Botany Blog Plants of the Northeastern U.S.

When many people hear the word thistle they think of the introduced bull thistle (Cirsium vulgare) or the erroneously named Canada thistle (Cirsium arvense), both weedy plants that are introduced from the Old World. There are however a number of less commonly encountered thistles that are native to the Northeastern U.S.

I have recently started growing one such native thistle in my garden. Pasture thistle (Cirsium pumilum) is a biennial species that spends its first year as a basal rosette and flowers the summer of the next year. It is monocarpic, meaning that once it flowers and sets seed the plant dies. There is a relatively rare variety of this species native to prairies in the Midwest, var. hillii, that is sometimes perennial.

Plants are easy to grow, however since so few people grow this species seeds are not commercially available. The seeds require about 60 days of cold moist stratification and then they will germinate sporadically with a few coming up within a week but some taking months to sprout. The plants that I started last spring are now coming up for their second year and the leaves have an interesting bluish cast.

They should begin flowering in July and continue into August. The flowers of this species are quite large relative to the rest of the plant. Here is a picture of a flowering specimen in the wild.

I visited southern New Jersey this past weekend to see a rare spring flower just starting to bloom. Swamp pink (Helonias bullata) is a federally threatened species that occurs along the coastal plain from NJ (where it is most abundant) to GA. It was once found on Staten Island in NY but is now considered extirpated from the state.

At the site where these were found the plants were most common on the edge of hummocks. The water next to these hummocks was up to 3 feet deep.

Closeup of the flowers. They had a spicy fragrance.

We also saw a couple interesting violets growing along one of the sand roads nearby. This is Viola sagittata var. ovata, which lacks the broad lobes at the base of the leaf typical of var. sagittata.

This is Viola pedata. It is one of the larger-flowered violets. Note the petals lack any hairs (they are not bearded). The leaf segments on these are broader than those of var. lineariloba that I’ve seen in sand prairies along Lake Michigan in IL.

It has been a long wait, but I finally have some seedlings of bladdernut (Staphylea trifolia).

I collected the seeds in 2013 and started them in plastic bags with some damp potting mix. The shiny light brown seeds require about 3 months cold followed by 3 months warm and then another 3 months of cold moist stratification before they break dormancy. I put them in the fridge after the warm period and then forgot about them, so they ended up in the fridge for about 6 months.

Update 12-14-2014: Most of the plants have put on 2 new sets of leaves.

Got the chance to visit an interesting wetland complex in the Pine Barrens of NJ a couple weeks ago and saw several species for the first time. Here are some of the highlights:

Collins’ Sedge (Carex collinsii)

Atlantic White Cedar (Chamaecyparis thyoides)

Thread-leaved Sundew (Drosera filiformis)

St. Andrew’s Cross (Hypericum stragulum)

Goldencrest (Lophiola americana)

Foxtail Bog-clubmoss (Lycopodiella alopecuroides)

Bog Asphodel (Narthecium americanum)

Little-leaved Milkwort (Polygala brevifolia)

Cross-leaved Milkwort (Polygala cruciata)

Lance-leaved Rose Gentian (Sabatia difformis)

Swamp fly honeysuckle (Lonicera oblongifolia) is blooming now in Central New York. This is a native species typically found in peatlands such as fens or conifer swamps. It can be distinguished from other honeysuckles by the following combination of traits: 1) style hirsute; 2) upper 4 petals fused; 3) peduncles over 5 mm; 4) leaves obtuse; 5) ovary glabrous; 6) pith of branchlets solid and white.

Lonicera oblongifolia flowers

Recognition of habitat, entire leaf margin, and the downy pubescence on the undersides of leaves can help when searching for this plant. The leaves are typically more symmetrical than those of Lonicera canadensis.

 Upper surface of leaves

Lower surface of leaves

Fruits ripen in July and can range from orange to red or red-purple

Here are some of the plants that are blooming now in Central NY.

Leatherwood (Dirca palustris)

Round-leaved Yellow Violet and Spring Beauty

Hepatica

I have been visiting some really nice natural areas this summer. The following are some orchids that were photographed in flower in June and July of this year. The first few were taken at a bog in Chenango County. Grass pink differs from our other orchids in that the flowers are not resupinate, that is they are not inverted from twisting of the pedicel. Therefore the lip is on the top rather than on the bottom as in most other orchids.

Grass pink

(Calopogon tuberosus)

White fringed orchid

(Platantheria blephariglottis)

Rose pogonia

(Pogonia ophioglossioides)

These showy lady’s slippers were found blooming in a rich fen in Onondaga County in mid June.

Showy lady’s slipper

(Cypripedium reginae)

These hooded lady’s tresses have just started flowering at another rich fen in Onondaga County. It differs from other members of the genus in that the lateral petals are fused with the sepals into a hood.

Hooded lady’s tresses

(Spiranthes romanzoffiana)

The last plant is not an orchid but was growing with the plant above. Kalm’s lobelia is characteristic of rich fens and is named in honor of Pehr Kalm, a 17th century botanist who cataloged New World plants on behalf of Linnaeus.

Kalm’s lobelia

(Bromus kalmii)