Azalea plant named ‘Crimson Princess’
United States Patent PP14360

A new and distinct variety of dwarf Azalea originated as a whole plant sport of Azalea ‘Crimson Majesty.’ The new variety possesses unique red foliage, (grayed purple group 187-A) and is a dwarf, with height about 15-18 inches.

Odom, Richard (Forest Hill, LA)
Application Number:
Publication Date:
Filing Date:
Primary Class:
International Classes:
A01H5/02; (IPC1-7): A01H5/00
Field of Search:
PLT/240, PLT/238
View Patent Images:

Primary Examiner:
Bell, Kent
Attorney, Agent or Firm:
Jones, Walker, Waechter, Poitevent, Carrere & Denegre, LLP
I claim:

1. A new and unique variety of Azalea plant named ‘Crimson Princess’ as herein shown and described.



The present invention relates to a new and distinct variety of evergreen azalea botanically known as Rhododendron indicum. Richard Odom discovered this new azalea variety, hereinafter referred to as ‘Crimson Princess’, as a naturally occurring whole plant sport mutation of Azalea ‘Crimson Majesty’, which originated as a naturally occurring branch sport of Azalea ‘Red Formosa’. ‘Red Formosa’ is an unpatented azalea that is well-know in the trade in zones 7-9.

Rooted cuttings of ‘Crimson Majesty’ were planted in containers. Two plants were discovered in a cultivated setting of ‘Crimson Majesty’ that were noticeably smaller in size with closer branching, smaller leaves and more red or purple pigmentation. Cuttings were taken from one of these plants only one time, and subsequent generation cuttings were taken from all plants with the same desirable characteristics. All work was undertaken at Country Pines Nursery, Inc. in Forest Hills, La. After several generations of asexual propagation from rooting cuttings, the present plant has been developed with unique coloration and dwarf growth habitat.

Asexual propagation of the new plant by rooting cuttings has been under Mr. Odom's direction at the same location. Several generations of the new plant have been evaluated and the distinctive characteristics of the plant have remained stable. The plant cannot be reproduced true from seed.

Plant cuttings are allowed to root and grow in a 2.25 inch diameter (rosecup) container for 6-8 months, at which time the plant is about 1.5-2.5 inches in height, and is then transferred to a one gallon container. After an additional 10-12 months of growth, the plant is about 6-7 inches in height and about 6-7 inches in spread. At this time, the plant is sufficiently large for commercial sale as a one gallon plant. If larger plants are desired for commercial sale, the plant can be re-potted from the one gallon container to a three gallon container. An additional 8-10 months of growth in the three gallon container is generally needed to produce a commercial three gallon container plant, at about 10-12 inches in height and 16-18 inches in spread.

Patent applications have been filed herewith for Azalea ‘Crimson Majesty’, U.S. patent application Ser. No. 09/930,573, a full size azalea which originated from a naturally occurring branch sport of ‘Red Formosa’, and azalea ‘Crimson Queen’, U.S. patent application Ser. No. 09/930,575, a semi-dwarf form which originated from a branch sport of Azalea ‘Crimson Princess’. The three ‘Crimson’ azaleas have similar leaf coloration (187-A, 187-B, grayed purple group)(the foliage of ‘Crimson Queen’ is lighter than that of ‘Crimson Princess’ but darker that of ‘Crimson Majesty’ in appearance) and differ primary in growth size characteristics: ‘Crimson Princess’ being a dwarf (about 10-12 inches in height at about two ½ years from cutting), ‘Crimson Queen’ a semi-dwarf (about 16-18 inches in height at about 2½ years from cutting) and ‘Crimson Majesty’ being a standard (about 24-28 inches in height at about 2½ years). See FIGS. 8 and 9. By contrast, the stock ‘Red Formosa’ is a standard azalea (about 24-28 inches at two ½ years from cutting, with an ultimate height of 5-8 feet). All of the ‘Crimson’ hybrid azaleas have strikingly different foliage coloration (187-A, 187-B, greyed purple group) from ‘Red Formosa’ (N189A greyed green group). See FIGS. 2 and 9.


Crimson on the upper and lower surfaces (greyed purple group, 187-A); shades of green somewhat more evident on the upper surface, less so on the lower. The crimson color is more intense on the new foliage and diminishes somewhat as the leaves age resulting in the older foliage having a deep crimson/green hue. Color differs significantly from standard ‘Red Formosa’ which has bright green foliage at all stages of maturity. Veins, especially the midvein and secondary veins, on the underside of the leaves on the ‘Crimson Princess’ retain the crimson color with age. The cultivar has a compact growth habitat. The flower is similar of that to Azalea ‘Red Formosa’, but is not considered a novel feature of the cultivar.

The following are the most outstanding and distinguishing characteristics of this new cultivar when grown under normal horticultural practices in Forest Hill, La.

1. The unique foliage coloration, color greyed-purple group, 187-A.

2. Easily propagated with semi-hardwood cuttings in late spring through the summer.

3. Fast growth rate under normal fertilization and moisture conditions.

4. Upright, dense and globose in nature.

5. Small compact growth.

6. Makes a good container plant.

7. Useful in confined landscape areas.

8. Suitable under low windows and in front of porches;

9. Suitable frontal plants in wide beds; and

10. Groupings within landscape beds.


This new Azalea Hybrid variety is illustrated by the accompanying photographic prints in which:

FIG. 1 is a view showing the “Crimson” varieties of azaleas in place adjacent to the usual green colored leafed azaleas, demonstrating the difference in the plant's coloration to that of standard azaleas.

FIG. 2 is a view showing the “Crimson” varieties in filtered light adjacent to ‘Red Formosa’ azaleas. ‘Crimson Princess’ is in the foreground, ‘Crimson Queen’ in the middle ground, and ‘Crimson Majesty’ in the background left of the photograph showing the difference in coloration from ‘Red Formosa’. All plants are approximately 2.5 years of age from cuttings.

FIG. 3 shows the variety adjacent to the ‘Red Formosa’ of the “Crimson” line.

FIG. 4 shows the foliage and stem color of the underside of the foliage of ‘Red Formosa’ the parent stock of the “Crimson” varieties.

FIG. 5 shows the foliage and stem color of the upper surface foliage of ‘Red Formosa’ the parent stock of the “Crimson” varieties.

FIG. 6 shows the dense, upright and globose growth habit of a three gallon plant 2.5 year old plant of the instant variety showing foliage and stem color of the underside surface of the foliage.

FIG. 7 shows the dense, upright and globose growth habit of a three gallon plant 2.5 year old plant of the instant variety showing foliage and stem color of the upper surface of the foliage.

FIG. 8 shows the three “Crimson” variety plants adjacent each other to show the distinction in plant growth characteristics, all plants being about 2.5 years of age from cuttings in a three gallon container.

FIG. 9 stems with foliage from all three “Crimson” variety of plants adjacent to stems of ‘Red Formosa’.

FIG. 10 show a close up of the stem and leaf structure of the instant variety showing the coloration.

FIG. 11 shows a close up of a flower representative of the instant Crimson variety.

FIG. 12 shows a close up of a flower from the ‘Red Formosa’ variety.

FIG. 13 shows a close up of a bud from the ‘Red Formosa’ variety.

The colors shown are as true as is reasonably possible to obtain by conventional photographic procedures. The colors of the various plant parts are defined with reference to The Royal Horticultural Society Colour Chart. Description of colors in ordinary terms are presented where appropriate for clarity in meaning. Colors in the photographs may appear different than actual colors due to light reflectance. Color values cited in the Botanical Description of the Plant accurately describe the actual colors of the new Azalea.


The following is detailed description of the new variety of Azalea based on my observations made of plants grown in wholesale commercial production practices, in greenhouses, and in established landscape plantings in Forest Hill, La., and was compiled with the assistance of Dr. Lowell E. Urbatsch, Director of the LSU Herbarium, Louisiana State University.

Botanical Description of the Plant

Scientific name: The plant belongs to a group of azaleas called the “Southern Indian azaleas” or “indicas” that are hybrids derived from various species of Rhododendron or derived directly from various species in that genus. Rhododendron indicum (L.) Sweet, although often given as the scientific name for this group of plants, has had little or no part in the parentage of the indicas. Most indicas are descendents of Rhododendron simsii Planch. R. mucronatum G. Don and/or R. pulchrum Sweet or their hybrids; in the industry, however, the accepted parentage is considered that of Rhododendron indicum.

Cultivar: ‘Crimson Princess’, a dwarf indica azalea.

Growth habit: Shape of the plant at maturity: Broad compact, mound-forming shrubs. Individuals approximately 15-18 inches tall at about 2.5 years of age and 15-18 inches broad. It has not been observed as a mature plant in the landscape.

Branching habit: Sympodial (branching without a main axis but with many, more or less, equal laterals). One to several stems are evident at or near ground level that branch and re-branch frequently and at close intervals. Branches ascending or arcuate-ascending to upright. Branch characteristics (on mature growth of the current season): branch length, 7-14 cm; branch diameter, 1.5-2.5 mm; internode length, 4-11 mm.

Characteristics of the plant in winter dormancy: During the winter the plants are evergreen, i.e., the leaves remain on the stems. No signs of growth or flowering are evident during winter. Hardiness is expected to be similar to ‘Red Formosa’ cultivars. It has proven to be hardy in regard to winter cold and summer heat in the southern portion of zone 8.

Bark: Stem coloration on twigs is 59-A Red Purple group; bark coloration (on stems greater than 2 years old) is 176-B grayed-orange group. The stems, at least the lower ones, are rarely visible due to the compact leafy nature of the plants and, therefore, contribute little to its ornamental qualities.


Flower arrangement: Arranged singly at stem terminus; flowers face outward and upward. However, observations were limited, as flowering is sparse in the plants of less than 4 years old.

Flower appearance: Corolla 5-lobed; star shaped; flaring open, about 7 cm across (lobe tip to lobe tip); 4.5-5.5 cm deep; diameter at base of lobes is 2-2.5 cm; corolla lobes are spreading at right angles to long axis of the flower, corolla is a single whorl of petals, occasionally with 1-2 additional petal internal to the corolla, these inner petals are smaller may be as long as 2 cm long and 1 cm wide and have a spatulate shape.

Flower bud: Rate of opening just after bud corolla becomes visible is about 2-3 days but rate is variable with temperature, sunlight, and possible other conditions. Corolla color becomes visible when bud is about 15 mm long and 8 mm wide. Flower bud shape is ovoid in shape when viewed dorsal-ventrally. It is about 4 cm long and 1.5-2 cm wide when the petals begin to open. In side view bud bulges slightly outward, inner surface is slightly concave. Overall, the bud has a somewhat falcate shape. As viewed from the top or in cross-section bud is slightly 5-lobed. Color of corolla in bud stage is near 71-C (Fan 2, Royal Horticultural Society Colour Chart).

Petals: The petals are 5 in number and basally fused forming a corolla tube 2-3 cm long. Petal appearance is satiny; texture is smooth; petals are spatulate (obovate) and 4.5-6 cm long and 2-2.5 cm wide with rounded lobes. The lobes are 2.7-3.3 cm long; they are somewhat undulate and margins of the lobes are entire to slightly crenate; margins are also undulate, with about 2 undulations per lobe giving the flower a ruffled appearance. External and internal petal color of the corolla lobes is near 71-B (Fan 2, Royal Horticultural Society Colour Chart). The petals (corolla tube) are slightly lighter toward the base being close to color 71-C (compare with ‘Red Formosa’ at 64-B). The anterior (upper) petal at about mid-level and below is mottled with darker spots close to 71-A in color (compare with ‘Red Formosa’ at 61-A). Otherwise petal color is rather uniform.

Sepals: Sepals are fused basally forming a 5-lobed calyx; each sepal is elliptic in shape and approximately 12 mm long and 5 mm wide with the lowermost 0.5-1 mm of each fused together forming a short calyx tube. The calyx lobes are approximately 11 mm long. Calyx diameter (sepal tip to sepal tip) is about 2 cm. The sepals have entire margins, acute apices, moderate amount of pubescence abaxially (outer surface) and glabrous adaxially (inner surface). Sepal color is close to 138-C (fan 3, green group) on both inner and outer surfaces.

Peduncle: Peduncle (i.e., the stalk supporting a cluster of flowers) length is about 25 mm long and about 2 mm in diameter; it is somewhat flexible and it provides strong support for the flower; it is moderately pubescent with uniseriate hairs; and near 186-A (fan 4, grey-purple group).

Reproductive organs: Androecium consists of 9-10 stamens. Filaments are 3.5-4.5 mm long with a diameter of less than 1.5 mm; filament color is closest to 61-A; filaments are flexible and slightly exceeding length of the corolla and, therefore, are slightly exerted. Anthers are 1.5-2 mm long; oblong in shape; and closest to 79-B in color; pollen is a creamy white, 155-D, and produced in moderate amounts. Gynoecium appears to consist of 5 fused carpels. The ovary is densely pubescent (sericeous) with the hairs fully obscuring ovary surface; hairs are shiny and closest to N155-A (fan 4, white group) in color; ovary shape is ovoid and about 4 mm long. The style is about 6.5 cm long, 1.5 mm in diameter and near 61-A in color. The stigma is truncate (i.e., with a flat surface) and circular to slightly lobed in end view with a diameter of 1.5 mm.


Arrangement.—Leaves alternate, that is one leaf per node. Leaves spaced about ⅛ to ½ inches apart along the stems. Leaf stalk (petiole) about ⅛ to ⅜ inches long.

Shape.—Leaves elliptic to oblanceolate in outline; apices acute to acuminate; bases cuneate to rounded. Margins entire although somewhat ciliate.

Size.—½ to 1 inch broad and 1 to 2 inches long including the petiole.

Color.—Crimson on the upper and lower surfaces; shades of green somewhat more evident on the upper surface, less so on the lower. The crimson color is more intense on the new foliage and diminishes somewhat as the leaves age resulting in the older foliage having a deep crimson/green hue. Color differs significantly from standard ‘Red Formosa’ which has bright green foliage at all stages of maturity. See FIG. 9. Veins, especially the midvein and secondary veins, on the underside of the leaves on the ‘Crimson Princess’ retain the crimson color with age. See FIG. 10.

The Royal Horticultural Society Colour Chart was used as per their instructions in order to better quantify the colors of the leaves. The results are summarized in the following Table 1.

Age ofRHS colorBest coloramong
NewlyUpper surfaceGreyed-Purple187-A
leavesLower surfaceGreyed-Purple185-A187-B
Veins, lowerGreyed-Purple185-A187-B
MatureUpper surface1Greyed-Purple187-A139-A,
leavesGroupGreen Group
Lower surface1Greyed-Purple184-B139-A,
GroupGreen Group
Veins, lowerGreyed-Purple183-B
1The mature leaves appear to be a blending of the green and reddish colors resulting in the greyed purple color. However, the green is somewhat more evident in the mature leaves compared to the younger ones.

As a comparison, coloration of ‘Red Formosa’ is as follows: leaves upper surface, grayed-green group, N189A; leaves lower surface, green group, 138A; stem coloration 138-B Green group; bark coloration, 177-B Grayed-orange group; petiole coloration 138-B, 138-C Green Group. See FIGS. 4 and 5.

Indumentum: The indumentum or plant hairs (trichomes) are hirsute in nature, i.e., the individual hairs are uniseriate, slender, tapering at the tip and arising more or less perpendicular to the epidermis, and becoming somewhat flexuous slightly about the leaf surface. The hairs give the leaves and twigs a somewhat bristly texture. The same type of hairs are present on both the upper and lower leaf surfaces. In terms of density the indumentum is characterized as being moderately pubescent with the hairs being spaced about {fraction (1/32)} inch (0.5 mm) apart. On the lower surface the hairs are somewhat more closely spaced along the veins and petioles. Indumentum on the stems is similar except for the hairs being somewhat more closely spaced than on the leaf blade surfaces.

Fruit: None apparent.


Petiole.—Length 5-6 mm; diameter 3 mm wide, 1.5 mm thick; coloration: upper and lower surfaces surface, 59-A Red Purple Group.

Fragrance.—Insignificant — none apparent.

Taste.—Not relevant.

Disease resistances.—No known Azalea diseases observed to date on plants grown under commercial conditions. Expected to be similar to ‘Red Formosa’ cultivars — resistant to flower and leaf gall, caused by exobasidium vaccinii and root rot caused phytophthora cinnamomi; susceptible to Lace bug and to petal blight caused by ovulinia azalea.

Vigor.—Similar to ‘Red Formosa’ cultivars, hardy in zones 7-9.

Seed production.—Seed production has not been observed.