ROSIDAE  (copy of overhead presented in lab)

This is the fifth dicot subclass. Unifying characters: showy flowers, perianth parts usually free, stamens = or > number of petals.

1. Crassulaceae-A family with many succulent members. Flowers perfectly 4- or 5-merous, apocarpous. Ex. Kalanchoe, Sedum, and Crassula.

2. Rosaceae-Large family. All have 5 sepals, 5 petals, many stamens. Gynoecium varies by subfamily (there is also Spiraeoideae, but we won't see this in lab):

a. Maloideae-ovary inferior, 2-5 carpels, fruit a pome.

b. Prunoideae-ovary superior, 1 carpel

c. Rosoideae-ovary superior, many separate carpels, fruit a cluster of achenes in a hip or a cluster of drupelets

3. Fabales (old name Leguminosae)-Large group which may be treated as 3 families or 1 family (Fabaceae, broad sense) with three subfamilies. Gynoecium is the same in all: one superior simple pistil, fruit a legume

a. Fabaceae (strict sense)-stamens usually diadelphous, corolla papilionaceous, banner outside wings

b. Mimosaceae-stamens showy, free; corolla regular, with or without fusion

c. Caesalpininaceae-stamens free, often not all alike; corolla zygomorphic, somewhat papilionaceous, banner inside wings, keel not fused

4. Onagraceae-Ours mostly herbs, ovary very inferior, often with long hypanthium; stamens 4 or 8; fruit a capsule Ex.: Oenothera

5. Euphorbiaceae-Ours mostly herbs. Gynoecium tricarpellate, flowers unisexual, of two kinds:

a. Euphorbia-type-Flowers without perianth, composed of a single stamen OR a pistil, arranged in a cyathium with glands and appendages-often resembling a single flower. Ex.: Euphorbia, which often has milky sap.

b. Non-Euphorbia-type-Flowers with or without perianth, variously arranged, but not in cyathia. Ex.: Croton

6. Apiaceae (Umbelliferae)-Herbs, often with compound leaves, leaf bases sheathing; flowers usually in simple or compound umbels; fruit a schizocarp, composed of two mericarps which are connected by the carpophore; enlarged style base= stylopodium. Ex. carrot, dill, parsley, celery, coriander

Return to the Rosidae lab exercise

last updated Sept. 28, 2000