Laudator Temporis Acti

Berries grow behind my house. When ripe they look like blackberries, but they're actually black raspberries, Rubus occidentalis.

For the genus see Nathaniel Lord Britton and Addison Brown, An Illustrated Flora of the Northern United States, Canada and the British Possessions, 2nd ed. (New York: Charles Scribner's Sons, 1913; rpt. New York: Dover, 1970), II, 275:

Perennial herbs, shrubs or trailing vines, often prickly, with alternate simple lobed or 3-7-foliolate leaves, the stipules adnate to the petiole. Flowers terminal or axillary, solitary, racemose or panicled, white, pink or purple, perfect or sometimes dioecious. Calyx persistent, not bracted, deeply 5-parted, its tube short and broad. Petals 5, deciduous. Stamens ∞, usually numerous, inserted on the calyx, distinct. Carpels ∞, rarely few, inserted on a convex or elongated receptacle, ripening into drupelets and forming an aggregate fruit, which in many species is edible, sweet and delicious, in others sour, or nearly tasteless. Ovules 2, one abortive. Style nearly terminal, slender. Seed pendulous. [The ancient name of the bramble, from ruber, red.]

For the species (common name thimble-berry), see Britton and Brown, II, 277:

Very glaucous, stems cane-like, recurved, often rooting at the tip, sometimes 10°-12° long, sparingly armed with small hooked prickles, rarely slightly glandular-bristly above. Stipules setaceous, deciduous; leaves pinnately 3-foliolate (rarely 5-foliolate); leaflets ovate, acuminate, coarsely incised-serrate, very white-pubescent beneath; flowers as in the preceding species [i.e. flowers 4"-5" broad]; inflorescence corymbose, compact, usually only terminal; pedicels short, ascending or erect in fruit; fruit purple-black (rarely yellow), depressed-hemispheric.

New Brunswick to Quebec, Ontario, Georgia and Missouri. Ascends to 3000 ft. in Virginia. The original of the Gregg, Hilborn and other raspberries. May-June. Fruit ripe July. Called also scotch-cap and black-cap. Purple raspberry. Black-berry.

Thoreau mentions black raspberries under the common name thimble-berries, e.g. Journal (July 16, 1851):

The black thimble-berry is an honest, homely berry, now drying up as usual. I used to have a pleasant time stringing them on herd's-grass stems, tracing the wallsides for them.

Journal (December 1, 1856):

I see great thimble-berry bushes rising above the snow, with still a rich, rank bloom on them, as in July. Hypaethral mildew, elysian fungus! To see the bloom on a thimble-berry stem lasting into midwinter! What a salve that would make, collected and boxed!

I usually eat black raspberries plain or with a little milk or cream, but this year I may try to make black raspberry liqueur as well.

Rubus occidentalis