Plant Tax Test 3

Rosid clade size and diversity

Approximately 58,000 species and 114 families, representing about 1/3 of all dicot families

Other major clade paired with Rosids

Asterid clade; together they form Pentapetalae

Hypanthium definition

A floral cup/tube formed from fused bases of sepals, petals, and stamens

Flower position types in Rosids

Perigynous or epigynous (often due to hypanthium presence)

Typical placentation in Rosids

Mostly axile or marginal with 1–2 ovules per locule

Common leaf feature in Rosids

Presence of stipules (sometimes elaborate)

Lower vs Higher Rosidae (flowers)

Lower: large, solitary; Higher: small, in tight inflorescences

Lower vs Higher Rosidae (gynoecium)

Lower: apocarpous; Higher: syncarpous

Lower vs Higher Rosidae (stamens)

Lower: numerous; Higher: equal to or fewer than petals

Lower vs Higher Rosidae (corolla)

Lower: apopetalous; Higher: sympetalous

Order Saxifragales significance

Possible sister group to remaining Rosids with mixed traits

Saxifragales possible synapomorphies

Hypanthium, 2 carpels, glandular leaf teeth, 5-merous flowers

Saxifragaceae leaf traits

Palmately lobed and veined leaves

Saxifragaceae atypical Rosid traits

Lack stipules, few stamens, capsule fruit, endosperm-rich seeds

Crassulaceae key trait

Succulent plants with CAM photosynthesis

Crassulaceae flower traits

Actinomorphic, apocarpous, usually 4- or 5-merous

CAM photosynthesis significance

Water-efficient photosynthesis found in multiple plant families

Hamamelidaceae key features

Woody plants with asymmetric leaf bases and explosive seed dispersal

Order Vitales growth form

Lianas with leaf-opposed tendrils

Vitaceae tendrils origin

Modified inflorescences

Vitaceae fruit type

Berry

Polygamodioecious definition

Plants with both male/perfect or female/perfect flowers on different individuals

Oxalidaceae distinguishing trait

High oxalate content giving a sour/lemony taste

Oxalidaceae floral structure

Two whorls of stamens and tristylous gynoecium

Oxalidaceae fruit type

Loculicidal capsule

Celastraceae seed feature

Seeds often have colorful arils

Euphorbiaceae defining feature

Cyathium (pseudoflower) with showy bracts

Euphorbiaceae latex

Often produce milky latex (e.g., rubber tree)

Euphorbia inflorescence type

Pseudanthium

Hypericaceae key trait

Numerous stamens often grouped in bundles

Passifloraceae unique structures

Corona and androgynophore in flowers

Rhizophoraceae adaptation

Vivipary (seed germinates while attached to parent)

Rhizophora dispersal mechanism

Floating propagules that establish upon substrate contact

Violaceae key traits

Zygomorphic flowers, stipules, often cleistogamous reproduction

Salicaceae pollination

Primarily wind pollinated

Salicaceae inflorescence

Catkin

Salicaceae reproductive strategy

Dioecious plants with unisexual flowers

Fabaceae defining feature

Nitrogen-fixing root nodules

Fabaceae leaf traits

Often compound with pulvini

Fabaceae fruit types

Legume or loment

Fabaceae flower symmetry

Usually zygomorphic and bee-pollinated

Rosaceae general traits

5-merous flowers, numerous stamens, hypanthium often present

Rosoideae fruit type

Aggregate fruits (drupelets or achenes)

Example: Strawberry fruit type

Aggregate of achenes on fleshy receptacle

Example: Raspberry fruit type

Aggregate of drupelets

Example: Rose fruit type

Hip (modified receptacle)

Prunus fruit type

Drupe

Maleae fruit type

Pome (e.g., apple, pear)

Rhamnaceae trait

Petals form hood over stamens

Ulmaceae leaf characteristic

Oblique bases and doubly serrate margins

Ulmaceae fruit type

Samara

Cannabaceae chemical trait

Presence of aromatic compounds like THC

Moraceae defining feature

Laticifers producing milky sap

Urticaceae defense

Stinging hairs (in some species)

Cucurbitaceae plant type

Herbaceous vines with inferior ovary

Cucurbitaceae fruit type

Pepo

Cucurbitaceae reproductive strategy

Monoecious with unisexual flowers

Begoniaceae key trait

Highly asymmetric leaf bases

Fagaceae fruit type

Nut with cupule

Fagaceae reproductive trait

Monoecious with catkin inflorescences

Betulaceae ecological role

Early successional or understory trees; some fix nitrogen

Casuarinaceae leaf structure

Scale-like leaves on needle-like twigs

Casuarinaceae nitrogen fixation

Uses different bacteria than Fabaceae

Juglandaceae key traits

Aromatic, pinnately compound leaves, often allelopathic

Juglandaceae fruit type

Nut or dried drupe