Phlox plant named ‘USPHL304’

#Botanical designation: Phlox hybrida.

#Cultivar denomination: ‘USPHL304’.

#The present Invention relates to a new and distinct cultivar of Phlox plant, botanically known as Phlox hybrida, and hereinafter referred to by the cultivar name USPHL304.

#The accompanying colored photographs illustrate the overall appearance of the new cultivar, showing the colors as true as it is reasonably possible to obtain in colored reproductions of this type. Colors in the photographs may differ slightly from the color values cited in the detailed botanical description which more accurately describe the actual colors of the new Phlox.

#The photograph at the bottom of the sheet comprises a side perspective view of a typical flowering plant of ‘USPHL304’ grown in a container.

#The photograph at the top of the sheet is a close-up view of typical flowers of ‘USPHL304’.

#In the following description, color references are made to The Royal Horticultural Society Colour Chart, 1995 Edition, except where general terms of ordinary dictionary significance are used. Plants grown in 15-cm containers were used for the aforementioned photographs and following description. Plants were about two months from planting rooted cuttings. Plants were grown under conditions which closely approximate commercial production conditions during the summer in Bonsall, Calif. in an outdoor nursery. During the production period, day temperatures ranged from 21° C. to 35° C. and night temperatures ranged from 10° C. to 18° C. Botanical classification: Phlox hybrida cultivar USPHL304. Parentage: Female parent.—Unidentified selection of Phlox hybrida, not patented. Male parent.—Unidentified selection of Phlox hybrida, not patented. Propagation: Type cutting.—Vegetative cuttings. Time to initiate roots.—About one to two weeks. Time to produce a rooted young plant.—About three to four weeks. Root description.—Fine, fibrous. Rooting habit.—Freely branching; moderately dense. Plant description: Plant form/habit.—Upright and outwardly spreading plant habit; broad inverted triangle; vigorous growth habit. Freely branching with about three to four main stems per plant each with multiple secondary lateral branches. Plant height.—About 24 cm. Plant width (spread).—About 38.5 cm. Lateral branches.—Length: About 29 cm. Diameter: About 3 mm. Internode length: About 1.5 cm. Strength: Strong. Texture: Pubescent. Color: 146A. Foliage description.—Arrangement: Alternate, simple; sessile. Length: About 2.1 cm. Width: About 7 mm. Shape: Lanceolate. Apex: Acute to acuminate. Base: Clasping to slightly auriculate. Margin: Entire. Texture, upper and lower surfaces: Slightly rough; pubescent. Venation pattern: Pinnate; arcuate. Color: Developing leaves, upper and lower surfaces: 146A. Fully expanded leaves, upper and lower surfaces: 147A. Venation, upper and lower surfaces: 147B. Flower description: Flower type/habit.—Single, rounded salverform flowers arranged in terminal panicles; flowers face upright and outward. Panicles roughly hemispherical in shape. Freely flowering habit with about 32 to 34 flower buds and flowers per lateral branch. Fragrance.—None detected. Natural flowering season.—Continuously flowering from spring through fall in Southern California Flowers persistent. Postproduction longevity.—Flowers last about four to five days on the plant. Inflorescence height.—About 3.5 cm. Inflorescence diameter.—About 4.5 cm. Flower buds.—Height: About 2 cm. Diameter: About 8 mm. Shape: Elongated ovoid. Color: 155A. Flowers.—Diameter: About 2.5 cm. Depth: About 1.6 cm. Throat diameter, distal: About 2 mm. Tube diameter, proximal: About 2 mm. Tube length: About 1.4 cm. Petals.—Quantity per flower: Typically five in a single whorl; petals fused at the base into a narrow tube. Lobe length: About 1.2 cm. Lobe width: About 1.9 cm. Lobe shape: Obovate. Lobe apex: Rounded. Lobe margin: Entire; slightly undulate. Texture: Lobes, upper and lower surfaces: Smooth, glabrous; satiny. Throat: Smooth, glabrous. Tube: Pubescent. Color: Developing petals, upper surface: 76A. Developing petals, lower surface: 155A. Fully expanded petals, upper surface: 82A; towards the base, 155A; star pattern at center, 83B and 83D; venation, 82A. Fully expanded petals, lower surface: 69D; venation, 69B. Throat: 157A; venation, 157A. Tube: 157A; venation, 157A. Sepals.—Quantity per flower: Typically five in a single whorl, fused; narrow tubular calyx. Length: About 5 mm. Width: About 1 mm. Shape: Lanceolate to apicular; recurved. Apex: Acuminate. Texture, upper and lower surfaces: Pubescent. Color, upper and lower surfaces: 146A. Peduncles.—Length: About 1 cm. Diameter: About 1 mm. Orientation: Erect to about 45° from vertical. Strength: Strong. Texture: Pubescent. Color: 146A. Pedicels.—Length: About 8 mm. Diameter: About 1 mm. Orientation: About 45° from vertical. Strength: Strong. Texture: Pubescent. Color: 146B. Reproductive organs.—Stamens: Quantity per flower: Typically five. Anther shape: Oblong. Anther size: About 1 mm by 2 mm. Anther color: 14A. Pollen amount: Scarce. Pollen color: 14A. Pistils: Quantity per flower: Typically one. Pistil length: About 4 mm. Stigma shape: Tri-parted. Stigma color: 12B. Style length: About 1.5 cm. Style color: 145D. Ovary color: 144A. Fruit/seed.—Fruit and seed development have not been observed. Disease/pest resistance: Plants of the new Phlox have not been noted to be resistant to pathogens and pests common to Phlox. Garden performance: Plants of the new Phlox have been observed to have good garden performance and tolerate rain, wind and temperatures ranging from −5° C. to 38° C.