NKU's General Botany Site (Bio 313 & L) for Sp 2024

Here are the promised notes on the seven plant families we're learning to recognize.

Asteraceae (formerly Compositae): the composites. Dandelions, chicory, asters, sunflowers, goldenrod, chrysanthemums, coneflowers, various daisies, and lettuce are all in this family. This is a cosmopolitan family, found worldwide both in temperate and tropical areas. These plants make a unique inflorescence type called a head (picture a daisy) where what looks like one flower is really made up many smaller, bilaterally symmetric (the "petals" or rays) and radially symmetric (in the disc) flowers. Our species are mostly summer and fall blooming, but a few show off in the spring, including:
Packera (Groundsel)
Erigeron (Fleabane daisy)
Taraxacum officinale (Dandelion): Europe.

Brassicaceae (formerly Cruciferae): the crucifers. Cabbage, mustard, turnips, radishes, broccoli, cauliflower, kale, and brussel sprouts all belong to this family. These dicots contain strong smelling mustard oils to help repel herbivores. The odd combination of four petals and six stamens in the flowers makes them easy to recognize in bloom. The four-petaled, cross-shaped flowers gave the family its old name, the Cruciferae (like cross or crucifix). This family prefers the temperate zones and is most diverse in Europe, temperate Asia, and North America. Most of ours are spring bloomers, with white, yellow, or occasionally purple flowers. Common examples include:
Alliaria petiolata (Garlic mustard): Invasive. Europe.
Cardamine (Toothworts): Includes native spring-ephemerals.
Brassica nigra (Black mustard): Europe.

Fabaceae (formerly Leguminosae): the legumes. This is a large, cosmopolitan family, including peas, beans, lentils, clover, vetch, alfalfa, sensitive plants, locust trees, mimosas, redbuds, and the Kentucky coffeetree, to name just a few. Most of them have a mutualistic relationship with Rhizobium bacteria, which live in their root nodules and fix nitrogen. They often have compound leaves. The bilaterally-symmetric flowers (loved by bees) have five petals, 10 stamens, and one superior carpel (leading to the typical bean-like, or "legume" fruit). Most of ours are summer to fall bloomers, but redbud is one of our most obvious flowering trees in the spring:
Cercis canadensis (redbud)
Trifolium (Clover)
Coronilla/Securigera varia (Crown vetch): Mediterranean.

Lamiaceae (formerly Labitae): the mint family. Peppermint, spearmint, chia, bee-balm, henbit, ground ivy, and salvia are all members of this large and cosmopolitan family. The opposite, simple leaves, square stems, and aromatic foliage (volatile oils) make this an easy family to recognize. The bilaterally symmetric flowers (loved by bees) have five fused sepals, five fused petals, four stamens, and two carpels. You'll see them blooming spring to fall, mostly because some of our most common lawn-weeds bloom almost continually:
Lamium (Henbit): Eurasia.
Ajuga reptans (Carpet bugleweed): Eurasia.
Glechoma hederacea (Ground ivy): Europe.
Monarda (Bee balm): Several natives. Mostly summer blooming.

Poaceae (formerly Graminae): the grasses (you'll hear "graminoid" for grass-like, too). A huge, cosmopolitan family of wind-pollinated monocots. Major food source for humans (and pandas!), including rice, wheat, oats, corn, and barley, but also bamboo, our native cane (Arundinaria), and Kentucky bluegrass (which isn't native to Kentucky). Parallel-veined leaves in two ranks along round or oval stems.
Poa praetensis (Bluegrass): Europe & NE US.
Arundinaria gigantea (Cane)
Zea mays (Corn)

Ranunculaceae: the buttercup family. This family is most diverse in the temperate zones (cooler climates). It includes buttercups (Ranunculus), clematis vines, columbine, Delphinium, and hellebores, among others. Most of ours are bee-pollinated. The flowers often have primitive floral traits (radial symmetry, many parts, parts free/unfused, superior ovary), though Delphinium is bilaterally symmetric, and both it and columbine have nectar spurs. Helleborus also has interesting nectaries in the flowers. Most of ours are spring blooming, though we have a couple of clematis that are fall bloomers:
Ficaria verna (Lesser celandine): Invasive. Europe.
Ranunculus (Buttercup): Native and introduced species.
Thalictrum (Meadow rue): Includes spring-ephemerals.
Clematis: Native, invasive, and cultivated species here.
Delphinium: Includes a spring-ephemeral.

Rosaceae: the rose family. This is a cosmopolitan family with some preference for cooler climates (so, not common in the tropical rainforest). We rely on this family for fruit (blackberries, strawberries, apples, peaches, pears, plums, cherries, apricots, nectarines), almonds, and flowers (roses, crabapple trees, hawthorns). We also have invasive species here, like Japanese multiflora rose and callery pear. The flowers have an unseal floral cup structure (hypanthium) at the base, which the flower parts connect around. The radially symmetric flowers have a hypanthium and five sepals, five petals, many stamens, 1 to 5 superior carpels. This flower setup is easy to recognize with a little practice, as it doesn't vary much across our species (unless you encounter a double-double domesticated flower). Apples and their relatives make a unique fruiting structure called a pome, which is a fleshy hypanthium expanded around a papery core (the core of an apple is its carpels, so botanically-speaking, that's actually the fruit). Many of our spring-blooming trees belong to this family, as well as smaller, summer-blooming herbs.

Rosa (Roses): Native species & an invasive from Asia.
Potentilla indica (Mock strawberry): Asia.
Malus (Apples & crabapples)
Rubus (Blackberries & raspberries) 較少 ↑