Great Botanical Books

Manual of Cultivated Plants Most Commonly Grown in the Continental United States and

Canada by L. H. Bailey (New York: Macmillan, 1949).

Sunset Western Garden Book by Kathleen Norris Brenzel (Birmingham, AL: Oxmoor House, 2007).

Horticultural Flora of South Eastern Australia by Roger Spencer and Su Pearson (Sydney: Univ. of New South Wales Press, 2002).

Mabberley’s Plant-Book by D. J. Mabberley (New York: Cambridge Univ. Press, 1997).

The Jepson Manual, Vascular Plants of California by Bruce Baldwin editor (Berkeley: Univ. of California Press, 2012).

Stearn's Dictionary of Plant Names for Gardeners by William T. Stearn (Portland: Timber Press, 1996).

Plant Systematics by Michael G. Simpson (New York: Academic Press, 2010).

Plant Form: An Illustrated Guide to Flowering Plant Morphology by Adrian D. Bell (Portland: Timber Press,2008).

Plant Names: A Guide to Botanical Nomenclature by Roger Spencer, Rob Cross, Peter Lumley (Canberra: CSIRO Publishing, 2007)

Pacific Islands Tree Information

Pacific Islands SelecTree

Linked PDF for Identifying Commonly Cultivated Trees of Hawaii and other Pacific Islands
Download this and you can use it on your phone to help identify trees in Hawaii and other Pacific Islands

Pacific Islands Tree Key Glossary of Terms
The key uses very few technical botanical terms, the remaining ones are defined here and linked in the key.

Download a copy of the presentation: An Overview of Hawaii’s Cultivated Trees & How to Identify Them
with Matt Ritter, Jenn Yost, and Kevin Eckert

Twenty Undeservedly Rare Trees for Southern California

A great diversity of different tree species can be grown in Southern California’s mild climate. Diverse tree plantings are more interesting and beautiful, and they make the urban forest more resilient to pests and diseases.

Yet, most trees sold and planted widely in Southern California come from a list of no more than a hundred or so species. The nursery and landscape industries are risky businesses, and growers and designers are often hesitant to experiment with new trees. 

When we grow only trees that are proven to succeed, we run the risk of continuing to diminish species diversity in our urban forests and never discovering new species that might prove to be of great merit. Nothing ventured...nothing gained. 

Here is a list of twenty undeservedly rare tree species that do well in Southern California and should be grown more often and widely than they are. 

See full list and article….

The Five Best Urban Tree Leaves to Use as Toilet Paper

As the coronavirus panic grips our nation and toilet paper shelves remain empty at stores, we can turn to the trees in our neighborhood parkways for a comfortable and convenient wipe. Simply find these common trees on your street and pick the number of needed leaves. Remember, leave some for others, and trees need to make food for themselves (photosynthesis) via their leaves, so don’t remove all of them. Also, if someone is already collecting from a tree, move on to another one to enforce appropriate social distancing. 

1. Sycamore (Platanus spp.)—These broad leaves allow for ample coverage. They are also thick enough to help avoid the danger of accidental tear-through, although doubling up might be safer. The finely textured fuzz will leave you feeling soft and clean. I recommend the newest leaves at the tips of branches as the soft hairs tend to disappear as the leaves age. 

2. Maidenhair Tree (Ginkgo biloba)—These leaves are on the smaller size, but are pliable and useful for getting harder to reach areas. The fan shape of the leaves also helps indicate a natural directionality to the wiping (always front to back!). I recommend tripling up.

3. Silver maple (Acer saccharinum)—A broadleaf with a fuzzy underside. I encourage you to not fold this leaf. The hairless topside will grip better against your hand while the soft, silver underside wipes without slippage.

4. Catalpas or cigar bean trees (Catalpa sp.)—These beautiful, heart-shaped leaves that turn golden in the fall can create a lush, almost tropical feel in the bathroom. They stack neatly on top of each other and can be hoarded for weeks without needing to resupply. Catalposide, a medicinal compound made in the leaves, will leave you feeling healthy (and a little numb). I recommend using the western catalpa (C. speciosa) as the leaves of southern catalpa (C. bignonioides) can have an unpleasant scent when crushed.

5. Southern Magnolia (Magnolia grandiflora)—This is the leaf for the larger man in the family. It’s thick, very resistant to tearing, has a large surface area, and an underside with a fine rust-colored, felt. I recommend collecting the larger, more flexible, shade-grown leaves for the comfort and coverage necessary for a generous backside. As one of the most widely grown ornamental trees on earth, you’ll be able to quickly locate one, near enough to your house as not to have to venture too far from where you are sheltering in place. 

Bonus his and hers wiping: Southern magnolia makes one of the largest tree flowers in the world, so collect and store the large leathery petals while you’re out there, your wife will appreciate it.

Leaves to avoid:

Pine trees, or conifers in general. Although these can leave you smelling fresh, the needles don’t have the flat surface area necessary to avoid making a total mess of your hands. It seems obvious, but worth saying that you should avoid poison ivy and poison oak. Several species of elms and hackberries are known as sandpaper leaf trees. Need I say more?

To learn more about these trees and many more in your neighborhood, check out SelecTree and my book, Trees among Us, from which the pages above were taken.

—Matt Ritter, www.mattritter.net

oak leaf.jpg

Cal Poly Plant Conservatory

The Cal Poly Plant Conservatory is a large glasshouse facility located in the center of the Cal Poly campus. The primary mission of the Cal Poly Plant Conservatory is to maintain a diverse, well-documented, and accurately labeled living plant collection supporting and enhancing teaching and research for the faculty and students of Cal Poly. A secondary goal of the Conservatory is to help foster education about plant biology and conservation of rare species through support of community outreach programs! 
 

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