Plant Notes

April 2007 Plant Notes

We had a few ,"What's This Plant" plants this month. Evelyn Kmetovic had a couple of succulents that could only be pinned down to Haworthia-like and maybe Crassula. Lee Read has a weedy, perennial Salvia that Betsy thought might be S. pratensis but will key it out for him. He also had a rose from a climber that was almost certainly "Fourth of July". Kerry brought in a coastal redwood cone to illustrate that the cone scales uniquely resemble a pair of closed lips.

Acer spp. (Aceraceae) Maple.
Grown by Nancy Schramm in Gilroy.
Acer is a very large and varied genus whose species defy generalities except that they all bear distinctive 2-winged fruit called samara and are all from the northern hemisphere. Nancy brought in a beautiful group of seed grown maples that I would love to detail for you, but I can just give you the list with a very brief comment on each and hope you looked at them carefully when you had the chance.
A. buergeranum (Trident Maple) has red fall color and nice flaky bark when older.
A. circinatum (Vine Maple) is a very graceful, small tree that provides spectacular color to forest understories from British Columbia into northern California.
A. davidii (David"s Maple) has shiny, green bark striped with silver.
A. griseum (Paperbark Maple) has great fall color and orange-brown bark that peels in wide, curling strips.
A. monspessulanum (Montpelier Maple) is a compact, rounded tree that tolerates heat and drought.
A. palmatum (Japanese Maple) is the airy, delicate tree from which hundreds of cultivars have been selected.
A. pentaphyllum is an elegant maple that is probably extinct in the wild and whose leaves are deeply divided into 5 very narrow lealets.
A. rubrum (Red Maple) is a large maple that provides dark red fall color to our eastern forests.
A.saccharum (Sugar or Rock Maple) is the commercial source of maple syrup and the leaf on the Canadian flag.
A. tataricum ssp. ginnala (Amur Maple) has fragrant flowers, showy seeds, slender arching branches, and deep red fall color.
A. truncatum (Shantung Maple) is very slow growing with yellow fall color.

Adenanthos sericeus (Proteaceae) Woollybush.
Grown by Judy Wong in Menlo Park.
Though this woollybush has small, red flowers, it is grown for its very silky, needle-like, gray foliage. It is relatively easy to grow in full sun to part shade in well-drained soil with little or no added phosphate. It will grow to about 8 ft. tall by 5 ft. wide, is drought tolerant, and hardy to about 25F. The cut foliage adds interesting texture to floral arrangements.

Asimina triloba (Annonaceae) Pawpaw, Prairie Banana.
Grown by Lee Read in Los Altos.
He received this from Ed Carmen about 17 years ago as a seedling. It is a small, deciduous tree found over most of the eastern US thanks to Native Americans who valued its banana-custard-like fruit. The interesting, purplish-brown flowers are pollinated inefficiently by flies and beetles. They are self-sterile and even resist pollination by closely related clones. Lee's tree had no fruit until about 3 years ago when it started giving him 3 pawpaws a year. The first two "crops" were inedible; but last year it was tasty, giving Lee hope for future pawpaw harvests. The poisonous leaves are the sole larval food for Zebra Swallowtails making them toxic to predators.

Carpenteria californica (Philadelphaceae) Bush Anemone.
Grown by Chris Egan in Los Altos Hills.
More abundant in English gardens than in the wild, this native is endemic to a tiny region of the Sierra foothills near Fresno. It is a formal looking, 5-10 ft. tall, evergreen shrub that blooms with terminal clusters of 3 inch lightly fragrant, white flowers with lots of bright yellow stamen. Some critics dislike its leggy bottom, but I like the ivory and tan peeling bark. Looks best with some afternoon shade, occassional summer water (though it is drought tolerant), and removal of old, dead leaves that can hang on forever.

Colletia paradoxa (Rhamnaceae) Anchor Plant, Crucifixion Thorn.
Grown by Betsy Clebsch in La Honda.
Dry Garden Nursery gave Betsy this unusual, seriously dangerous shrub. It is native to Uruguay and Brazil, grows 4 feet tall by 3 feet wide, with stiff, deep blue-gray stems. The leaves have been modified into flattened, spin-tipped triangles with each pair of triangles held at right angles to the next pair. In fall, clusters of small, dainty, white bells with a lovely fragrance hang from the base of each triangle. It prefers full sun and moderate water.

Echium gentianoides (Boraginaceae) Mountain Blue Bugloss.
Grown by Liz Calhoon in Los Altos Hills.
From Annie's Annuals, this is a rare and endangered Echium endemic to the pine forests on the highest peaks of La Palma Island in the Canaries. It is a branching, woody shrub that can grow to 5 feet tall. Liz's has 8 or 9, 3 ft. branches terminating in spikes of large, gentian blue flowers. It prefers full sun and relatively inorganic soil.

Gentiana acaulis Krebs (Gentianaceae) Stemless Gentian, Trumpet Gentian.
Grown by Kerry Barrs in Woodside.
A gorgeous, evergreen native of southern Europe, it is a 1 feet tall mat of shiny, dark green foliage topped with many solitary, deep blue tubular flowers up to 2 inches long.This is Kerry's fourth attempt at growing gentians. He is certain he could succeed if only he had a cooling table to keep their finicky, alpine roots in the 60F range.

Hermannia spp (Malvaceae, formerly Sterculiaceae) Honey Bells.
Grown by Cheryl Renshaw in Santa Clara.
Hermannia is a large genus mostly from southern Africa. They all have small, fragrant flowers with 5 spiraling, overlapping petals. Most are yellow; a few are orange to red. They need a warm sunny spot, sandy soil, and moderate water.
H. verticillata is a 2 feet H x 4 plus feet W shrub with small, finely dissected, bright green leaves and yellow flowers from winter into spring. Cheryl's has totally engulfed nearby rocks.
H. flammea is somewhat more upright, has matte green foliage and brick red flowers. Both of these make nice hanging plants.

Rosa eglanteria x californica (Rosaceae) Blue Oak Ranch Rose.
Grown by Judy Wong in Menlo Park
Judy got it as a division of a plant in Barbara Worl's garden who told the story that Gerda Eisenberg collected the rose at Blue Oak Ranch near Mt. Hamilton thinking that it was a California native to propagate for her nursery. When it turned out to be a hybrid, she gave it to Barbara. It has single, pink flowers all summer and carries hips and flowers at the same time. The foliage smells like apples. On the downside, it is loved by curculio beetles and wants to form a thicket 5 feet H x 20 feet W. Judy donated it to the raffle table for anyone with space for it.

Wisteria floribunda Macrobotrys (Fabaceae) Japanese Long-Cluster Wisteria.
Grown by Dick Dunmire in Los Altos
W. floribunda has longer leaves and longer flower clusters than the more frequently planted W. sinensis. The cultivar W. f. Macrobotrys has violet flowers in spectacular 18-36 inch long clusters, the longest of all the Wisterias. Dick has actually measured a 51 inch long cluster on his vine and the longest on the branch he brought to us was 41 inches. However, this is still far short of the 90 inches promised by its Japanese cultivar name, Kyushaku, meaning 9 times a unit of measure equal to about 10 inches. The flowers open sequentially starting at the base in typical Japanese Wisteria fashion making for a very long bloom time.

Dick Dunmire showing his wisteria

Jackie N. Doda

References: Am. Hort. Soc. A-Z Encyclopedia, Botanica, Flora, Sunset Western Garden Book, and various websites.