Poinsettia plant named `721`

Abstract

Poinsettia `721` is a new cultivar, distinguished by bright red flower bract, dark green foliage, self-branching characteristics, uniform growth habit and 9-week flowering response time. The new plant produces a very desirable branched flowering pot plant for the mid-season holiday market. Poinsettia `721` is resistant to epinasty after being confined to shipping containers. The post-production foliage and bract retention is excellent even under low light intensities in the consumer's home.

Description

BACKGROUND OF THE PLANT

This new poinsettia cultivar, `721`, originated as an induced self-branching sport of a seedling known as "M-02" (not patented) in my greenhouse in Encinitas, Calif. It was selected because of its bright red flower bracts, dark green foliage, self branching characteristics, and uniform growth habit; traits that distinguish it from other poinsettia cultivars, and seem to make it a desirable plant for commercial greenhouse production. After selection, `721` was vegetatively reproduced from stem cuttings for test purposes in Encinitas, Calif. "M-02" is a proprietary plant and there are no specimens in the public domain. Poinsettia "M-02" is not self-branching in that no axillary branches develop as long as the apical bud is not removed (pinched). `721` is self-branching in that during development axillary branches elongate without removal of the apical bud. If under short day conditions, the axillary branches will develop inflorescences. Poinsettia `721` most closely resembles poinsettia `140` (U.S. Plant Pat. No. 7,874), but differs in these aspects: `721` has a more uniform growth habit, more cyathia, smoother flower bracts and flowers later than `140` under the same cultural conditions. By subjecting clones of this plant to successive generations of vegetative propagation, it was demonstrated that the distinctive characteristics of `721` held true from generation to generation.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

Poinsettia `721` is illustrated in the accompanying color photographs.

The upper photograph is a side view of a branched `721` plant in full bloom.

The lower photograph is a top view of the same `721` plant showing flower and bract formation.

DESCRIPTION OF THE PLANT

The following is a detailed description of this new poinsettia as observed in Encinitas, Calif., USA during December 1996. Observations were recorded from flowering plants, grown as one branched plant per pot. The pot was 14 cm in diameter and 11 cm in height. Color designations are compared to the 1986 edition of R.H.S. Colour Chart, first published in 1966 by The Royal Horticultural Society, London, England.

THE PLANT

The following chart summarizes some of the differences between Poinsettia `721` and the plant it closely resembles, Poinsettia `140` (U.S. Plant Pat. No. 7,874) under the same cultural conditions.

  ______________________________________                                    
     Plant       '721'          '140'                                          
     ______________________________________                                    
     Flowering response                                                        
                 9 weeks        8 weeks                                        
     No. of Bracts                                                             
                       16-18                  10-12                            
     Bract color        RHS 45A             RHS 46A-B                          
     No. of cyathia                                                            
                       14-15                   8-10                            
     Leaf margins                                                              
                       Undulant            Smooth                              
     Leaf color          Darker than RHS139A                                   
                                Darker than RHS147A                            
     Nectar cups        No nectar                                              
                                          Abundant nectar                      
     ______________________________________                                    

Origin: Sport of poinsettia seedling "M-02". The sport was induced by application of the procedures set forth in U.S. Pat. No. 4,724,276 to the seedling parent plant. Rootstock used was `Angelika` (U.S. Plant Pat. No. 5,492).

Classification:

Botanical.--Euphorbia pulcherrima Willd.

Common name.--Poinsettia.

Cultivar name.--`721`.

Form: Shrub.

Height: Short -- medium.

Growth habit: As a single stemmed plant, upright and vigorous with self-branching side shoots. Leaf internodes are typically 1.6 cm. The application of a chemical growth retardant may not be needed to restrict height for commercial pot plant production. I observed a branched plant in a pot with an overall height of 39 cm and an overall width of 46 cm. The diameter of individual inflorescences is 26 cm.

Branching: Axillary branches will develop and terminate in an inflorescence without pinching. However, it is usually desirable to pinch `721` before flower induction and remove all terminal dominance. Then, all axillary branches will develop uniformly and at a faster rate.

Growth rate: Rooting of stem cutting occurs in 12-18 days under intermittent mist. The plant will flower in about nine weeks under continuous long night conditions and night temperatures of about 16-18.degree. C.

Foliage: The foliage is clean and uniformly dark green from bottom to top of the plant. The leaves are of medium size, leaf blades typically 13-15 cm long and 9-10 cm wide. Leaf petioles are about 6 cm long, dark red on the top surface and reddish on the under surface. The upper leaf surface is glabrous and the under surface is slightly pubescent.

Leaf shape.--Typical leaves are generally ovate with obtuse bases and acute tips. Leaf margins are mostly entire but undulant.

Color.--Upper side -- Dark green, much darker than R.H.S. 139A. Under side -- Green, R.H.S. 147A-B.

Retention.--The foliage lasts extremely well even under low light intensities in the consumer's home.

Bracts: Generally there are 16-18 bright red bracts of various sizes subtending the cyathia. The primary bracts have blades typically 14-15 cm long and 8 cm wide with petioles 4 cm long.

Shape.--Primary bracts are ovate with acute bases and acuminate tips. Primary bract margins are somewhat lobed with 1 or 2 indentations on either side of the bract. Secondary bracts are of various sizes, broadly elliptical, and have acute bases, acuminate tips and entire margins.

Color.--Upper side -- Bright red, near R.H.S. 45A. Under side -- Red, between R.H.S. 53C-D.

Flowers: Generally, 14-15 cyathia (flowers) per inflorescence are present when the plant is in full bloom. Each cyathium is about 6 mm long and 5 mm wide, green in color, and fringed with red at the distal end. A yellow nectar cup protrudes from the side of each cyathium. The flower pedicel is also green and about 5 mm in length. The stamens protruding from the cyathia are dark red. The anthers are bifurcate; the pollen is yellow and copious, The stigmas are dark red and trifurcate.

Nectar exudate.--None observed.

Seeds.--Self-incompatible.

Fertility.--Not observed.

Post production: Poinsettia `721` is resistant to epinasty after being confined to shipping containers and retains its leaves and flower bracts for several weeks in the consumer's home environment.

Disease Resistance: Typical of the species.

Claims

1. A new and distinct Poinsettia plant, substantially as herein shown and described, distinguished by its bright red flower bracts, dark green foliage, self-branching characteristics and uniform growth habit.