lab manual

 

<< Lab 3 Caryophyllales (Caryophyllineae: Caryophyllaceae, Chenopodiaceae, Amaranthaceae, Montiaceae, Aizoaceae, Cactaceae; Polygonineae: Polygonaceae, Droseraceae); Rosids II: Geraniales (Geraniaceae), Myrtales (Onagraceae), Malvales (Malvaceae), Brassicales (Brassicaceae, Limnanthaceae), Sapindales (Anacardiaceae, Sapindaceae) >>

 

Caryophyllales, Caryophyllineae

Caryophyllaceae - This family is important in this course, because you will encounter species of this family in many different plant communities. The non-native species are common components of many CA grasslands. The features of this family of herbs are easy to memorize and are fairly consistent.

Fill in the blanks: phyllotaxy (usually): ______________ ; node characteristic (usually): _____________; sepal #: _______; if present, the petals are (circle one):  fused     free;
The ovary placement is (circle one): superior     inferior;    placentation type: _____________

  • Silene "catchfly" (native and non-native species in CA) or Lychnis "campion" (non-native)
    The members of these two genera are characterized by their prominent, ribbed calyx tubes (the sepals are connate into tube). If you don't look closely, you might assume that the petals are fused as well - but inside the tube, the petals are actually free. Our material of Lychnis is dioecious. Note the shape of the petals with the long "claw" and notched "blade"; this shape is typical of many species of Caryophyllaceae.

  • Stellaria "chickweed" - In CA there are 12 species, both native and non-native.
    This non-native, S. media is a very common weed of grasslands and roadsides. Vegetatively, it can be identified by the rather strange line of hairs that goes down just one side of the stem. Its flowers are typical of the family in terms of arrangement and number of parts. The petals are so deeply notched that sometimes it appears that there are 10 petals rather than 5.

  • Cerastium "mouse-eared chickweed" - In CA there are 5 species, and 3 are non-native.
    Look carefully at our material of Cerastium. We may have one of our non-native species, such as C. glomeratum or perhaps a cultivated variety. How do the hairs on the stem differ from those of the Stellaria that you just examined? __________________________________________________
    Examine the flowers. Are the petals notched? _______ How many styles are there? __________

 

Chenopodiaceae - The members of this family have very reduced flowers with 3-5 membranous or fleshy sepals and no petals, sometimes with fleshy bracts subtending each flower. Many of the species are tolerant of saline soils. The Chenopodiaceae often have diagnostic epidermal hairs that look either scaly or like small white, powdery granules.

  • Chenopodium - "pigweed" "lambsquarters" "goosefoot"
    In CA, we have almost as many non-native introduced species as native species in this genus, and some of the non-natives are weedy species of cultivated fields. They are all herbs with alternate leaves that have small flowers clustered in terminal and/or axillary inflorescences. The ovary (and fruit) is depressed spheric with the 5 sepals curved over it. Examine the leaf surface. What type of hairs are present? _____________________________

  • Atriplex - "saltbush"
    The majority of our species in this genus are native to CA, and they can be important components of our dry, alkaline areas. Some species are salt excretors - they excrete the salt that they have absorbed from the soil onto their leaf surfaces. Some of the herbaceous species resemble the species of Chenopodium; but the flowers are unisexual. Surrounding each pistillate flower are 2 leaf-like structures called ____________. Examine the leaf surface and compare the hairs with those of Chenopodium.

  • Salicornia - "glasswort" "pickleweed"
    These interesting species are important dominants of salt marshes. Note the succulent stems. The species handle growing in salty soil by sequestering the salts into compartments of their segmented stems. The segments that have excess salt turn reddish and in time, fall off. Are these stem succulents or leaf succulents? __________________ What is the phyllotaxy? _____________________

 

Amaranthaceae - As in the Chenopodiaceae, the flowers of the species of Amaranthaceae are very reduced and lack petals. Unlike some Chenopodiaceae, there are no granular or scaly hairs, the sepals are usually scarious (thin, dry, and not green), and the floral bracts, also scarious, are sometimes spiny.

  • Amaranthus "amaranth" "pigweed"
    Yes, this genus has a common name that is the same as for Chenopodium - and that is the problem with common names! The seeds of some species of this genus are currently used in some cereals. The seeds and whole plants are important foods in some areas of Latin America (used for cereals and edible greens). A number of the species in CA are non-native and are common weeds of disturbed areas and cultivated fields. The stems of many of the species are reddish. What is the phyllotaxis? __________

 

Montiaceae - A few genera in this family, such as Claytonia and Calendrinia are relatively common components of the native California flora. The family consists of herbs, many of which are somewhat fleshy (note this in all the examples you see today). The flowers typically have 2 "sepals" which are actually floral bracts (thus the "corolla" is actually the calyx).

  • Calandrinia - 4 native species.
    The species that we have for you in lab is C. ciliata "redmaids". Note the narrow leaves and dark pink corolla which may be closed up in lab. How many petals are there? _______ How many stamens? _____________

  • Claytonia - 14 native species
    One of the species that we have for you in lab is either Claytonia perfoliata "miners lettuce" or a close relative C. parviflora; both are relatively common in CA. Both species have cauline leaves that form a disk surrounding the stem and subtending the inflorescence. What is the phyllotaxis? __________________

  • Lewisia - 16 native species in CA.
    This beautiful genus contains a number of rare or uncommon species and varieties. Examine the demo and note the succulent leaves in a basal rosette, as well as the many "petals." Unlike most of the other CA members of the Montiaceae, two of the CA species of Lewisia have more than 2 "sepals."

 

Aizoaceae - Another family with leaf succulents. As you examine the material of this family, think about how you can differentiate it from the other leaf succulents you've already seen. How do members of Aizoaceae differ from members of Crassulaceae or Montiaceae?

  • Carpobrotus “fig-marigold”, "ice plant" - there are naturalized species in CA.
    Carpobrotus edulis, the non-native member of this genus has been used extensively as a dune stabilizer in coastal areas of CA. In that capacity, this species has crowded out many native dune plant communities.
    Note the succulent leaves. How do they differ in shape from those of Lewisia? _____________________________________________ Examine the demo of a long section of a flower. Is the ovary placement superior or inferior? _______________ Look at the flower parts and note the many narrow petals. How many sepals are there? ____ How many stamens? ____

  • Mesembryanthemum crystallinum "crystalline iceplant"
    This non-native species is found along the coast, especially in southern California. Notice the succulent leaves which look like they have ice-crystals on their surfaces.

 

Cactaceae - A family of stem succulents. You are not responsible for knowing any particular genus in this family. Examine the demonstration material and note the characteristics of the family as a whole.

  • Opuntia "prickly pear", Mammillaria "nipple cactus", Echinocereus "hedgehog cactus"
    In terms of the plant body, what are the spines equivalent to? _____________________
    What is the advantage of stem succulence to a desert plant like a cactus? ____________
    ___________________________________________________________________
    Where does photosynthesis occur in these plants? _____________________________
    Examine the flowers. Is the perianth divided into petals and sepals? __________
    How many stamens are there? ___________
    What is the ovary placement in the flowers? __________________

 

Caryophyllales, Polygonineae

Polygonaceae - There are 27 genera in CA in this family, many of which contain only one or two species. We have material of the three genera common in CA.

  • Polygonum (“knotweed") and relatives: Aconogon, Bistorta, Fallopia (“knotweed”), Persicaria (“smartweed”).
    California has many common native and non-native species in these genera. Some of the species are found in weedy situations (roadsides, cultivated fields, gardens); others are found in moist or wetland areas; still others are uncommon endemics. The California species are mostly herbs, however several are shrubs and one is a vine. The stems may be erect or prostrate. The species of Polygonum have an interesting feature at the nodes of the stem called an _______________, which is really a sheathing stipule. Also note the swollen nodes (which is why it is called "knotweed"). The leaves are alternate and simple.
    Examine the flowers. Most species have 5 identical greenish or colored perianth segments, a few have 6. This perianth type is an exception to the rule that was given in lecture: "if you have between 3 and 5 perianth segments, generally the perianth is called calyx." In the case of Polygonum, the 5 or 6 perianth segments are called tepals. This is because many Polygonaceous flowers have 6 tepals in two whorls of 3. In most species of Polygonum, however, two of the six tepals have fused, leaving 5 tepals.
    Look also at the pistil. What shape is the ovary in cross-section? ______________

  • Rumex
    These herbs are similar to the members of Polygonum in that many (but not all) of the species are found in wet or marshy/salty areas. Some are weeds of cultivated fields and others are uncommon. In CA, we have both non-native weeds and common and uncommon natives in this genus. The stems are usually erect, with many narrow ribs, often with reddish areas (rhubarb is a member of this genus). At the nodes is a stipular structure called the __________. The leaves are alternate and simple.
    Examine the flowers. How many perianth parts are there? __________ In fruit, are the perianth parts all of equal size? ____________ Note how species like Rumex crispus (an important non-native weed) have a large tubercle structure on the enlarged inner perianth parts, while other species lack these tubercles.
    There will be at least two species of Rumex for you to examine. Can you find both pistils and stamens on the same plant in both species? __________ If Rumex acetosella is available in lab, note the interesting shape of its leaves. This non-native is an edible herb that can be used to flavor salads.  Taste a tiny piece of a leaf and note the sour taste, which is due to its oxalic acid content.
    How can you tell the species of Rumex from those of Polygonum? _______________________________________________________________

  • Eriogonum "wild buckwheat"
    This is one of the largest (having the most species) plant genera in California. Many are rare endemics; others are widely distributed species with a multitude of varietal forms. All are natives. This is not the "buckwheat" of buckwheat pancakes; the buckwheat that we eat is from the genus Fagopyrum, also in the Polygonaceae.
    Eriogonum species are herbs, subshrubs, or shrubs. Their leaves may be alternate, opposite or whorled and are usually hairy, often tomentose (with matted hairs) at least on the underside. The name "eriogonum" comes from the words "erio" = hairy and "gonum" = knees, referring to the hairy nodes of the stem. Are there stipules at the nodes? _____________
    The inflorescence is characteristic of the genus. Note how within the inflorescence, the small flowers are grouped together in involucres (a whorl of bracts - in this case fused bracts that form a cup). The involucres are arranged in cymes, but may appear like umbels or heads, and each involucre subtends 2-many flowers.
    Look at an individual flower. How many perianth parts are there? ___________ Are the perianth parts green (as in Rumex) or colored (as in many Polygonum species)? _____________ How many stamens are there? ____________

 

Droseraceae - A family of carnivorous plants. The members of this family are found in habitats low in nitrogen, and the species have developed methods of capturing insects and digesting them for their nitrogen.

  • Drosera "sundew"
    Look at the potted plants of this genus. You will be able to identify the genus based solely on the appearance of the leaves. Note the sticky-glandular, insect-catching hairs which secrete enzymes to digest the insect (bacterial digestion may also be involved).

 

Geraniales

Geraniaceae - There are three genera in this family in CA, and most of the species are non-native.

  • Geranium and/or Erodium
    The species of these two genera are important components of our grasslands, and the non-native species are good competitors, crowding out our native wildflowers. Look at the material of these two genera.
    The leaf venation and lobing in Geranium is ______________________, whereas in Erodium the leaf venation, lobing and/or compounding is __________________________. The flowers in the two genera are similar in appearance, but is the stamen number the same? ______________________________ Examine the Geranium fruits and the Erodium fruits to see how the carpels of the fruit separate into segments when ripe. In Erodium, each fruit segment has a long point that coils and uncoils, twisting itself into the ground. In Geranium, each fruit segment rolls up the central axis.

 

Myrtales

Onagraceae - This family contains some very showy wildflowers in the genera Oenothera, Camissonia and segregates, and Clarkia. Although the genus Epilobium contains many natives (including "California fuschia"), it also contains some non-native weeds.
In general, how many petals and stamens are found in the flowers of this family? ________________________________ What is the ovary placement? ________________.

  • Oenothera "evening primrose" and Clarkia "farewell to spring"
    These two genera sometimes resemble each other. In Oenothera the anthers are attached to the filaments at the _______________, whereas in Clarkia the anthers are attached to the filaments at the _____________. As you examine the anthers, note the unusual "webby" pollen in Oenothera (as you touch it with your needle, the pollen sticks together by threads).

 

Malvales

Malvaceae - Members of this family are characterized by valvate sepals (in bud they close together with edges in contact - but not overlapping - like the valves of a capsule), palmate leaf venation, a whorl of bracts subtending the calyx, and usually stellate hairs. In addition, there is connation in the stamen whorl as well as adnation of the stamens to the bases of the petals, resulting in the ovary being hidden. Is the ovary placement inferior or superior in this family? ________________

  • Malacothamnus clementinus "San Clemente Island bush mallow"
    The members of this genus are native shrubs with rather showy flowers. You probably keyed this plant out earlier in the lab and so have examined its flowers rather closely. If you haven't already done so: 1) examine the stellate hairs on the leaves; 2) look at the ovary (make a cross section) to see the segments which separate upon maturation of the fruit (notice the mucilage, when you cut the ovary - this mucilage is characteristic of the order Malvales); and 3) examine the valvate sepals (look at the buds). Are there stipules on this plant? ________________

  • Malva "mallow" "cheeses"
    This is a non-native genus of weedy herbs. It has some similarities to Malacothamnus, however, the two genera differ in habit, density of pubescence, and the shape of the stigmas. Are the hairs on this plant stellate or simple? _______________ The fruits of Malva look like small gouda cheeses which break into neat cheese wedges upon maturity.

  • Sphaeralcea ambigua "apricot mallow"
    This native herb of California desert areas may be present as a demo. Note the very dense hairs on the leaves.

  • Sidalcea calycosa "sidalcea"
    The genus Sidalcea is relatively large and complex in California; the species can be difficult to key out. All of the species are herbs, and the upper leaves are usually deeply lobed to compound. The inflorescence is often spike-like. The species on display is found in vernal pools in the Sacramento area.

  • Fremontodendron "flannel bush"
    The members of this genus are shrubs to small trees with alternate, palmately veined and lobed leaves. The pubescence is often brownish and densely stellate. There are bracts subtending the one whorl of perianth (the yellow calyx). How does the stamen number differ from that in the other genera of Malvaceae you’ve looked at? _____________

 

Brassicales

Brassicaceae - This family has an alternative name: Cruciferae (from the cross-shaped flowers). This is an extremely important family in CA with ca. 65 genera! Twenty-five of those genera are introduced, and several more genera have both native and non-native species. Some of the non-natives, such as Brassica and Raphanus are extemely common along roadsides. Most of the native genera have relatively few species; a few, such as Arabis, Draba, Streptanthus and Caulanthus have over 20 species each.

The 2nd edition of The Jepson Manual has two keys to genera for this family, one based primarily on flowering material and one based primarily on fruiting material. The fruit of this family has 2-locules (from 2 carpels) separated by a partition called a septum. If the fruit is long and thin, it is called a "silique." If it is wide and short, it is called a "silicle." Most of the fruits in this family are dehiscent by two valves that separate from the septum. In a few cases, the fruits break into segments instead. Try to decide based on the shape of the ovary and developing fruits whether you will have a silique or silicle. With immature fruits, it is harder to imagine whether the fruits will dehisce by valves or break into segments. If the fruit is very lumpy, it may end up breaking into segments.

We provide a diversity of demonstration materials not to overwhelm you but to show you the diversity within this large family. As you look at this family, think about how you can tell members of this family from those of the Onagraceae. In both families, the flowers have four petals and the developing fruits can be long and thin and arranged in a raceme or panicle of racemes. Superficially, they may resemble each other. However, look at the stamens in the Brassicaceae. How many are there? _______ Are they all of the same height? Explain __________________________________________________ Is the ovary superior or inferior in this family? _____________________ Also, note how in the Brassicaceae, the flowers are often clustered at the tip of the inflorescence, and then as the fruits mature, the internodes of the inflorescence elongate.

  • Raphanus "radish"
    A non-native genus with two species in CA that are common roadside weeds. The leaves are pinnately lobed with a relatively large terminal lobe. The petals are relatively large and showy, arranged in large panicles of racemes; the flower color is purple to yellow or white, depending on the species. Look at the petals, which have a well-developed claw and limb. The ovaries and fruits (carol witham raphanus fruits) are lumpy and break into segments upon maturity.

  • Capsella bursa-pastoris "shepard's purse"
    A non-native genus with one species in CA. The leaves are mostly basal and pinnately lobed. The flowers are tiny, arranged on a raceme, clustered at the tip. How would you describe the fruit shape? ___________________

Other genera of the Brassicaceae that may be on display:

  • Brassica "mustard"
    A non-native genus with several common species in CA.
    Herbs with yellow petals that grow on our roadsides. Be careful, there are several Brassica look-alikes in CA, including the genera Hirschfeldia, Sinapis, and Sisymbrium. The species of Brassica have fruits that open by valves, ovules arranged in 1 row per locule, a rather well-developed "beak" on the fruit, and one midvein per valve. The "beak" is the top part of the silique that develops from the style.

  • Cakile "sea rocket"
    A non-native genus with 2 species.
    Herbs that grow on the sand at the beach - right where high tide stops. The leaves and stem are somewhat succulent. The petals are purple to white. The fruits look like little rocket ships and break into two segments at maturity; the segments are probably dispersed by the ocean.

  • Lepidium "pepperweed"
    A mostly native genus marred by several non-natives, one of which, Lepidium latifolium, is a noxious weed that is taking over our wetlands. The leaves are basal and cauline. The petals are white, in a raceme or panicle of racemes. The fruit is a silicle that is compressed at right angles to the replum; sometimes, there is a notch at the tip of the fruit.

  • Thysanocarpus "fringepod"
    A native genus with 4 beautiful species. The flowers are tiny, and it is the fruits that you will use to recognize this genus. The silicles are round and have a flattened, lacey border at their margin.

 

Limnanthaceae - A family with 2 native genera.

  • Limnanthes "meadowfoam"
    Annual herbs, often growing in moist areas, including vernal pools. The leaves are pinnately lobed to compound. The flowers are 4-5 merous, with twice as many stamens as petals. The petals are white, purplish, or yellow with clear striations. How many pistils are there? _______________

 

Sapindales

Anacardiaceae - The poison oak family. Many of the species in this family are allergenic.

  • Rhus "sumac" "lemonadeberry" - a native genus with 3 species in CA.
    Shrubs with alternate leaves. In California, these species are not allergenic. Some species, such as Rhus integrifolia, have simple evergreen leaves. Our common local species is Rhus aromatica, which is a poison-oak look-alike with deciduous, dull green, palmately trifoliolate leaves. The middle leaflet has a wedge-shaped base that comes to a point which is quite different than that found in the leaves of Toxicodendron. Also, the flowers of R. aromatica are borne in terminal inflorescences, and the fruits are red.

  • Toxicodendron diversilobum "poison oak" - a native genus with one species.
    Shrubs with alternate leaves that are sometimes reddish, sometimes greenish, often glossy when new. The oils on the leaves and stems are highly allergenic to susceptible individuals, causing dermatitis. Leaves are pinnately trifoliolate, the middle leaflet having a small petiolule (need photo) at the base. The flowers are borne in axillary inflorescences, and the fruits are white.

 

Sapindaceae - The soapberry family. A large, primarily tropical family with two genera in CA.

  • Acer "maple"
    Trees with opposite, deciduous, palmately lobed or pinnately trifoliolate leaves. The flowers are not particularly showy, but those of our "big leaf maple", Acer macrophyllum, are showier than most maples that you'll see in the U.S. Sometimes the flowers are unisexual, with the species being monoecious or dioecious. Some of the species are wind-pollinated. In A. macrophyllum, one commonly sees staminate and bisexual flowers on the same raceme, while A. negundo is dioecious. Look at the ovary. Draw its shape. How would you describe the shape? _____________ Why does the ovary have those funny "shoulders" on it? What do they become as the fruit matures? __________________________________

  • Aesculus californica "horse chestnut" "buckeye"
    Small to large tree, the branches often drooping. Leaves opposite, palmately compound. The bilateral flowers are clustered in large showy inflorescences.  From each inflorescence, only one fruit develops - a leathery capsule with just one seed. The seeds and other parts of the plant contain saponins and are toxic. However native Californians prepare the seeds for eating by leaching out the saponins and roasting the seeds. This species is also used to stun fish before catching them.

 

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