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

ASPARAGACEAE
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spreading from cultivation in Austin (Travis Co.) and has escaped in Bandera Co. (Edwards Plateau);
in the U.S. known only from TX, but widespread from Mexico to Central America.
Spring–Fall. [S. exul (O.F. Cook) L.H. Bailey, S. texana (O.F. Cook) Becc.] While rare in TX, S.
mexicana is “one of the most common palms of lowland tropical Mexico” (Zona 1990). The species
is often cultivated in the s part of TX (but can survive winters much further north—e.g., Austin
and even Dallas—Lockett 2003). Because the wood was useful in wharf building (resistant to
the shipworm, which destroys wood in warm salt water) and the plants prized as ornamentals
(Lockett & Read 1990; Lockett 2003), it is likely that most native populations have been harvested,
and that this species was much more common in presettlement times. (TOES 1993: IV) �
Sabal minor (Jacq.) Pers., (smaller), DWARF PALMETTO, BUSH PALMETTO, DWARF PALM, BLUE PALM,
BLUE STEM, SWAMP PALM, BLUE PALMETTO, SWAMP PALMETTO, LATANIA, LATANIER. Plant to ca. 2 m tall
(rarely taller—to nearly 5 m), usually acaulescent with a pithy crown or rarely with a short
trunk (10–20 cm in diam.); leaf blades � suborbicular in outline, to ca. 1.6 m wide. Usually in
stream bottoms, floodplains, riverbanks, and swamps (but curiously also known from dry,
open, upland habitats in parts of the Edwards Plateau—e.g., Lockett 1991); Pineywoods and Gulf
Prairies and Marshes w along larger rivers to Dallas, Kaufman (BRIT), and McLennan (BAYLU)
cos. in the Blackland Prairie and Gonzales (Turner et al. 2003; Palmetto State Park), Van Zandt,
and Wood (BRIT) cos. in the Post Oak Savannah, also Hays and Travis cos. on w margin of East
TX w to Gillespie Co. (BRIT) on the Edwards Plateau and naturalized in Tarrant Co. (R.
O’Kennon, pers. obs.); se U.S. from NC s to FL w to OK and TX; recently a population was discovered
in n Mexico, ca. 225 miles sw of the nearest known population (Goldman 1999); this
area of Mexico is known to share a number of floristic components with the e U.S. (Dressler
1954; Martin & Harrell 1957). Mainly spring–summer, but nearly year round in lower Rio
Grande Valley (Davis in Lockett & Read 1990). [S. louisiana (Darby) Bomhard] While S. minor is
typically acaulescent, populations of trunked individuals are known, especially in the w portion
of the species range (particularly in LA and TX); stems of 1–1.5 m in height are not uncommon
(Ramp & Thien 1995). Such populations have long caused taxonomic confusion (e.g., the
name S. louisiana). Bailey (1961) indicated that “There appear to be no botanical characters
separating the two extremes except such dimensions of parts as are associated with stature.”
Recent electrophoretic studies support the inclusion of the trunked populations in S. minor
(Ramp & Thien 1995). A Brazoria Co. population (of larger trunked individuals up to 27 feet
tall) may be hybids between S. minor and S. mexicana (Lockett 1991, 2003). According to Zona
(2000), “Further research is needed to test this hypothesis.” Part of the hybrid population is now
protected in a satellite unit of the San Bernard National Wildlife Refuge (Lockett 2003). m/296
ASPARAGACEAE Juss.
ASPARAGUS FAMILY
AA small family of 2 genera and ca. 305 species (Judd 2001). In addition to Asparagus, the family
includes only Hemiphylacus, a small Mexican group of 5 species (Hernández 1995). While previously
often placed in the Asphodelaceae or Hyacinthaceae, recent evidence (primarily molecular
data) suggests that Hemiphylacus be included in the Asparagaceae (e.g., Rudall et al. 1997, 1998b;
Judd 2001). Members of the Asparagaceae are typically adapted to dry conditions. According to
Kubitzki and Rudall (1998), “Most species are found in regions with semiarid to arid and Mediterranean-type
climate, and extreme xeromorphic adaptations are common.” Many authorities have
put the taxa here treated as Asparagaceae in a broadly defined and clearly polyphyletic (but
practical) Liliaceae (e.g., Correll & Johnston 1970; Cronquist 1988; Diggs et al. 1999), based on superficial
similarities in flower structure to the genus Lilium. Others (e.g., Mabberley 1997) have
recognized the Asparagaceae but have treated it in a broad sense (6 genera). However, based on
phylogenetic analyses, we are following Judd (2001) in recognizing the Asparagaceae as a mono-