Chrysanthemum plant named Yellow Vero

A Chrysanthemum plant named Yellow Vero particularly characterized by its flat capitulum form; daisy capitulum type; yellow ray floret color; diameter across face of capitulum of up to 85 mm at maturity; uniform nine week photoperiodic flowering response to short days; medium plant height when grown as a single stem spray cut mum; and excellent tolerance to low temperature for bud initiation and flower development.

The present invention comprises a new and distinct cultivar of 
Chrysanthemum, botanically known as Dendranthema grandiflora, and referred 
to by the cultivar name Yellow Vero. 
Yellow Vero, identified as 81064A02, is a product of a mutation induction 
program which had the objective of creating new Chrysanthemum cultivars 
that would expand the color range of an existing cultivar while retaining 
all other traits. 
Yellow Vero was discovered and selected by Cornelis P. VandenBerg on Dec. 
18, 1985 in a controlled environment in Salinas, Calif. as one flowering 
plant within a flowering block established as rooted cuttings from stock 
plants which had been exposed as unrooted cuttings to an X-ray source of 
1750 rads. The irradiated parent was the cultivar identified as Vero, 
disclosed in U.S. Plant Pat. application Ser. No. 005,762. 
The first act of asexual reproduction of Yellow Vero was accomplished when 
vegetative cuttings were taken from the initial selection in March 1986 in 
a controlled environment in Salinas, Calif., by technicians working under 
formulations established and supervised by Cornelis P. VandenBerg. 
Horticultural examination of controlled flowerings of successive plantings 
has shown that the unique combination of characteristics as herein 
disclosed for Yellow Vero are firmly fixed and are retained through 
successive generations of asexual reproduction. 
Yellow Vero has not been observed under all possible environmental 
conditions. The phenotype may vary significantly with variations in 
environment such as temperature, light intensity, and daylength. 
The following observations, measurements and comparisons describe plants 
grown in Salinas, Calif. under greenhouse conditions which approximate 
those generally used in commercial greenhouse practice. The low 
temperature tolerance was determined in repeated flowerings in Bogota, 
Colombia. 
The following traits have been repeatedly observed and are determined to be 
basic characteristics of Yellow Vero, which, in combination, distinguish 
this Chrysanthemum as a new and distinct cultivar: 
1. Flat capitulum form. 
2. Daisy capitulum type. 
3. Yellow ray floret color. 
4. Diameter across face of capitulum up to 85 mm at maturity. 
5. Uniform nine week photoperiodic flowering response to short days. 
6. Peduncle length ranging from 15 to 20 cm on open terminal sprays. 
7. Medium plant height requiring two long day weeks prior to short days to 
attain a flowered plant height of 100 to 110 cm for year-round flowerings. 
8. Excellent tolerance to low temperatures for bud initiation and flower 
development.

Of the commercial cultivars known to the inventor, the most similar in 
comparison to Yellow Vero is the parent cultivar Vero. All traits of 
Yellow Vero are similar to those of Vero, except the color of ray florets. 
The color of the ray florets of Yellow Vero is a bright yellow, whereas 
Vero has white ray florets. 
In the following description, color references are made to The Royal 
Horticultural Society Colour Chart. The color values were determined on 
plant material grown as a single stem cut spray mum in Salinas, Calif. on 
Oct. 17, 1987. 
Classification: 
Botanical.--Dendranthema grandiflora, cv Yellow Vero. 
Commercial.--Daisy cut spray mum. 
INFLORESCENCE 
A. Capitulum: Form: Flat. Type: Daisy. Diameter across face: Up to 85 mm at 
maturity. 
B. Corolla of ray florets: 
Color (general tonality from a distance of three meters).--Yellow. 
Color (upper surface).--5B when just opening; 4B when flower is completely 
open. 
Color (under surface).--4C. 
Shape.--Flat, oblong. 
C. Corolla of disc florets: 
Color (mature).--Closest to 12A to 12B. 
Color (immature).--Closest to 144A to 144B. 
D. Reproductive organs: 
Androecium.--Present on disc florets only; scant pollen. 
Gynoecium.--Present on both ray and disc florets. 
PLANT 
A. General appearance: 
Height.--Medium; 100 to 110 cm as a single stem cut mum with two long day 
weeks prior to short days. 
B. Foliage: 
Color (upper surface).--137A. 
Color (under surface).--137B. 
Shape.--Lobed and slightly serrated.