Flower School

At Flower School, flowers are the teachers.  There are no texts to read.  Just pick any of our 24 teachers you’d like to study with.  Let them show you their personal photo albums.  They all have something special to teach us.

Faculty Members

(and FAMILY)
Campanula americana
American Bellflower
Shows “plunger pollination” in which female style offers pollen from her own brothers! She then cleans herself up before becoming receptive to outside pollen.
Cercis canadensis
Corolla is “papilionaceous” (butterfly-shaped) with 5 petals (1 banner, 2 wings, 2-part keel). But unlike others, the banner petal is innermost instead of outermost!
Chelone glabra
Flower looks like a fish head. Has a prominent staminode (sterile stamen) like fellow family member Penstemon. Shows us dissected bud and ovary containing 2 locules.
Circaea canadensis
Enchanter’s Nightshade
Inferior ovary. Ovary (and fruit) covered with hooked hairs. Show us dissected ovary (showing 2 locules). Shows us nectar disc and droplet.
Cornus florida
Flowering Dogwood
Inferior ovary. Large, white, petal-like bracts surround inflorescence of about 20 flowers. 4 sepals, 4 petals, 4 stamens, 1 style with capitate stigma.
Desmanthus illinoensis
Illinois Bundleflower
Shows development of spherical cluster (containing dozens of flowers) from bud stage to fruit stage.
Frangula caroliniana
Carolina Buckthorn
Strange petals! They appear as 5 tiny individual shields partially enclosing the 5 stamens.
Impatiens capensis
Flower changes in time from male to female. Anthers fused into one unit covering gynoecium. 5 sepals (1 petal-colored & inflated into a hornlike nectar spur). 3 petals.
Ipomoea lacunosa
White Morning Glory
5 sepals, 5 petals, 5 stamens (with purple anthers!), 1 style with 2-lobed capitate stigma; shows us magnified pollen grains and ovary locules with developing seeds;
Lythrum alatum
Winged Loosestrife
Even though it’s a eudicot, it has 6 sepals, 6 petals, and 6 stamens. Shows us the inside of its hypanthium.
Persicaria pensylvanica
5 tepals (sepals and petals that look the same).
6-8 stamens (with pink anthers).
Forked style with 2 globose stigmas.
Phacelia purshii
Miami Mist
Famous for her frilly petals, these are photos of Phacelia like you’ve never seen her before!
Phlox divaricata
Blue Woodland Phlox
Finally, a chance to look inside that narrow throat! See how the stamens are stuck (adnate) to the corolla. See all those glandular hairs covering the fingerlike sepals.
Phryma leptostachya
Lopseed flowers face 3 different directions:
(1) the flower buds angle upward
(2) the open flowers face straight outward
(3) the fruit flops (“lops”) down against the stem
Phytolacca americana
5 sepals, 0 petals, 10 stamens, 1 green ovary with 10 carpels and 10 tiny styles in a white crownlike circle. Each style has a stigmatic area near the tip.
Ptelea trifoliata
Wafer Ash
Male flowers have 4 or 5 stamens, plus a pistillode (a sterile gynoecium).
Female flowers have a gynoecium, plus 4 or 5 staminodes (sterile stamens).
Ruellia humilis
Wild Petunia
One style with 2 unequal stigmas.
Very long corolla tube.
Sassafras albidum
Male flower has 9 stamens (in 2 whorls).
Female flower has ovary, style, stigma, plus several short little staminodes.
Scutellaria incana
Downy Skullcap
Has a “scutellum” (tractor seat) on its calyx;
2 big lips (it’s a mint); 4-lobed ovary;
gynophore (elevates the ovary);
very tip of style splits into 2 branches;
Silene stellata (sy-LEE-nee)Starry Campion or Starry Catchfly
5 petals, but they are so deeply lobed that it looks like there are dozens of petals; gynoecium unusual because the ovary has 3 styles;
Solanum carolinense
Carolina Horsenettle
5 banana-like anthers with pores on their tips;
Sepals and pedicels covered with stellate hairs;
Cross-section of anther reveals its anatomy;
Cross-section of fruit reveals ovary structure;
Stenaria nigricans
4 petals covered in short, white, rubbery hairs
Flowers in 2 different morphs:
Pin : style and stigmas higher than anthers (like a hat pin);
Thrum (=bundle of stamens): anthers higher than stigmas
Valerianella radiata
Corn Salad
Our math teacher (rectangular inflorescences and dichotomous branching)
1 style (with 3-lobed stigma); 3 stamens;
5-lobed corolla; no calyx (but bracts and bractlets)
Wolffia brasiliensis
Brazilian Watermeal
St. Louis has the world’s smallest flowering plant!
In these photos, we get to see its microscopic anther!
We get to see its microscopic stigma!
We get to witness its entire life cycle!

These hundreds of Flower School photos were created using a special camera technique called “Focus Stacking” by St. Louis botanist and teacher George Van Brunt.

​[All photos are by George Van Brunt and are licensed as CC BY-NC-SA (Creative Commons George Van Brunt – Non-Commercial use only – Share Alike). For an explanation of Creative Commons licensing, please see Insects and their Plants by Fr. James Sullivan, pages 91-92]