Quercus havardii Rydb.
Havard Oak, Havard Shin-oak, Shinnery Oak
Fagaceae (Beech Family)
USDA Symbol: QUHA3
GROWTH FORM: rhizomatous shrub with a normal height of 3 feet (0.9 m) and exceptional speciments to 30 feet (9.1 m). BARK: papery, light gray. TWIGS and BUDS: brown pubescent twigs, becoming smooth with age; ovoid terminal buds are a dark reddish- brown. LEAVES: short petiole to 1⁄4 inch (6 mm); leaves are ovate or elliptical, 2 - 4 inches (51 - 101 mm) long, 3⁄4 - 2 inches (19 - 51 mm) wide; thick and with a rounded or cuneate base, margins generally have deep lobes with 2 - 3 rounded teeth on each side, apex rounded; upper surface shiny light green, lower surface has densely tawny tomentum.
This species was named for the U.S. Army surgeon and botanist, Valery Havard. Because Havard oak thrives in a harsh environment, it functions as a sand dune stabilizer and provides critical habitat for the endangered sand dune lizard (Sceloporus arenicolus). Although the acorns are an important food source for wildlife, the leaves are toxic to livestock. Use of herbicides to eradicate Havard oak has resulted in habitat loss and a drastic decline in sand dune lizard populations. The largest known Havard oak grows in Yoakum County, Texas.
From the Image Gallery
Plant CharacteristicsDuration: Perennial
Leaf Retention: Deciduous
Leaf Arrangement: Alternate
Leaf Complexity: Simple
Leaf Shape: Elliptic , Ovate
Leaf Venation: Pinnate
Leaf Margin: Dentate , Lobed
Leaf Base: Cuneate , Rounded
Breeding System: Flowers Unisexual , Monoecious
Fruit Type: Nut
Fruit: Acorns annual; solitary or paired on a peduncle up to 3⁄8 inch (10 mm), a pubescent reddish- brown cup, which covers 1⁄3 - 1⁄2 of nut; brown, ovoid nut, 1 inch (25 mm) long.
Size Class: 1-3 ft.
Bloom InformationBloom Color: Green
Bloom Time: Mar , Apr , May
DistributionUSA: CO , NM , OK , TX , UT
Native Distribution: New Mexico, Oklahoma, and Texas.
Native Habitat: Sandy soils and sand dunes; grows in areas devoid of almost all other trees.
Growing ConditionsWater Use: Low
Light Requirement: Sun , Part Shade
Soil Moisture: Dry
Soil Description: Sandy
From the National Organizations DirectoryAccording to the species list provided by Affiliate Organizations, this plant is on display at the following locations:
Texas Parks and Wildlife Department - Austin, TX
BibliographyBibref 766 - Dale Groom's Texas Gardening Guide (2002) Groom, D.
Bibref 1134 - Field Guide to Native Oak Species of Eastern North America (2003) Stein, John D. and Denise Binion
Bibref 318 - Native Texas Plants: Landscaping Region by Region (2002) Wasowski, S. & A. Wasowski
Bibref 291 - Texas Wildscapes: Gardening for Wildlife (1999) Damude, N. & K.C. Bender
Bibref 297 - Trees of Central Texas (1984) Vines, Robert A.
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Additional resourcesUSDA: Find Quercus havardii in USDA Plants
FNA: Find Quercus havardii in the Flora of North America (if available)
Google: Search Google for Quercus havardii
MetadataRecord Modified: 2015-11-18
Research By: TWC Staff