Prickly comfrey or Rough
comfrey [Symphytum asperum Lepechin][SYMAS][CDFA list: B] Photographs
[Symphytum officinale L.][SYMOF]
DESCRIPTION:Coarse, clumped perennial herbs, typically
to 1 m tall, with deep taproots and coiled inflorescences. Once
established, plants are difficult to remove because small pieces
of broken roots generate new plants. Roots and leaves of both
species contain small amounts of toxic pyrrolizidine alkaloids
that can cause liver damage when consumed in sufficient quantities.
ascending to erect, thick, angular, hollow, usually branched,
covered with rough, bristly hairs. Leaves alternate, ovate to
lanceolate, mostly stalked. Upper stem leaves sometimes sessile.
and UNDERGROUND STRUCTURES:Taproots usually branched, deep, thick, brittle,
internally white, covered with a thin blackish bark, contain much
mucilage. Small broken pieces can generate new plants.
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Cymes (determinate infloresences where the terminal flower is
oldest) loosely coiled, raceme-like, axillary or terminal, consist
of pairs of stalked, bell-shaped tubular flowers on the
upper sides of stems. Sepals fused at base, deeply lobed, covered
with bristly hairs. Flower tubes 10-15 mm long, with 5 lanceolate
appendages within the tube that alternate with 5 stamens.
Style 1, with 1 stigma, persistent in fruit, attached to
receptacle between ovary lobes. Stamens mature before ovary. Ovary
superior, deeply 4-lobed. Bee pollinated.
and SEEDS:Fruits consist of 4 nutlets (sometimes only 1-3
mature) that separate at maturity. Nutlets ovoid, attached at
the base, contain 1 seed but do not open.
on moist soils of open sites, waste places, fields, ditches, abandoned
gardens. Plants thrive on fertile garden soils. Tolerates cold
by seed and vegetatively from
root fragments. Above ground parts die back in cold winter
FAVORING/DISCOURAGING SURVIVAL:Although fragmented roots can generate new plants,
repeated cultivation can eliminate weedy populations, especially
when timed to prevent seed production. Mowing before seed is produced
can help control weedy populations.
officinalis L.] is a common garden plant that sometimes escapes
cultivation. Unlike common and prickly comfrey,
borage is an annual and has bowl-shaped flowers,
with petals fused at the base, lobes long and widely
spreading, and stamens arranged to form a conspicuous cone.
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