the following is a detailed description of the new prune tree cultivar that was obtained from the observation of eight year - old asexually propagated trees during the 1999 growing season ( except where otherwise indicated ). the trees were propagated on prunus cerasifera ‘ myrobalan 29c ’ plum rootstock . the trees were grown at the kearney agricultural center of the university of california located at parlier , calif . tree spacing was 5 . 49 m between rows and 4 . 88 m spacing between trees down the row . the color chart used in the identification of colors is that of the royal horticultural society , london ( r . h . s . colour chart ). other color terminology is to be accorded its customary dictionary significance . size .— the height during october at the end of the growing season ranges from approximately 4 . 2 to 4 . 7 m including approximately 1 . 7 to 1 . 8 m of current season &# 39 ; s growth . the width across the crown ranges from approximately 3 . 7 to 4 . 3 m . hardiness .— hardy under typical san joaquin valley of california climatic conditions . size .— average in thickness for prunus domestica . the trunk circumference at 35 cm above the ground is approximately 12 cm . texture .— relatively smooth with only a slight amount of short scarfskin . lenticels .— numerous , prominent , oval in configuration , most pronounced on the trunk and large scaffold limbs where they are the most abundant , and commonly raised with a calloused surface . the height commonly ranges from approximately 1 . 5 to 2 . 0 mm and the width from approximately 2 . 0 to 6 . 0 mm . the coloration is brownish - tan , near grey - orange group 173c . diameter .— average thickness for prunus domestica . the diameters of primary scaffold branches average 7 . 4 cm and range from 6 . 1 to 8 . 4 cm , and the diameters at the base of the secondary scaffold branches average 4 . 5 cm and range from 3 . 3 to 5 . 7 cm . the basal diameters of fruiting hanger limbs average 1 . 1 cm and range from 0 . 7 to 1 . 7 cm . the diameters of fruiting spurs average 0 . 5 cm with a range from 0 . 3 to 0 . 7 cm . these dimensions were obtained from the observation of ten - year - old trees during april 2001 . surface .— substantially pubescent especially on current season &# 39 ; s growth . such pubescence is moderately dense and short . color .— branch color is somewhat variable . mature current season &# 39 ; s shoots are medium brown of near brown group 200d . immature shoots range from light green of yellow - green group 144b to darker green of yellow - green group 144a on more mature growth . young shoots exposed to the direct sunlight often are blushed with a rose - red hue of red group 48a . new expanding shoot tips commonly are bright yellow - green of yellow - green group 151a . two year - old or older branches commonly are near grey - brown group 199b to darker brown of grey - brown group 199a . lenticels .— substantial presence on mature current season &# 39 ; s shoots , and two year - old or older branches . internode length .— normal for prunus domestica . the distance between nodes commonly ranges from approximately 19 to 36 mm on moderately vigorous current season &# 39 ; s shoots . size .— medium to large . leaves produced near mid - shoot on vigorous current season &# 39 ; s shoots range in length from approximately 10 . 9 to 15 . 4 cm including the petiole and in width from approximately 5 . 5 to 6 . 8 cm . the leaves are moderately thick and are slightly above average in thickness . form .— variable , frequently obovate , and with the occasional presence of oval leaves . the leaf apices are acute and commonly are very slightly reflexed sideways . with advancing maturity some older leaves are folded downwards from the midrib . color .— the upper surface is dark green . yellow - green group 146a to yellow - green group 147a . the under surface is lighter green , yellow - green group 147c to yellow - green group 148c . the primary mid - vein on the under surface is pale green , yellow - green group 145c . both the under surface and the leaf mid - vein on the under surface are highly pubescent . margin .— crenate with large somewhat irregular crenations . the margins tend to be slightly undulate . petiole .— average in size , commonly approximately 17 to 32 mm in length , approximately 1 . 5 to 2 . 0 mm in thickness , and light green , yellow - green group 145b , in coloration . with advancing age the petiole coloration can darken and assume a reddish blush near red group 37a . such blush tends to be most evident along the ridges of the petiole groove . glands .— from 0 to 2 small glands commonly can be observed at the extreme base of the leaf blade margin . such glands are globose in configuration and occur on stalks which are distinct or indistinct . usually no glands are present on the petiole itself . the gland position is alternate . the coloration when young is bright green , yellow - green group 151c , with darkening and deterioration with age . stipules .— medium to large in size , linear lanceolate in configuration , located at the very base of the petiole and arise from the base of the petal groove area , partially deciduous with some stipules remaining on the leaf throughout the growing season , margins are serrate and substantially pubescent , commonly approximately 5 to 11 mm in length and 1 . 5 to 2 . 0 mm in width at full maturity , and the coloration of young stipules is green , yellow - green group 145a . picking .— first pick was july 30th and the last pick was aug . 9 , 1999 . the 1999 fruit growing season in the san joaquin valley area of california was one of the latest on record and ranged from 12 to 15 days later than average . a more typical first - pick date is july 15th and a more typical last pick date is july 25th . size .— very large for the species and of relatively good uniformity . fruit from a well - thinned tree ranges from approximately 40 to 53 mm in the suture diameter and approximately 54 to 68 mm in the axial diameter . form .— most frequently oval in lateral aspect , is well rounded basally and apically , and tends to be slightly more pointed apically . nearly globose to slightly oval in the apical aspect and at times is slightly irregular . the fruit varies from symmetrical to slightly asymmetrical . suture .— very thin , with a somewhat indistinct line extending from the base to apex . most frequently is similar in coloration to that of the surrounding skin surface . at times is slightly depressed especially over the ventral apical shoulder . a very slight amount of stitching occasionally is observed over the apical shoulder . ventral surface .— usually quite smooth ; however , at times a very low lipping is observed . stem cavity .— oval , quite regular in configuration , very small , tight and very shallow . the width commonly ranges from approximately 2 . 5 to 5 . 0 mm and the depth commonly ranges from 2 . 0 to 2 . 5 mm . at times a small oval fleshy ring is observed within the cavity basin which surrounds the stem at the point of attachment to the basal cavity . such ring is narrow and averages approximately 1 . 0 mm in thickness . when the stem is removed from the fruit , the ring can remain in the cavity or be attached to the distal end of the stem . base .— regular and rounded . the stem attachment and stem cavity frequently are not positioned at the highest point of the fruit base , but rather are positioned approximately 5 to 8 mm down the ventral edge from the basal apex . the basal angle tends to be decidedly oblique to the fruit axis . apex .— slightly raised and somewhat more pointed than the fruit base with no depression at the apex . the pistil point is variable and at times is apical and at times is moderately oblique . stem .— medium in length and pubescent with the abundant presence of short and stiff hairs . the length commonly ranges from approximately 11 to 18 mm . the thickness commonly ranges from 1 . 5 to 2 . 0 mm . the color is pale green at commercial maturity , near yellow - green group 146c . skin pubescence .— generally glabrous but with a small amount of scattered very fine pubescence covering the surface of the fruit . skin tendency to split .— no tendency to crack or split has been observed . skin color .— grey - blue , violet - blue group 97b , at commercial maturity when the waxy cuticle bloom is intact . once the bloom is removed the coloration is dark purple , greyed - purple group 187a . the fruit usually is fully colored with no visible ground color . occasionally a lighter reddish - purple , greyed - purple group 187c , is observed especially on an exposed fruit surface . at full maturity a small number of light colored dots sometimes are observed , primarily on the lateral surfaces and over the basal shoulder . flesh color .— commonly varies from yellow - orange group 20b to a darker yellow orange , yellow - orange group 20a . a small number of fibers also commonly are observed within the stone cavity and along the margins of the stone . flesh texture .— at commercial maturity the flesh is firm , relatively fine textured , and moderately juicy . at more advanced maturity the fruit becomes softer and very juicy . flavor .— mild and sweet with a relatively low acidity . during the 1999 growing season on july 30th , soluble solids reached 17 degrees brix at 5 . 0 pounds pressure for fresh shipment . on august 13th of the same year , soluble solids reached 20 degrees brix at a drying maturity of 2 . 6 pounds pressure . aroma .— very slight to lacking at commercial maturity . the aroma becomes slightly stronger as maturity progresses . attachment .— semi - freestone . the flesh fibers are attached primarly at the base of the stone and along the suture edges , but are generally free laterally . the stone tends to become more free with advancing maturity . size .— relatively large , commonly ranges from approximately 28 to 33 mm in length , approximately 14 to 17 mm in width , and approximately 7 . 5 to 9 . 5 mm in thickness . hilum .— very small and commonly averages approximately 2 to 3 mm in length . is oval , but the shoulder commonly is distinctly eroded along the ventral edge . the basal area under the hilum scar is somewhat necked . distinct ridges commonly are present on the basal neck which converge basally . surface .— slightly rough with the lateral surfaces being covered with very low netted ridges . ventral edge .— relatively narrow , smooth and regular . very low wings of often less than 1 mm sometimes are present on the basal one - third of the ventral edge and sometimes are completely absent . commonly a shallow but distinct groove is present laterally and runs roughly parallel to the ventral edge at approximately 2 to 3 mm below the edge . the ventral edge sometimes is slightly pitted and at times is discontinuous . dorsal edge .— a distinct groove commonly is present along the dorsal edge from the base to the apex . at times the dorsal groove is discontinuous at or near med - suture . the dorsal groove is usually wider and more distinct from the base of the stone up to mid - suture . the groove tends to be narrower beyond mid - suture towards the apex . color .— cinnamon , greyed - orange group 165c . the wet color is darker , greyed - orange group 165b . chilling season .— data for this description was obtained during march 1999 . there were approximately 1331 chilling hours below 45 ° f . for the 1998 - 1999 winter season . floral buds .— medium in size , commonly 4 to 5 mm in length and 2 to 3 mm in width , conic in form , plump , slightly appressed to the bearing stem , and hardy under typical san joaquin valley climatic conditions . the bud surface scales are dark brown , brown group 200b , in coloration , are lightly pubescent , and are most distinct along the margins . the number of buds per node can range from approximately 1 to 6 and most commonly is approximately 3 . such buds commonly are present in abundance on one year - old wood which is uncommon for the species . blooming time .— early in relation to other prunus domestica cultivars . initial sustained bud burst began on mar . 14th during 1999 . full bloom occurred on mar . 19th during 1999 . the duration of bloom was approximately 10 days with nearly complete shatter by mar . 24th in 1999 . in contrast the ‘ improved french ’ cultivar attained full bloom on march 28th under the same conditions . size .— medium to large for the species . the fully expanded flower diameter commonly is approximately 22 to 30 mm . petals .— medium to large in size and commonly range from approximately 11 to 14 mm in length and approximately 10 to 12 mm in width . the number is 5 per flower . the form varies from oval to very slightly obovate and at times is notched at the apex . the coloration is white , white group 155b . the petal claw is short and truncate , approximately 0 . 5 to 1 . 0 mm in length and approximately 1 . 0 mm in width . the margins are variable and range from relatively smooth to slightly undulate and are somewhat cupped inwards . the apices are also somewhat variable and range from smoothly rounded to distinctly notched . pedicel .— commonly approximately 7 to 12 mm in length and a thickness of approximately 0 . 8 to 1 . 0 mm . the coloration is light green , green group 143c , and the surface is pubescent with short erect hairs throughout . calyx .— lightly pubescent with short fine pubescence , and greenish - yellow in coloration , yellow - green group 146c . sepals .— five in number , approximately 5 mm in length , approximately 3 to 4 mm in width , pubescent on the surfaces with greater density along the margins , oval in form , and the external coloration is light green , green group 143c . anthers .— average in size , and yellow - gold , yellow group 13a , both ventrally and dorsally in coloration . stamens .— approximately 20 to 27 and most frequently approximately 25 , the length is variable and commonly approximately 5 to 9 mm , and commonly equal in height to slightly shorter than the pistil . the filament color is white , white group 155b . pistils .— the surface of the ovary is pubescent and surface of the style is substantially glabrous . the length including the ovary is approximately 10 to 13 mm . the style is yellow - green , yellow - green group 145c , and the ovary is darker shiny green , yellow - green group 144b , in coloration . under normal environmental conditions only one pistil is present per flower . in seasons following very hot summers it is possible to observe a low number of double pistils ( e . g ., 2 to 3 percent ).
a new and distinct cultivar of prune tree is provided that resulted from a controlled breeding program . the new cultivar exhibits extreme precocity and a vigorous growth habit . flowers are formed in abundance . very large early - maturing fruit also is formed in abundance on a regular basis that is dark purple under a greyish and waxy epidermal bloom . the fruit is particularly well suited for the fresh prune market .