Commelinaceae -- the spiderwort family (42-50/500-700; cosmopolitan)

Monocots II

Habit herbs; somewhat succulent and with mucilaginous sap; stems somewhat jointed with swollen nodes

Leaves alternate; simple; leaf bases with closed sheath surrounding stem; parallel venation; with or without pseudopetiole

Inflorescences basically a panicle or 1-many scorpioid cymes (i.e. a “thyrse” in the literature), each subtended by one or more boat-shaped spathes; sometimes appearing umbelliform because the main axis is reduced to only 1-2 scorpoid cymes fused back to back

Special floral characters stamen filaments sometimes ornamented with long trichomes; flowers colorful

Calyx 3 sepals distinct or connate

Corolla 3 petals distinct (connate)

Androecium 6 (1-3) stamens, distinct (rarely filaments connate) often 1 or more reduced to staminodes

Gynoecium 3 (2) carpels, connate; superior with 3 (2) locules and 1-few axile ovules; style 1, undivided

Fruit= capsule (rarely a berry)

(Floral formula: Ca 3 Co 3 A 3 + 3 G 3 )

Commelinaceae -- commentsMonocots II

Genera: Tradescantia (spiderwort), Zebrina (wandering jew), Commelina (dayflower), Rhoeo (boat-flower, oyster-plant), Gibasis (bride’s veil), Geogenanthus (the seersucker plant), Setcreasea (purple heart), Callisia.

Comments: Only important as an ornamental, this family is nonetheless a hardy houseplant, and in some mild areas, has escaped to become a weed.

The flowers in this family are insect pollinated, but do not produce nectar. The pollen is the reward, and since a lot of pollen has to be produced to supply enough for both pollination and the pollinator, it is believed that this family may be part of a trend that culminated in wind-pollination.

Poaceae (Gramineae) -- the grass family (650-660/10,000; cosmopolitan)

Monocots II

Habit herbs, shrubs or trees; rhizomatous or stoloniferous; stems mostly round with swollen nodes, mostly hollow (sometimes a pith); intercalary meristems

Leaves alternate or basal; simple; two ranked; leaf bases with open sheath surrounding stem, upper margins of the sheath may bear small ear-like apical lobes called auricles; parallel venation; ligulate; blades flat or absent

Inflorescences spikes and spikelets that are 2º clustered into inflorescences (spikes, racemes, or panicles); each spikelet subtended by 2 basal bracts (glumes), then

within the spikelet, each flower subtended by two bractlets (lemma to the outside and palea to the inside) all attached to the rachilla

Special floral characters lodicules are interpreted as reduced perianth parts; wind-pollinated; glumes or lemma can be ornamented with awns

Perianth 2 (3) lodicules distinct, fleshy and becoming turgid at anthesis

Androecium 3 (1-2 or 4-6) stamens, distinct (rarely filaments connate in groups)

Gynoecium 3 carpels (only 2 apparent), connate; superior with 1 locule and 1 basal ovule usually adnate to ovary wall; styles 2 (1 or 3), distinct or united

Fruit= caryopsis (achene, utricle, nut, or drupe), often shed from the plant together with the enclosing bracts

(Floral formula: A 3 G 2 )

Poaceae (Gramineae) -- comments

Monocots II

Genera: Triticum spp. (wheat), Avena sativa (oats), Zea mays (corn), Oryza sativa (rice), Saccharum officinarum (sugar cane), Hordeum vulgare (barley), Sorghum bicolor (sorghum), Secale (rye), Bambusa spp. (bamboo)

Comments: Without a doubt, the most important family in the average human’s life! If aliens were to land on this planet and take a quick look around, they would probably describe a planet in which the grasses had millions of human slaves tending to their every need...

Rice feeds more humans than any other grain. “Wild rice” is actually a different species (Zizania aquatica) and is native to North America. Wild rice has a bit more, nutrition-wise, than rice, but the bracts are harder to separate from the fruit, and is more expensive to harvest.

As well as the grains that we eat, grass is very important as fodder for many of our livestock. Range management has become very important in the West (after overgrazing and catastrophic droughts killed lots of cattle in the past), and you can take courses that concentrate only on grasses!!

Poaceae (Gramineae) -- comments

Comments: Several species of bamboo (Bambusa sp.), are used not only as food, but also for timber, pulp, and utensils. Some bamboos grow vegetatively for years (up to 150 yrs), flower, and then die. This has caused problems in the past (particularly for pandas) because clones can spread over large areas of land, and when it is time for that plant to flower all the clones simultaneously flower and die.

Ornamental uses for grasses include turf-grasses (billions and billions of dollars are spent on residential and commercial lawns every year) such as St. Augustine grass and Bermuda grass (Cynodon sp.), and as accent plants in perennial borders and the landscape.

Fermented grains are the main source of many alcoholic beverages, and some anthropologists have theorized that these recreational drinks may have had a profound effect on the beginnings of agriculture!

Monocots II

Cyperaceae -- the sedge family (70-100/4000-9300; cosmopolitan)

Habit herbs (rarely shrubs), often semiaquatic; rhizomatous; stems are typically triangular, internodes filled with pith

Leaves alternate or basal; usually three-ranked; simple and entire; leaf bases with closed sheath surrounding stem; linear, parallel venation; ligulate or eligulate; blades

flat, terete, triangular or absent

Inflorescences one to many spikelets aggregated into clusters (racemose, paniculate, often umbels). Each spikelet organized on a central rachilla to which the bracts/flowers

are attached. Flowers subtended by a bractlet and perianth reduced to bristles or absent

Special floral characters the gynoecium in Carex (and a few close relatives to Carex) is surrounded by a second bract termed a perigynium that is a hollow, sac-like structure

Perianth reduced to bristles (rarely scales) or absent

Androecium 1-3 (4-many) stamens, distinct

Gynoecium 2 or 3 carpels, connate; superior with 1 locule and 1 basal ovule; style 1, with 2 or 3 branches

Fruit= achene

(Floral formula: A 3 G 2 or 3 )

Monocots II

Cyperaceae -- comments

Genera: Cyperus, Carex, Scirpus, etc.

Comments: A “grass-like” family that is easily separable from Poaceae based on floral and vegetative characters. Carex is the largest genus, a taxonomic nightmare with over 3000 species and incredible variation. If you ever want a real challenge, try to key some of these out!

Cyperus papyrus (Papyrus) was used to make one of the early types of paper, and today it is still the toughest paper made. The family contains many ethnobotanically important members including: Cyperus used for making mats in Asia, Cladium used for making thatched houses in Europe, and Scirpus used as medicinals, as well as many others.

Chinese water chestnuts are slices of corms harvested from Eleocharis tuberosa.

Monocots II