How to Identify Plants

After a visit to the poison garden, it is obvious that being able to identify plants is an asset. Today’s resource is a little book called How to Identify Plants, by H.D. Harrington. The book is published by Swallow Press books (Ohio University Press), with copyrights in 1957 and 1985; and illustrated by L.W. Durrell. Harold David Harrington (1903 - 1981) was a professor of botany and zoology at Colorado State University from 1944 through 1968, and the curator of the CSU Herbarium for 25 years. Harrington was an expert on edible and poisonous plants, grasses, and aquatic plants in Colorado and the West, and authored several books. His wife, Edith, was also a botanist, and assisted him with his specimen collecting forays and manuscripts. Two species are named in his honor – Penstemon harringtonii and Oenothera harringtonii.

The initial chapters describe why it is important to identify plants, and how plants are classified and named. The bulk of the book defines terms relative to plant parts, including the flower, inflorescence, underground parts, stems, leaves, fruits and seeds, and surfaces. Many illustrations enhance the definitions. Additional chapters provide helpful reference material, such as how to use keys to identify plants, how to collect and press plants, and what regional manuals and floras are available. The glossary provides access to the terms in alphabetical order.

This is a great book for beginners just learning the language of plants, and for experienced plant lovers who need a quick reminder of how to describe a leaf shape, or flower construction. The book is small enough to toss in a day pack, or keep on your desk.

Poison Gardens – Water Hemlock

Water hemlock (Cicuta douglasii) is a flowering perennial herbaceous plant in the carrot family (Apiaceae). The United States Department of Agriculture (USDA) considers water hemlock the most poisonous plants in the Western United States, with a range from Alaska to California. Several other plants may be mistaken for water hemlock, including poison hemlock (Conium maculatum – used in the poisoning death of Socrates), wild parsnips, and other herbs or perennial plants).

Water hemlock. Photo by Barry Breckling, used under Creative Commons Attribution-NonCommercial-ShareAlike 3.0 (CC BY-NC-SA 3.0) license.

The heavy scented plant grows up to 8 feet tall (2.5 meters), with a sturdy, hollow stalk; small white flowers in terminal compound umbels; leaves decompounded (side veins lead to notches, not to tips, at the outer margins); poisonous roots; and slightly flattened fruits.  The thick rootstalk includes several chambers containing the poisonous compound cicutoxin, which is an unsaturated aliphatic alcohol (although all parts of the plant are poisonous).

 Cicutoxin works on the central nervous system. Symptoms include nervousness, excessive salivation and frothing, muscular twitches, dilation of the pupils, rapid pulse and breathing, tremors, violent convulsions, and death from asphyxiation and cardiovascular collapse. A very small amount can cause death in people, pets, and livestock. Contact a poison control center immediately if symptoms occur.

The plant is found in riparian areas, near stream banks, bogs, and marshy areas. It can be used in a wild or bog landscape, but may not be an appropriate choice for small children, pets, or livestock.

Poison Gardens – Purple Nightshade

A couple of years have passed since we last visited the poison garden (California Buckeye, Poison Oak, and Stinging Nettle). Halloween seems the perfect time for another foray! Many plants in the San Francisco Bay Area have some level of toxicity, enabling them to fend off predators.

Purple nightshade (Solanum xanti) is a perennial, flowering, evergreen shrub that is native to the Western United States, including California. It grows to 35 inches high, with a hairy stem; leaves that are lance shaped to oval, somewhat lobed, and 2 - 3 inches long; a distinctive umbel-shaped inflorescence with purple-blue flowers up to an inch and half wide; and a green berry fruit that is ½ - ¾ inches wide. Nightshade can thrive in a variety of environments, including chaparral, conifer forests, and oak woodlands.

Purple Nightshade (Solanum xanti) - photo by Dawn Endico,
taken on Mitchell Canyon trail, Mt. Diablo, Northern California. (Jepson)

 

Nightshade is toxic, as are other members in the Solanaceace family. All parts of the plant are poisonous, especially the unripe fruit. Toxicity is from Solanine and glycol-alkaloids, chaconine, and solasodine. There is no antidote for Solanum poisoning. Symptoms include:

• Cardiovascular system (tachycardia, arrhythmia, and hypotension)
• Central nervous system (delirium, psychomotor, agitation, paralysis, coma, and convulsion)
• Gastrointestinal track (nausea, vomiting, diarrhea)

The plant is desirable in the landscape, as it is drought-tolerant, tolerates clay soil, grows under native oak, is deer resistant, and commonly blooms from January to May. Since the plant is poisonous, it may not be an appropriate choice for small children or pets.