Flora of New Zealand Series

American dewberry

Low-growing scrambling shrub; primocanes spreading (but fruiting stems often ± prostrate), purplish or red, usually ± terete, sometimes somewhat angled and ± flat between, with scattered subsessile glands, otherwise sparsely clothed in only simple hairs or almost glabrous; armature of many, short, erect prickles on angles or scattered. Young shoots moderately clothed in simple hairs and glandular. Leaflets (3)-5, almost glabrous to sparsely pilose on upper surface, sparsely to moderately pilose on veins but not tomentose on lower surface, irregularly serrate-dentate; terminal leaflet lamina narrow- to broad-ovate, acuminate, 40-100 × 40-90 mm, with petiolule c. ⅖-3/5 length of lamina. Stipules linear to broadly lanceolate. Infl. sparsely to moderately hairy, with sessile glands. Sepals rounded and apiculate to acuminate, sparsely to moderately pilose but tomentose only on margins and within, without pricklets. Petals rounded, crinkled, white. Anthers glabrous.

N.: N. Auckland (Kaikohe, Kerikeri, Waikumete and Oratia), S. Auckland (Whitianga, Pongakawa, Tauranga, Matata, Opotiki and Wairakei); S.: Nelson (The Glen).

N. America 1958

Roadsides, plantations, pasture, cemeteries, often in damp situations.

FL Oct-Dec FT Nov-Jan.

This sp. is easily distinguished from most other members of subgen. Rubus in N.Z. by the large fls (petals up to 30 mm long) borne on long pedicels, the 1-few-flowered infls terminating short lateral branches on the prostrate stems, and the sepals which clasp the fr. rather than recurve as in all other spp. except R. tuberculatus and R. caesius. It has usually been identified as R. caesius and matches that sp. in many characters especially in the terete stems, large fls, erect sepals, and the fr. which at least sometimes has a glaucous bloom; however, R. flagellaris, as represented in N.Z., frequently has 5 leaflets in the primocane lvs, has many more drupelets per fr. than R. caesius and does not seem to have the very pruinose stems of that sp. N.Z. plants are referable to R. flagellaris sens. lat., an extremely variable complex with many proposed segregates. N.Z. plants have a chromosome number of 2 n = c. 46-52 (M. Dawson, pers. comm.).