasive.

Skeleton has capsules “crowded on a prolonged spikelike raceme. Capsules are round, 2-parted, splitting along the septum, with 2 sides or more cleft.” (Bloom picture from USDA plant database.)

Curly Dock (Rumex crispus) Invasive.

Skeleton has “straight brown stalks dense clusters of dried 3-winged heart-shaped sepals hanging from stems, with a shiny, 3-angled fruit between each sepal wing.”

Soapwort (Saponaria officinalis) Invasive.

Capsules are “dehiscent, 4-toothed, 1-chambered, elliptic to oblong, surrounded by rugged calyx”.

Bull Thistle (Cirsium vulgare) Invasive.

"Stems are conspicuously spiny. Achenes are elongated, with a pappus of numerous feathery white hairs”.

Virginia Pepperweed (Lepidium virginicum) Invasive.

"Single stalk or bushy branching, numerous and persistent fruit septa. Silvery central septum remaining on stem after chambers open.”

Saltwort (Salsola kali) Invasive.

"Exceedingly spiny plant of sandy beaches. One-seeded bladdery fruit (utricle) enclosed in a 5-lobed calyx.”

Devils Head (Trapa natans) Invasive.

A seed not a skeleton, with “four curved, spike-like “horns” projecting from a knobby hub.” The picture on the left was taken at Shadow Lake in Middletown of the “circular cluster or rosette of leaves, each equipped with an air bladder along the stem.” “Distinctive four-pointed seedpods … sink to the bottom of a waterway” and eventually get washed out into downstream watersheds. The picture on the left are the seedpods collected from an ocean beach at Sandy Hook after a Nor'easter.

FRESHWATER WETLANDS

Spanish Needles (Bidens bipinnata) Invasive.

“Numerous achenes with barbed teeth or awns.”

Swamp Rose Mallow (Hibiscus moscheutos)

"Upward branches few, terminating in 5-chambered capsules that are round at the summit, sometimes with a short beak.”

Purple Loosestrife (Lythrum salicaria) Invasive.

"Four to six feet high with candelabra branching. Stems terminate in long fruited spikes. Small, 2-chambered capsules split along the septum in whorls. Capsules enclosed by persistent hypanthium. Fruits disintegrate early, leaving stubs and stalks.” (Skeleton picture from here)

Seedbox (Ludwigia alternifolia)

"Fruit capsules are square boxes with persistent sepals.” One siting at Sandy Hook, in the freshwater wetlands across from Guardian Park.

FORT HANCOCK

Yucca (Yucca filamentosa)

"Fruit remnants are in branched racemes raised far above leaves on tall stems. Basal leaves are thick, rigid and ascending (spreading horizontally, then becoming erect), with loose twisting threads on margins.”

Japanese Knotweed (Reynoutria japonica) Invasive.

"Grows in large, dense clumps. Stems arch out while fruit stalks zig-zag upward. Fruit falls early and leaves small stems.” This paper from Pennsylvania shows just how thoroughly Japanese Knotweed takes out native species: “Our results suggest that F. japonica has reduced the diversity and abundance of native understory riparian plant species. The species also appears to have suppressed long-term tree recruitment, setting up a trajectory whereby the eventual decline of trees currently in the canopy could shift this community from a tree-dominated riparian forest to a knotweed-dominated herbaceous shrubland.”

Jimsonweed (Datura stramonium) Invasive.

"Fruits are erect, spiny capsules on short stems in branching axils. Fruits are 4-chambered, opening in 4 parts longitudinally by the valves (part of the fruit wall). The calyx leaves a collar under the fruit.”

False Indigo (Amorpha fruticosa) Invasive.

"Pods are black oval-elliptic, ascending (spreading horizontally, then becoming erect) or divergent (spreading in different directions), and narrowed below a thick stem and above to a curved beak.” Small, "warty, kidney-shaped pod is persistent into winter”.

Common Lilac (Syringa vulgaris) Invasive.

Skeletons have “dense terminal panicles, with loose clusters of smooth, brown, flattened, dehiscent seed capsules.”

NEXT STEPS

You can zoom-in to Sandy Hook to see a map of these pictures –as well as over 14 million observations worldwide - that have been geolocated and posted at iNaturalist.org.

If you are into winter ID here are 2 excellent references:

Levine, Carol. 1995. A Guide to Wildflowers in Winter: Herbaceous Plants of Northeastern America. Yale University Press, New Haven and London.

Wojtech, Michael, 2011. Bark: A Field Guide to Trees of the Northeast. University Press of New England, Lebanon, NH.