This is the fourth dicot subclass--about halfway between
primitive Magnoliidae and derived Asteridae. Unifying characters:
None! In members with showy flowers and fused corollas, stamens are
usually more than the petals.
1. Malvaceae--Ours usually herbs. Palmate leaf
venation and/or lobing; EPICALYX of bracts often subtending calyx, stamens
MONADELPHOUS (united by filaments); petals free, carpels some multiple
of 5. Ex: Gossypium (cotton) and Callirhoe (winecup).
2. Salicaceae--Trees or shrubs. Dioecious,
both sexes of flowers in catkins; flowers without perianth, subtended by
bracts, nectary glands or scales present; ovary bicarpellate, seeds many,
comose. Ex: Salix (willow) and Populus (poplar or aspen).
3. Brassicaceae (Cruciferae)--Herbs with watery
juice, often biennial; flowers cruciform (cross-shaped), stamens tetradynamous
(4 + 2); fruit a silique or silice with 2 locules separated by a replum.
Important family with food crops--cabbage, broccoli, cauliflower, kale,
kohlrabi--all Brassica oleracea.
4. Ericaceae--Acid loving plants; corolla
urceolate or campanulate; stamens often poricidal. Only local genus
Vaccinium. Other ex: Gaylussacia. Many ornamentals,
5. Cucurbitaceae--Vines with tendrils; flowers
unisexual, both sexes with nectary disks; stamens united by anthers; ovary
inferior, tricarpellate; fruit a pepo with parietal placentation. Ex:
Cucumis (cucumber, also melon). Also Cucurbita (squashes,
gourds, pumpkins) and Citrullus (watermelon).
6. Carnivorous plants--Plants of acid bogs with low soil nutrients. Plants supplement their "diet" by obtaining nitrogen from digested insects. Sticky traps, pitfall traps, and snap traps are common. Drosera (sundew) and Dionaea (Venus flytrap)--Droseraceae, Sarracenia (pitcher plant)--Sarraceniaceae. Please don't touch!
Return to the Dilleniidae exercise
last modified Sept. 27, 2000 by MDR