Helianthus praecox Engelm. & A.Gray

Texas sunflower (en)

Species

Angiosperms > Asterales > Asteraceae > Helianthus

Characteristics

Annuals, 40–150 cm. Stems erect to ± procumbent, hispid, hispid-hirsute, or hirsute. Leaves mostly cauline; mostly opposite; petioles 5–9 cm; blades deltate to ovate (sometimes constricted near middles, subsp. praecox) , 3–9 × 2–7 cm, bases cordate , cuneate, or trun-cate, margins serrate to serrulate, abaxial faces hirsute to hispid, usually not gland-dotted. Heads 1–3. Peduncles 15–40 cm. Involucres hemispheric, 13–18 mm diam. Phyllaries 30–39, lanceolate, 9–15 × 2–4 mm, apices short-attenuate to short-acuminate (subsp. praecox), abaxial faces hispidulous to hispid-hirsute. Paleae 6.5–8 mm, 3-toothed (middle teeth acuminate, equaling or slightly surpassing discs, apices puberulent or bearded, hairs whitish). Ray florets 11–16; laminae 16–26 mm. Disc florets 35+; corollas 5–6 mm, lobes reddish; anthers dark, appendages purplish red (style branches reddish). Cypselae 2.5–3.3 mm, ± villous; pappi of 2 aristate scales 1.2–1.5 mm.
Life form annual
Growth form herb
Growth support free-standing
Foliage retention deciduous
Sexuality hermaphrodite
Pollination -
Spread -
Mature width (meter) -
Mature height (meter) 0.4 - 1.5
Root system -
Rooting depth (meter) -
Root diameter (meter) 0.4
Flower color
Blooming months
JanFebMar
AprMayJun
JulAugSep
OctNovDec
Fruit color -
Fruiting months -
Nitrogen fixer -
Photosynthetic pathway -

Environment

Light 7-9
Soil humidity 3-7
Soil texture -
Soil acidity -
Soil nutriment -
Hardiness (USDA) -

Usage

Uses gene source
Edible -
Therapeutic use -
Human toxicity -
Animal toxicity -

Cultivation

Mode -
Germination duration (days) 10 - 14
Germination temperacture (C°) -
Germination luminosity -
Germination treatment -
Minimum temperature (C°) -
Optimum temperature (C°) -
Size -
Vigor -
Productivity -

Distribution

Helianthus praecox world distribution map, present in United States of America

Conservation status

Helianthus praecox threat status: Least Concern

Identifiers

LSID urn:lsid:ipni.org:names:119226-2
WFO ID wfo-0000114033
COL ID 3K5ZJ
BDTFX ID -
INPN ID -
Wikipedia (EN) Link
Wikipedia (FR)

Synonyms

Helianthus praecox Helianthus praecox var. praecox

Lower taxons

Helianthus praecox subsp. runyonii Helianthus praecox subsp. praecox Helianthus praecox var. hirtus