I feel the need – the need for Milkweed: PART 2

I’m not done with milkweed yet. Out of the thirteen species that occur in Ohio, my last post featured five, plus a dogbane guest star. After making that post I have had the opportunity to photograph four more species plus a cool hybrid. Given my newly developed milkweed obsession and the fact that I have a lot of time on my hands currently, I thought I should write a second part to my previous post.

A friend of mine was kind enough to show me a site where he stumbled across two species he while doing a pollinator survey; Sullivant’s Milkweed (Asclepias sullivantii) and Showy Milkweed (Asclepias speciosa). Sullivant’s Milkweed, also known as prairie milkweed, is named after William Starling Sullivant, a prominent Ohio botanist and bryologist. Its flowers are bubblegum pink with less pointed hoods than common milkweed. The leaves are hairless, point upward, and are sessile, meaning they attach directly to the stem with no pedicel.

The flowers were buzzing with tons of bees and I was able to get a photo showing a honey bee with pollinea stuck to three of its six little feet. Pollinea are paired packages of pollen (say that 5 times fast) that milkweed flowers produce. This is neat because most flowering plants produce loose pollen grains and very few plants, such as milkweeds and orchids, package their pollen in this way.

Bee visiting a Sullivant’s Milkweed (Asclepias sullivantii)
Close up of the bee. Look at the pollinea stuck to its feet!!!

Sullivant’s milkweed has been shown to hybridize with Common milkweed (A. syriaca) and produce offspring with morphologically intermediate characters. Since both species occur at this site and there are plenty of bees and other pollinators to carry pollinea from flower to flower, there were hybrids present as well. For further reading on how to tell these two species and their hybrid apart, as well as some notes on the potential consequences of hybridization check out this paper by Dr. Robert Klips who, much like Sullivant, is an awesome Ohio botanist and bryologist.

Common milkweed (Asclepias syriaca)
Hybrid with intermediate morphological characters

Sullivant’s Milkweed (Asclepias sullivantii)

Who put this Showy milkweed here? Showy milkweed (Asclepias speciosa) is native to the western US and only gets as far east as Illinois. It grows mainly in prairies and areas with sandy soils (1). My friend who I visited this site with suggested it may have been included in a seed mix used at that site but wasn’t sure. A milkweed mystery!

Showy milkweed (Asclepias speciosa)
Showy milkweed (Asclepias speciosa)

Butterfly Ridge Butterfly Conservation Center is an awesome place for those interested in milkweeds. Or butterflies I guess. Located near Conkle’s Hollow in the Hocking Hills region, Butterfly Ridge is home to 8 species of milkweed: Common, Swamp, Poke, Four-leaved, Purple, Whorled, Butterflyweed, and Tall Green milkweed. They plant these milkweeds to attract and provide habitat for different species of butterflies. When I visited, the Poke and Four-leaved milkweed had finished blooming and the Purple milkweed was nearing the end of its flowering.

Purple milkweed (Asclepias purpurascens) is one of the more shade tolerant milkweeds. It occurs in prairies, oak savannas, meadows, and forest edges. It is threatened or endangered in many states including Massachusetts and Wisconsin, and is extirpated (locally extinct) in Rhode island, Maine, Delaware, and Minnesota (2,3). Compared to Common milkweed, Purple milkweed have larger and more brightly colored flowers and also tend to have pointier leaves (4).

Purple milkweed (Asclepias purpurascens)
Purple milkweed (Asclepias purpurascens)

Common Milkweed and Butterflyweed were well into bloom at Butterfly Ridge, whereas Swamp, Tall green, and Whorled Milkweed had not quite begun to bloom. Whorled milkweed (Asclepias verticillata) is a short milkweed with very thin grass-like leaves and small white flowers. Whorled milkweed along with Butterflyweed appear to be less preferred choice for monarch butterflies when deciding which milkweed to lay eggs on, which might be due to the small size of their leaves (5, 6). They are very dainty milkweeds that night be mistaken at a glance for Mountain mint (Pycnanthemum virginianum), particularly before their flowers appear.

Whorled milkweed (Asclepias verticillata) flowers, not open yet
Mountain mint (Pycnanthemum virginianum) might look like whorled milkweed at a distance

BONUS! Not a milkweed, but there was also a cool orchid in the woods at Butterfly Ridge. Ragged fringe orchids (Platanthera lacera) are moth pollinated, so the various habitats at Butterfly ridge that are specially constructed with butterflies and moths in mind, are a great place for this orchid and other plants that rely on lepidopteran pollination.

Besides orchids, milkweeds, butterflies, and educational tours, Butterfly Ridge also has events such as Moth lighting where tarps are put up with lights to attract moths. As the moths fly onto the tarp they are identified, photographed, and admired, as they rightly deserve. Moths rule! Milkweeds rule!

Sources: 1, 2, 3, 4, 5, 6,

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