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

386 THELYPTERIDACEAE/THELYPTERIS
segments extending to margin of blade tissue above (= beyond) sinuses between adjacent
ultimate segments ________________________________________________________________ T. palustris
1. Lateral veins of ultimate leaf segments usually not forked; margins of fertile ultimate segments
usually not turned downward; leaf blades with at least some basal lateral veins of ultimate segments
extending to, joined at, or united below the sinuses between the adjacent ultimate segments.
2. Basal veins of adjacent ultimate leaf segments united below the sinus between the segments,
with the resulting single vein extending toward the sinus.
3. United portion of veins below sinuses usually 2–4 mm long; midveins of pinnae with hairs
mostly very short (0.3 mm or less long) on the lower surface (= abaxially); petioles often
purplish; leaves usually with more than 2 pairs of greatly reduced basal pinnae ____________ T. dentata
3. United portion of veins below sinuses usually � 2 mm long; midveins of pinnae with hairs
variable in length (0.3–0.8 mm long) on the lower surface; petioles straw-colored; leaves
usually with 0–2 pairs of slightly reduced basal pinnae _______________________________ T. hispidula
2. Basal veins of adjacent ultimate leaf segments not united and thus reaching margin of segments
slightly above the sinus OR meeting at the sinus.
4. Upper surface of midveins of pinnae glabrous or with a few minute hairs, these never
much longer than width of the midveins; a few scales often persistent on lower surface of
rachises and midveins of pinnae of mature leaves _____________________________________ T. ovata
4. Upper surface of midveins of pinnae with conspicuous (use hand lens) hairs usually longer
than width of the midveins; scales absent on lower surface of rachises and midveins of
pinnae of mature leaves.
5. Basal veins of adjacent ultimate leaf segments not united, sometimes meeting at the
sinus between the segments; leaf blades usually broadest at or near base, the basal
pinnae as long as or only slightly shorter than more distal pinnae; leaf blades glabrous
or sparsely hairy above, except along veins _______________________________________ T. kunthii
5. Basal veins of adjacent ultimate leaf segments variable, some not united, some meeting
at the sinus, some united below the sinus into a single vein; leaf blades broadest above
base, the basal and near basal pinnae noticeably shorter than more distal pinnae; leaf
blades often somewhat hairy above, on regular blade tissue as well as along the veins ___ T. hispidula
Thelypteris dentata (Forssk.) E.P. St. John, (toothed), DOWNY SHIELD FERN, DOWNY MAIDEN FERN.
Stems short-creeping; leaves somewhat dimorphic, evergreen; leaf blades (25–)40–100 cm long,
usually with more than 2 pairs of greatly reduced basal pinnae; basal veins of adjacent ultimate
leaf segments (= smallest subdivisions of leaf) united below the sinus between the segments,
with the resulting single vein extending toward the sinus, the united portion usually 2–
4 mm long; midveins of pinnae abaxially with mostly very short (0.3 mm or less long) hairs;
petioles often purplish; sori round, medial to supramedial; indusia pubescent. Wooded slopes,
damp woods, swamp hummocks, and along streams; Angelina (Turner et al. 2003) and Sabine
(Correll 1956) cos. in the Pineywoods; also Harris Co. (Turner et al. 2003) at the n margin of the
Gulf Prairies and Marshes; naturalized in the se U.S. from SC s to FL w to TX, also KY. Sporulating
summer and fall. Native to the tropics and subtropics of Asia and Africa. [Dryopteris dentata
(Forssk.) C. Chr., Polypodium dentatum Forssk.] I
Thelypteris hispidula (Decasne) C.F. Reed var. versicolor (R.P. St. John) Lellinger, (sp.: diminutively
hairy or bristly; var.: changing color), VARIABLE MAIDEN FERN, ST. JOHN’S SHIELD FERN,
ROUGH-HAIRY MAIDEN FERN. Stems short-creeping to ascending at tip; leaves monomorphic, evergreen;
leaf blades 14–55 cm long, broadest above base, the basal and near basal pinnae usually
noticeably shorter than more distal pinnae; basal veins of adjacent ultimate leaf segments variable,
some united below the sinus into a single vein (usually for � 2 mm) which then runs to