Thursday, June 9, 2022

[Botany • 2021] Begonia lanuzaensis (Begoniaceae, sect. Petermannia) • A New Species from Surigao del Sur, Mindanao Island, Philippines


Begonia lanuzaensis Blasco, Rubite, Cortes & Alejandro.

in Blasco, Rubite, Cortes & Alejandro, 2021. 
 
Abstract
Begonia lanuzaensis from Mt. Nabuywang, Lanuza, Surigao del Sur, is described as a new species endemic to the Philippines. B. lanuzaensis is allied to B. mindanaensis and B. agusanensis in having oblanceolate leaves with short petioles and four-tepalled staminate flowers but is distinct in having glabrous stems and petioles; bigger, triangular and glabrous stipules and larger leaves.

Key words: Begonia, endemic, monoecious, Mindanao, Surigao del Sur, taxonomy 

Begonia lanuzaensis Blasco, Rubite, Cortes & Alejandro.
A. Habit; B. Cross-section of ovary; C. Female bud; D. Fruit; E. Female flower (front view); F. Male flower (front view); G. Female flower attached to the node.
 Illustration by: Propa Joy Santor.

Begonia lanuzaensis Blasco, Rubite, Cortes & Alejandro.
 A. Habit; B. Female flower; C. Ovary; D. Stipule; E. Male flower.


Begonia lanuzaensis Blasco, Rubite, Cortes & Alejandro, sp. nov.  
Sect. Petermannia

Diagnosis:—Begonia lanuzaensis is similar to B. mindanaensis Warb. in its habit with arching stems, oblanceolate leaves with short petioles, and four–tepalled staminate flowers. However, the new species differs in having larger leaves (18–20 × 7–9 cm, not 7–10 ×2–4 cm) with tiny pink bristles on the margin (vs. without bristles), glabrous stipules (vs. pubescent), glabrous stems (vs scabrid), and female flowers with 4 tepals (vs. 5). 

It superficially resembles B. agusanensis Merr. in having erect stems and leaves with short petioles, but differs in leaf shape (base obliquely acute, not obliquely cordate) and male flowers solitary in the axils (not in many flowered cymes on a long peduncle).

Etymology:—The specific epithet “lanuzaensis” is derived from the type locality. 

Distribution and ecology:—Endemic to the Province of Surigao del Sur, Mindanao, Philippines. It grows on shady, moist rocky slopes along sides of small streams. 


Freddie A. Blasco, Rosario R. Rubite, Junelito  C. Cortes, Grecebio Jonathan D. Alejandro. 2021. Begonia lanuzaensis (sect. Petermannia, Begoniaceae) A New Species from Surigao del Sur, Mindanao Island, Philippines. Phytotaxa. 523(3); 203-207. DOI: 10.11646/phytotaxa.523.3.1
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