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

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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 )
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Commelinaceae -- comments
Monocots II
Genera Tradescantia (spiderwort), Zebrina
(wandering jew), Commelina (dayflower), Rhoeo
(boat-flower, oyster-plant), Gibasis (brides
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.
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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 )
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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 humans 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!!
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Poaceae (Gramineae) -- comments
Monocots II
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!
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Cyperaceae -- the sedge family (70-100/4000-9300
cosmopolitan)
Monocots II
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 )
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Cyperaceae -- comments
Monocots II
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.