Test you knowledge of horticulture on the following questions.

Milky sap is one indication of poisonous plants. However, it is not totally true. Name two common vegetables which have milky sap.

In plants there are three different reproductive options. Plants can have male and female parts on each flower or male flowers and female flowers on the same plant or entire plants which are male or female. Name a vegetable which fits each category. Now name a fruit or nut tree for each category. Finally name a common ornamental which falls into each category.

Poinsettia and dogwoods have a common flower petal color. What is it?

Name the only plant native to the US which contains caffeine?

Tea is derived from a plant which has two common relatives used as ornamentals in Cabarrus County. Name one of these plants.

Several plants have edible flowers. Name a plant with edible flowers from the following categories; vegetable, wildflower, annual, perennial, fruit, and shrub.

ANSWERS. This quiz is not easy. If you get half of the answers you can consider yourself an advanced gardener.

Lettuce and sweet potatoes have white sap. I don't use rules to identify poisonous plant. I assume all plants are poisonous unless I know otherwise. The local plants with white sap include several types of spurge which are poisonous, dogbane which is poisonous, milkweed which is poisonous unless collected and prepared properly, and wild lettuce which is edible. Poison sumac also has milky sap but I haven't seen any around here. I understand some plants from tropical areas have white sap which can cause burns on contact.

Beans and tomatoes among others have complete blooms. Corn and all the cucurbits which include squash, cucumbers, cantaloupes, and watermelons have male and female blooms on the same plant. The male blooms show up first and many people get worried when they drop and don't produce fruit but this is natural. Asparagus is the only vegetable I know with entire plants either male or female (dioecious). Some of the newer hybrids are all male which puts more energy into stalks and none into fruit production.

Many fruits have complete flowers including apples, peaches, pears and strawberries. Pecan trees have separate male and female blooms. Persimmon trees can be either male or female (dioecious). You can't tell until they start blooming which is a good argument for purchasing a grafted variety. One kiwi species is the only other fruit I can think of with male and female plants. One species of kiwi has complete flowers. Some people incorrectly use the term male for muscadine grapes. There are some varieties with only female flowers but the other varieties have male and female flowers.

There are numerous ornamentals with complete flowers. Oaks are a common ornamental plant with male and female blooms.

Hollies are either completely male or completely female. The male is desirable when you only want green foliage. Some hollies will turn yellow when they sink all their nitrogen into berry production. The female is necessary for berry production. Aucubas and gingkos are two more dioecious plants. Ginkgoes are grafted to avoid the female plant. The first nursery I worked for would mix male and female aucuba plants when selling more than one. However, the fruit is not very showy so I doubt the homeowners cared. Maybe the plants were happier.

The flower petals on dogwoods and poinsettias are yellow. The flower bracts may be white, pink or red but the petals are yellow.

Yaupon (Ilex vomitoria) contains some caffeine and was used as a drink. I have never tried it. I don't drink much tea of any kind. Yaupon is a very hardy plant and is used as an ornamental. There is a weeping form, a dwarf form and the standard. I have never heard a comparison of the taste of the different cultivars or of the caffeine content. Maybe the weeping form would hold its limbs up better if it had more caffeine.

Camellia japonica and camellia sasanqua are in the same genus as Camellia sinesis. Camellia sinesis is hardy here. I don't know of any growing in Cabarrus County but recall seeing a specimen near Williams Hall on NCSU University. I have never seen it in bloom but it reportily blooms white for several weeks in the fall of the year. It has a single petal so isn't as flashy as many of the other camellias.

My list of edible flowers; squash, violets (Viola odorata although Viola cornuta and Viola tricolor are also suppose to be edible), nasturtiums, dianthus or daylilies, apple or elderberry, and rose. Daylilies are commonly used in the Orient. I have tried it as well as violets, dianthus and rose. During the season, violets regularly find a place on salads. The other flowers didn't suit my taste.

By definition trivia is trivial but for some reason it is a lot of fun.


 Article was written by David Goforth Agriculture Extension agent North Carolina Cooperative Extension Cabarrus County Center.  Visit my homepage http://cabarrus.ces.ncsu.edu/ or http://cabarrus.ces.ncsu.edu/index.php?page=lawngarden or my blog http://gardeninggurugoforth.blogspot.com/

Contact me at David_Goforth@ncsu.edu.  Reviewed 2007.