Friday, June 20, 2008

Wildflowers on the San Gabriel River Trail, Is Global Warming Causing Them to Bloom Earlier?

by Phyllis Dolich

Phyllis Dolich has been a resident of Sun City Texas in Georgetown for eight years. She served as president of the Sun City Texas Nature Club and president of the Williamson County chapter of the Native Plant Society of Texas. She is a member of the Lady Bird Johnson Wildflower Center and the Butterfly Forum of Austin. Her garden was featured in the Wildflower Center’s Native Plants magazine and on PBS’ Central Texas Gardening.

In 1852 and 1853, Eliza Griffin Johnston, who was living in Austin, Texas created 100 watercolor paintings of the wildflowers which surrounded her home. Each was accompanied by a hand-written observation which included the bloom time. Many of the wildflowers I have observed on the North San Gabriel River Trail are included in Mrs. Johnston’s collection which was donated to, and later allowed to be published by, the Daughters of the Republic of Texas. The book, Texas Wildflowers, was published by Shoal Creek Publishers in Austin in 1972.

Although I have observed and recorded 123 wildflower species on the trail between 2001 and 2007, I will limit the following analysis to just those found in Eliza’s collection. The following table lists the plants by family and compares Eliza’s bloom times with the bloom times reported by Marshall Enquist in Wildflowers of the Texas Hill Country (Lone Star Botanical, Austin, Texas 1985). His observations correspond with my own (in some cases, mine are even earlier).

Conservation biologist, Richard Primack, of Boston University is conducting a similar analysis at Walden Pond where Henry David Thoreau made observations of flowering plants and their bloom times 155 years ago. (See The Science Journal in the Wall Street Journal, Friday, June 13, 2008, page A10) Species

Blooming Earlier

Ruellia nudiflora (Engelm. & Gray) Urban, wild petunia
Bloom Time 1852: May throughout summer
Bloom Time Now: April-Nov

Yucca rupicola, twist-leaf yucca
Bloom Time 1852: May
Bloom Time Now: April-June

Engelmannia pinnatifida, Engelmann's daisy
Bloom Time 1852: from May until the end of summer
Bloom Time Now: Feb/March-July

Symphyotrichum drummondii, Texas aster
Bloom Time 1852: November
Bloom Now: Sept-Oct/Nov

Opuntia macrorhiza Engelm, Prickly Pear, Grassland
Bloom Time 1852 (O. engelmannii var. lindheimeri): May
Bloom Time Now: April-May

Viburnum rufidulum Raf. , rusty blackhaw viburnum
Bloom Time 1852: Mar 21
Bloom Time Now: Feb/March-May

Ibervillea lindheimeri (Gray) Greene, balsamgourd
Bloom Time 1852: middle of June
Bloom Time Now: April-Sept

Lupinus texensis Hook, Texas bluebonnet
Bloom Time 1852: end of March
Bloom Time Now: Feb/March-May

Phacelia congesta, blue-curls
Bloom Time 1852: during May and June
Bloom Time Now: Feb-May

Calylophus berlandieri Spach, Berlandier's sundrops, Square-bud primrose
Bloom Time 1852: 6 or 8 weeks fr beg of April
Bloom Time Now: Feb/March-Aug

Gaura lindheimeri, White Guara,
Bloom Time 1852: March 25
Bloom Time Now: Feb/March-June

Oenothera jamesii Torr. & Gray, james evening or river primrose
Bloom Time 1852: August and September
Bloom Time Now: July-Oct/Nov

Oenothera speciosa Nutt. pink or showy evening primrose
Bloom Time 1852: early April
Bloom Time Now: Feb/March-July

Argemone albiflora Hornem. ssp. texana G.B. Ownbey white pricklypoppy
Bloom Time 1852: April
Bloom Time Noww: Feb/March-May

Clematis pitcheri Torr. & Gray, pitcher clematis, purple leatherflower
Bloom Time 1852: August
Bloom Time Now: May-July

Agalinis heterophylla (Nutt.) Small ex Britt., prairie agalinis, false-foxglove
Bloom Time1852: 2 or 3 weeks in October
Bloom Time Now: Sept-Oct/Nov

Castilleja indivisa Engelm. Texas paintbrush
Bloom Time 1852: April
Bloom Time Now: Feb/March-May

Solanum elaeagnifolium Cav. silverleaf nightshade.
Bloom Time 1852: June and July
Bloom Time Now: April-Sept

Solanum rostratum Dunal, buffalobur
Bloom Time 1852: June and July
Bloom Time Now: May-Oct/Nov

Glandularia bipinnatifida (Nutt.) Nutt. var. bipin , Dakota verbena Bloom Time 1852: from April to December
Bloom Time Now: Feb/March-Oct/Nov

Lantana horrida, Texas lantana, calico bush
Bloom Time 1852: April and May
Bloom Time Nov: Feb/March-Oct/Nov

Species Not Blooming Earlier

Ilex decidua, Possumhaw, Deciduous Holly
Bloom Time 1852: end of March
Bloom Time Now: May-July

Gaillardia pulchella Foug., rosering gaillardia, indian blanket, blanketflower
Bloom Time 1852: April and May
Bloom Time Now: April-June

Berberis trifoliolata, Agarita
Bloom Time 1852: Feb 20 - Mar 15
Bloom Time Now: Feb/March-April

Lesquerella gracilis, Bladder-pod or Cloth-of-Gold
Bloom Time 1852: March 21
Bloom Time Now: Feb/March-May

Tradescantia occidentalis (Britt.) Smyth (T.humilis), spiderwort, western spiderwort
Bloom Time 1852: April and May
Bloom Time Now: April-June

Cnidoscolus texanus (Muell.- Arg.) Small, bullnettle
Bloom Time 1852: April - November
Bloom Time Now: April-Sept

Chamaecrista fasciculata (Michx.) Greene, partridge pea
Bloom Time 1852: April (earlier than now?)
Bloom Time Now: May-Oct/Nov

Indigofera miniata Ortega, western indigo, scarlet pea
Bloom Time Now: April-Oct/Nov

Nemophila phaceloides, baby blue-eyes
Bloom Time 1852: mid-March
Bloom Time Now: Feb/March-May

Callirhoe involucrata (Torr. & Gray) Gray, winecup
Bloom Time 1852: last of March
Bloom Time Now: Feb/March-May

Malvaviscus arboreus var. Drummondii, Turk's Cap
Bloom Time 1852: May to November (earlier)
Bloom Time Now: June-Oct/Nov

Ipomopsis rubra (L.) Wherry, Texas plume, standing cypress
Bloom Time 1852: from early May till October
Bloom Time Now: May-June

Clematis texensis Buckl., Texas clematis, scarlet leatherflower
Bloom Time 1852: late April
Bloom Time Now: April-June

Ungnadia speciosa Endl., Mexican buckeye
Bloom Time 1852: Mar 15
Bloom Time Now: Feb/March-May

Vitis mustangensis, Mustang Grape
no bloom info


Will Howard said...

Phyllis and Ben,
Nice blog, it's new? I'm compiling a list of "Texas History and Literary Blogs." Your entries so far are ecological. Your summary suggests you'll also be adding some traditional history as well. Is that likely? Will at &

Ben Pierce said...

Will: The blog is new. I do plan on including information on the history of the San Gabriel. You are correct that most of the current posts are ecological, but see the post on San Gabriel River Crossings. Ben

Carey said...

Phyllis, on bloomdates of flowers here are some more things to consider: In my own observation of flower bloom dates since about 1990 I found that plants are "in tune" with climatic conditions, blooming earlier or later depending on when the right combination of temperature and moisture occurs. This is to maximize opportunity for pollination and seed production. Some perennials and a few annuals will bloom both in the spring and in the fall, and through wet, cool summers when they occur. In 1852 the flowers growing then had just endured the 300-year Little Ice Age, and they were likely very used to it staying colder longer into the season. Perhaps the real question is whether the earlier warm, wet weather is the result of global warming or a normal variation in climate.