St. Juliens.—The St. Julien that the writer has seen in American and European nurseries is unmistakably an Insititia. At one time St. Julien stocks were used almost exclusively in New York nurseries, and few large plum orchards are free from trees which have through accident to the cion grown from the stock. Such trees bear fruit so like the Damson that one is warranted in saying that the two are identical, and that St. Julien is but a name used for a Damson when the latter is employed as a stock. The fruit is sweetish with a taste identical with that of the sweet Damsons.
Plum-growers who have had experience with plums on several stocks are almost united in the opinion that the St. Julien is the best of all for the Domesticas, at least. St. Julien stocks were formerly imported in great numbers from France, where it is still largely grown for European use. The name seems to have come in use in France more than a century ago, but why given or to what particular Insititia applied does not appear. There is, however, a distinct variety or type of Insititia used by the French in producing stocks, for French pomologists advise careful selection of mother-plants for the production of the young trees by suckers or layers, and caution growers of stocks in no case to use seeds which bring twiggy, spiny and crooked stocks.[73] St. Julien plums are seemingly nowhere grown at present for their fruits.
There are several ornamental forms of plums which are given specific names by European horticulturists, mentioned in the last paragraph in the discussion of the Domestica plums, which some writers place, in part at least, with the Insititias. These plums are not found in America and it is impossible to place them with certainty in either of the two species upon the contradictory evidence of the Europeans.
3. PRUNUS SPINOSA Linnaeus.
1. Linnaeus Sp. Pl. 475. 1753. 2. Hudson Fl. Anglic. 186. 1778. 3. Ehrhart Beitr. Nat. 4:16. 1789. 4. Pursh Fl. Am. Sept. 1:333. 1814. 5. Hooker Fl. Bor. Am. 1:167. 1833. 6. Torrey and Gray Fl. N. Am. 1:408. 1840. 7. Koch, K. Dend. 1:98. 1869. 8. Ibid. Deut. Obst. 143. 1876. 9. DeCandolle Or. Cult. Pl. 212. 1885. 10. Schwarz Forst. Bot. 339. 1892. 11. Koch, W. Syn. Deut. und Schw. Fl. 1:726. 1892. 12. Dippel Handb. Laubh. 3:637. 1893. 13. Koehne Deut. Dend. 316. 1893. 14. Beck von Managetta Nied. Oester. 818. 1893. 15. Bailey Cyc. Am. Hort. 1447 fig. 1901. 16. Schneider Handb. Laubh. 1:628. 1906.
Plant low, spreading, much-branched, thorny, shrubby, seldom attaining the dimensions of a small tree; branchlets distinctly pubescent; leaves small, ovate or oblong-ovate, sometimes obovate, numerous, nearly glabrous at maturity, obtuse at the apex, cuneate or rounded at the base, margins closely and finely serrate.
Flowers white, one-third or one-half inch in diameter, expanding before the leaves; borne singly, in pairs or sometimes in threes, in lateral clusters.
Fruit globose, usually less than one-half inch in diameter, dark blue, almost black, with a heavy bloom; flesh juicy, firm, with an acid, austere taste, scarcely edible for a dessert fruit but making a very good conserve; stone turgid or but little flattened, acute on one edge.
European botanists commonly break the species into a number of sub-species, as:—Prunus spinosa typica Schneider,[74] flower-pedicels and calyx-cup glabrous; Prunus spinosa praecox Wim. and Grab.,[75] pedicels short, blossoms appearing before the leaves; Prunus spinosa sessiliflora Beck,[76] with sessile flowers, possibly the same as the next preceding form; Prunus spinosa coatanea Wim. and Grab.[77], blossoming with the leaves and with long pedicels; and Prunus spinosa dasyphylla Schur.[78], flower-pedicel and calyx-cup more or less hairy. Besides these botanical sub-divisions there are several horticultural forms as follows: