keys to the vascular plants of east texas - Botanical Research ...

750 NOLINACEAE
NOLINACEAE Nakai
BEAR-GRASS FAMILY
Dioecious or polygamo-dioecious, xerophytic perennials with a woody crown or short trunk;
leaves numerous, clustered in a dense rosette, linear, smooth to prickly-margined; inflorescences
many-flowered pedunculate panicles; flowers mostly unisexual (reduced parts of opposite
sex present); perianth radially symmetrical, of 6 segments; stamens 6; ovary superior, with
1 or 3 cells; fruit a 3-winged samara or � inflated 3-lobed capsule; seeds 1–3 per fruit.
AA small family of 4 genera and ca. 50 species (Bogler 1998a) of perennial xerophytes with
many adaptations related to water conservation. Growth forms vary from small and nearly
trunkless to large and tree-like, but all share leaves in a terminal rosette. The family ranges
from n Central America through Mexico to the s U.S. (Bogler 1998a; Irish & Irish 2000), with
most species in Mexico. It includes the unusual Beaucarnea, a genus of tree-like species with
often strikingly swollen stem bases. In the past, taxa included here in the Nolinaceae were
sometimes included in a broadly conceived Liliaceae (e.g., Kartesz 1999) or often in the
Agavaceae (e.g., Correll & Johnston 1970; Diggs et al. 1999; Verhoek & Hess 2002 following
Cronquist 1988), based on certain morphological similarities. However, recent evidence suggests
that the Agavaceae and Nolinaceae are not closely related and should be recognized separately
(Dahlgren et al. 1985; Eguiarte et al. 1994; Bogler & Simpson 1995, 1996; Kubitzki et al.
1998; Chase et al. 2000). Molecular evidence indicates that the Nolinaceae is closely related to
the Asparagaceae and Convallariaceae, and some studies (e.g., Chase et al. 1995a; Chase et al.
2000; Fay et al. 2000) suggest that the Nolinaceae should be included in the Convallariaceae.
Following such preliminary studies, Judd et al. (1999) submerged the Nolinaceae into the
Convallariaceae. On the other hand, Rudall et al. (2000a), Judd et al. (2002), and Judd (2003)
included the Nolinaceae in a broadly interpreted Ruscaceae. More recently, the Angiosperm
Phylogeny Group (APG II 2003) suggested placing them either in Ruscaceae or in a very
broadly defined Asparagaceae (along with such families as Agavaceae). However, there has
been disagreement in molecular analyses of the family and its presumed relatives (see e.g.,
Rudall et al. 2000a; Yamashita & Tamura 2000). Since the Nolinaceae appears to be a well-defined
monophyletic group (Bogler & Simpson 1995, 1996), and until the phylogeny of this complex
is clarified and the nomenclature more stable, we are recognizing it as a distinct family.
Some species are used as ornamentals (e.g., Beaucarnea), while the leaves of others “have been
used since prehistoric times for weaving baskets, sandals, sleeping mats, hats, and other household
items” (Bogler 1998a). Pollination is primarily by small bees (Bogler 1998a). (subclass
Liliidae—Cronquist; order Asparagales—APG II as part of Ruscaceae)
FAMILY RECOGNITION IN THE FIELD: dry-adapted, somewhat grass-like perennials with a rosette
of numerous, linear, smooth to conspicuously prickly-margined leaves from a woody crown or
short trunk; flowers small, white or greenish, numerous in a panicle.
REFERENCES: Dahlgren et al. 1985; Eguiarte et al. 1994; Bogler & Simpson 1995, 1996; García-
Mendoza & Galván 1995; Bogler 1998a; Irish & Irish 2000; Yamashita & Tamura 2000; Walker
2001; Judd 2003.
1. Leaf margins with sharp, curved, spine-like prickles 1–3 mm long, the prickles visible at a glance;
fruits 3-winged, with only one seed, 1-celled; inflorescences with branches so densely covered
with flowers that they are finger-like ___________________________________________________ Dasylirion
1. Leaf margins smooth to strongly serrulate, but without spine-like prickles, the teeth much less
than 1 mm long and visible only on close inspection; fruits unwinged (but dry and inflated),
usually with more than one seed, 3-celled and 3-lobed; inflorescences relatively open, the
branches not finger-like ________________________________________________________________ Nolina