Oklahoma Native Plant Record

Front Matter

Gloria Caddell — 2022-11-02

Volume 2021

various — 2022-11-02

Foreword

Gloria Caddell — 2022-11-02

Growth Patterns and Ages of Trees from Martin Park Nature Center, Oklahoma County, Oklahoma

Chad King — 2022-11-02

This paper provides insight into ages and patterns of radial growth from mature trees at Martin
Park Nature Center, Oklahoma County, Oklahoma. A total of 80 trees were sampled and
crossdated using dendrochronology from the three most common genera at Martin Park Nature
Center: Quercus, Celtis, and Ulmus. The oldest trees at the park were Q. macrocarpa and C. laevigata
with individuals dating back to the 1920s and 1930s. A pulse of C. laevigata recruitment occurred
in the 1960s that likely reflected changes in land-use as the property transitioned from private
ownership to the City of Oklahoma City. A sequence of growth suppressions and releases was
identified in C. laevigata that is related to park maintenance and forest development at the park.

Measuring Changes in Phenology of Oklahoma Asteraceae Using Herbarium Specimens

John A. Unterschuetz — 2022-11-02

Analyzing shifts in plant flowering times (flowering phenology) in response to changing climate is
crucial to understanding the impacts of climate change on plants. Herbaria contain the physical
record of reproductive events from past seasons, making them an important source of long-term
data for studies of phenology. We measured changes in flowering phenology of four Oklahoma
native plants in the Asteraceae (sunflower) family: Grindelia ciliata, Liatris punctata, Ratibida
columnifera, and Vernonia baldwinii. These species were selected to represent the morphological and
phylogenetic diversity of the Asteraceae in Oklahoma and were represented in the Robert Bebb
Herbarium (OKL) with over 100 specimens each. We created novel protocols for scoring the
flowering phenology of these species into numeric categories, called phenophases. We looked for
correlations between the collection date and both the year of collection and the temperature in
that year. There was a significant relationship between collection date and year only in peak
flowering specimens of G. ciliata. There was a significant relationship between statewide annual
temperature and collection date only in peak flowering specimens of V. baldwinii. There was a
significant relationship between the annual temperature of the climate division of the state where
the plants were collected and collection date for peak flowering in G. ciliata, R. columnifera, and V.
baldwinii, for first flowers in V. baldwinii, and for last flowers in L. punctata. More precise
temperature data thus lead to an improvement of the model, but in all cases temperature or year
explained relatively little of the total variation in flowering time.

Literature Review of Dendrochronology Research in Oklahoma, U.S.A.

Carmen L. Esqueda — 2022-11-02

Dendrochronology, the study of tree-rings to help understand events of the past, is a growing
body of research that has become well-established in scientific literature within the last century.
Oklahoma is a distinct resource to dendrochronology as it exists at the eastern deciduous forests
and western prairies/grasslands transition. The extent of dendrochronological research conducted
in Oklahoma has not yet been determined. A literature review was performed to catalogue and
quantify dendrochronological research for Oklahoma. Thirty-seven written works were identified
ranging through years 1923 to 2018. Nine research topics were developed to aid publication
synthesis, with climate reconstruction, fire history, and stand dynamics being the most frequently
encountered topics. Reviewed publications indicated that humans and climate, specifically
drought, largely impacted Oklahoma forests historically, and remain a current threat. Results
provide a detailed resource of dendrochronological applications within Oklahoma that spans the
past century. Presented literature can be referenced for future Oklahoma dendrochronology
studies, with presented knowledge also benefiting studies of similar forest types elsewhere.

Cold Stratification of Salvia azurea var. grandiflora Benth. (Lamiaceae) seeds to Break Dormancy

Samantha Coplen — 2022-11-02

Seed dormancy and its maintenance rely on a range of environmental signals and cues such as
light, temperature, soil pH, and moisture. A significant contributor to the cycle of dormancy and
germination is temperature. Salvia azurea var. grandiflora Benth. is an Oklahoma native perennial
that produces blue flowers with one seed per flower. Seeds were collected from four sites in
Oklahoma and Cleveland Counties, OK, and randomly assigned to one of three treatment groups:
no cold stratification, 3-week cold stratification, and 6-week cold stratification. Seeds were
monitored daily, and seed germination date was recorded for analysis. Survival analysis indicated
there was a significant correlation between the amount of time in a cold stratification environment
and number of seeds that germinated. Seeds in the 6-week cold stratification treatment group
exhibited increased germination compared to the other two treatment groups.

Critic's Choice Essay: Musings at Dusk

Paul Buck — 2022-11-02

Five Year Index to Oklahoma Native Plant Record

Gloria Caddell — 2022-11-02